IOSR Journal of Dental and Medical Sciences (IOSR-JDMS) e-ISSN: 2279-0853, p-ISSN: 2279-0861.Volume 17, Issue 3 Ver.17 March. (2018), PP 04-12 www.iosrjournals.org DOI: 10.9790/0853-1703170412 www.iosrjournals.org 4 | Page Long-Course Conventional Neoadjuvant Chemoradiotherapy Versus Short Course(5*5 Gy) Radiotherapy Followed By Consolidation Chemotherapy With Delayed Surgery In Locally Advanced Carcinoma Rectum: Results Of A Prospective Randomized Study Niketa Thakur, R.K. Seam, M.K. Gupta, M. Gupta, V. Fotedar, S.Vats, Sakshi Rana, (Department Of Radiotherapy And Oncology, Regional Cancer Center, IGMC, Shimla , India). Corresponding Author: Niketa Thakur Abstract: Background: Chemoradiotherapy followed by surgery followed by adjuvant chemotherapy is the mainstay of treatment in stage II and III rectal cancer.There are two approaches to pelvic RT for resectable rectal cancer: short-course radiation and long course chemoradiotherapy(CRT).Polish and Australian randomized studies compared short-course radiation and immediate surgery with long-course CRT and delayed surgery.In these studies similar long-term survival and local control have been reported for both these approaches but pathological complete response(pCR) is not better with short course RT. Moreover studies have shown better tumor downstaging with delayed surgery. So the idea is to combine the benefits of delayed surgery for improved tumor downstaging with short course RT by adding two cycles of chemotherapy between short course RT and surgery to improve pCR rates.In this context the use of short-course radiotherapy may have some advantages and needs to be tested in clinical trials. Aim: To compare the tumour response clinically, radiologically and histopathologically To compare the toxicities between the two arms Materials and Methods: This prospective randomized study was a two arm study in which short course radiotherapy followed by two cycles of chemotherapy was compared with conventional neoadjuvant chemoradiotherapy in rectal cancer.Patients assigned to study group(short course RT) were given 25 Gy (5 Gy/fraction) in 5 days.Following a gap of 1 week after RT, patients were given two cycles of Capecitabine and Oxaliplatin (CAPOX) based chemotherapy.Patients assigned to control group(conventional CRT) were given radiation of 50.4 Gy in 28 fractions along with tablet Capecitabine on RT days.Patients were assessed for surgery after 4-6 weeks of completion of chemoradiation.Overall treatment time to surgery was similar in both the arms i.e. 10-12 weeks. Results: Of the 28 entered patients, 27 were eligible for analysis; 14 in study arm and 13 in control arm.The pCR rate was 6.7% in study arm while it was 0 in control arm(p=0.343). 33.3% patients in study arm and 53.8% patients in control arm had partial response(p=0.274). 53.3% patients in study arm and 46.2% patients in control arm had stable disease(p=0.705).None of the patients in both the arms had progressive disease.Acute toxicities were lower in study arm.The absence of hematological toxicity in 60% patients in study arm was statistically significant (p=.001).20% patients in study arm and 92.3% patients in control arm had grade 2-3 toxicity (p=0.005).The absence of skin toxicity in 73.3% patients in study arm was statistically significant(p=.001).Grade 3 toxicity was seen in 15.4% patients in control arm and no patient in study arm(p=0.116). Conclusions: pCR rates in the two arms are comparable.But the major advantage for the 5*5 Gy regimen with chemotherapy in neo-adjuvant setting is the improved toxicity profile compared with conventional CRT with significant reduction in acute toxicities in short course RT arm. Keywords: Short-course RT, rectal neoplasm, chemoradiotherapy --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 16-03-2018 Date of acceptance: 31-03-2018 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction