절제 불가능 직장암에서 방사선 치료의 역할

Abstract

Purpose: Unresectabel rectal cancer has a grave prognosis, regardless of the therapy used and median survival is less than 1 year. Also, it is reported by many authors that 50-80% of unresectable lesions were rendered respectable by radiation therapy and the median survival time for the completely resected patients were better than that of the unresected patients. So we analyzed retrospectively our data for the better treatment outcome in these patients.

Materials and Methods: From 1980 to 1992, 45 patients with initially unresectable tumors in the rectum were treated with radiation therapy with/without surgery in Department of Radiation Oncology, Yonsei Cancer Center. 10 MV radiation and multiple field technique( box or AP/PA) were used. The total dose was 8-70 Gy and median dose was 48 Gy. We evaluated the lesion status at 45-50 Gy for operability. If the lesions appeared to be respectable, the patients were operated on 4-6 weeks after radiation therapy. But if the lesions were still fixed, the radiation dose was increased to 60-65 Gy.

Results: For all patients, the 2-year actuarial survival was 13.3% and median survival was 9.5 months. Of 6 patients who had received less than 45 Gy, only 17% of patients responded, but in the patients who had received more than 45 Gy, 60% of response rate was achieved. Six of the 24 patinets(25%) underwent surgical resections following RT. For patients undergoing curative resection, the two-year survival was 50%, but that of the patients without resection was 9.5% (p<0.01). Survival of patients with complete response following RT was 50% at 2 years. Survival of patients with partial response, stable disease and progressive disease after RT was 13.4%, 15.4%, 0% respectively (p<0.05).

Conclusion: Our data suggests that the efforts which can increase the response rate and aggressive surgical approach are needed to achieve the better local control and survival in unresectable rectal cancers.