Abstract 256P
Background
Organ preservation is an increasingly popular concept for the treatment of early rectal cancer. Contact x-ray brachytherapy (CXB) has been shown to achieve high rates of complete clinical response (cCR) and is an attractive option for patients who are stoma averse or unfit. However, there is little information on the optimal frequency and accuracy of endoscopic and imaging surveillance for patients who enter watch and wait following CXB. The current standard is 3 monthly endoscopy and imaging for 2 years and 6 monthly thereafter which is resource intensive.
Methods
All patients treated at the Queen’s Centre for Oncology, Hull between November 2011 and September 2023 with CXB either as primary or adjuvant therapy for rectal cancer were identified. Demographics, imaging and endoscopic results and clinic outcomes were collected from patients’ medical records.
Results
A total of 237 patients successfully completed CXB during the study period; 165 patients underwent CXB as primary rectal cancer treatment, and 72 patients had CXB as adjuvant therapy following local excision (see table). Five patients in the primary treatment group were excluded due to failure to achieve cCR. The overall median follow-up was 30.5 months. In the primary CXB group, there were 30 (18%) local recurrences and 6 (6/72, 8%) in those who had adjuvant CXB. 97% (35/36) of the local recurrences were luminal and were accurately identified on endoscopy. MRI/CT of pelvis only picked up 61% (22/36) of the local recurrences and had a false negative rate of 25%. There was 1 (1/232, 0.4%) mesorectal nodal recurrence. There were 23 (23/232, 10%) distant recurrences.
Conclusions
The majority of local recurrences seen during watch and wait are luminal rather than nodal. Endoscopy is superior at detecting luminal recurrence than imaging. The frequency of MRI imaging during watch and wait could be reduced as a result.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.