Long-term follow-up of 111In-capromab pendetide (ProstaScint) scan as pretreatment assessment in patients who undergo salvage radiotherapy for rising prostate-specific antigen after radical prostatectomy for prostate cancer.
OBJECTIVE
To evaluate the long-term failure patterns in patients who underwent an (111)In-capromab pendetide (ProstaScint) scan as part of their pretreatment assessment for a rising prostate-specific antigen (PSA) level after prostatectomy and subsequently received local radiotherapy (RT) to the prostate bed.


METHODS
Fifty-eight patients were referred for evaluation of a rising PSA level after radical prostatectomy. All patients had negative findings for metastatic disease after abdominal/pelvis imaging with CT and isotope bone scans. All patients underwent a capromab pendetide scan, and the sites of uptake were noted. All patients were treated with local prostate bed RT (median dose 66.6 Gy).


RESULTS
Of the 58 patients, 20 had biochemical failure (post-RT PSA level >0.2 ng/mL or a rise to greater than the nadir PSA), including 6 patients with positive uptake outside the bed (positive elsewhere). The 4-year biochemical relapse-free survival (bRFS) rates for patients with negative (53%), positive in the prostate bed alone (45%), or positive elsewhere (74%) scan findings did not differ significantly (p = 0.51). The positive predictive value of the capromab pendetide scan in detecting disease outside the bed was 27%. The capromab pendetide scan status had no effect on bRFS. Those with a pre-RT PSA level of <1 ng/mL had improved bRFS (p = 0.003).


CONCLUSIONS
The capromab pendetide scan has a low positive predictive value in patients with positive elsewhere uptake and the 4-year bRFS was similar to that for those who did not exhibit positive elsewhere uptake. Therefore, patients with a postprostatectomy rising PSA level should considered for local RT on the basis of clinicopathologic factors.
Nagda
Suneel N
SN
Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL 60153, USA. snagda@gmail.com
Mohideen
Najeeb
N
Lo
Simon S
SS
Khan
Usman
U
Dillehay
Gary
G
Wagner
Robert
R
Campbell
Steven
S
Flanigan
Robert
R
D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D005500:Follow-Up Studies; D006801:Humans; D007202:Indicators and Reagents; D007205:Indium Radioisotopes; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000000981:diagnostic imaging* / Q000532:radiotherapy / Q000601:surgery; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D016879:Salvage Therapy
D000911:Antibodies, Monoclonal; D007202:Indicators and Reagents; D007205:Indium Radioisotopes; C101315:Capromab Pendetide; D017430:Prostate-Specific Antigen