The investigators noted that because patients who have skip metastases and negative pelvic lymph nodes have been found to later develop distant metastases, ProstaScint imagine was instrumental in detecting metastatic disease and prompting further investigation." (2004) The work of Murphy and Troychak (2000) entitled: "Follow-Up Prostascint Scans Verify Detection of Occult Soft-Tissue Recurrence After Failure of Primary Prostate Cancer Therapy" published in the Prostrate Journal reports a study conducted for the evaluation of the ability of ProstaScint scan in the detection of prostatic bed recurrent and metastases to regional or distant lymph nodes. The study reported is of one hundred sequential patients who were evaluated with repeated ProstaScint scans due to evidence of recurrence during the disease course. These patients were followed from November 1994 and April 1999 and had "concurrent bone scans and serum prostate-specific antigen (PSA) evaluations. They have had hormone therapy (n = 53) and/or experienced a rising PSA after radical prostatectomy (n = 38) or after radiation therapy (n = 56). Scan images were scored 0-3, where score 0 = negative, score 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-up scan(s) was compared to that of the initial scan." (Murphy and Troychak, 2000)

Results of the study relate that the median age of participants 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 least 2 scans, 35 patients had 3 scans, and 11 patients had 4 scans. No individual exhibited detectable adverse clinical reactions during or after the scan. The findings of the initial and consecutive scans were anatomically consistent in 79%, whereas in 21% there were skip metastases. In 24 patients the lesions progressed by scan and PSA, 10 patients showed progression of scan but no PSA progression, 49 patients showed no change, and 17 patients showed a remission related to adjuvant therapy." (Murphy and Troychak, 2000) Conclusions of this study state: "The consistency on repeating the scan (79%) and the high percentage of patients showing persistent uptake at the prostate bed (43%) as well as the percentage of detection of regional nodes (20%) and distant nodes (32%) reflects the importance of using the ProstaScint scan in finding occult recurrences after primary treatment failure of prostate cancer. These results are similar to those reported earlier in autopsy series studies in similar populations." (Murphy and Troychak, 2000)

The work of Murphy, Snow, Brandt and Brawer (2000) reports the evaluation of prostrate cancer patients who received multiple staging tests including ProstaScint scans and states that: "Multiple serum tests were performed on archival samples from patients who participated in trials to assess the ProstaScint scan staging ability. Traditional statistical analysis as well as artificial neural network (ANN) analysis were employed to evaluate individual patients and the group as a whole. The results were evaluated so that each factor was tested for prognostic value." (Murphy, Snow, Brandt and Brawer, 2000) Methods used in this study include data which was obtained from: "...serum tests, bone scans, and ProstaScint scans were evaluated by traditional statistical methods and ANN to determine the individual value in clinical staging of prostate cancer." (Murphy, Snow, Brandt and Brawer, 2000) Results of this study state: "Two hundred seventy-five patients (180 postprostatectomy, 95 intact prostate) with prostate cancer (14 with distant metastases) were available for analysis. Data available included: clinical state (remission or progression), most recent clinical TNM stage, bone scan, and ProstaScint scan. Serum was tested for prostate-specific membrane antigen (PSMA), prostate-specific antigen (PSA), free PSA (fPSA), and complexed PSA (cPSA). Additional calculations included percent free PSA, and percent complexed PSA. Spearman individual statistical assessment for traditional group evaluation revealed no significant factors for T-stage. The free PSA and complex PSA had a significant association with node status. The distant metastases (M) stage correlated well with the bone scan and clinical stage. ANN analysis revealed no significant T-stage factors. N-stage factors showed a 95% sensitivity and 49% specificity. These factors included the presence or absence of a prostate, PSA serum levels, bone scan, and ProstaScint scans as major associated indicators. ANN analysis of the important variables for M-stage included ProstaScint scan score, and PSA levels (total, percent complexed, percent free, and fPSA). These factors were associated with a 95% sensitivity and 15% specificity level." (Murphy GP, Snow PB, Brandt J, Elgamal a, Brawer MK. (2000) Evaluation of prostate cancer patients receiving multiple...

Conclusions of the study state that: "Two hundred seventy-five patients receiving treatment for prostate cancer were evaluated by ANN and traditional statistical analysis for factors related to stage of disease. ANN revealed that PSA levels, determined by a variety of ways, ProstaScint scan, and bone scan, were significant variables that had prognostic value in determining the likelihood of nodal disease, or distant disease in prostate cancer patients." (Murphy, Snow, Brandt and Brawer, 2000)
The work of Elgamal, Troychak and Murphy (1998) entitled: "Prostascint Scan May Enhance Identification of Prostate Cancer Recurrences After Prostatectomy, Radiation, or Hormone Therapy: Analysis of 136 Scans of 100 Patients" published in the Prostate Journal relates that: "Primary extraprostatic spread or failure after prostate cancer treatment can occur locally in the prostatic fossa and/or metastasize to regional and/or distant lymphatics and/or in bone." (Elgamal, Troychak and Murphy, 1998) it is reported by Elgamal, Troychak and Murphy that an evaluation of the "...ability of the ProstaScint (Cytogen Corp., Princeton, NJ) scan to identify soft tissue recurrence of prostate cancer in patients who failed primary treatment, and we monitored their responses to a secondary treatment. ProstaScint was evaluated in a series of 136 consecutive scans associated with a complete set of relevant clinical and biochemical data. These scans represented 100 patients, imaged between November 1994-May 1998, who underwent a definitive prostate cancer treatment followed by evidence of recurrence. All patients had serum prostate-specific antigen (PSA), Western-blot serum prostate-specific membrane antigen (PSMA), and bone scans. Prostatic fossa and/or lymph node biopsies were available in 33 patients." (Elgamal, Troychak and Murphy, 1998)

Results of the study state: "Overall, no adverse reactions were related to any of the radioactive antibody infusions. The average age was 69 years (range, 48-89 years), serum PSA was 55.9 ng/ml (range, 0-2,185 ng/ml), and serum PSMA was 0.32 (relative intensity levels range, 0.04-0.55). The initial therapies given were radical prostatectomy (55 scans), prostate radiation (74 scans), and/or hormonal therapy (77 scans). Twelve patients exhibited a negative scan. Local recurrence alone was identified in 58 scans (42.6%). Lymph node metastases were identified in 66 scans (48.5%). Of these, 21 had regional metastases alone, and 45 had distant lymph node metastases. Ten scans showed skip lymph node metastases without regional failure. PSA significantly correlated with negative, pelvic, and extrapelvic scan findings (P < or = 0.02). PSMA correlated best with pelvic recurrence and extrapelvic metastases in prostatectomized patients. Thirty-four patients had repeated scans for monitoring treatment response. Of these patients, 19 (56%) showed progression on the second scan, consistent with persistent increase in PSA and PSMA levels in all but 2 patients. Another 11 patients showed no change, and 4 patients showed partial remission, suggesting a response to the salvage treatment. All 20 positive prostate biopsies and 4 of the 7 positive lymph node biopsies correlated with ProstaScint findings, whereas 4 of the 6 patients with a negative biopsy had negative scans (i.e., 89% sensitivity and 67% specificity). Bone metastases were identified in 42 bone scans; 45% of these showed no lymph node metastasis on ProstaScint. In another 24 patients (57%), bone metastases were detected on ProstaScint examinations." (Elgamal, Troychak and Murphy, 1998)

The work of Petronis, Regan, and Lin (1998) reports a study which evaluated the usefulness of in-111 capromab pendetide imaging in the detection of prostate cancer metastases or local recurrence. The study relates that scan outcomes were "correlated with prostate-specific antigen levels, pathologic stage, Gleason score, weighted Gleason score, and clinical data. Of 51 scans, 70.6% (36 of 51) were positive. Eight patients had abnormal activity in the prostatic fossa, 12 patients had abnormal activity in the abdominal or pelvic lymph nodes, and 16 patients demonstrated abnormal activity in both areas. One patient with a positive scan underwent lymphadenectomy and was confirmed to be a true positive. Patients with a prostate-specific antigen level greater than 10 ng/ml, a weighted Gleason score higher than 4.5, or prostate-specific antigen levels greater than 2 ng/ml plus a weighted score higher than 4.5 showed positive rates of 100% (6 of 6), 88.2% (14 of 16), and 100% (6 of 6), respectively. in-111 capromab pendetide imaging was useful to detect metastases or local recurrence. Serum prostate-specific antigen levels and weighted Gleason scores are good predictive factors of the likelihood of a positive scan outcome." (Petronis and Regan, 1998)

SUMMARY of FINDINGS

The work of Murphy, Snow, Brandt, and Brawer (2000) has informed this study that…