The role of external beam radiotherapy with I-125/Pd-103 brachytherapy for prostate carcinoma.
OBJECTIVE
To compare the biochemical outcomes of patients treated with Pd-103/I-125 brachytherapy alone vs. brachytherapy combined with external beam radiotherapy for early stage prostate carcinoma.


METHODS
Brachytherapy monotherapy was used in 403 patients. Brachytherapy was combined with 45 Gy of external beam radiotherapy in 231 patients. Median follow-up was 58 months. To compare the biochemical outcomes of these two treatment approaches, patients were stratified into three relative risk groups: low risk, T(1)-T(2), Gleason 2-6/10, PSA< or =10.0; intermediate risk, T(3), Gleason 7-10/10, PSA>10.0 (one factor); high risk, T(3), Gleason 7-10/10, PSA>10.0 (two factors).


RESULTS
The actuarial biochemical progression-free rate (bNED) for the entire 634 patients was 85% at 10 years. The bNED outcomes by risk group for monotherapy vs. combined therapy respectively were: low risk, 94 vs. 87%; intermediate risk, 84 vs. 85%; high risk, 54 vs. 62%. These differences did not reach statistical significance for any risk group. Rectal morbidity was slightly greater in the combined treatment patients.


CONCLUSIONS
Although the addition of external beam irradiation to brachytherapy is conceptually appealing for patients with higher risk prostate carcinoma, we were unable to demonstrate a benefit. Whether this is because of patient selection biases within the risk groupings, an artefact of retrospective review, or because external radiotherapy does not offer additional benefit is uncertain.
Blasko
J C
JC
Seattle Prostate Institute, 1101 Madison Street, Suite 1101, WA 98104, Seattle, USA.
Grimm
P D
PD
Sylsvester
J E
JE
Cavanagh
W
W
D001918:Brachytherapy / Q000009:adverse effects; D002277:Carcinoma / Q000175:diagnosis / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D010165:Palladium / Q000009:adverse effects / Q000627:therapeutic use*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011868:Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate
D007457:Iodine Radioisotopes; D011868:Radioisotopes; D010165:Palladium; D017430:Prostate-Specific Antigen