Gp. Murphy et al., Follow-up ProstaScint (R) scans verify detection of occult soft-tissue recurrence after failure of primary prostate cancer therapy, PROSTATE, 42(4), 2000, pp. 315-317
BACKGROUND. A reliable imaging modality is required to uncover occult soft-
tissue recurrence after failure of primary prostate cancer therapy. This re
trospective study was done to evaluate the ability of the (111)Indium-label
ed monoclonal antibody (ProstaScint(R)) scan in detection of prostatic bed
recurrence and/or metastases to regional and/or distant lymph nodes.
METHODS. One hundred sequential patients were evaluated with repeated Prost
aScint(R) scans because of evidence of recurrence during the course of thei
r disease. These 100 patients were followed closely from November 1994 and
April 1999, and had concurrent bone scans and serum prostate-specific antig
en (PSA) evaluations. They have had hormone therapy (n = 53) and/or experie
nced a rising PSA after radical ppostatectomy (n = 38) or after radiation t
herapy (n = 56). Scan images were scored 0-3, where score 0 = negative, sco
re 1 = prostate bed uptake, score 2 = regional lymph node uptake, and score
3 = distant lymph node uptake. In each patient, the uptake of the follow-u
p scan(s) was compared to that of the initial scan.
RESULTS. The median age was 70 years (range, 45-87), and 23 patients had a
positive bone scan. The average PSA was 40.5 ng/ml (standard deviation, 223
.5). There was 257 scans representing 100 patients. All patients had at lea
st 2 scans, 35 patients had 3 scans, and 11 patients had 4 scans. No indivi
dual exhibited detectable adverse clinical reactions during or after the sc
an. The findings of the initial and consecutive scans were anatomically con
sistent in 79%, whereas in 21% there were skip metastases. In 24 patients t
he lesions progressed by scan and PSA, 10 patients showed progression of sc
an but no PSA progression, 49 patients showed no change, and 17 patients sh
owed a remission related to adjuvant therapy.
CONCLUSIONS, The consistency on repeating the scan (79%) and the high perce
ntage of patients showing persistent uptake at the prostate bed (43%) as we
ll as the percentage of detection of regional nodes (20%) and distant nodes
(32%) reflects the importance of using the ProstaScint(R) scan in finding
occult recurrences after primary treatment failure of prostate cancer. Thes
e results are similar to those reported earlier in autopsy series studies i
n similar populations. Prostate 42:315-317, 2000. (C) 1000 Wiley-Liss, Inc.