Imaging prostate cancer with technetium-99m-7E11-C5.3 (CYT-351).
To evaluate the performance of the 99mTc-labeled monoclonal antibody CYT-351 in visualizing prostate cancer, radioimmunoscintigraphy (RIS) was performed in 35 patients.


METHODS
Antibody (0.5 mg) labeled with 600 MBq 99mTc was injected intravenously after obtaining informed consent. Planar and SPECT imaging was performed at 10 min and 6-8 and 22-24 hr postinjection. The scans were evaluated for visualization of the primary focus or local recurrence, extraprostatic invasion, lymph node involvement and uptake in bone and soft tissue metastases.


RESULTS
Thirty-six studies in 35 patients were performed. In 13/14 evaluable studies with clinically localized prostate cancer, RIS had a true-positive rate of 92% (12/13). In eight patients with previous incidental carcinoma detected during transurethral resection undertaken for clinically benign disease, there were 86% true-positive results (6/7) and one true-negative result, which were confirmed by systematic needle biopsies. In six patients with evidence of local recurrence after a previous radical prostatectomy, the true-positive rate was 100% (6/6), which was confirmed by raised or rising prostate-specific antigen levels (PSA) and/or by biopsy. In the eight patients with known metastases, the disease was visualized in 4/4 with progression but not in the 3/3 with regression; one patient demonstrated regressing disease as determined by PSA levels. The overall accuracy was 92%.


CONCLUSIONS
RIS with 99mTc CYT-351 is capable of providing good quality images and yielding clinically useful information safely. It has a potentially important clinical role for patients with rising PSA levels but negative images by conventional modalities.
Chengazi
V U
VU
Department of Nuclear Medicine, St. Bartholomew's Hospital, London, United Kingdom.
Feneley
M R
MR
Ellison
D
D
Stalteri
M
M
Granowski
A
A
Granowska
M
M
Nimmon
C C
CC
Mather
S J
SJ
Kirby
R S
RS
Britton
K E
KE
D000911:Antibodies, Monoclonal; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D009367:Neoplasm Staging; D011467:Prostate / Q000000981:diagnostic imaging*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D016719:Radioimmunodetection; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D013667:Technetium; D015899:Tomography, Emission-Computed, Single-Photon
D000911:Antibodies, Monoclonal; C101173:CYT-351 monoclonal antibody; D013667:Technetium; D017430:Prostate-Specific Antigen