Purpose: This work is a retrospective analysis of a series of patients treated with endocavitary irradiation stressing the role of transrectal ultrasound (TRUS), which has been used routinely in the staging since 1987.
Methods and materials: Between 1977 and 1993, 101 patients with infiltrating adenocarcinomas were treated. Clinical staging was 65 T1 N0 and 36 T2 N0. TRUS used in 36 patients showed: 22 UT1 N0, 10 UT2 N0, and 3 UT2 N1. Contact x-ray was delivered with a 50 kV radiotherapy unit. The median dose was 92 Gy (60-125) in five fractions, 55 days. In 28 patients a boost was given with 192Ir implant delivering a median dose of 25 Gy/21 h.
Results: Complete response was observed in all patients at the completion of treatment. Loco-regional failures were seen in 14 patients (local in 7 patients, nodal pararectal in 6 patients, and local + nodal in 1 patient). A curative salvage treatment was attempted in 13 patients and resulted in an ultimate pelvic control rate of 99 patients. Rectal preservation was possible in 92 patients. Overall and specific 5-year survival was 83.3% and 94.4%. No serious complication was observed. TRUS was more sensitive than digital rectal examination to detect involvement of pararectal metastatic nodes (N1). No loco- regional relapse was observed out of 22 UT1 N0.
Conclusion: Endocavitary irradiation can cure early adenocarcinoma of the rectum without complication. TRUS appears as a significant improvement in the selection of patients amenable to this treatment. If restricted to UT1 N0 tumors, endocavitary irradiation should control locally more than 90% of these patients. Any UN1 is a contraindication for endocavitary irradiation alone.