Treatment results of brachytherapy vs. external beam radiation therapy for intermediate-risk prostate cancer with 10-year followup.
To compare 10-year treatment outcomes of brachytherapy vs. external beam radiation therapy for patients with intermediate-risk prostate cancer (IRPC).



Between 2004 and 2007, 93 IRPC patients underwent brachytherapy using iodine-125 to a dose of 145 Gy without supplemental external radiation. A retrospective comparison was performed to a contemporary cohort of 597 patients treated with external beam radiation therapy to a median dose of 75.3 Gy using a propensity score-matched analysis.



Median followup was 7.8 years. With brachytherapy, 51.6% had Gleason score 7 vs. 72.0% for external radiation (p < 0.001). Median initial prostate-specific antigen was 8.3 for brachytherapy vs. 9.4 for external radiation (p = 0.01). Neoadjuvant androgen deprivation therapy was given in 59.5% of external radiation vs. 10.8% of brachytherapy patients (p < 0.001). The 10-year freedom from biochemical failure (FFBF) for brachytherapy was 81.7% vs. 54.5% for external radiation (p = 0.002). Unfavorable intermediate-risk patients experienced borderline significant improved FFBF with brachytherapy (p = 0.08). The 10-year freedom from salvage therapy for brachytherapy was 93.2% vs. 72.2% for external radiation (p = 0.006). There were no significant differences in distant metastases-free survival, prostate cancer-specific survival, or overall survival after adjusting for age. Multivariate analysis with propensity score matching showed that brachytherapy remained an independent predictor for improved FFBF (p = 0.007). Grade 1 and 2 late rectal complication rate was 6.5% for brachytherapy vs. 15.2% for external radiation (p = 0.02).



Brachytherapy using iodine-125 without supplemental external radiation is a reasonable treatment option for selected IRPC patients.
Department of Radiation Oncology, Kaiser Permanente, Los Angeles Medical Center, Los Angeles, CA. Electronic address: barry.w.goy@kp.org.
Barry W
BW
Goy
Department of Radiation Oncology, Kaiser Permanente, Los Angeles Medical Center, Los Angeles, CA.
Margaret S
MS
Soper
Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, IA.
Tangel
T
Chang
Department of Research and Evaluation, Kaiser Permanente, Pasadena, CA.
Jeff M
JM
Slezak
Department of Radiation Oncology, Kaiser Permanente, Los Angeles Medical Center, Los Angeles, CA.
Harry A
HA
Cosmatos
Department of Radiation Oncology, Kaiser Permanente, Los Angeles Medical Center, Los Angeles, CA.
Michael
M
Tome
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001918:Brachytherapy / Q000379:methods*; D017024:Chemotherapy, Adjuvant / Q000379:methods; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D057216:Propensity Score; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016879:Salvage Therapy / Q000706:statistics & numerical data
D018931:Antineoplastic Agents, Hormonal; D017430:Prostate-Specific Antigen
Brachytherapy; Intermediate risk; Prostate cancer; Radiation therapy