Dosimetric analysis of urinary morbidity following prostate brachytherapy (125I vs. 103Pd) combined with external beam radiation therapy

✍ Scribed by Christopher T. Chen; Frank M. Waterman; Richard K. Valicenti; Leonard G. Gomella; Stephen E. Strup; Adam P. Dicker

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: French
• Weight: 108 KB
• Volume: 96
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.10350

✦ Synopsis

The purpose of this analysis was to correlate isotope selection with the urinary symptoms of patients who received a combination of external beam radiotherapy (EBRT) and a transperineal interstitial permanent prostate brachytherapy (TIPPB) boost with either a 103 palladium ( 103 Pd) or a 125 iodine ( 125 I) radioisotope. Postimplant dosimetry was performed to evaluate both urethral dose and implant quality. The American Urologic Association (AUA) scores in both the 125 I and 103 Pd groups were similar initially. However, at 1, 3, 6, and 12 months of follow-up, the mean AUA scores for the 125 I and 103 Pd patients were 18 ؎ 6 vs. 11 ؎ 9, 17 ؎ 7 vs. 11 ؎ 7, 10 ؎ 3 vs. 9 ؎ 4, and 14 ؎ 8 vs. 7 ؎ 5, respectively (P < 0.01). The only significant difference between the postimplant dose-volume histogram (DVH) of the 125 I and 103 Pd implants was the minimum dose that 90% of the urethra received (D 90 ). The increased AUA score of the 125 I group was weakly correlated (R 2 ‫؍‬ 0.20) with the D 90 dose but that of the 103 Pd patients was not (R 2 ‫؍‬ 0.00). This suggests that the higher AUA score of the 125 I patients was not necessarily the result of the higher D 90 dose. Thus, patients who received 103 Pd experienced less urinary morbidity than those implanted with 125 I. We recommend further validating these findings in prospective studies in which the quality of the 125 I and 103 Pd implants can be evaluated.