Seed implant retention score predicts the risk of prolonged urinary retention after prostate brachytherapy.
OBJECTIVE
To risk-stratify patients for urinary retention after prostate brachytherapy according to a novel seed implant retention score (SIRS).


METHODS
A total of 835 patients underwent transperineal prostate seed implant from March 1993 to January 2007; 197 patients had (125)I and 638 patients had (103)Pd brachytherapy. Four hundred ninety-four patients had supplemental external-beam radiation. The final downsized prostate volume was used for the 424 patients who had neoadjuvant hormone therapy. Retention was defined as reinsertion of a Foley catheter after the implant.


RESULTS
Retention developed in 7.4% of patients, with an average duration of 6.7 weeks. On univariate analysis, implant without supplemental external-beam radiation (10% vs. 5.6%; p = 0.02), neoadjuvant hormone therapy (9.4% vs. 5.4%; p = 0.02), baseline alpha-blocker use (12.5% vs. 6.3%; p = 0.008), and increased prostate volume (13.4% vs. 6.9% vs. 2.9%, >45 cm(3), 25-45 cm(3), <25 cm(3); p = 0.0008) were significantly correlated with increased rates of retention. On multivariate analysis, implant without supplemental external-beam radiation, neoadjuvant hormone therapy, baseline alpha-blocker use, and increased prostate volume were correlated with retention. A novel SIRS was modeled as the combined score of these factors, ranging from 0 to 5. There was a significant correlation between the SIRS and retention (p < 0.0001). The rates of retention were 0, 4%, 5.6%, 9%, 20.9%, and 36.4% for SIRS of 0 to 5, respectively.


CONCLUSIONS
The SIRS may identify patients who are at high risk for prolonged retention after prostate brachytherapy. A prospective validation study of the SIRS is planned.
Lee
Hoon K
HK
Regional Radiation Oncology, Staten Island, NY 10310, USA. Dr.Hoon@gmail.com
Adams
Marc T
MT
Shi
Qiuhu
Q
Basillote
Jay
J
Lamonica
Joanne
J
Miranda
Luis
L
Motta
Joseph
J
D000368:Aged; D000704:Analysis of Variance; D000726:Androgen Antagonists / Q000627:therapeutic use; D001918:Brachytherapy / Q000009:adverse effects*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D020360:Neoadjuvant Therapy; D009929:Organ Size; D010165:Palladium / Q000627:therapeutic use; D011467:Prostate / Q000473:pathology; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D011868:Radioisotopes / Q000627:therapeutic use; D018570:Risk Assessment; D014546:Urinary Catheterization; D016055:Urinary Retention / Q000209:etiology* / Q000628:therapy
D000726:Androgen Antagonists; D007457:Iodine Radioisotopes; D011868:Radioisotopes; D010165:Palladium