Permanent prostate implant using high activity seeds and inverse planning with fast simulated annealing algorithm: A 12-year Canadian experience

Int J Radiat Oncol Biol Phys. 2007 Feb 1;67(2):334-41. doi: 10.1016/j.ijrobp.2006.08.042. Epub 2006 Nov 2.

Abstract

Purpose: To report outcomes and toxicity of the first Canadian permanent prostate implant program.

Methods and materials: 396 consecutive patients (Gleason < or =6, initial prostate specific antigen (PSA) < or =10 and stage T1-T2a disease) were implanted between June 1994 and December 2001. The median follow-up is of 60 months (maximum, 136 months). All patients were planned with fast-simulated annealing inverse planning algorithm with high activity seeds ([gt] 0.76 U). Acute and late toxicity is reported for the first 213 patients using a modified RTOG toxicity scale. The Kaplan-Meier biochemical failure-free survival (bFFS) is reported according to the ASTRO and Houston definitions.

Results: The bFFS at 60 months was of 88.5% (90.5%) according to the ASTRO (Houston) definition and, of 91.4% (94.6%) in the low risk group (initial PSA < or =10 and Gleason < or =6 and Stage < or =T2a). Risk factors statistically associated with bFFS were: initial PSA >10, a Gleason score of 7-8, and stage T2b-T3. The mean D90 was of 151 +/- 36.1 Gy. The mean V100 was of 85.4 +/- 8.5% with a mean V150 of 60.1 +/- 12.3%. Overall, the implants were well tolerated. In the first 6 months, 31.5% of the patients were free of genitourinary symptoms (GUs), 12.7% had Grade 3 GUs; 91.6% were free of gastrointestinal symptoms (GIs). After 6 months, 54.0% were GUs free, 1.4% had Grade 3 GUs; 95.8% were GIs free.

Conclusion: The inverse planning with fast simulated annealing and high activity seeds gives a 5-year bFFS, which is comparable with the best published series with a low toxicity profile.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Algorithms
  • Brachytherapy / adverse effects
  • Brachytherapy / methods*
  • Canada
  • Disease-Free Survival
  • Gastrointestinal Tract / radiation effects
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / radiotherapy*
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted / methods
  • Risk Factors

Substances

  • Prostate-Specific Antigen