Magnetic resonance image-guided salvage brachytherapy after radiation in select men who initially presented with favorable-risk prostate cancer: a prospective phase 2 study.
BACKGROUND
The authors prospectively evaluated the late gastrointestinal (GI) and genitourinary (GU) toxicity and prostate-specific antigen (PSA) control of magnetic resonance imaging (MRI)-guided brachytherapy used as salvage for radiation therapy (RT) failure.


METHODS
From October 2000 to October 2005, 25 men with a rising PSA level and biopsy-proven, intraprostatic cancer at least 2 years after initial RT (external beam in 13 men and brachytherapy in 12 men) who had favorable clinical features (Gleason score < or =7, PSA < 10 ng/mL, negative pelvic and bone imaging studies), received MRI-guided salvage brachytherapy to a minimum peripheral dose of 137 gray on a phase 1/2 protocol. Estimates of toxicity and cancer control were calculated using the Kaplan-Meier method.


RESULTS
The median follow-up was 47 months. The 4-year estimate of grade 3 or 4 GI or GU toxicity was 30%, and 13% of patients required a colostomy and/or urostomy to repair a fistula. An interval < 4.5 years between RT courses was associated with both outcomes with a hazard ratio of 12 (95% confidence interval [95% CI], 1.4-100; P = .02) for grade 3 or 4 toxicity and 25 (95% CI, 1.1-529; P = .04) for colostomy and/or urostomy. PSA control (nadir +2 definition) was 70% at 4 years.


CONCLUSIONS
The current results indicated that MRI-guided salvage brachytherapy in men who are selected based on presenting characteristics and post-failure PSA kinetics can achieve high PSA control rates, although complications requiring surgical intervention may occur in 10% to 15% of patients. Prospective randomized studies are needed to characterize the relative cancer control and toxicity after all forms of salvage local therapy.
Nguyen
Paul L
PL
Department of Radiation Oncology, Brigham and Women's Hospital and Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts.
Chen
Ming-Hui
MH
D'Amico
Anthony V
AV
Tempany
Clare M
CM
Steele
Graeme S
GS
Albert
Michele
M
Cormack
Robert A
RA
Carr-Locke
David L
DL
Bleday
Ronald
R
Suh
W Warren
WW
D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods; D002277:Carcinoma / Q000276:immunology / Q000532:radiotherapy*; D005500:Follow-Up Studies; D005767:Gastrointestinal Diseases / Q000209:etiology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D052801:Male Urogenital Diseases / Q000209:etiology; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000276:immunology / Q000532:radiotherapy*; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000276:immunology / Q000532:radiotherapy*; D018570:Risk Assessment; D012307:Risk Factors; D016879:Salvage Therapy / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome
D017430:Prostate-Specific Antigen