The role of palliative re-irradiation in management of rectal cancer
Authors: T. Janjua, M. Hingorani, R. Cooper, P. Hatfield, N. Casanova, M. Williams, M. Teo, D. Sebag-Montefiore
Journal: Annals of Oncology (2018)

Introduction: The role of re-irradiation for management of loco-regional pelvic recurrence in rectal cancer remains poorly defined. Previous studies have employed range of dose-schedules with variable outcomes and the use of higher biological effective dose (BED) regimes has been associated with increased rates of Grade 3-4 toxicity ranging from 20-30 percent. We report on retrospective evaluation of outcomes in rectal cancer following re-irradiation with a palliative fractionated regime of 15 Gy in 5 fractions. Methods: Twenty rectal cancer patients were identified from the radiotherapy (RT) data registers all of whom received re-irradiation with a dose-schedule of 15 Gy in 5 fractions between 2012-2017. The hospital clinical and RT records of patients were reviewed to evaluate the following study parameters: demographics, stage of disease and treatment at presentation, pattern of relapse, specifics of re-irradiation schedule, symptom control, toxicity, and survival outcomes. Results: The median age of patients was 71.5 years (males =18, females=2). Nineteen patients had pathologically confirmed diagnosis of adenocarcinoma and in one patient biopsy was inconclusive. Most patients (n = 16) had localised disease at original diagnosis and 15 patients were treated with common neo-adjuvant RT regimes [short-course RT = 8 (25 Gy/5 fractions), chemo-RT=7 (45 Gy/25 fractions with concurrent chemotherapy)]. Twelve patients underwent subsequent surgery (APER=6, anterior resection=4, Hartmann's=2). Five patients were initially treated with palliative RT using 20 Gy in 5 fractions. All patients developed loco-regional pelvic recurrence (local progression=9, sacral=5, rectal stump=2, pelvic side wall=2, anastomotic =2). There were equal proportion of patients with localised (n = 10) and metastatic disease (n = 10) at time of re-irradiation. The common symptoms were bleeding and mucus discharge (n = 8), pain (n = 10), tenesmus (n = 3), and numbness (n = 1). The median time interval of re-irradiation from original RT was 33 months (inter-quartile range = 13-65 months). There was definite evidence of symptomatic improvement in more than 50% of patients (n = 11) with only 3 patients reporting no improvement in local symptoms. Six patients were discharged following re-irradiation and had limited follow-up to comment on the level of symptomatic improvement. Most importantly, there were no reports of significant toxicity and only one patient reported grade 2 fatigue and nausea. The median survival of patients who had previously received RT for localised disease was 10.25 months (range=7.3-13.1 months) after irradiation. Conclusion: Palliative re-irradiation with 15 Gy in 5 fractions is well tolerated in patients with rectal cancer and associated with good symptomatic improvement and minimal toxicity. It should be considered as a possible therapeutic option in those with symptomatic loco-regional recurrence after previous radiotherapy. Further studies should be designed to evaluate the dose-response characteristics of reirradiated tissues with the aim of defining an optimum dose-level that may be safely employed to treat such patients.