High-Dose-Rate Brachytherapy for Medically Inoperable Stage I Endometrial Cancer 1 Thu-Van Nguyen, M.D., FRCPC,* and Daniel G. Petereit, M.D.* , ² ,2,3 *Department of Radiation Oncology and ² Department of Obstetrics and Gynecology, University of Wisconsin Medical School, Madison, Wisconsin 53792 Received March 3, 1998 Purpose. The objective of this study was to determine the efficacy of high-dose-rate (HDR) brachytherapy in 36 medically inoperable patients with stage I endometrial cancer. Methods and Materials. From October 1989 to August 1997, 36 patients presented with clinical stage I inoperable endometrial cancer. Surgery was precluded because of obesity and/or poor cardio–pulmonary reserve. Obesity was assessed using the body mass index (BMI) scale (kg/m 2 ). Patients received 5 weekly HDR outpatient brachytherapy applications while under intravenous conscious sedation. Three-year clinical endpoints were calculated using the Kaplan and Meier method. Grade 3 and above compli- cations were scored using the Radiation Therapy Oncology Group system. Results. The median age, Karnofsky performance status, BMI, and weight were 65 years old, 80%, 47 kg/m 2 , and 268 lbs, respec- tively. Nineteen patients were inoperable due to morbid obesity (median weight and BMI: 316 lbs and 56 kg/m 2 ) while the remain- ing patients had other significant medical problems. Two patients died from acute cardiovascular events within 30 days of the last insertion. With a median follow-up of 32 months the 3-year uter- ine control, disease-free survival, survival, and complications were 88, 85, 65, and 21%, respectively. Conclusion. Excellent uterine control rates (88%) were achieved using HDR brachytherapy for patients with medically inoperable endometrial cancer, but with significant acute and late morbidi- ties. These toxicities were observed in a previous interim analysis that resulted in major modifications of the HDR program. No severe complications have developed since these changes were implemented. The current approach used for these challenging inoperable patients is a viable alternative to observation or hor- monal therapy. © 1998 Academic Press INTRODUCTION Endometrial carcinoma is the most common gynecologic malignancy, accounting for 36,000 annual cases in the United States [1]. The majority of patients can undergo a total abdom- inal hysterectomy and bilateral salpingo-oophorectomy (TAH/ BSO) in conjunction with surgical staging and postoperative radiotherapy as indicated. The same risk factors and co-morbid medical problems associated with endometrial cancer also pre- clude a minority of patients from surgical intervention. For these patients, primary radiation therapy is the only curative option with 5-year survival ranging from 24 –77% [2–23]. The majority of publications describe low-dose-rate (LDR) brachy- therapy [7–23], with only a few reporting high-dose-rate (HDR) brachytherapy [2– 6]. Knocke et al. described the largest primary radiotherapy series to date in which 280 patients were treated with HDR brachytherapy. In their series, 116 patients with clinical stage IA disease had a 5-year survival and disease-specific sur- vival (DSS) of 64 and 85%, respectively [2]. This paper describes the University of Wisconsin experience using HDR brachytherapy in 36 patients with medically inop- erable stage I endometrial cancer. MATERIALS AND METHODS Patients From October 1989 to August 1997, 778 patients with endometrial carcinoma were evaluated at the University of Wisconsin. Of these, 36 clinical stage I patients were consid- ered medically inoperable because of co-morbid medical prob- lems and/or obesity (Table 1). Morbid obesity, severe cardiac disease, and poor pulmonary function were the primary con- traindications to surgical intervention. Every patient had biopsy-proven endometrial cancer except one. She was an elderly, nursing-home patient with atypical glandular hyperplasia on whom repeat biopsies could not be performed due to logistical problems. Patients were seen and evaluated by the gynecologic oncol- ogy team. Workup included a complete history and physical examination, routine blood studies, and chest X ray. In select patients, a pelvic CT scan and/or ultrasound were obtained. Patients were clinically staged according to the 1971 FIGO (International Federation of Gynecology and Obstetrics) clas- sification [24]. The distribution of histology, grade, stage, and 1 Presented at the American Radium Society, Monte Carlo, Monaco, May 2– 6, 1998. 2 To whom reprint requests should be addressed at University of Wisconsin, Department of Radiation Oncology, 600 Highland Avenue, K4/B100, Madi- son, WI 53792-0600. Fax: 608-263-9167. E-mail: dgpetere@facstaff.wisc.edu. 3 D.G.P. is a recipient of the American Cancer Society Clinical Research Training Grant (No. CRTG-97-119-01-CCE). GYNECOLOGIC ONCOLOGY 71, 196 –203 (1998) ARTICLE NO. GO985148 196 0090-8258/98 $25.00 Copyright © 1998 by Academic Press All rights of reproduction in any form reserved.