[High-dose rate iridium-192 brachytherapy combined with external beam radiotherapy for localized prostate cancer]

We report our technique and also preliminary results in the cases with localized prostate cancer treated by the combination of high-dose rate Iridium-192 (HDR-Ir192) brachytherapy and external irradiation.

From June 1999 to August 2000, 17 patients were treated by the combination of HDR-Ir 192 and external beam. The mean age of patients was 72 years (range, 48-81 years). The clinical stage was B1 in 5, B2 in 7 and C (no cancer with seminal vesicle) in 5 cases. Of 10 patients without neoadjuvant hormonal therapy, the median initial pretreatment PSA was 15.3 ng/ml (6.93-222.32 ng/ml). The treatment was given by HDR-Ir 192 brachytherapy (6 Gy x 3 times/2 days) and external beam irradiation (40 or 45 Gy). The brachytherapy was given using TRUS guided percutaneously inserted temporary needles with a high dose rate remote afterloading control. Local control was evaluated by digital rectal examination. TRUS-guided biopsies and serum PSA evaluations. Follow-up ranged from 2 to 14 months, with a median of 8 months.

In 4 (40.0%) of 10 patients without neoadjuvant hormonal therapy the level of serum PSA was decreased to less than 4.0 ng/ml within 3 months after the therapy. The effective grade in the biopsy specimens of 8 patients without neoadjuvant hormonal therapy was Grade Ob in 4, Grade 1 in 1, Grade 3 in 3 cases at 3 months after the therapy. No severe intra- or peri-operative complications occurred.

The combined radiotherapy treatment is safe and effective for use in the patients with localized prostate cancer. However, more comprehensive studies involving long-term follow-up and great numbers of the cases with localized prostate cancer treated by the combination of HDR-Ir 192 brachytherapy and external irradiation will be necessary to determine whether this therapy contributes to better prognosis.