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BACKGROUND: The authors present long-term results from a phase 2 study that assessed the efficacy of transrectal ultrasound hyperthermia plus radiation with or without androgen suppression for the treatment of locally advanced prostate cancer. METHODS: Patients with clinical T2b-T3bN0M0 disease (according to 1992 American Joint Committee on Cancer [AJCC] criteria) received radiation plus 2 transrectal ultrasound hyperthermia treatments. After the first 4 patients, 6 months of androgen suppression were allowed. The study was designed to assess absolute improvement in the 2-year disease-free survival rate compared with the short-term androgen suppression arm in Radiation Therapy Oncology Group (RTOG) study 92-02. RESULTS: Thirty-seven patients received a total of 72 hyperthermia treatments. The mean cumulative equivalent minutes (CEM) T9043°C was 8.4 minutes. According to the 1992 AJCC classification, there were 19 patients with T2b tumors, 8 patients with T2c tumors, 5 patients with T3a tumors, and 5 patients with T3b tumors. The median Gleason score was 7 (range, 6-9), and the median prostate-specific antigen (PSA) level was 13.3 ng/mL (range, 2-65 ng/mL). Thirty-three patients received androgen suppression. At a median follow-up of 70 months (range, 18-110 months), the 7-year overall survival rate was 94%, and 61% of patients remained failure free (according to the American Society for Therapeutic Radiology and Oncology definition for failure free survival). The absolute rate of disease-free survival at 2 years, which was the primary study endpoint, improved significantly (84%) compared with a rate of 64% for similar patients on the 4-month androgen suppression arm of RTOG 92-02. When Phoenix criteria (PSA nadir + 2 ng/mL) were used to define biochemical failure, 89% of patients were failure free at 2 years. CONCLUSIONS: Hyperthermia combined with radiation for the treatment of locally advanced prostate cancer appeared to be promising. The current results indicated that further study of hyperthermia for the treatment of prostate cancer with optimal radiation and systemic therapy is warranted. [ABSTRACT FROM AUTHOR]

Purpose : Hyperthermia is used to treat several pelvic tumours. An important step in establishing a broader role for hyperthermia in treatment of prostate cancer is verification of an acceptable toxicity profile. In this report, short- and long-term toxicity profiles of a completed phase II trial of transrectal ultrasound hyperthermia combined with radiation in treatment of locally advanced prostate cancer are presented. Methods and materials : Thirty-seven patients enrolled on a phase II study of external beam radiation  ±  androgen suppression with two transrectal ultrasound hyperthermia treatments were assessed for short- and long-term toxicity. Prostatic and anterior rectal wall temperatures were monitored. Rectal wall temperatures were limited to 40°C (19 patients), 41°C (three patients) and 42°C (15 patients). Univariate logistic regression was used to estimate the log hazard of developing NCI CTC Grade 2 toxicity based on temperature parameters. Hazard ratios, 95% confidence intervals, p -values for statistical significance of each parameter and proportion of variability explained for each of the parameters were calculated. Results : Median follow-up was 42 months. Both short- and long-term GI toxicity were limited to grade 2 or less. Acute grade 2 proctitis was greater for patients with allowable rectal wall temperature of >40°C. Eleven of 18 patients in this group had acute grade 2 proctitis vs three of 19 patients with rectal wall temperatures limited to 40°C ( p   =  0.004). Long-term grade 2 GI and GU toxicity occurred in 5% and 19% of patients. No late grade 3 or greater toxicity occurred. Late GI and GU toxicity were not associated with the allowable rectal wall temperature. Conclusion : Transrectal ultrasound hyperthermia combined with radiation for treatment of advanced clinically localized prostate cancer is safe and well tolerated. [ABSTRACT FROM AUTHOR]

Purpose: Although hyperthermia has been used for more than two decades in the treatment of pelvic tumors, little is known about the potential impact of heat on rectal toxicity when combined with other treatment modalities. Because rectal toxicity is a concern with radiation and may be exacerbated by hyperthermia, definition of the association of thermal dose parameters with rectal toxicity is important. In this report, we correlate rectal toxicity with thermal dose parameters for patients treated with hyperthermia and radiation for prostate cancer.Methods and Materials: Thirty patients with T2b-T3b disease (1992 American Joint Committee On Cancer criteria) enrolled in a Phase II study of external beam radiation ± androgen-suppressive therapy with two transrectal ultrasound hyperthermia treatments were assessed for rectal toxicity. Prostatic and anterior rectal wall temperatures were monitored for all treatments. Rectal wall temperatures were limited to 40°C in 19 patients, 41°C in 3 patients, and 42°C in 8 patients. Logistic regression was used to estimate the log hazard of developing National Cancer Institute Common Toxicity Criteria Grade 2 toxicity based on temperature parameters. The following were calculated: hazard ratios, 95% confidence intervals, p values for statistical significance of each parameter, and proportion of variability explained for each parameter.Results: Gastrointestinal toxicity was limited to Grade 2. The rate of acute Grade 2 proctitis was greater for patients with an allowable rectal wall temperature of >40°C. In this group, 7 of 11 patients experienced acute Grade 2 proctitis, as opposed to 3 of 19 patients in the group with rectal wall temperatures limited to 40°C (p = 0.004). Preliminary assessment of long-term toxicity revealed no differences in toxicity. Hazard ratios for acute Grade 2 proctitis for allowable rectal wall temperature, average rectal wall Tmax, and average prostate Tmax were 9.33 (p = 0.01), 3.66 (p = 0.03), and 2.29 (p = 0.08), respectively. A model combining these three parameters explained 48.6% of the variability among groups.Conclusion: Rectal toxicity correlates with maximum allowable rectal wall temperature, average rectal wall Tmax, and average prostate Tmax for patients undergoing transrectal ultrasound hyperthermia combined with radiation for treatment of advanced clinically localized prostate cancer. Further definition of this association of thermal dose parameters with rectal toxicity in treatment of pelvic malignancies with hyperthermia should advance the goal of delivering thermal therapy in an effective yet safe manner. [Copyright &y& Elsevier]