A single centre experience of in-field recurrence following pre-operative radio(chemo)therapy in patients with rectal cancer

Abstract

discharge (n ¼ 8), pain (n ¼ 10), tenesmus (n ¼ 3), and numbness (n ¼ 1). The median time interval of re-irradiation from original RT was 33 months (inter-quartile range ¼ 13-65 months). There was definite evidence of symptomatic improvement in more than 50% of patients (n ¼ 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 (range¼7.3-13.1 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. P À 316 Is there any association of dose received by pelvic bone marrow in preoperative radiotherapy in rectal cancer with hematological Onkologii-Instytut im. M. Sklodowskiej Curie, Warsaw, Poland Introduction: Preoperative radio(chemo)therapy in rectal cancer may irreversibly damage pelvic bone marrow (PBM) and impair the tolerance of subsequent chemotherapy. The aim of the study was to assess the association between irradiated volume of PBM and the tolerance of subsequent FOLFOX-4 chemotherapy in rectal cancer. Methods: The target population was a retrospective cohort of consecutive patients with adenocarcinoma of rectum who received FOLFOX-4 as adjuvant or because of cancer relapse in our institution between 2011-2016. The PBM was automatically contoured and divided into iliac (IM), lumbosacral (LSM), and lower pelvic (LPM) marrow. We assessed mean dose, and percentage of volume receiving 10-90% (V10%-V90%) of the prescribed dose for PBM, IM, LSM, LPM. To evaluate the association between mean dose, V20% and V40% with !2 (TOX2) and ! grade 3 (TOX3) hematological toxicity, Chi-2 and T-test were used. Generalized linear model (GLM) was used to test an influence of dose-volumes distribution on TOX2 and TOX3.Results: 39 patients met eligibility criteria. 26 of them received preoperative 5x5 Gy, 7 of them underwent 5x5 Gy with consolidative 3 cycles of FOLFOX-4, 6 of them received 25x2 Gy with concomitant 5-FU/LV. No dependence of V20% and V40% of PBM and its areas on toxicity was found. We found no influence of dose-volume distribution on TOX2 and TOX3. Conclusion:No relationship between doses received by pelvic bone marrow in preoperative radio(chemo)therapy in rectal cancer and hematological tolerance of subsequent FOLFOX-4 chemotherapy was found.