3487 Rectal eus guided hdr- brachytherapy in patients with anal and perianal malignancies.

Abstract

Purpose: Nowadays radiotherapy of anal or perianal malignancies is the treatment method of choice to avoid lost of continence due to rectum exstirpation. Material and methods: In 1992 a new endosonography related interventional tissue ablation was inaugurated using interstitial HDR- 192Iridium radiation for anal and perianal malignancies; based on ERS a threedimensional reconstruction of the tumor and the surrounding tissue was calculated. This reconstruction was used to perform a computed radiation simulation. The patients underwent percutaneus radiation (45Gy). Six weeks after percutaneus radiation the interstitial afterloading therapy was done. For HDR- Implantation we inserted needles transperineally under ERS guidance corresponding to the computed simulation into the tumor. The afterloading procedure was repeated one after one week (2x6 Gy, reduced to 2x4 Gy since 1993). Results: From 1992 to 1997 we had treated 36 patients in 71 afterloading procedures. Diagnosis was anal cancer (n=29), anal cancer recurrence (n=1), perianal sarcoma (n=3) and advanced vaginal cancer with infiltration of the rectum (n=3). Complete tumor regression could be achieved by ERS guided interstitial HDR afterloading therapy in all cases. Five recurrent tumors (13,9%) were detected in follow up (mean = 44 month; 3-66 month); 2 in anal carcinoma patients (local recurrence rate for anal cancer 6,7%), two in patients with advanced vaginal cancer and one in sarcoma patient. Every recurrence was treated by abdominoperinal exstirpation of the rectum, all patients are aliving to today. Complication ratio was low, we found two radiogenic anal ulcer, of which one could be healed by conservative management. After reduction of brachytherapy dose to 2x4 Gy we did not any severe side effects furthermore. Conclusion: ERS- based 3D- reconstruction and ERS- guided interstitial HDR- brachytherapy allows treatment in curative intention of anal or perianal malignancies with a high rate of curation. Due to optimized target field reduction and online ultrasound control of the afterloading needle position a low complication rate could be achieved.