Radiation dose predicts for biochemical control in intermediate-risk prostate cancer patients treated with low-dose-rate brachytherapy.
OBJECTIVE
To evaluate the influence of patient- and treatment-related factors on freedom from biochemical failure (FFbF) in patients with intermediate-risk prostate cancer.


METHODS
From a prospectively collected database of 2250 men treated at Mount Sinai Hospital from 1990 to 2004 with low-dose-rate brachytherapy for prostate cancer, 558 men with either one or more intermediate-risk features (prostate-specific antigen [PSA] level 10-20 ng/mL, Gleason score 7, or Stage T2b) were identified who had a minimum follow-up of 24 months and postimplant CT-based dosimetric analysis. Biologically effective dose (BED) values were calculated to compare doses from different isotopes and treatment regimens. Patients were treated with brachytherapy with or without hormone therapy and/or external-beam radiotherapy. Patient- and treatment-related factors were analyzed with respect to FFbF. The median follow-up was 60 months (range, 24-167 months). Biochemical failure was defined according to the Phoenix definition. Univariate analyses were used to determine whether any variable was predictive of FFbF. A two-sided p value of <0.05 was considered significant.


RESULTS
Overall, the actuarial FFbF at 10 years was 86%. Dose (BED <150 Gy(2) vs. >or=150 Gy(2)) was the only significant predictor of FFbF (p < 0.001). None of the other variables (PSA, external-beam radiotherapy, Gleason score, treatment type, hormones, stage, and number of risk factors) was found to be a statistically significant predictor of 10-year FFbF.


CONCLUSIONS
Radiation dose is an important predictor of FFbF in intermediate-risk prostate cancer. Treatment should continue to be individualized according to presenting disease characteristics until results from Radiation Therapy Oncology Group trial 0232 become available.
Ho
Alice Y
AY
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10029, USA.
Burri
Ryan J
RJ
Cesaretti
Jamie A
JA
Stone
Nelson N
NN
Stock
Richard G
RG
D000704:Analysis of Variance; D000726:Androgen Antagonists / Q000627:therapeutic use; D000813:Anilides / Q000627:therapeutic use; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001706:Biopsy; D001918:Brachytherapy / Q000379:methods*; D005485:Flutamide / Q000627:therapeutic use; D005500:Follow-Up Studies; D017273:Goserelin / Q000627:therapeutic use; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D016729:Leuprolide / Q000627:therapeutic use; D008297:Male; D009570:Nitriles / Q000627:therapeutic use; D010165:Palladium / Q000627:therapeutic use; D011467:Prostate / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D011868:Radioisotopes / Q000627:therapeutic use; D011879:Radiotherapy Dosage; D012062:Relative Biological Effectiveness; D014105:Tosyl Compounds / Q000627:therapeutic use; D017211:Treatment Failure
D000726:Androgen Antagonists; D000813:Anilides; D018931:Antineoplastic Agents, Hormonal; D007457:Iodine Radioisotopes; D009570:Nitriles; D011868:Radioisotopes; D014105:Tosyl Compounds; D017273:Goserelin; D010165:Palladium; D005485:Flutamide; C053541:bicalutamide; D017430:Prostate-Specific Antigen; D016729:Leuprolide