Abstract book - ESTRO meets Asia

7-9 December 2018 Singapore

ABSTRACT BOOK

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ESTRO MEETS ASIA 2018 TABLE OF CONTENTS

FRIDAY 7 DECEMBER 2018

Teaching Lecture DNA damage and repair, chromosome damage, checkpoints. ............................................ (Abs. 1) From 2D to IMRT: technology, treatment planning, delivery and QA ................................... (Abs. 2-4) Head and Neck – Oropharynx ....................................................................................... (Abs. 5-6) Cell death mechanisms, cell & tissue survival assays . ...................................................... (Abs. 7)

Symposium Putting knowledge in practice: Oropharynx ..................................................................... (Abs. 8-10)

Teaching lecture Cell survival & models - intro to LQ ................................................................................(Abs. 11)

Proffered Papers Dose planning and verification (physics) . ........................................................................(Abs. 12-18) CL1: H&N, Haematology, Gyn ........................................................................................(Abs. 19-25)

Poster Viewing Dose planning and verification (RTT) ..............................................................................(Abs. 26-31)

Teaching lecture Dose response, therapeutic ratio .................................................................................... (Abs. 32) IGRT and treatment verification .....................................................................................(Abs. 33-35) Rare Tumors............................................................................................................... (Abs. 36-37) Normal tissue response and mechanisms ........................................................................(Abs. 38)

Symposium Putting knowledge at work in Lymphoma . .......................................................................(Abs. 39-41)

Teaching lecture Tumour radiobiology and kinetics ...................................................................................(Abs. 42)

Proffered Papers IGRT and treatment verification (RTT) . ...........................................................................(Abs. 43-47) CL2: Upper GI and thorax .............................................................................................(Abs. 48-54)

Poster Viewing IGRT and treatment verification (physics) . ......................................................................(Abs. 55-61)

Symposium HERO .........................................................................................................................(Abs. 62-63)

SATURDAY 8 DECEMBER 2018

Teaching Lecture Fractionation and overall time . ......................................................................................(Abs. 64) Quality management ....................................................................................................(Abs. 65-67) Perineum ....................................................................................................................(Abs. 68-69) Oxygen effect, sensitizers, microenvironment ..................................................................(Abs. 70)

Symposium Rectum ......................................................................................................................(Abs. 71-73)

Teaching Lecture LET, RBE, particles .......................................................................................................(Abs. 74)

Proffered Papers Quality management and verification (physics) ................................................................(Abs. 75-81) CL3: Lower GI and radiomics. ....................................................................................... (Abs. 82-88)

Poster Viewing Quality management and verification (RTT) .................................................................(Abs. 89-94)

Symposium Global Impact of Radiotherapy in Oncology (GIRO) .......................................................(Abs. 95-97)

Teaching Lecture Volume effects, retreatment ......................................................................................(Abs. 98) Brachytherapy ......................................................................................................... (Abs. 99-101) High tech technologies ............................................................................................. (Abs. 102-103) Clinical manifestations of normal tissue damage ........................................................... (Abs. 104)

Symposium Thorax high tech ..................................................................................................... (Abs. 105-107)

Teaching Lecture Radiation carcinogenesis, prenatal, heritable ...............................................................(Abs. 108)

Proffered Papers Stimulating topics for discussion (RTT) . ...................................................................... (Abs. 109-115) CL4: Prostate .......................................................................................................... (Abs. 116-120)

Poster Viewing Stimulating topics for discussion (physics) . ................................................................. (Abs. 121-127)

SUNDAY 9 DECEMBER 2018

Round table/Debate Setting the scene: advocacy and education ................................................................. (Abs. 128-132) Advocacy initiatives and priorities in the global setting .................................................. (Abs. 133-137) Posters Clinical: Head and neck ............................................................................................ (Abs. 138-162) Clinical: CNS ........................................................................................................... (Abs. 163-174) Clinical: Haematology. ............................................................................................. (Abs. 175-178) Clinical: Breast........................................................................................................ (Abs. 179-200) Clinical: Lung.......................................................................................................... (Abs. 201-214) Clinical: Upper GI (oesophagus, stomach, pancreas, liver) ............................................. (Abs. 215-226) Clinical: Lower GI (colon, rectum, anus) ..................................................................... (Abs. 227-234) Clinical: Gynaecological (endometrium, cervix, vagina, vulva) ........................................ (Abs. 235-246) Clinical: Prostate ..................................................................................................... (Abs. 247-252) Clinical: Urology-non-prostate ................................................................................... (Abs. 253-257) Clinical: Paediatric tumours ....................................................................................... (Abs. 258-259) Clinical: Palliation .................................................................................................... (Abs. 260-262) Clinical: Elderly ....................................................................................................... (Abs. 263-265) Clinical: Health services research / health economics .................................................... (Abs. 267-268) Clinical: Communication ...........................................................................................(Abs. 269) Physics: From 2D to IMRT: technology, treatment planning, delivery and QA .................... (Abs. 271-284) Physics: IGRT, patient positioning and mobilisation....................................................... (Abs. 285) Physics: Dosimetry, audits and risk assessment ........................................................... (Abs. 286-291) Physics: Brachytherapy . ...........................................................................................(Abs. 292) Physics: Other . ....................................................................................................... (Abs. 293-298) Interdisciplinary: Professional Education and training.................................................... (Abs. 299-301) Radiobiology: Radiobiology of stem cells (cancer and normal tissue) ............................... (Abs. 302) Radiobiology: Radiobiology of particles and heavy ions .................................................. (Abs. 303-305) Radiobiology: Radiation-induced signalling pathways .................................................... (Abs. 306-309) Radiobiology: Immuno-radiobiology ........................................................................... (Abs. 310) Radiobiology: Miscellaneous ...................................................................................... (Abs. 311-313) RTT: Treatment verification .......................................................................................(Abs. 314)

ABSTRACTS

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Friday 7 December 2018

replaced the Electronic Portal Imaging Device as the gold standard for precise and accurate patient positioning. Besides that, the Conebeam-CT gave us insight in flaws in Portal Imaging, for instance in underestimating set-up inaccuracies in case of breast cancer imaging. At a later stage, the value of more detailed soft-tissue became more prominent and opened the door for adaptive strategies based on Conebeam-CT. On one hand, 3D imaging has given us the ability to monitor patients' anatomy and pathology during treatment. This gave a better insight on the anatomical dynamics over the course of treatment, especially clinically relevant when it comes treatment in the thoracic region. In the end, it also led to the creation of a protocol on how to deal with these changes during treatment. Another development that was enabled by 3D volumetric imaging was the introduction of so called plan of the day protocols. This protocol allows us to deal with changes that are hard to control, mainly for changes caused by the bladder. In the treatment preparation phase, two CT's are performed with a fully filled as well as an empty bladder. During planning target and OAR structures are delineated. Using inter- and extrapolation algorithms more potential bladder filling situations are virtually generated, finally leading to 3 to 5 treatment plans. On the treatment unit the optimal plan is selected based on images made with Conebeam-CT. Different studies have showed a successful reduction of dose in the surrounding organs at risk in the treatment of bladder and cervical cancer. More changes are about to occur in near future. All these paradigm shifts impact the daily work of the Radiation TherapisT (RTT). RTTs need continuously update their knowledge and competences to be able to optimally perform in a quickly changing environment. SP-004 Introducing advanced technologies: the reality P. Ravindran 1 1 Christian Medical College Hospital, Radiotherapy, Vellore, India Abstract text Background: There is considerable cancer burden in low- and middle-income countries (LMIC). Radiotherapy is a cost-effective cancer treatment modality that offers the potential for cure, control, and palliation of disease in greater than 50% of patients. As LMICs have lesser access to newer technologies in Radiation therapy, implementation of latest technologies in these countries could be a challenging task. Aim : The purpose of this presentation is to share the experiences gained by involving in the establishment of new radiation therapy technologies in a few Low and Middle-income countries, discuss the issues and the methods to address them. Methods : During the last decade, the author had the opportunity to visit a few of the LMICs either to help in establishing advanced radiotherapy technology or to participate in the training programs in radiation therapy as a faculty member. In addition to his involvement in establishing new technologies in India, he was involved in commissioning a Treatment planning system for Cobalt unit at Ulaanbaatar, Mongolia, a linear accelerator at Myanmar, state of the art linear accelerators at a new Radiotherapy centre at Brunei Darussalam, and a couple of Radiation therapy Physics training programs at Bangladesh. During these assignments he had the opportunity to train the staff on the safe use of the advanced technologies.

Teaching lecture: DNA damage and repair, chromosome damage, checkpoints

SP-001 DNA damage and repair, chromosome damage, checkpoints A.Potter 1 1 Royal Adelaide Hospital, Radiation Oncology Department, Adelaide, Australia

Abstract not received

Teaching lecture: From 2D to IMRT: technology, teartment planning, delivery and QA

SP-002 From 2D to 3DCRT to IMRT T. Wong 1 1 Seattle Proton Therapy Center, Medical Physics, Seattle, USA Abstract text Radiation therapy is one of the most technologically driven treatment modalities for cancer patients. Tremendous advances in treatment planning and delivery technology have improved radiation dose conformity to target volumes while sparing critical healthy tissues. We have evolved from basic 2-dimensional (2D) radiation therapy of the 1980s to 3D conformal radiation therapy (3DCRT) of the 1990s, and eventually to modern intensity modulated radiation therapy (IMRT). Improvement in computational hardware of linear accelerators and software of treatment planning systems now supports modulation of the number of treatment fields, the intensity of radiation within each field, and its dynamically controlled shape in IMRT. By expanding our ability to sculpt radiation dose around target volumes, IMRT has increased the therapeutic window through safe dose escalation to improve treatment outcomes in certain disease sites. Whereas the evolution from 2D to IMRT in conventional radiation therapy took place over the course of 20 years, we have observed accelerated development and deployment of proton beam therapy (PBT) in the past several years, moving from simple passive-scattered treatment delivery to sophisticated image-guided pencil beam scanning (PBS) treatment delivery across a variety of clinical platforms. This presentation will review the technological advancements in radiation therapy from 2D to 3DCRT to IMRT. It will highlight improved treatment delivery with multileaf collimators and linear accelerators, improved target definition with computed tomography (CT) and multimodality imaging, and enhanced dose calculation engines and optimization algorithms during inverse treatment planning. The rapid evolution of PBT, from passive scattering to uniform scanning and PBS techniques, will also be discussed. SP-003 Changing paradigms in RTT practice from 2D to ART M. Kamphuis 1 1 Academic Medical Center, Academic Physics , Amsterdam, The Netherlands Abstract text Since the introduction of Conebeam-CT in 2003, the use of volumetric imaging has become more and more common. First, benefits were mainly seen in an improved accuracy of image registration. Conebeam-CT

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SP-006 Hypoxia: imaging driven strategies for modern radiotherapy TBC

As the healthcare implementation in the LMICs is undergoing major changes, there is a significant interest in these countries to embrace new and state of the art technologies. As they embrace advanced technologies in radiation therapy, one of the major challenges is to have adequately trained human resources for safe operation of the equipment and regular maintenance. The other challenges are to have adequate financial resources for maintenance of the equipment, importing spare parts within a short time frame and providing regulated electric power to operate the equipment. Results : The challenges in these countries in implementing advanced technology in radiation therapy are multi- dimensional. Though there is keen interest among the radiotherapy healthcare professionals in LMICs to learn and adapt the newer technologies, there is lack of trained senior healthcare professionals in Radiation therapy Physics in these countries to train the new staff in safe use of the advanced technologies. Similarly, shortage of trained human resources among the equipment maintenance staff is also evident. Conclusion : It is necessary for international organisations to support these countries in capacity building, particularly with respect to addressing the need for training of personnel. Providing structured interactive online training programs with adequate hands-on training in a well-equipped institution in the region could be one of the ways to address this issue. SP-005 Strategy for radiosensitization by increasing tumor tissue oxygen tension M. Masahiko 1 1 Tokyo Medical and Dental University, Department of Oral Radiation Oncology, Tokyo, Japan In radiotherapy for head and neck cancer, hypoxia has been attracting much attention. Indeed, plenty of studies have been reported regarding hypoxic fractions and prognosis or hypoxic modification and radiosensitization. Meta-analysis of randomized clinical trials proved that hypoxic modification by varying methodologies is statistically valid. Recently, particularly in oropharynx cancer, human papilloma virus (HPV) or its surrogate marker p16 expression becomes an important biomarker. The DAHANCA study revealed that a hypoxic radiosensitizer, nimorazole, significantly enhanced local control for HPV-negative larynx and pharynx tumors, but not for HPV-positive cases. The same results were obtained when restricted to oropharynx tumors. Interestingly, analysis using hypoxic imaging like FAZA- PET/CT exhibited no significant difference in hypoxic fractions between HPV-negative and -positive tumors. Enhanced reoxygenation in HPV-positive cases during radiotherapy is suggested as its possible mechanism. Despite such high level of clinical evidence regarding hypoxic modification and extensive basic research, it is peculiar that there are no widely-used hypoxic modifiers yet in clinical practice. Such situation is called “adored and ignored” by Overgaard. In this lecture, I will review hypoxia-associated translational research on head and neck cancer and consider its perspective. I will also introduce our unique radiosensitizer possessing the ability to transiently increase tumor tissue oxygen tension. Teaching lecture: Head and neck oropharynx

Abstract not received

Teaching lecture: Cell death mechanisms, cell & tissue survival assays

SP-007 Cell death mechanisms, cell & tissue survival assays E. Hau 1 1 Sydney West Radiation Oncology Netword, Radiation Oncology, Sydney, Australia Abstract text Following radiation, tumour and normal cells undergo various forms of cell death. This lecture will cover the various types of cell death, its mechanisms and also methods which are used to quantify the cell survival including clonogenic assays in vitro and in vivo assays. Symposium: Putting knowledge into practice: Oropharynx SP-008 Is HPV related oropharyngeal cancer more chemo- radiosensitive than HPV negative OPC in Chinese patients? X. Wang 1 1 Fudan University Shanghai Cancer Center, Department of Radiation Oncology, Shanghai, China Abstract text HPV related oropharyngeal squamous cell carcinoma (OPSCC) is steadily increasing in USA and Europe. A series of studies have demonstrated that HPV related OPSCC has a superior treatment response, prognosis and survival rates compared to traditional OPSCC , which has sparked interest in de-escalation treatment for patients with HPV related OPSCC. However, whether HPV positive OPSCC is sensitive to chemotherapy and radiotherapy remains unknown for Chinese patients. In our center, locally advanced OPSCC is routinely given induction chemotherapy followed by radiotherapy alone or concurrent chemoradiotherapy (CCRT) regardless of HPV status, while surgery is only reserved for salvage. We explored the correlation between chemosentivity and HPV status, EGFR expression, gender, smoking and drinking status in OPSCC. Our study demonstrated that HPV status, gender, smoking and drinking status could not predict chemosensitivity for Chinese OPSCC. Our results suggested that de-escalation treatment according to HPV status alone might not be feasible for Chinese OPSCC at the present. SP-009 Chemotherapy in HPV+ patients in IMRT era J.Bouhris 1 1 Centre Hospitalier Universitaire Vaudois, Department of Radiation Oncology, Lausanne Vaud, Switzerland

Abstract not received

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SP-010 How to deal with nodal involvement in OPC V. Gregoire 1 1 Centre Léon Bérard Radiation Oncology, Lyon, France

and 2 year PFS were 72 and 27%, 55 and 21%, 46 and 13% respectively in the three treatment techniques (p < 0.001). The toxicities assessed were similar in both IMRT and VMAT. The prognostic factors found to be influencing the treatment outcomes included age, gender, grade of tumor and Karnofsky performance status (KPS) of the patient. Conclusion The treatment outcomes in the form of overall survival and toxicities are found to be better with VMAT and also to spare the normal brain parenchyma and structures at risk. With modern treatment techniques available to permit better tumor dose conformity and spare normal tissue, outcomes of the disease can be achieved in desirable manners. VMAT is an excellent technique for treatment of high grade gliomas and needs to be looked in to in future large prospective trials. OC-013 Dosimetric comparison of breath hold and free breathing technique in stereotactic body radiotherapy K.R. Mani 1 , R. Lingaiah 1 , M.M. Alam 1 , M.A. Bhuiyan 1 , K.A. Haque 1 , S. Ahmed 1 , M.A. Sumon 1 , S. Basu 1 , A.K. Sengupta 1 , M.R.U. Nabi 1 , S. Chadhuri 1 1 UNITED HOSPITAL LTD, Radiation Oncology, Dhaka, Bangladesh Purpose or Objective To compare the dosimetric advantage of stereotactic body radiotherapy (SBRT) for localized lung tumor between deep inspiration breath hold technique and free breathing technique. Material and Methods We retrospectively included ten previously treated lung tumor patients in this dosimetric study. All the ten patients under went CT simulation using 4D-CT free breathing (FB) and deep inspiration breath hold (DIBH) techniques. Plans were created using three coplanar full modulated arc using 6 MV flattening filter free (FFF) bream with a dose rate of 1400 MU/min. Same dose constraints for the target and the critical structures for a particular patient were used during the plan optimization process in DIBH and FB datasets. We intend to deliver 50 Gy in 5 fractions for all the patients. For standardization, all the plans were normalized at target mean of the planning target volume (PTV). Doses to the critical structures and targets were recorded from the dose volume histogram for evaluation. Figure 1 Illustrate the dose distribution in DIBH & FB scan, which clearly describes the target volume reduction and lung expansion in the DIBH technique compared to the FB technique Results The mean right and left lung volumes were inflated by 1.55 and 1.60 times in DIBH scans compared to the FB scans. The mean internal target volume (ITV) increased in the FB datasets by 1.45 times compared to the DIBH data sets. The mean dose followed by standard deviation (x̄ ± s x̄ ) of ipsilateral lung for DIBH-SBRT and FB-SBRT plans were 7.48 ± 3.57 (Gy) and 10.23 ± 4.58 (Gy) respectively, with a mean reduction of 36.84% in DIBH-SBRT plans. Ipsilateral lung were reduced to 36.84% in DIBH plans compared to FB plans. We found that the increase in the PTV volume in the FB-SBRT compare to the DIBH-SBRT, FB- SBRT resulted in the higher dose to the lung and the critical structures. In DIBH-SBRT the mean heart dose was reduced by 11.98% and V20 by 28.31% (both the mean dose and V20 shows statistical significance) compare to the FB- SBRT. Ipsilateral lung for the DIBH-SBRT plans shows a mean reduction of 36.84% in mean dose, 46.21% in V20 and

Abstract not received

Teaching lecture: Cell survival and models – intro to LQ

SP-011 Cell survival and models – intro to LQ M. Joiner 1 1 Wayne State University, Academic Physics, Detroit, USA

Abstract not received

Proffered papers: doseplanning and verification (physics) OC-012 Analysis of Newer Treatment Techniques in High Grade Glioma: VMAT Versus IMRT Versus 3DCRT V. Pareek 1 , R. Bhalavat 1 , M. Chandra 1 , P. Bauskar 1 1 Jupiter Hospital, Radiation Oncology, Mumbai, India Purpose or Objective In high grade gliomas, clinical outcomes depend on the tumor dose coverage and toxicities depends on the dose to surrounding organs at risk. With advent of newer modalities in the form of Intensity Modulated Radiation Therapy (IMRT) and VMAT, there is a need to look in to the dosimetric and clinical outcomes compared to the standard 3D conformal radiation therapy (3DCRT). This study, aims to evaluate the dosimetric and survival outcomes with respect to tumor doses and normal organs at risk and form a consensus on better treatment modality. Material and Methods Between 2011 and 2016, total 140 patients were evaluated of which 110 were WHO Grade IV and 30 patients were Grade III. Of these, 45 patients each underwent radiation therapy with VMAT and IMRT and 50 patients underwent 3DCRT treatment. The patients received 50.4Gy followed by boost of 9Gy with 1.8Gy per fraction dose. Planning was done with the aim of 98% of PTV covered by 95% isodose. Mean OAR dose were maximally decreased without reducing PTV coverage or violating hotspot constraint. The treatment plans were evaluated using standard dose volume histogram. The median follow-up of the patients was 13 months. The local control, overall survival and progression free survival were evaluated. Response was recorded using the Response Assessment in Neuro- Oncology criteria and toxicities graded according to CTCAE version 4.0. The dosimetric parameters were assessed using unpaired t test and the Wilcoxon matched-pair signed-rank test for non-parametrically distributed data used to compare the means. Maximum and mean OAR doses were directly used as part of the optimization process and, along with MU and timing, were considered as primary endpoints. Results All three techniques achieved an adequate dose conformity to the target volume. The conformity and Homogeneity index were found to be better with IMRT and VMAT (p < 0.005). The monitor units (MU) and treatment times were better with VMAT (p < 0.01). The doses to brainstem, optic nerve, retina, lens and normal brain parenchyma were found to be significantly better with VMAT. The median overall survival with VMAT, IMRT and 3DCRT were 16, 13 and 10 months respectively. The 1 year

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76.12% in the V40 compare to the FB-SBRT plans. In this study we have not removed the PTV from the ipsilateral lung volume, hence compare to the other studies higher mean dose were documented. Conclusion DIBH-SBRT plans are much superior due to smaller PTV due to its capability of immobilizing the target motion during the treatment within the threshold window. In this study we also found that the DIBH based SBRT significantly reduces the doses to the ipsilateral lung due to lung inflation, which will results in less lung toxicity compare to the FB based SBRT. We need well equipped advanced CT simulator with gating system and image guidance tool to practice safe DIBH based SBRT treatment. OC-014 Evaluation of a New Commercial Automated Breast Planning Software: A first experience in Japan N. Mizuno 1 , R. Yamauchi 1 , S. Fukushima 1 , S. Kashiyama 1 , T. Itazawa 1 , J. Kawamori 1 1 St. Luke's International Hospital, Department of Radiation Oncology, Tokyo, Japan Purpose or Objective Automated breast treatment planning (ABP) may bring intensity-modulated radiation therapy (IMRT) into routine clinical practice for a large number of patients with breast cancer, without causing excessive effort for the treatment planning. The purpose of our study was to validate a new commercial ABP software for tangential IMRT and compare ABP plans with clinical treatment plans by standard manual planning. Material and Methods We prospectively enrolled 150 patients with Stage 0-І breast cancer who underwent breast-conserving surgery at our institution between September 2016 and August 2017. The study protocol was approved by an institutional review board, and all patients provided informed consent before CT-simulation for treatment planning of whole- breast irradiation. In clinical treatment plans, 142 patients received two-field tangential irradiations using a forward-planned field-in-field (FIF) technique. Clinical treatment plans were performed with a total dose of 42.56 Gy in 16 fractions (n = 98) or 50 Gy in 25 fractions (n = 44). All plans were retrospectively re-planned using an ABP software, with the same planning CT images as obtained for clinical plans. The setting for the ABP software included whole-breast and breast-coverage modes for all patients. For both clinical and ABP plans, each beam parameter was recorded for isocenter location, gantry angle, collimator angle, and JAW opening. The number of segments, total monitor units, and planning time were compared for each plan. The dose-volume data were analyzed with respect to 90% of prescribed dose-volume overlap, homogeneity index (HI) of target, lungs, heart (for left-sided breasts only), and maximum dose of irradiated volume. Furthermore, three experienced radiation oncologists reviewed the ABP plans. Results Beam parameters differed based on the technique (i.e., simple FIF technique and tangential IMRT) used in clinical plans vs. ABP plans. However, the adverse clinical impact seems to be small. The planning time significantly decreased in ABP plans than in clinical plans (clinical plans: 53.1 ± 6.7 min, ABP plans: 4.8 ± 1.4 min, P < 0.001). The dice similarity coefficient of 90% of prescribed dose- volume overlap was 0.80–0.90 in most patients (0.84 ± 0.05). The HI of CTV was significantly smaller in ABP plans than in clinical plans (clinical plans: 0.110 ± 0.031, ABP

plans: 0.077 ± 0.019, P < 0.001). V20 Gy of the lungs, Dmean of the heart, and D2 CC of the irradiated volume in ABP plans were 4.2 ± 1.2%, 115.3 ± 76.5 cGy, and 105.8 ± 1.7% (prescribed dose: 100%), respectively. Experienced radiation oncologists deemed 136 ABP plans (95.8%) to be clinically usable. Conversely, six ABP plans (4.2%) were rejected due to the coverage of target volume (n = 2, 1.4%) or the heart dose (n = 4, 2.8%). Conclusion ABP software demonstrated a high clinical acceptability, and the cost-efficiency of planning was dramatically improved. ABP software is a useful tool for delivering high- quality treatment to a large number of patients. OC-015 Dosimetric Influence of Jaw tracking in IMRT and VMAT for Carcinoma of Cervix M.A. Muneem 1 , N. Sultana 2 , T. Hossain 2 , T. Basharat 2 , K.R. Mani 1 1 United Hospital Ltd, Department of Radiation Oncology, Dhaka, Bangladesh 2 Dhaka University, Deaprtment of Biomedical Physics & Technology, Dhaka, Bangladesh Purpose or Objective To Study the dosimetric advantage of the Jaw tracking technique in Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) for carcinoma of cervix patients. Material and Methods We retrospectively selected ten previously treated Cervix patients in this study. All the ten patients under went CT simulation along with immobilization and positional devices. Targets and organ at risk (OAR) were delineated slice by slice for all the patients. All the patients were planned for IMRT and VMAT with intend to deliver 50 Gy in 25 fractions. All the plans were planned with 6 MV photons using Millennium 120 MLC using the TrueBeam linear accelerator. IMRT and VMAT plans were performed with jaw tracking (JT) and with static jaw (SJ) technique by keeping the same constraints and priorities for the target volumes and critical structures for a particular patient. For standardization all the plans were normalized at the target mean of the planning target volume. All the plans were accepted with the criteria of bladder mean dose < 40 Gy, rectum mean dose < 40Gy and cauda maximum point dose < 45 Gy without compromising the target volumes. Target conformity, dose to the critical structures and low dose volumes were recorded and analyzed for IMRT and VMAT plans with and without jaw tracking for all the patients. Results The conformity index average of all patients followed by standard deviation (x̄ ± s x̄ ) of the JT-IMRT, SJ-IMRT, JT- VMAT and SJ-VMAT were 1.176 ± 0.14, 1.174 ± 0.14, 1.193 ± 0.22 and 1.23 ± 0.19 and homogeneity index were 0.089 ± 0.02, 0.085 ± 0.02, 0.102 ± 0.016 and 0.100 ± 0.016. In low dose volume JT-IMRT shows a 5.4% (p-value < 0.001) overall reduction in volume receiving at least 5 Gy (V5) compare to SJ-IMRT, whereas 1.2% reduction in V5 volume in JT-VMAT compare to SJ-VMAT. JT-IMRT shows mean reduction in rectum and bladder shows of 1.34% (p-value < 0.001) and 1.46% (p-value < 0.001) compare to SJ-IMRT, while only 0.30% and 0.03% reduction were observed between JT-VMAT and SJ-VMAT. JT-IMRT plans also shows considerable dose reduction to bowel, right femoral head, left femoral head and cauda compared to the SJ-IMRT plans.

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and eyes were better with DSC 0.92(0.03) and 0.88(0.04) as compared to parotids 0.78(0.07).The accuracy of propagated contours is limited for complex deformations that include large volume and shape change, hence, visual validation of propagated contours is recommended for clinical implementation. Conclusion The DIR algorithm was commissioned and validated for adaptive contouring using AAPM TG132 protocol. VMAT Planning with Functional Lung Imaging N. Bucknell 1 , N. Hardcastle 2 , S. Prasad 1 , D. Ball 1 , T. Kron 2 , S. Siva 1 1 Peter MacCallum Cancer Center, Radiation Oncology, Melbourne, Australia 2 Peter MacCallum Cancer Center, Physical Sciences, Melbourne, Australia Purpose or Objective Functional lung imaging has the ability to enhance understanding of underlying lung function and facilitate tailoring treatment planning to an individual’s own lung function and potentially minimise toxicity. This planning study was conducted to evaluate if incorporating functional lung information could improve functional dose-metrics while boosting dose to the primary tumour and avoiding excess dose to organs at risk (OARs). This is the first reported planning study investigating minimisation of dose to both perfused and ventilated lung. Material and Methods 11 patients with locally advanced lung cancer with pre- treatment V/Q-PET/CT as part of a prospective observational clinical trial were planned using a VMAT technique in Eclipse 13.6 planning system (Varian Medical Systems, USA).(1, 2). High functioning (HF) lung was defined as the intersection of the top 70% of ventilated and perfused lung and functional (F) lung as the intersection of the remaining ventilated and perfused anatomical lung. 60Gy in 30 fractions was prescribed to the primary and nodal PTV and 69 Gy in 30 fractions to the primary tumour. Anatomical plans were optimised to anatomical lung and functional plans to the HF and F lung volumes. Heart volume receiving 50 Gy was limited to <25% and mean heart dose <20Gy.(3, 4) Proximal bronchial tree was limited to 1cc <64.5Gy. Other OAR constraints were consistent with our published protocol and RTOG guidelines.(2,5) Two tailed paired t-tests were used to test for significant differences between functionally adapted and anatomical plans. Results There were no significant differences in target coverage (PTV or primary tumour), mean heart and oesophagus dose, or near maximum heart, oesophageal and spinal canal doses. The only OAR constraint with a significant difference between plans was heart V50 with a mean difference of 0.11%; the highest heart V50 was 7.63% Both functional and to a lesser extent, anatomical lung doses were significantly reduced in functional plans. HF lung fMLD was reduced by a mean of 1.1Gy (p=0.002) and fV20 by 4.1% (p=0.02). F lung fMLD was reduced by a mean of 0.7Gy (p=0.0001) and fV20 by 2.3% (p=0.004). Table 1 summarises the statistically significant results showing a difference between anatomical and functional lung plans OC-017 Personalising Lung Radiation Therapy: Optimising

Conclusion Jaw tracking resulted in decreased dose to critical structures in IMRT and VMAT plans. But significant dose reductions were observed for critical structure in the JT- IMRT compared to SJ-IMRT technique. In JT-VMAT plans dose reduction to the critical structure were not significant compared to the JT-IMRT due to relatively lesser monitor units. OC-016 Commissioning and validation of deformable image registration (DIR) software using AAPM TG132 R. Phurailatpam 1 , K. Joshi 1 , D. Deshpande 2 , J. Sv 1 1 ACTREC-Tata Memorial Centre, Radiation Oncology Dept, Navi Mumbai, India 2 Tata Memorial Hospital-TMC, Medical Physics, Mumbai, India Purpose or Objective To commission and validate deformable image registration software (Velocity 3.2.0) using TG132 Material and Methods DIR (Velocity 3.2.0) was validated using TG132 protocol, using physical phantoms, virtual phantoms and clinical images. Solid Phantoms, made in-house with various known deformations and a set of 10 virtual phantoms were used. Deformation field vectors in lateral, AP and SI direction were evaluated for various organs and compared with the ground truth. Two clinical sites HN (n=9) and prostate (n=16) were validated. .Organs were manually delineated by a radiation oncologist, compared with the DIR generated contours. Dice Similarity Co-efficient (DSC) and Hausdorff distances Hf avg . were analysed. Results Mean (SD) DSC and Hf avg (mm) of the physical phantoms were 0.86(0.07) and 0.9(0.43)mm respectively. The virtual phantom resulted in consistent results for all the ROIs investigated. In prostate, the contours propagated for bladder resulted in better DSC of 0.91(0.04) as compared to rectum 0.85(0.05). However, in extreme cases when the change in bladder volume was more than 200 cc, DSC was 0.46. Similarly, in rectum, due to the presence of gas and faecal filling; DSCs were observed as 0.66 and 0.46 respectively. In HN, contours propagated for Brainstem

S6 ESTRO meets Asia 2018

Structure

improved treatment delivery for VMAT plans using 6X-FFF compared to 6X-FF. BOT values (Mean ± SD) 6.892 ± 0.91 & 3.174 ± 0.17 min. Conclusion Evaluation of plan based on different quality parameter gives better assessment of Treatment plans. Appreciation of FFF and FF plans should not be limited only to reduction of treatment time. Correlation of inter fraction motions for patients on couch will be a valid tool for the appraisal of FFF-RA treatments. The increase in the speed of MLC can further add advantage to a faster treatment delivery. The lateral scatter was low in FFF compared with FF beams. Linac FFF mode has an advantage of faster treatment capability compared to FF modality. Clinical significance of our findings depends on the size and location of the tumor and FFF plans were a touch superior when compared to FF with analyzed with the analyzed parameters. OC-019 Long-term report of total marrow or total lymphoid IMRT in advanced leukemia, myeloma and lymphoma. S. Vagge 1 , A. Dominietto 2 , F. Guolo 3 , A.M. Carella 2 , R.M. Lemoli 3 , A. Bacigalupo 4 , E. Angelucci 2 , R. Corvò 5 1 IRCCS Policlinico San Martino, Radiation Oncology, Genova, Italy 2 IRCCS Policlinico San Martino, Hematology, Genova, Italy 3 University of Genoa, Hematology, Genova, Italy 4 Policlinico Universitario A. Gemelli, Hematology, Roma, Italy 5 University of Genoa, Radiation Oncology, Genova, Italy Purpose or Objective During the last three decades, total body irradiation (TBI) continues to play an important role in the conditioning regimens for patients undergoing stem-cell transplant (SCT) for a wide variety of advanced hematological malignancies. However, TBI showed boundaries in dose limits for toxicity in allogenic and moreover in autologous stem cell transplantation. Currently, the choice of conditioning regimen is based on the use of the least-toxic regimen to achieve the optimal therapeutic result. This report aims to assess the feasibility of a conditioning strategy based on high dose chemotherapy and whole- body radiotherapy focused on selective extensive tumor burden irradiation, both in allogenic and autologous stem Since December 2009, sixty-two patients (pts) have been irradiated by helical tomotherapy (HT) to extensive target before allogenic or autologous transplantation. Selected total marrow irradiation (TMI) schedules were planned to treat high risk or fragile acute leukemia patients (ALL or AML) or multiple myeloma (MM) before autologous or allogenic transplantation. While total lymphoid irradiation (TLI) was planned to treat patients with refractory or relapsed (R/R) Hodgkin (HD) or Non-Hodgkin lymphomas (NHL). Results TMI and TLI allowed delivering therapeutic dose over extensive selected targets with wide reduction of toxicity to all the organs at risk (OARs). The higher radiation doses rate to the OARs is reduced from 30% to 70%. Allogenic conditioning regimen was TLI (4Gy x 3fx) than fludarabine + endoxan for patients with HD ( 4 pts ). TMI (4Gy x 3fx) + fludarabine + melphalan for patients with MM Proffered papers: Head and neck, haematology, gyn cell transplantation. Material and Methods

Conclusion This planning study extends on previous studies and shows MLD and functional V20 can be reduced to lung that is both perfused and ventilated, without clinically significant increases in dose to the heart or other organs at risk. Further prospective evaluation of this technique is required to determine if clinical benefit is realised. OC-018 Dosimetric comparison of Flattened and Un-flattened Beams for Brain Lesions. P.K. Mani 1 , S. Paulpandi 1 , K. Vittal 1 , K. Bayyareddygari 1 , V. Manoor Ural 1 , N. Veeraragavan 1 , V.R. Subramanian 2 , C.A. Radha 2 1 Apollo Hospital, Radiation Oncology, Bangalore, India 2 Vellore Institute of Technology, Department of Physics, Vellore, India Purpose or Objective To compare FF & FFF with Volumetric Modulated Arc Therapy (VMAT) for brain metastasis and apprise the dosimetric differences based on various Plan Quality Indicies (PQI) Material and Methods 20 patients with single Brain mets were selected for this study. VMAT treatment plans were generated using 6X-FF and 6X-FFF of TrueBeam ST X Linear Accelerator (Varian medical systems, USA), modeled in Eclipse Treatment Planning System (Version 11.0.31). 15Gy in single fraction was prescribed to the target volume. VMAT planning involves placement of 1-2 full arcs with dose rate of 600MU/min, 1400MU/min for 6X-FF and 6X-FFF respectively. Optimization process was carried out with constraints to keep normal structures doses as low as possible following the QUANTEC constraints. Final dose calculation was performed with Analytical Anisotropic Algorithm (AAA). All plans were normalized to target mean. Plan Evaluation was done based on RTOG plan quality parameters- Conformity Index, Homogeneity Index, delivery time, monitor unit, Quality of Coverage, Tumor coverage factor, Tumor Under Dosage factor, Healthy tissue over dosage. Confirmation number between 6FF vs. 6FFF. Organs at Risk (OAR’s) like Brain stem, Optic chiasm, Lens (Right and Left), Eye (Right and Left) and Brain were analyzed statistically using D Max and D Mean . Technical parameters. Results The following are results of FFF and FF are as follows, CI values (Mean ± SD) were 1.09 ± 0.65 & 1.07 ± 0.60. HI values (Mean ± SD) were 1.10 ± 0.04 & 1.10 ± 0.05. Brain Stem values (D Max ) (Mean ± SD) were 11.87 ± 0.65 & 11.72 ± 0.68 Gy . Optic Chiasm values (D Max ) (Mean ± SD) 9.15 ± 1.28 & 8.92 ± 1.22 Gy . Eye (Right & Left) values (D Max ) (Mean ± SD) 2.01 ± 0.63, 2.00 ± 0.66 and 2.02 ± 0.80, 2.01 ± 0.66 Gy. Lens (Right & Left) values (D Max ) (Mean ± SD) 1.11 ± 0.56, 1.13 ± 0.59 and 1.22 ± 0.53, 1.33 ± 0.54 Gy . Normal Brain values (D Max ) (Mean ± SD) 11.04 ± 0.24 & 11.09 ± 0.22 Gy. MU values (Mean ± SD) 4086.7 ± 545.1 & 4311.9 ± 339.1 MU.This study showed reduced BOT with

S7 ESTRO meets Asia 2018

( 4 pts ). TMI (4Gy x 2 fx) + thiotepa + fludarabine + busulfan for advanced LAM patients ( 4 pts ). TMI as the boost (2- 3Gy) after conventional TBI was (12 Gy in 6 bi-fractionated doses) by cyclophosphamide ( 18 pts ). Autologous preparation to SCT consisted of TLI (4Gyx 3fx) followed by high-dose bendamustine and melphalan for patients older than 40 years and conventional FEAM (Fotemustine, Etoposide, Cytarabine, and Melphalan) for younger patients, in HD e NHL ( 20 pts ). While TMI (4Gy x 3 fx) plus melphalan was delivered for autologous SCT in MM and LAM ( 12 pts ). No unexpected acute toxicity was found. In the allogenic setting, all the patients’ engraftment was achieved in all patients. No acute graft versus host disease increasing was detected. Within the autologous setting, only 33% developed grade 3/4 mucositis. None experienced grade 3/4 extra-hematological toxicity. Outcomes of the specific disease will be reported. Conclusion The current report describes the clinical feasibility of using HT to deliver TMI or TLI in the setting of autologous transplantation or during allogenic stem cell conditioning regimen, to allow all patients (old, fragile or with high tumor burden) to achieve an ablative regimen before SCT. To our knowledge, this single institution experience describes data from one of the largest cohort of patients treated in Europe since the development of this irradiation techniques. OC-020 The value of prognostic nutritional index in follicular lymphoma S.F. Lee 1 , T.Y. Ng 1 , F.C.S. Wong 1 1 Tuen Mun Hospital, Department of Clinical Oncology, Tuen Mun, Hong Kong SAR China Purpose or Objective Previous studies reported that prognostic nutritional index (PNI), a marker of host inflammatory and nutritional status, is associated with prognoses in a number of cancer types. Thus, we investigated PNI at diagnosis as a prognostic factor in follicular lymphoma (FL). Material and Methods We reviewed FL patients in Tuen Mun Hospital, Hong Kong from 2000 to 2014 (n = 88). PNI was calculated by serum albumin (g/L) + 5 x absolute lymphocyte count (10 9 /L). We determined the best PNI cut-off value using receiver- operating characteristic curves. The extent to which progression-free survival (PFS) and overall survival differed by PNI cut-off was assessed using Kaplan–Meier and logrank tests. Cox proportional hazards model was utilized to adjust for covariates. Results The best cut-off value for PNI was determined to be 45. Patients with high PNI (>45) had a higher complete response (CR) rate after primary treatment, 46 out of 61 (75.4%) patients with high PNI had CR, compared with 10 out of 23 (43.5%) for low PNI (Two-sample test of proportions p-value = 0.006). Further, PNI at relapse as a continuous variable was associated with post-progression survival with a hazard ratio (HR) 0.88 (95% confidence interval [CI] 0.81–0.96). In multivariate analysis (see Table 1 and Figure 1), high PNI at diagnosis had superior PFS (adjusted HR of 0.37, 95%CI 0.15–0.93).

Table 1. Multivariate analyses for PFS of PNI at diagnosis, n = 88.

Figure 1. Adjusted PFS predicted by different levels of PNI. PFS estimates of high and low PNI at diagnosis (n = 88).Grey lines denote upper and lower 95% confidence limits. Conclusion PNI was shown to be an independent prognostic factor of PFS in FL. It is low cost and widely available biomarker for predicting prognosis. Future study is needed to validate our finding in a prospective cohort. OC-021 IMRT plus S-1 chemotherapy in locally advanced nasopharyngeal carcinoma:a multicenter phase II study X. Wang 1 , T. Lv 1 , Y. Wang 1 , L. Liu 2 , P. Lou 3 , S. Qin 4 1 Fudan University Shanghai Cancer Center, Department of Radiation Oncology, Shanghai, China 2 Taizhou Cancer Hospital, Department of Radiation Oncology, Wenling, China 3 Ningbo First Hospital, Center of Chemoradio-oncology, Ningbo, China 4 the First Affiliated Hospital of Soochow University, Department of Radiation Oncology, Soochow, China Purpose or Objective The standard treatment for patients with locally advanced nasopharyngeal carcinoma (NPC) is intensity-modulated radiation therapy (IMRT) combined with cisplatin concurrent chemoradiotherapy. However, the toxicities related to cisplatin-based chemoradiotherapy can not be ignored. The compliance rate was relatively poor. Many studies have reported that S-1 was effective with mild toxicities in multiple solid cancers. But, knowledge is lacking regarding the combination of S-1 and IMRT for locally advanced NPC. Therefore, we conducted this multicenter phase II trial to evaluate the efficacy and safety of IMRT combined with S-1 concurrent chemoradiotherapy in patients with locally advanced NPC. Material and Methods Patients with histologically confirmed locally advanced NPC but without chemotherapy contraindications were eligible for this study. IMRT was administrated as follow ,

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