ESTRO 2022 - Abstract Book

S1087

Abstract book

ESTRO 2022

Conclusion Our preliminary results showed that SIB/ SIP approach in pancreatic SBRT is feasible and may prevent damage to duodenum giving a safe administration of ablative doses to the tumor. This dose-painting could facilitate the conversion to negative margin resection and to enhance local tumour control and survival, increasing the therapeutic window of clinical benefit. Despite the volume difference among the clinical presentations, the technique is also proving to be reproducible through its optimization. A prospective clinical study is currently ongoing to confirm the efficacy on outcomes.

PO-1289 Toxicity and treatment outcomes in dose escalated radiotherapy for upper third oesophageal carcinoma

M.M.N. Win 1 , C. Barker 2 , L. Bhatt 1 , H. Sheikh 3 , G. Radhakrishna 1

1 The Christie Hospital NHS Foundation Trust, Clinical Oncology, Manchester, United Kingdom; 2 The Christie Hospital NHS Foundation Trust, Clinical Oncology, Manchester , United Kingdom; 3 The Christie Hospital NHS Foundation Trust , Clinical Oncology, Manchester, United Kingdom Purpose or Objective The incidence of the carcinoma of the upper third oesophagus is rare, accounting for 11% of all oesophageal cancer cases in the UK. Definitive chemo-radiotherapy (dCRT) is the recommended treatment option in patients with the carcinoma of the upper third oesophagus. This “real-world” data aimed to provide the treatment outcomes and toxicity for patients treated with dose-escalated radiotherapy (RT) for upper third oesophageal cancer. Materials and Methods This was a retrospective study of patients treated at the Christie Hospital between 2010 and 2021. 44 patients (male=24, female =20) were identified with squamous cell carcinoma of the upper third oesophagus. RT was delivered using either IG -IMRT or VMAT with 60-67 Gy in 30 fractions with daily volumetric imaging. 40 Patients received concurrent chemotherapy including 31 patients who were also given induction chemotherapy. The regimes were platinum based, with 2 patients receiving cetuximab. Results Median age at treatment was 63 (range 27-79). All patients completed 30 fractions of RT. Grade 3 toxicities (CTCAE version 5) were observed in 12 patients (27%): oesophagitis in 7 patients (16%) with 3 patients requiring emergency gastrostomy insertion, nausea and vomiting in 3 patients (7%) and non-neutropenic sepsis in 2 patients (4%). The 30-day mortality and 90-day mortality rates were 2% and 7% respectively. 50% of patients at 6 month follow-up had subjective improvement in dysphagia. At a median follow-up of 19 months (0-83months), 6 patients (14%) developed local relapse in the high dose radiotherapy field and 14 patients (32%) developed distant metastases. Median overall survival (OS) was 23 months. OS at 1 and 2 year were 78% and 48% respectively. Median progression-free survival (PFS) was 15 months and PFS at 1 year and 2 year were 53% and 38% respectively. Data will be matured at the time of presentation. Conclusion This study demonstrates that dose-escalated RT of 60-67Gy has an acceptable safety profile and offers improved local disease control in patients with upper third oesophageal cancer. Further studies on dose escalated RT in upper third oesophageal cancer are required.

PO-1290 Does setup and internal margin differ on verification modality and location in carcinoma oesophagus?

N. Aggarwal 1 , S. Misra 2 , S. Singh 2 , K.J.M. Das 2 , S.K.S. Kumar 2 , S. Kumar 2

1 Sanjay Gandhi Post Graduate Institute of Medical Sciences , Radiotherapy, Lucknow, India; 2 Sanjay Gandhi Post Graduate Institute of Medical Sciences, Radiotherapy, Lucknow, India Purpose or Objective To evaluate tumor motion and setup errors using MV portal imaging (PI) & KV three-dimensional Cone Beam CT (CBCT) in patients of carcinoma oesophagus receiving radical intent radiotherapy (RT).