Treatment of high-grade low-stage prostate cancer by high-dose-rate brachytherapy

The best management of patients with low-stage, high-grade prostate cancer remains unclear. In an attempt to improve the outcomes of this high-risk group, we have offered those with Gleason > or =7 cancers removable-source high-dose-rate (HDR) brachytherapy in combination with external-beam radiation.

We reviewed the clinical histories of 61 consecutive patients with high-grade clinical stage T1-T2 lesions who received the combination radiation therapy between March 1997 and November 1998. The average Gleason score was 7.5. The HDR brachytherapy was given in three sessions with removable-source afterloaded (192)Ir to a minimum peripheral dose of 6 Gy. Conformal external-beam radiation in 25 fractions to a dose of 50 Gy was given beginning 1 week later. Patients with prostate volumes >40 cc received a luteinizing hormone-releasing hormone analog before brachytherapy.

Among the 52 patients available for follow-up (average duration 11.8 months), there has been one death from prostate cancer. After treatment, only one patient had an initial rise in serum prostate specific antigen (PSA) concentration. In addition to the patient who died, there have been three confirmed treatment failures. Toxicity was mild, with only two patients having RTOG grade 3 or 4 effects. Neither of them required surgery.

Although long-term results are not available, available data suggest that HDR brachytherapy plus external-beam radiation is at least as effective as any single therapy for high-risk, low-stage prostate cancer. The toxicity is acceptable.