10-year experience with I-125 prostate brachytherapy at the Princess Margaret Hospital: results for 1,100 patients.
OBJECTIVE
To report outcomes for 1,111 men treated with iodine-125 brachytherapy (BT) at a single institution.


METHODS
A total of 1,111 men (median age, 63) were treated with iodine-125 prostate BT for low- or intermediate-risk prostate cancer between March 1999 and November 2008. Median prostate-specific antigen (PSA) level was 5.4 ng/ml (range, 0.9-26.1). T stage was T1c in 66% and T2 in 34% of patients. Gleason score was 6 in 90.1% and 7 or 8 in 9.9% of patients. Neoadjuvant hormonal therapy (2-6 months course) was used in 10.1% of patients and combined external radiotherapy (45 Gy) with BT (110 Gy) in 4.1% (n = 46) of patients. Univariate and multivariate Cox proportional hazards were used to determine predictors of failure.


RESULTS
Median follow-up was 42 months (range, 6-114), but for biochemical freedom from relapse, a minimum PSA test follow-up of 30 months was required (median 54; n = 776). There were 27 failures, yielding an actuarial 7-year disease-free survival rate of 95.2% (96 at risk beyond 84 months). All failures underwent repeat 12-core transrectal ultrasound -guided biopsies, confirming 8 local failures. On multivariate analysis, Gleason score was the only independent predictor of failure (p = 0.001; hazard ratio, 4.8 (1.9-12.4). Median International Prostate Symptom score from 12 to 108 months ranged between 3 and 9. Of the men reporting baseline potency, 82.8% retained satisfactory erectile function beyond 5 years.


CONCLUSIONS
Iodine-125 prostate BT is a highly effective treatment option for favorable- and intermediate-risk prostate cancer and is associated with maintenance of good urinary and erectile functions.
Crook
Juanita
J
Department of Radiation Oncology, Princess Margaret Hospital, Toronto, Ontario, Canada. jcrook@bccancer.bc.ca
Borg
Jette
J
Evans
Andrew
A
Toi
Ants
A
Saibishkumar
E P
EP
Fung
Sharon
S
Ma
Clement
C
D000230:Adenocarcinoma / Q000097:blood / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D018572:Disease-Free Survival; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D009367:Neoplasm Staging; D009864:Ontario; D010410:Penile Erection / Q000502:physiology; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011467:Prostate; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D014555:Urination Disorders / Q000188:drug therapy
D007457:Iodine Radioisotopes; D017430:Prostate-Specific Antigen