2321 - Toxicity and Quality of Life (QOL) Outcomes of Short Course Radiotherapy (SCRT) by Intensity Modulated Radiotherapy (IMRT) in Rectal Cancer - Institutional Prospective Database
Presenter(s)
T. Basu1, J. P. Sahu1, G. Roshan1, R. R. Menon1, S. Kamat1, A. U. Gadekar1, I. Ammbulkar2, A. Karpe3, H. Dsouza3, T. Pawar4, P. Modi1, K. Parwani1, D. Kurkure Jr1, R. Kabre1, and R. Talukdar1; 1Department of Radiation Oncology-HCG Cancer Centre, Mumbai, India, 2Department of Medical Oncology-HCG Cancer Center Mumbai, India., Mumbai, India, 3Medical Oncology-HCG Cancer Center., Mumbai, India, 4Surgical Oncology- HCG cancer centre, Mumbai, India
Purpose/Objective(s): RAPIDO trial demonstrated a definite impact of SCRT on locally advanced rectal cancer patients. SCRT followed by systemic chemotherapy remains a feasible and practical option in locally advanced and oligometastatic rectal adenocarcinomas. IMRT has helped in better tolerance and reduced acute side effects. This study reports acute toxicity and QOL data for rectal adenocarcinomas from diagnosis to 6 months after treatment.
Materials/Methods: Rectal cancer patients with clinical stage T2-3N0-2M0-1 undergoing SCRT were identified. All received IMRT as per standard international guidelines. The dose prescribed was 25 Gy/5 fractions over 5-7 days and in select cases simultaneous integrated boost (SIB) of 30 Gy/5 fractions to lateral pelvic nodes. Acute toxicity reporting for bowel and bladder and QOL by EORTC C30 and EORTC-CR29 questionnaires before SCRT, at 3 and 6 months post SCRT were recorded. Standard dosimetric parameters for bladder (D45%) and bowel (V400,250 and 200 cc) were documented. Post SCRT patients received systemic chemotherapy as total neoadjuvant approach (TNT) and surgical evaluation between 10-14 weeks. Patients having complete clinical response were discussed about wait and watch approach.
Results: 101 patients received SCRT by IMRT. Median age was 60 years (range:26-86 years) with 63% male. 34.3% were distal rectum location and 68.7% were moderately differentiated adenocarcinomas. 51.5% patients were stage IIIB and 22% had oligometastatic disease. The EMVI and MRF positivity were seen in 29.3% and 52.5% cases respectively. Median serum CEA level was 13.6 (range: 0.82-330.6). Treatment compliance was 98%. The grade 2 gastro-intestinal (GI) and genitourinary (GU) acute toxicity was reported in 85% and 90% respectively. The median dose for bowel V400, 250, 200 cc were 12.8, 15.2 and 16.2 Gy respectively whereas D45% for bladder was 19 Gy. Complete clinical response was observed in 15/101 (14.8%) and 22/101 (21%) patients at 3 and 6 months respectively. Post SCRT up to 3 months 15/101 (14.8%) patients reported grade 3 diarrhea requiring hospitalization. At 3 months the major changes on QOL scores were diarrhea (60%), mucus in stool (38%), blood in stool (15%) and vague lower abdominal pain (12%). Patients evaluated at 6 months reported improvement in these parameters. General anxiety persisted over 6 months among majority of patients. The clinical outcome data remained immature since the study analyzed up to 6 months only post SCRT. Chemotherapy related toxicities (FOLFOX or CAPOX) will be captured at a longer follow up.
Conclusion: SCRT by IMRT in our series showed promising results in accordance with published literature in terms of acute toxicity profile and maintained QOL. The long term follow up data related to clinical outcome, late toxicity and probable comparison with long course chemoradiation would be beneficial.