The results of real-time brachytherapy for the management of low- and intermediate-risk prostate cancer in patients with prostate volumes up to 100 mL

Objectives: • To report the results of real-time brachytherapy in the management of low-risk and intermediate-risk prostate cancer in patients with prostate volumes up to 100 mL, over a 6-year period. • To prospectively determine whether prostate volume influences the ability to achieve a quality implant and therefore impact upon prostate-specific antigen (PSA) relapse-free survival, and urinary and rectal toxicity.

Subjects and methods: • In all, 216 men with localized prostate cancer were treated with real-time prostate brachytherapy using (125) I implants between November 2003 and December 2009. • Patient selection was based upon functional parameters; International Prostate Symptom Score (IPSS) and flowmetry. • Patients had computed tomography imaging at 1 month to assess post-implant dosimetry. PSA, IPSS and Radiation Therapy Oncology Group rectal toxicity scores were recorded prospectively over the follow-up period. • Patients with prostate volumes ≤50 mL and those with volumes >50 mL were compared.

Results: • Overall PSA relapse-free survival was 98.8%; 97.0% for intermediate-risk patients and 100.0% for low-risk patients. By volume, 98.5% of men with standard prostates were free from PSA relapse compared with 100.0% of men with large prostates. • The mean post-implant D90 was 177.0 Gy; 175.5 Gy in standard prostates and 183.5 Gy in large prostates. • The overall acute urinary retention rate was 1.9%; 1.7% in standard prostates and 2.4% in large prostates. There were three urethral strictures, all in the standard prostate group. The mean IPSS increased to 11 and 14 at 3 months for the standard and large prostate groups, respectively, before settling to 2 above baseline for both groups at 12 months. • There were no rectovesical fistulae. Persistent rectal bleeding was reported by one (0.5%) patient in the standard prostate group.

Conclusions: • Prostate brachytherapy is effective in the treatment of low-risk and intermediate-risk prostate cancer. • It is technically possible to deliver a quality implant in a large prostate using real-time brachytherapy. • The treatment itself is well tolerated. Prostate volumes up to 100 mL should not exclude patients from brachytherapy providing either flow rate ≥14 mL/s or symptom score (IPSS) ≤ 10.