Abstract book - ESTRO meets Asia

S72 ESTRO meets Asia 2018

relatedquality of life (HRQOL) between diffuse large B celllymphoma (DLBCL) survivors of different age categoriesand to compare their HRQOL with an age- and sexmatchednormative population. Material and Methods From the medical records of Jupiter Hospital, all patientsdiagnosed with DLBCL from 2009 to 2016 were enrolledfor the evaluation. Patients (n = 175) were invited tocomplete the European Organization for Research andTreatment of Cancer Quality of Life Questionnaire- Core30 (EORTC QLQ-C30) questionnaire. Data from an ageandsex-matched normative population (n = 155) wereused for comparison. Results aged 18–59 years scored better on physical functioning, quality of life, appetite loss and gastrointestinalfunctioning than survivors of 76– 85 years old (p < 0.005). Financial problems more often occurred in survivors aged18–59 years compared to survivors of 76–85 years old (p <0.01). Compared to the normative population, DLBCLsurvivors aged 18–59 years showed worse scores oncognitive and social functioning and on dyspnea andfinancial problems (p <0.01). In survivors of the other age categories, only differences with trivial or small-sizeeffects were found Conclusion There was significant difference in the affected quality oflife in younger population compared to the normativepopulation. The younger DLBCL survivors have betterHRQOL than older survivors. DLBCL has a greater impacton younger than older survivors and that the worseHRQOL observed is caused by age and the disease impacton the quality outcome is minimal. PO-178 A Simplified Three-Isocenter VMAT for Craniospinal Irradiation I. Takahashi 1 , Y. Adachi 1 , N. Imano 1 , Y. Takeuchi 1 , I. Nishibuchi 1 , K. Miki 1 , A. Saito 1 , T. Kimura 1 , Y. Murakami 1 , Y. Nagata 1 1 Hiroshima University, Radiation Oncology, Hiroshima, Japan Purpose or Objective Craniospinal irradiation (CSI) has become an important treatment method for Central nervous system (CNS) relapse of hematological malignancies. However, conventional CSI is technically very challenging and field edge matching is needed because of the mechanical limitations of standard linear accelerators. We have developed a simple Linac based volumetric modulated arc therapy (VMAT) technique for CSI and compared dose homogeneity and dose to organs at risk (OAR) with conventional three-dimensional conformal radiotherapy Data of seven patients with CNS relapse of hematological malignancies positioned supine was used. A dose of 22.5 Gy was prescribed to be delivered in 15 fractions. Planning target volume (PTV) included the whole brain and spinal canal to the S3 vertebral level. The VMAT plan used three full arcs, each with a unique isocenter (Brain, Superior Spine, Inferior Spine). Spinal two arcs turned off lateral beams (225-315 o and 45-135 o ) to minimize lung dose. Adjacent fields were intentionally overlapped to eliminate the issues of beam edge matching, and the optimization process smoothly integrated the dose inside the overlapped junction. The 3D-CRT plan used edge matching field sets and shifted junctions three times. Results Comparing the VMAT plan with the 3D-CRT plan, the average simplified homogeneity index (HI=Dmax/Dmin) of PTV was 1.19 ± 0.11 and 1.46 ± 0.13, respectively. Mean doses to avoidable OAR were significantly decreased (for the heart: 5.3 Gy and 11.1 Gy, for the esophagus: 11.6 Gy (3D-CRT) technique. Material and Methods

and 19.7 Gy, for the parotid glands: 8.8 Gy and 20.5 Gy, using VMAT and 3D-CRT, respectively). The lung V5, V10 and Dmean were 28.3%, 5.4%, 3.4 Gy, in VMAT, 20.1%, 15.3 %, 4.6 Gy, in 3D-CRT. The doses of lung except V5 were lower in VMAT. Conclusion We have developed a simplified three-isocenter Linac based VMAT approach for CSI. The dose to the brain and spine is significantly improved, compared to the conventional 3D-CRT. The single VMAT plan is easier to manage. This new technique simplifies the set up and eliminates the need for shifting junctions during course of CSI treatment and saves OAR for patients with CNS relapse of hematological malignancies. PO-179 VMAT applied to SBBC radiotherapy: dosimetric study on DIBH versus FB set up. D. Gaudino 1 , S. Cima 2 , M. Frapolli 2 , D. Daniele 2 , B. Muoio 2 , G.A. Pesce 2 , F. Martucci 2 , N.C. Azinwi 2 , D. Bosetti 2 , L. Bellesi 1 , M. Casiraghi 1 , M.A. Piliero 1 , F. Pupillo 1 , S. Presilla 1 , A. Richetti 2 , M.C. Valli 2 1 Ente Ospedaliero Cantonale, Medical Physics Unit, Bellinzona, Switzerland 2 Oncology Institute of Southern Switzerland, Radiation Oncology, Bellinzona-Lugano, Switzerland Purpose or Objective Aim.The purpose of this planning report is to compare dosimetric results of deep inspiration breath hold (DIBH) and free breathing (FB) set up in patientswith synchronous bilateral breast cancer (SBBC) treated with adjuvant radiotherapy. Material and Methods Material andmethods. Fourteen patientswith early stage bilateral breast cancer were treatedwith breast conservative surgery. Bilateral breast planning treatment volume (PTV) and organs at risk (OARs) were delineated forDIBH and FB datasets on the planning computed tomography (CT).Volumetricmodulated arc therapy (VMAT/RapidArc ®) planswere generated in the twoset up modalities.During plan optimization the objectives were to obtain comparable target coverage, dose conformity and homogeneity with an acceptable dose levels forOARs: both lungs, heart, left anterior descending coronary artery (LAD) and thyroid. Results The maximum and the mean dose to the heart were reduced in DIBH modality with anaverage of 19.2 Gy and 6.5 Gy versus 25.9 Gy and 8Gy in FB. The mean dose to the sum of lungs was 13.3 Gy in DIBH modality versus 14.3Gy in FB. We observed a better sparing of LAD in DIBH with a maximum dose of 14.5Gy versus 18Gy in FB modality. Conclusion The use of DIBH and VMAT technique improves heart, LAD and both lungs sparing in synchronous bilateral breast cancer adjuvant RT. We have been able to treat all patients with DIBH modality due to its feasibility and reproducibility. The OAR sparing is comparable with previous experiences and we been able to respect the constraints considered for single breast RT. The clinical impact of this innovative technique on acute/late toxicities is under investigation. PO-180 Heart dose difference for prone left breast radiation therapy on Elekta Synergy and Varian 21iX B. Naydich 1 , K. Feng 1 , P. Hopko 1 , L. Shaw 1 , K. Settle 1 , S. Parikh 1 1 Chesapeake Potomac Regional Cancer Center, Radiation Oncology, Waldorf, USA Clinical: Breast