Main Session
Sep
29
PQA 06 - Genitourinary Cancer, Gynecological Cancer, and Health Care Access and Engagement
Presenter(s)
Olabisi Ogunbiyi, MBBS, BSc - Royal Surrey County Hospital NHS Foundation Trust, London, Surrey
O. Ogunbiyi1,2, A. Withanage Don1, M. Bradford1, C. Mullany1, G. Daniel1, E. Hart1, S. Kolli1, S. Nasrin1, M. Abdulfattah1, M. Bolt3, R. Hollingdale3, D. Mcquaid3, C. Williamson1, and C. Mikropoulos1; 1Royal Surrey Cancer Centre, Guildford, United Kingdom, 2Institute of Cancer Research, London, United Kingdom, 3Department of Radiotherapy Physics, Royal Surrey County Hospital, Guildford, United Kingdom
Purpose/Objective(s):
Bladder radiotherapy is technically challenging due to the organ’s mobility and deformability. Daily online adaptive radiotherapy (ART) offers the potential to account for daily anatomical variation, maintaining target coverage while reducing dose to surrounding organs at risk. Real-world evidence on clinical outcomes and toxicity with bladder ART remains limited. We aimed to evaluate oncological and toxicity outcomes from two UK centres delivering daily Cone Beam Computed Tomography (CBCT)-based online ART for radical-intent bladder radiotherapy.Materials/Methods:
We conducted a retrospective analysis of all consecutive patients treated with radical-intent adaptive bladder radiotherapy at two tertiary centres from January 2021 to October 2025. Patient demographics, tumour characteristics, treatment details, relapse and mortality data were extracted from electronic health records. Overall survival (OS) and progression-free survival (PFS) were estimated using Kaplan Meier method in R. Acute and late toxicities were graded according to CTCAEv6.Results:
Sixty-three patients were included, with a median age was 74 years (range 60 – 88). Fourty-nine patients (78%) had T2 disease. Neoadjuvant chemotherapy was administered in twenty-nine patients (46%) and twenty-six patients (41%) had concurrent radiosensitising chemotherapy. The median follow-up period was 18 months (1 - 56) months. Sixty-two (98%) patients received 55Gy in 20 fractions, whilst one patient (2%) received 57.75Gy in 21 fractions. The median number of adaptive fractions was 19 (range 12 – 20). Grade = 3 acute radiotherapy-related toxicity occurred in seven (11%) of patients and grade =3 late toxicity in five patients (8%). One (1.6%) patient had grade =3 acute bowel toxicity and no patients had grade =3 late bowel toxicity. Five (8%) patients had grade =3 acute bladder toxicity and four (6%) patients had grade =3 late bladder toxicity. The overall response rate was 82%. The 2-year PFS was 61% (95% CI, 48 –78%). The 2-year OS was 76% (95% CI, 64 – 89%).Conclusion:
Daily CBCT-based online adaptive radical-intent bladder radiotherapy demonstrates favourable early oncological outcomes with acceptable acute and late toxicity in a real-world setting. These data support adaptive bladder radiotherapy as a viable alternative to conventional bladder radiotherapy. Prospective randomised studies are warranted to validate these findings and to compare toxicity and oncological outcomes against other radical treatment modalities.