ESTRO 2022 - Abstract Book

S308

Abstract book

ESTRO 2022

Flab reconstructions are frequently used after surgical resection in head and neck cancer. Many of these patients undergo postoperative radiotherapy or chemoradiation. Radiation oncologists need to decide whether the flab needs to be included in part or in total into the CTV. In the absence of reliable data, in theory, one would expect that the flap-tissue junction is at highest risk of local recurrence compared to other areas of the flab, especially in case of a positive or close resection margins. Accordingly, a strong agreement among GORTEC and international experts was reported that the flap-tissue junction should be included into the high risk CTV. However, no agreement was reached, which margin from the flap-tissue junction should be used for the CTV. Furthermore, no consensus was reported regarding several other items of delineation and imaging in this situation that will be discussed. This reflects a remarkable knowledge gap and the need for further research.

SP-0356 Which dose and techniques should be used in reconstructed tissue?

J. Thariat

1 France Abstract not available

SP-0357 Radiation-induced toxicity in the postoperative setting

H. Langendijk

1 The Netherlands Abstract not available

SP-0358 TBC

Abstract not available

Symposium: 2020 - Losing ground for radiotherapy?

SP-0359 Locally advanced oesophagus where more is not better G. Crehange

1 France Abstract not available

SP-0360 Lung cancer: When does post-operative radiotherapy not provide a benefit?

A. Levy 1 , O. Mercier 2 , A. Botticella 1 , A. Traore-Diallo 1 , C. Berthold 1 , G. Auzac 1 , A. Bardet 3 , C. Le Péchoux 4

1 Gustave Roussy, Radiation Oncology, Villejuif, France; 2 Marie-Lannelongue, Thoracic and Vascular Surgery, Le Plessis- Robinson, France; 3 Gustave Roussy, Statistics, Villejuif, France; 4 Gustave Roussy, Radiation Oncology, Villejuif , France Abstract Text Patients with locally advanced resected non-small cell lung cancer (NSCLC) are at high risk of relapse. Although platinum- based adjuvant chemotherapy has become standard, the role of postoperative radiotherapy (PORT) is controversial, especially in stage IIIA pN2 patients. Two prospective randomized phase III studies evaluating modern PORT in patients with completely resected stage IIIA-N2 NSCLC who received (neo)adjuvant chemotherapy have been reported: the European Lung ART trial (n=501 patient) and the single-centre Chinese PORT-C trial (n=364 patients). No difference in disease-free survival (DFS) at 3 years was found, these two trials being therefore negative for their primary endpoint. Overall survival (OS) was also not different between the groups in both trials. Differences between studies will be highlighted. An improvement in locoregional control (decreased rate of mediastinal relapse) was however shown in both trials. Ongoing analyses could identify a subgroup of patients for whom PORT could be considered.

SP-0361 Pancreas: Preoperative chemoradiation in LAPC - Evidence from randomised trials TBC Abstract not available

SP-0362 Rectum: Does chemotherapy intensification improve tumour response more than radiotherapy does? E. Fokas

1 Germany Abstract not available

Symposium: The use of imaging in prostate brachytherapy

SP-0363 Imaging for target definition in HDR prostate