PL 24. The combination of intermittent hormonal therapy (IHT) with 125I brachytherapy (BT) for the treatment of locally advanced prostate cancer.

To evaluate the clinical efficacy of combination of intermittent hormonal therapy (IHT) and 125I brachytherapy (BT) for the treatment of locally advanced prostate cancer. Methods: The joint treatment was applied to 46 cases of prostate cancer (PCa) with T3 clinical staging. Internal irradiation therapy was a treatment which used planning system for 3D radiotherapy with transrectal ultrasound guided radioactive 125I seed implantation. The number of cycles and the duration o f ON / OFF therapy for 46 PCa patients receiving IHT were observed. Maximal androgen blockade (MAB) were used for six to nine months after the operation, and then stopped until the serum prostate specific antigen (PSA) was decreased below 0.2 ng/mL, which lasted for three months. A PSA relapse was defined according to the ASTRO consensus definition (PSA was more than 0.5 ng/mL and three successive PSA elevations after nadir were achieved). Results: 46 patients completed the operation smoothly. The number of used needles is 21-36. The number of implanted seeds was 52-99, with an average number of 73. The average follow up time was 38 months (12-75), 25 patients started the second cycle of treatment, 12 patients entered the third cycle, 5 patients entered the fourth cycle, From the first to the fourth courses of treatment the average intervals were 15.2(7-28), 10.5(5-17), 6.6(5-8) months respectively. Five patients developed bone metastasis. 1 patient was diagnosed as bone metastasis and died 52 months after operation. Twenty one of the 46 patients did not suffer the PSA relapse during the follow up. The duration of first off phase was 12-57 months, averaging about 26.9 months. Conclusion: Combination of intermittent androgen deprivation and 125I brachytherapy is an effective and safe treatment for locally advanced prostate cancer. Our result need to be approved by multicenter prospective randomized trial.