ESTRO 37 Abstract book

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ESTRO 37

while not increasing the oncological risk. Routine hysterectomy after finishing fertility plans is not necessary. SP-0122 Radiotherapy perspective in locally advanced disease R. Pötter 1 1 Medizinische Universität Wien, Department of Radiation Oncology, Vienna, Austria Abstract text General management of locally advanced cervical cancer* Stage T1b2/T2a2 and negative lymph nodes on radiological staging Treatment strategy should aim for avoiding combination of radical surgery and postoperative EBRT, due to the significant increase of morbidity and no evident impact on survival (grade B) . Definitive platinum-based concomitant chemoradiotherapy (CCRT) and brachytherapy(BT) is the preferred treatment (grade A) . Radical surgery is an alternative option, in particular in patients without negative risk factors (combinations of tumour size, LVSI, and/or depth of stromal invasion). Quality of surgery is of key importance. Intraoperative assessment of lymph node status is recommended as the first step. Stage T1b2/T2a2 and involved lymph nodes on radiological staging Definitive CCRT and BT are recommended in patients with unequivocally involved pelvic lymph nodes on imaging (grade A) . An additional radiation boost to the involved lymph nodes should be applied. Stages T2b, T3a/b, T4a Definitive platinum based CCRT and BT is recommended (grade A) . An additional radiation boost to involved lymph nodes should be applied. Para-aortic lymph node dissection, at least up to inferior mesenteric artery, may be considered before CCRT and BT. Pelvic lymph node dissection is not required (grade C) (also applies for T1b2/T2a2 N+). Principles of radiotherapy* Definitive chemoradiotherapy and brachytherapy: general aspects Definitive management (without tumour related surgery) consists of pelvic CCRT (platinum based) and BT or pelvic EBRT alone and BT. Overall treatment time for the definitive treatment should not exceed 7-8 weeks. Delay of treatment and/or treatment interruptions have to be avoided. Definitive chemoradiotherapy EBRT is recommended minimum as 3D conformal RT. The preferred treatment is IMRT due to the more conformal dose distribution that maximizes sparing of organs at risk. EBRT can be applied as CCRT with total dose of 45-50 Gy (1.8 Gy per fraction) and single agent radio-sensitizing Chth, preferably cisplatin (weekly 40mg/m2) so that definitive RT is not compromised (alternative options fluorouracil (5FU) or carboplatin). EBRT may also be applied without concomitant Chth if e.g. patients are unfit for any Chth. Tumor and lymph node related target volume for EBRT includes the primary cervical tumour and the adjacent tissues and the pelvic lymph nodes. In case of pelvic lymph node involvement EBRT may include the para- aortic region up to the renal vessels (45 Gy). A reduced target volume for EBRT resulting in a small pelvic field not including the common iliac nodes may be considered in low and intermediate risk T1b1 patients with negative lymph nodes on imaging and no LVSI.

Boost treatment for involved lymph node(s) may be applied as simultaneous integrated boost (SIB) within the IMRT treatment or as sequential boost up to a total EQD 2 of 55-60 Gy. IGRT is recommended for IMRT to ensure safe dose application in the tumour related targets, to account for motion uncertainties, to reduce margins and to achieve reduced doses to organs at risk. Overall treatment time for EBRT should not exceed 5-6 weeks. Definitive brachytherapy Image guided adaptive brachytherapy (IGABT) is recommended, preferably using MRI at the time of BT. Alternative imaging modalities such as CT and ultrasound may be used. The tumor related target for BT includes the residual GTV (GTV-T res ) after CCRT, the adaptive high risk CTV (CTV- T HR ) and the intermediate risk CTV (CTV-T IR ). The BT applicator should consist of a uterine tandem and a vaginal component (ovoids/ring/mould/combined ring/ovoid). Combined intracavitary/interstitial BT for adjusting the application further to the individual target should be considered. The vaginal component carries holes for straight or oblique needle guidance into the parametria. In IGABT the planning aim should be to deliver a BT dose of 40-45 Gy (EQD2) to reach a total EBRT+BT dose of ≥ 85-90 Gy EQD2 (D90) (assuming 45 Gy through EBRT) to the CTV-T HR , ≥ 60 Gy (D98) to the CTV-T IR, and ≥ 90 Gy (D98) to the GTV-T res . 3D and 2D dose volume and point constraints for rectum, bladder, vagina, sigmoid and bowel are recommended and they have to be based on the published clinical evidence. BT should be delivered in several fractions as high dose rate (usually 3-4) or in 1-2 fractions as pulse dose rate BT. For the tumour related targets (GTV-T res , CTV-T HR , CTV- T IR ) the use of EBRT for giving extra dose (e.g. parametrial boost, cervix boost) is discouraged, even when using advanced EBRT technology such as stereotactic RT. Definitive 3D conformal EBRT or chemoradiotherapy and radiography based brachytherapy 3D conformal RT alone or as definitive CCRT (platinum based) ± para-aortic RT and/or 2D radiography based BT is recommended, if IMRT and/or IGABT are not available. *Cibula, Pötter et al. ESGO ESTRO ESP guidelines for cervical cancer RadiothOncol in press SP-0123 Panel discussion with a case presentation U. Mahantshetty Tata Memorial Hospital, Mumbai, India

Abstract not received

Symposium: Quality assurance in brachytherapy

SP-0124 Sharing of learning from brachytherapy error and near miss events U. Findlay 1 1 Public Health England, Medical Exposures Group, Oxford, United Kingdom Abstract text The planning and delivery of radiotherapy treatments is complex. It is reliant on input from a team of skilled professionals using sophisticated technology to manage and process large amounts of unique data generated on a per patient basis and interpreting it correctly for each fraction of treatment. The potential of error across the patient pathway is high. When the opportunity for error