Single photon emission computerized tomography with capromab pendetide plus computerized tomography image set co-registration independently predicts biochemical failure.
OBJECTIVE
We evaluate the usefulness of pretreatment (111)Indium capromab pendetide (ProstaScint) planar imaging (immunoscintigraphy) plus single photon emission tomography co-registration with computerized tomography scans to detect occult metastatic disease and predict for biochemical failure, in a cohort of patients with a clinical diagnosis of localized adenocarcinoma of the prostate referred for primary radiotherapy.


METHODS
Patients were followed after radiotherapy for evidence of biochemical failure using 2 criteria of prostate specific antigen clinical nadir +2 ng/ml and American Society for Therapeutic Radiology and Oncology Consensus definitions. Median followup was 58.8 months (mean 64.8). Clinical risk factors defined 3 risk groups of high (51), intermediate (72) and low (116).


RESULTS
Overall biochemical failure was 18.3% vs 11.8% by the 2-BFC at 8-year actuarial analysis with 58.8 months median followup. By the CN +2 definition the control date for the cohort is 34.8 months. Pretreatment SPECT/CT suggested prostate cancer metastasis (22), seminal vesicle extension (20) and organ confined disease (197). Biochemical failure in patients having extra-periprostatic metastatic prostate cancer, seminal vesicle extension and organ confined disease uptake on SPECT/CT was 43.2%, 16.0% vs 14.7% (p = 0.0006); and 33.3%, 15.0% vs 8.7% (p = 0.0017) by the 2-BFC, respectively. Cox multiple regression analysis demonstrated that a finding of extra-periprostatic metastatic prostate on SPECT/CT significantly predicted a 4.2-fold greater risk (p = 0.0012) and a 4.5-fold greater risk (p = 0.0011) of failure by the 2-BFC than organ confined disease adjusting for treatment and risk group.


CONCLUSIONS
Unconfirmed findings of extra-periprostatic metastatic prostate cancer on SPECT/CT immunoscintigraphy independently and significantly predicted an increased risk of biochemical failure in patients presenting for radiotherapy with a clinical diagnosis of localized prostate cancer.
Ellis
R J
RJ
Department of Radiation Oncology, Aultman Hospital, Canton, Ohio, USA. rodney.ellis@case.edu
Zhou
E H
EH
Fu
P
P
Kaminsky
D A
DA
Sodee
D B
DB
Faulhaber
P F
PF
Bodner
D
D
Resnick
M I
MI
D000230:Adenocarcinoma / Q000097:blood / Q000175:diagnosis* / Q000532:radiotherapy / Q000556:secondary*; D000368:Aged; D000911:Antibodies, Monoclonal; D001918:Brachytherapy; D006801:Humans; D007205:Indium Radioisotopes; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000532:radiotherapy; D016719:Radioimmunodetection; D011879:Radiotherapy Dosage; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
D000911:Antibodies, Monoclonal; D007205:Indium Radioisotopes; C101315:Capromab Pendetide; D017430:Prostate-Specific Antigen