Effects of Preoperative Radiotherapy for T2, T3 Distal Rectal Cancer / 대한방사선종양학회지

ABSTRACT

PURPOSE: Preoperative radiotherapy has been used to induce tumor regression and allow complete resection of rectal cancer with a sphincter preservation surgery. This study was performed to determine the effectiveness of preoperative radiotherapy for T2, T3 distal rectal carcinoma. MATERIALS AND METHODS: From November 1995 to June 1997, fifteen patients with invasive distal rectal cancer were treated with preoperative radiotherapy followed by sphincter preservation surgery. Classification by preoperative T stage consisted of 7 T2 and 8 T3 tumors. Radiation therapy was delivered with 6 MV and 15 MV linear accelerator, at 1.8 Gy fractions for 5 days per week. Total radiation doses were 45 Gy to 50.4 Gy (median 50.4 Gy). Sphincter preservation surgery was performed 4~6 weeks after the completion of radiotherapy. Median follow-up was 22 months (range 16~37 months). RESULTS: One patient (6.7%) had a complete pathologic response. Comparing the stage at the diagnostic workup with the pathologic stage, tumor downstaging of T stages occurred in 11 of 15 patients (73.3%) and N1 stages occurred in 2 of 5 patients (40%). No patient developed progressive disease undergoing treatment. Two patients suffered local recurrence at 7 and 20 months, and one a distant metastasis at 30 months. No grade 3 or 4 toxicity was observed. CONCLUSION: Our experience suggests that preoperative radiotherapy followed by sphincter preservation surgery is well tolerated, and can significantly reduce the tumor burden for T2, T3 distal rectal cancer.