Volume de-escalation in neoadjuvant chemoradiotherapy of rectal cancer.

Long-term results of a prospective phase II study on volume de-escalation in neoadjuvant chemoradiotherapy of rectal cancer.:

Long-term results of a prospective phase II study on volume de-escalation in neoadjuvant chemoradiotherapy of rectal cancer.

Pract Radiat Oncol. 2020 Sep 28;:

Authors: Michele F, Carlo G, Roberto C, Marco C, Damiano C, Pasquale T, Barnaba F, Germana RC, Edy I, Teresa CG, Raffaele G, Bruno BZ, Maria DR, Lucio T, Sara R

Abstract

PURPOSE: In the current study, we evaluated if neoadjuvant chemoradiotherapy (CRT), with reduced treatment volumes due to the exclusion of elective pelvic nodal irradiation, is a feasible strategy to be proposed in selected patients with locally advanced rectal cancer (LARC).

METHODS AND MATERIALS: Patients with T2-low lying/T3, N0-N1, rectal lesions, without evidence of disease in lateral lymph nodes, were prospectively recruited. All patients underwent pre-treatment work-up including CT of chest, abdomen and pelvis with iv contrast, pelvic MRI with iv contrast and 18-fluorodeoxyglucose PET/CT. The Clinical Target Volume (CTV) included the primary tumour and the mesorectum with vascular supply containing the perirectal and presacral nodes, with upper border at the S2/S3 interspace. Total radiation dose was 50.4 Gy and fluoropyrimidine-based chemotherapy was associated concomitantly. The primary endpoint of the study was the reduction of gastrointestinal (GI) toxicity; secondary endpoints were the pathological complete response (pCR), the local control (LC) rate, the overall survival (OS) and the disease-free survival (DFS).

RESULTS: Fifty-two patients (30 males, 22 females) with a median age of 67 years (range, 45-85 years) were enrolled in the study. Acute grade 3 GI toxicity was 7.6% and there were no cases of grade 4 toxicity. Three patients (5.7%) developed local recurrence. No relapse occurred in the lateral lymph nodes. LC rate at 5 years was 96.1%. With a median follow-up of 72.9 months (range, 2.5 - 127.6 months), the 3-year and 5-year OS rates were 89.4% and 87%, respectively. The 3-year and 5-year DFS rates were 82.4%, 82.4 %, respectively.

CONCLUSIONS: De-escalation of radiotherapy target volume reduces gastrointestinal side effects without compromising efficacy in patients with rectal cancer. These results cannot be clearly extended to high-risk disease and need further evaluation in future randomized trials.



PMID: 33002647 [PubMed - as supplied by publisher]