ESTRO 2021 Abstract Book

S1152

ESTRO 2021

response

PO-1402 Retrospective analysis of RCT for bladder cancer – Reflection of the real patient cohort R. von Bestenbostel 1 , C. Baudermann 1 , P. Rogowski 1 , C. Trapp 1 , C. Belka 1 , N. Schmidt-Hegemann 1 , M. Li 1 1 LMU Munich, Radiation Oncology, Munich, Germany Purpose or Objective muscle invasive bladder carcinomas (miBC) are treated according to stage, with surgical procedures being given preference. While miBCs are usually treated by radical cystectomy (CE), several clinical studies have shown that miBC can be cured by simultaneous radiochemotherapy (RCT). By using this approach, many patients (pts) were able to preserve their bladder and benefited from a significantly better quality of life. Until now, this procedure has been available rather as a second choice of curative therapy for pts who either refuse CE or are functionally inoperable. The aim of this retrospective study is to evaluate the therapeutic effects, side effects and the preservation of bladder function after R(C)T as an alternative to cystectomy. Materials and Methods We retrospectively evaluated data on survival, time to progression and bladder function of consecutive pts treated for BC in the Department of Radiation Oncology University Hospital LMU Munich between 01/2000 and 12/2020. Exclusion criteria were treatment of metastases or postoperative RT after radical CE. Results 90 patients, 75 males (83.3%) and 15 females (27.7%) with a median age of 80 years (yrs) (range: 43-93 yrs) and a median Karnofsky Performance Status (KPS) of 70% (range:40-100%) were analysed. 80 (88.9%) pts had a miBC (T2 to T4) and another 10 pts (11.1%) had a non-miBC (T1 and Ta). 49 pts (54.4%) received RT with curative intent, 41 pts (45,6%) with palliative intent. 18 pts (20%) received RCT, the other 72 pts (80%) received RT alone. In 85 cases (94.4%), R(C)T was completed, in 5 cases (5.6%), RT was discontinued prematurely due to severe deterioration or death. RT techniques which were used included IMRT and VMAT in 34 (37.8%) cases and 3D-planned RT in 56 (62.2%) cases. The median total dose was 47.5 Gray (range:8 - 69.36 Gy). The median total dose for curative, completed treatment was 58.8 Gy (range:45-69.36 Gy). Pts with palliative, completed treatment received a median total dose of 36.5Gy (range:8–40.0Gy). The median overall survival (mOS) was 12 months. Pts with curative intent showed a mOS of 23 months, pts with palliative intent showed a mOS of 5 months (p= 0.012). In the multivariate analysis modern radiation technique was associated with better survival independent of the intention of treatment: patients treated with VMAT/IMRT showed a mOS of 32 months and pts treated 3D-planned RT showed a mOS of 6 months (p= 0.00). Pts treated with a curative intention, the mOS was 34 months for VMAT/IMRT techniques and 12 months for 3D technique (p= 0.003). Follow-up information was found in 41 of 49 curative treated pts. After a median time of 4 months (range:1-46 months), 24 pts showed progression in form of local recurrence (15 pts), regional nodal metastases (2 pts) and/or distant metastases (15 pts). Conclusion Pts who were referred to R(C)T for miBC were rather old and unfit in the real world. However, after a curative intended R(C)T, they still had a fair local control and mOS with organ preservation. PO-1403 High dose palliative radiotherapy in bladder cancer - A single centre experience from the UK M. Jackson 1 , N. Hannaway 2 , A. Burns 3 , R. Pearson 3 , R. Chandler 3 , J. Frew 3 , A. Azzabi 4 , X. Jiang 3 1 Newcastle upon Tyne Hospitals NHS Foundation Trust, Northern Centre for Cancer Care (NCCC) - Oncology, Newcastle upon Tyne, United Kingdom; 2 The Newcastle upon Tyne Hospitals NHS Foundation Trust , Northern Centre for Cancer Care, Newcastle upon Tyne, United Kingdom; 3 Newcastle upon Tyne Hospitals NHS Foundation Trust, Northern Centre for Cancer Care, Newcastle upon Tyne , United Kingdom; 4 Newcastle upon Tyne Hospitals NHS Foundation Trust, Northern Centre for Cancer Care, Newcastle upon Tyne, United Kingdom Purpose or Objective High-dose palliative radiotherapy to the bladder is a treatment in clinically frail patients with bladder cancer. Limited studies including the recent HYBRID phase II trial have shown local control of potentially over 80% and a median overall survival of 18 months. This single centre retrospective study reviews the outcomes of patients that received external beam radiotherapy with 36 Gy in 6 weekly fractions for muscle invasive bladder cancer. Materials and Methods A retrospective analysis of 85 patients who received 36Gy in 6 weekly fractions of radiotherapy to the bladder at a regional cancer centre between 2016 and 2021 was performed. Data collected included patient demographics, performance status (PS), staging, histology, treatment received, local control, progression free survival (PFS) and overall survival (OS). Local control included symptomatic improvement as some patients did not receive follow-up cystoscopy or axial imaging surveillance. Statistical analysis used logrank and Kaplan- Meier curves. Results Median follow up time was 8.8 months (0-48). As of March 2021 25% of patients are alive. Mean age of the cohort was 79.8 years old (59-90) with 66% patients >=80; N=35 (41%) were PS <2 and N=50 (59%) PS >=2. N=74 (87%) TXN0; 12% N1 and 6% M1 disease. N=81 (95%) of patients had symptomatic disease of which 73% had haematuria. Median OS in the overall cohort was 8.6 months (0-48) and median PFS was 7.1 months (0-47). 85% completed 6/6 fractions. In those completing 6 vs <6 fractions PFS was 8 vs 1.7 months (p=0.000025) and OS 9.5 vs 2.3 months respectively (p=0.000002). Initial local control N=75 (88%) of which N=35 (46%) had subsequent local or distant disease progression. N=17 (23%) had later local progression. Subsequent local vs distant progression conveyed different OS 8.4 vs 5.9 months respectively.