Radioimmunoscintigraphy with In-111-labeled capromab pendetide predicts prostate cancer response to salvage radiotherapy after failed radical prostatectomy.
OBJECTIVE
We investigated the ability of In-111-capromab pendetide to separate patients who have failed radical prostatectomy into categories of those who would versus those who would not respond to salvage radiotherapy.


METHODS
Prostate-specific antigen (PSA) levels in 32 men with prostate cancer who had failed radical prostatectomy and had undergone a whole-body In-111-capromab pendetide scan were followed-up for 13 months (median) after salvage radiotherapy to the pelvis. A logistic regression model was used to determine whether the scan findings, as well as other clinical variables, were associated with a durable complete response (DCR), a nondurable response (NDR), or no response (NR).


RESULTS
Sixteen of 23 (70%) men with a normal scan outside the prostatic fossa achieved a DCR after salvage radiotherapy versus two of nine (22%) who had a positive scan outside the prostate fossa and pelvis (P = .0225, Fisher's exact test). Predicted probability (95% confidence interval [CI]) that a DCR would be obtained with a normal scan was 0.88 (0.55 to 0.98); for men with a positive scan limited to the prostatic fossa it was 0.62 (0.42 to 0.79); and for men with a positive scan outside the pelvis it was 0.27 (0.09 to 0.58). No other variables before radiotherapy showed a significant association with the DCR rate.


CONCLUSIONS
Salvage radiotherapy is statistically more likely to lead to a durable complete PSA response in men with prostate cancer who have failed radical prostatectomy and have a negative In-111-capromab pendetide scan outside the pelvis as compared with those who have a positive scan.
Kahn
D
D
Iowa City Veterans Affairs Medical Center and University of Iowa College of Medicine, 52246, USA. daniel_kahn@uiowa.edu
Williams
R D
RD
Haseman
M K
MK
Reed
N L
NL
Miller
S J
SJ
Gerstbrein
J
J
D000368:Aged; D000911:Antibodies, Monoclonal; D001706:Biopsy; D006801:Humans; D007205:Indium Radioisotopes; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011467:Prostate / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D011877:Radionuclide Imaging; D016879:Salvage Therapy; D017211:Treatment Failure
D000911:Antibodies, Monoclonal; D007205:Indium Radioisotopes; C101315:Capromab Pendetide; D017430:Prostate-Specific Antigen