Online

ESTRO 2020

Session Item

Clinical track: Lower GI (colon, rectum, anus)
9306
Poster
Clinical
23:00 - 23:00
Short Course Radiationtherapy chemotherapy and delayed surgery in locally advanced rectal carcinoma
PO-1088

Abstract

Short Course Radiationtherapy chemotherapy and delayed surgery in locally advanced rectal carcinoma
Authors: Mitra|, Swarupa(1)*[swarupamitra@rediffmail.com];Aggarwal|, Sumeet(2);Dewan|, Abhinav(3);Kaur Wahi|, Inderjeet(2);Barik|, Soumitra(4);Dobriyal|, Kiran(5);Mukhee|, Jwala(5);Jajodia|, Ankush(6);Khurana|, Himanshi(7);Dewan|, Ajay Kumar(8);
(1)Rajiv Gandhi Cancer Institute & Research Centre, Senior Consultant Radiation Oncologist, Rohini- Delhi, India;(2)Rajiv Gandhi Cancer Institute & Research Centre, Attending Consultant Radiation Oncologist, Rohini- Delhi, India;(3)Rajiv Gandhi Cancer Institute & Research Centre, Consultant Radiation Oncologist, Rohini- Delhi, India;(4)Rajiv Gandhi Cancer Institute & Research Centre, Senior Radiation Oncologist, Rohini- Delhi, India;(5)Rajiv Gandhi Cancer Institute & Research Centre, Resident Radiation Oncologist, Rohini- Delhi, India;(6)Rajiv Gandhi Cancer Institute & Research Centre, Resident Radiologist, Rohini- Delhi, India;(7)Rajiv Gandhi Cancer Institute & Research Centre, Research Radiation Oncology, Rohini- Delhi, India;(8)Rajiv Gandhi Cancer Institute & Research Centre, Senior Consultant Surgical Oncologist, Rohini- Delhi, India;
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Purpose or Objective


Objective :Short Course RT (scRT) and chemotherapy followed by delayed surgery has been hypothesized to increase the pathological complete response (pCR), decrease distant failures and improve survival in locally advanced rectal cancer patients.

Material and Methods

Methods: This is a prospective non randomized study approved by the institutional review board. All enrolled patients who have undergone scRT from November 2018 till May 2019 were included in an intention to treat analysis. All scRT patients were planned by IMRT technique with daily single fraction to a  dose of 25Gy/5fractions/5 days. These patients then received FOLFOX based chemotherapy for 4-6 cycles followed by surgery and adjuvant chemotherapy. T3/T4 tumors, including synchronous liver metastasis were included in the study. Radiological evaluation was done by PET MRI at baseline and after completion of chemotherapy prior to surgery. The primary endpoint is complete pathological response (cPR). Secondary endpoints are survival analysis and toxicity evaluation

Results


Results: Out of 54 patients enrolled till November 2019, 30 patients were analyzed during the specified period. All patients completed scRT. 27% (8/30) were Metastatic (Liver) while 73% (22/30) were non metastatic. Local surgery was done in 22/30 patients, 3/8 in the metastatic group after hepatic resection and 19/22 in nonmetastatic group. In the metastatic cohort, 3 patients had progressive disease and 2 patients were lost to follow up. In nonmetastatic cohort, 1 patient refused surgery and 2 patients were lost to follow up.  12/22 had APR, 9/22 had LAR and 1/16 had total proctocolectomy (underlying ulcerative colitis). All patients achieved negative resection margins. AJCC pathological tumour regression grade (pTRG) was assessed: 7/22(32%) had pTRG 0 (Complete response), 10/22(45%) patients pTRG 1 (Moderate/significant response), 5/22(23%) had pTRG 2 (Minimal response). No patient had pTRG3 (Poor response). Five patients had node positivity in the surgical specimen which 80%(4/5) had a minimal response (TRG2). PNI positivity was found in 1/16 patients and it had a minimal response (TRG2). No patient had any break or any toxicity requiring admission during radiotherapy. GI toxicity was assessed in terms of diarrhea, pain abdomen (colitis), need for supportive care and admission. (Figure1). Grade 3 neutropenia was observed in 24% of patients while on chemotherapy. MRTRG, ADC values in MRI and SUV change in PET were also correlated with pTRG and pathological T staging but no parameter had a significant correlation in the number of subjects analyzed to date.

Hospital admissions for supportive Care1-2 admissions2-5 admissions>5 Admissions
N=3041340
Gastrointestinal ToxicityGrade 2Grade 3Grade 4
Diarrhea7100
Colitis840
Conclusion

Conclusion:Short course radiation therapy followed by adjuvant chemotherapy and a delayed surgery is a well tolerated and promising regimen with good pathological response rates. Long term results related to late effects and survival analysis are awaited.