ProstaScint Scan Research Articles

A Theranostic “SMART” Aptamer for Targeted Therapy of Prostate Cancer

A Theranostic “SMART” Aptamer for Targeted Therapy of Prostate Cancer

Intensity Modulated Radiation Therapy (IMRT) for Prostate Cancer: Phase I/II Study of Concomitant Boost using Indium in 111 Capromab Pendetide (Prostascint) Imaging

Intensity Modulated Radiation Therapy (IMRT) for Prostate Cancer: Phase I/II Study of Concomitant Boost using Indium in 111 Capromab Pendetide (Prostascint) Imaging

The Impact of a Negative 111Indium-Capromab Pendetide Scan Before Salvage Radiotherapy

We determined the prognostic role, if any, of the ProstaScint (111)indium-capromab pendetide scan before salvage radiotherapy for biochemical recurrence after RP for localized prostate cancer. We reviewed the records of 649 patients who underwent a ProstaScint scan from 1998 to 2004. A total of 44 patients were identified who had biochemical recurrence after RP and underwent a ProstaScint scan immediately before salvage radiotherapy. All patients received salvage radiotherapy to the prostatic bed unless pelvic lymph node uptake was identified on the scan, resulting in initial whole pelvic radiotherapy with 45 Gy, followed by a conformal boost to the prostate bed in 6. The median salvage radiotherapy dose to the prostate bed was 72 Gy. Patient demographics, pathological information, PSA values and ProstaScint results were collected retrospectively. The majority of ProstaScint scans were digitally fused with noncontrast pelvic computerized tomography images for interpretation. PSA progression after radiotherapy was defined using American Society for Therapeutic Radiation and Oncology criteria. At a mean followup of 22 months 43 of 44 patients (97%) experienced a PSA decrease after salvage radiotherapy with a mean PSA nadir of 0.16 ng/ml compared to a mean pre-radiotherapy PSA of 1.7 ng/ml. Of the 44 patients 15 (34%) showed post-radiotherapy PSA progression. When the entire cohort was analyzed, patients with negative ProstaScint scans had statistically lower post-radiotherapy PSA progression rates than patients with positive scans (1 of 10 or 10% vs 14 of 34 or 41%, p = 0.026). Patients with negative ProstaScint results were also statistically more likely to have a pre-radiotherapy PSA of less than 1.0 ng/ml (p = 0.005), no seminal vesicle involvement (p = 0.006), a greater mean PSA doubling time (p = 0.008) and received no hormone therapy (p = 0.003). When patients with pre-radiotherapy PSA less than 1.0 ng/ml were analyzed, a negative ProstaScint scan suggested but did not provide a statistically significant advantage over pre-radiotherapy PSA alone for predicting post-radiotherapy PSA progression (1 of 9 or 11% for negative vs 5 of 15 or 33% for positive scans, p = 0.20). Our early experience supports an improved prognosis in patients receiving salvage pelvic radiotherapy for biochemical recurrence after RP who have a negative pre-radiotherapy ProstaScint scan. However, this finding is not necessarily independent of pre-radiotherapy PSA.

Nuclear Medicine Studies of the Prostate, Testes, and Bladder

During the last decade, there has been a significant advancement in imaging of urologic diseases. Transrectal ultrasound (TRUS), computerized tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET) are still experiencing new developments in urology. Despite these many technological advances, the initial diagnostic procedure for a patient with suspected prostate cancer (PC) is multiple site blind prostate biopsies. There is a need for a noninvasive metabolic imaging modality to direct the site of biopsy to decrease the sampling error. MRS seems promising but as it is a costly and more time-consuming test, further studies are needed to evaluate its clinical utility. Currently, PET does not play any role to direct biopsy. Acetate and choline appear to be better tracers than FDG for the detection of a prostate lesion, however, further well-organized studies are needed before any of these agents can be used clinically. Incidental detection of intense focal uptake in the prostate during whole body PET scanning should be evaluated with prostate-specific antigen (PSA) and TRUS-guided biopsy. Although FDG is inferior to other tracers for primary staging, it may be useful in selected patients with suspected high-grade cancer. The role of ProstaScint scan is still controversial for detection of recurrent PC. This study may be helpful for evaluating nodal metastases when PSA is elevated and bone scan is negative. Bone scan remains the study of choice when bone metastases are suspected (PSA>15-20 ng/mL+/-bone pain). Acetate and choline provide better accuracy than FDG in the detection of local soft tissue disease, nodal involvement, and distant metastases. High FDG uptake may be indicative of more aggressive and possibly androgen-independent disease. PET/CT with any of the above PET tracers will most likely be preferred to the PET scan alone due to better localization of a hot lesion in PET/CT. Nuclear medicine studies also have been used to evaluate acute scrotum and testicular neoplasms. Scrotal scintigraphy has lost its popularity to Doppler ultrasound in the evaluation of the acute scrotum. In testicular tumors, FDG-PET appears to be superior to conventional imaging modalities in initial staging, detection of residual/recurrence, and monitoring treatment response. Tumor markers after treatment occasionally are elevated and cannot locate the site of recurrence, FDG-PET can play a very important role in this regard. Nuclear medicine studies also have been used to evaluate diseases of the urinary bladder. Radionuclide cystography is more sensitive and has less than 1/20 the radiation exposure of the conventional contrast enhanced micturating cystourethrogram (MCU). However, the utility of FDG-PET in the evaluation of bladder cancer seems to be limited to the evaluation of distant metastases. 11C-Methionine and choline may be a better option for local and nodal disease due to their negligible excretion in the urine.

661: Prostascint Scan in the Assessment of Patients who Undergo Radiation Therapy for Rising Prostate Specific Antigen after Radical Prostatectomy

You have accessJournal of UrologyDiscussed Poster, Monday, May 23, 2005, 8:00am - 12:00 pm1 Apr 2005661: Prostascint Scan in the Assessment of Patients who Undergo Radiation Therapy for Rising Prostate Specific Antigen after Radical Prostatectomy Suneel N. Nagda, Najeeb Mohideen, Robert Flanigan, Steven C. Campbell, Usman Khan, Simon Lo, Gary Dillehay, and Robert Wagner Suneel N. NagdaSuneel N. Nagda More articles by this author , Najeeb MohideenNajeeb Mohideen More articles by this author , Robert FlaniganRobert Flanigan More articles by this author , Steven C. CampbellSteven C. Campbell More articles by this author , Usman KhanUsman Khan More articles by this author , Simon LoSimon Lo More articles by this author , Gary DillehayGary Dillehay More articles by this author , and Robert WagnerRobert Wagner More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(18)34901-2AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "661: Prostascint Scan in the Assessment of Patients who Undergo Radiation Therapy for Rising Prostate Specific Antigen after Radical Prostatectomy." The Journal of Urology, 173(4S), p. 180 © 2016 by American Urological AssociationFiguresReferencesRelatedDetails Volume 173Issue 4SApril 2005Page: 180 Advertisement Copyright & Permissions© 2016 by American Urological AssociationMetricsAuthor Information Suneel N. Nagda More articles by this author Najeeb Mohideen More articles by this author Robert Flanigan More articles by this author Steven C. Campbell More articles by this author Usman Khan More articles by this author Simon Lo More articles by this author Gary Dillehay More articles by this author Robert Wagner More articles by this author Expand All Advertisement Loading ...

Long-term follow-up of prostascint scan pretreatment assessment in patients who undergo radiation therapy for a rising prostate specific antigen (PSA) after radical prostatectomy for prostate cancer

The Prostascint scan is a radioimmunoconjugate of a monoclonal antibody against prostate specific membrane antigen, which has high prostate tissue specificity. The purpose of our study was to evaluate long term failure patterns in patients who had undergone this scan as part of their pre treatment evaluation for a rising PSA after prostatectomy and went on to receive local radiotherapy (RT) to the prostatic bed. The study comprises of 59 patients who after radical prostatectomy for prostate cancer were referred to the department of radiation oncology for evaluation when their PSA started rising. All patients underwent imaging with Computerized Tomography (CT) scans of the abdomen and pelvis and an isotope bone scan. All patients also underwent a prostascint scan as part of the evaluation. The scans were read as negative, positive in the prostate bed alone, positive in the lymph node regions in the pelvis alone, positive in metastatic sites including lymph node regions outside the pelvis or positive in more than one of these areas. Regardless of the prostascint scan findings all patients were treated only with local radiotherapy to the prostatic bed to a dose of 66.6 Gy to 70.2 Gy in 1.8 Gy fractions. 7 patients had adjuvant short-term hormones for 3-6 months along with radiation. All patients were followed up with clinical evaluations, PSA tests and imaging where appropriate. The median follow-up from radiation was 41 months. The median follow-up after surgery was 79 months. Their postoperative stages were T2a: 5, T2b: 12, T2c: 14, T3a: 21, T3b: 6, T4a: 1. 46.5 % had Gleason 6 or less and 50% of the patients had positive margins. All the CT scans and bone scans were negative for metastatic disease. The mean PSA prior to RT was 0.9 ng/ml. The prostascint scan was negative in 15 patients, positive in the bed: 22, the bed and lymph node: 4, bed and metastatic site: 7, lymph nodes alone: 3, metastatic sites alone: 4, lymph node and metastatic sites: 2 and all 3 sites: 2. The 5-year biochemical relapse free survival (BRFS) in patients with a pre-RT PSA less than 1 was 57.9% which was statistically significantly better than those with a pre-RT PSA greater or equal to 1 ng/ml (p = 0.0027). The 5-year BRFS for patients with Gleason score 6 and below was 59.6 % compared to 42.8% for those with a higher Gleason score (p = 0.35). 19 patients have failed biochemically: 8/22 patients with scan positive in the bed alone, 5/15 patients with a negative scan and 6/22 in patients with a positive uptake outside the bed. The 5-year biochemical relapse free survival rates for patients with a negative scan (53.3%) positive scan in the bed alone (45.2%) or positive scan outside the bed (55.3%) were all not statistically different (p = 0.5) by log rank analysis. On multivariate analysis PSA less than 1 ng/ml was the only significant factor predicting improved BRFS. Prostascint Scan status had no effect on BRFS. 5-year BRFS rates were similar regardless of the pre-treatment prostascint scan status for patients who undergo post-prostatectomy salvage radiotherapy. Hence if other imaging studies are negative for metastatic disease, patients should still be considered for local therapy. Pre-radiotherapy PSA less than 1 ng /ml was the most important prognostic factor in our study

Long-term follow-up of prostascint scan pretreatment assessment in patients who undergo radiation therapy for a rising prostate specific antigen (PSA) after radical prostatectomy for prostate cancer

Long-term follow-up of prostascint scan pretreatment assessment in patients who undergo radiation therapy for a rising prostate specific antigen (PSA) after radical prostatectomy for prostate cancer

THE ROLE OF 111INDIUM-CAPROMAB PENDETIDE IMAGING FOR ASSESSING BIOCHEMICAL FAILURE AFTER RADICAL PROSTATECTOMY

Conventional imaging modalities, such as computerized tomography and magnetic resonance imaging, lack sensitivity and specificity for detecting recurrent prostate cancer after radical surgery. We evaluated the role of the indium-capromab pendetide scan, otherwise known as the ProstaScint (Cytogen Corp., Princeton, New Jersey) scan, in this setting. A retrospective review was performed of 42 patients undergoing ProstaScint imaging for biochemical progression after radical prostatectomy. Of these patients 16 (38.1%) subsequently completed a course of salvage radiation therapy. Median prostate specific antigen (PSA) immediately prior to ProstaScint imaging was 1.2 ng/ml (range 0.2 to 4.8). Abnormal accumulation on the ProstaScint scan was detected in 36 patients (85.7%). Of the 16 patients undergoing salvage radiation therapy 15 had uptake isolated to the prostatic fossa on ProstaScint imaging. Ten of these 15 patients (66.7%) achieved undetectable PSA after radiation therapy, while 5 (33.3%) had little or no response. Using American Society for Therapeutic Radiology and Oncology criteria 3 of 10 responders had relapse after an average of 9 months. The remaining 7 patients remained biochemically free of disease at last followup. ProstaScint imaging is capable of detecting recurrent prostate cancer at low PSA levels. However, only 7 of 15 men (46.7%) with ProstaScint uptake isolated to the prostatic fossa showed a durable response to salvage radiation therapy. Based on these findings patients might be better treated based on the rate of increase in PSA rather than on routine scanning with this test.

Detection of a non-Hodgkin’s lymphoma by capromab pendetide scintigraphy (ProstaScint) in a patient with prostate carcinoma

A 77-year-old man with Gleason score 7 prostate cancer, after radical prostatectomy, in whom the prostate-specific antigen level increased to 5.0 ng/mL 8 years later, underwent a ProstaScint scan. Radiotracer deposition was noted in the prostatic “fossa,” highly suspicious of recurrence. An additional focus in the mid abdomen was suspicious of adenopathy. Computed tomography disclosed an abdominal mass that, at biopsy, proved to be a malignant B-cell lymphoma. That lesion resolved after chemotherapy, and the prostate-specific antigen level substantially decreased with hormonal treatment. The possible association of prostate cancer and lymphoma is discussed.

The utility of monoclonal antibodies in the imaging of prostate cancer.

Monoclonal antibodies (mAbs) to prostate-specific antigens, such as PSMA, have great potential as diagnostic and therapeutic tools in the management of advanced prostate cancer. PSMA is a very attractive target for mAb-based imaging. It is expressed by virtually all prostate cancers and its expression is further increased in poorly differentiated, metastatic, and hormone-refractory carcinomas. The ProstaScint scan (Cytogen, Princeton, NJ), based on the mAb 7E11-C5.3, is currently approved for the imaging of prostate cancer in soft tissue but is not approved for imaging bone metastases. It appears superior to conventional imaging studies for soft-tissue disease but has limitations attributed to its intracellular binding site on PSMA. Overcoming this limitation, new mAbs to the extracellular domain of PSMA have been developed. The radioisotopes, (111)Indium, (90)Yttrium, and (177)Lutetium have been conjugated to one such mAb, J591. Radioimmunoscintigraphy with this immunoconjugate has demonstrated excellent tumor targeting of prostate cancer sites not only in soft tissue but also in bone.

Does the prostascint scan help in the pretreatment assessment of patients who undergo radiation therapy for a rising psa (prostate specific antigen) after radical prostatectomy for prostate cancer

Purpose: The Prostascint scan is a radioimmunoconjugate of a monoclonal antibody against prostate specific membrane antigen, which has high prostate tissue specificity. The purpose of our study was to evaluate its role in the assessment of patients who have a rising PSA after prostatectomy who undergo radiotherapy (RT) to the prostatic bed.

Radioimmunoguided imaging of prostate cancer foci with histopathological correlation

Purpose: We have previously presented a technique that fuses ProstaScint and pelvic CT images for the purpose of designing brachytherapy that targets areas at high risk for treatment failure. We now correlate areas of increased intensity seen on ProstaScint-CT fusion images to biopsy results in a series of 7 patients to evaluate the accuracy of this technique in localizing intraprostatic disease. Methods and Materials: The 7 patients included in this study were evaluated between June 1998 and March 29, 1999 at Metrohealth Medical Center and University Hospitals of Cleveland in Cleveland, Ohio. ProstaScint and CT scans of each patient were obtained before transperineal biopsy and seed implantation. Each patient’s prostate gland was biopsied at 12 separate sites determined independently of Prostascint-CT scan results. Results: When correlated with biopsy results, our method yielded an overall accuracy of 80%: with a sensitivity of 79%, a specificity of 80%, a positive predictive value of 68%, and a negative predictive value of 88%. Conclusion: The image fusion of the pelvic CT scan and ProstaScint scan helped identify foci of adenocarcinoma within the prostate that correlated well with biopsy results. These data may be useful to escalate doses in regions containing tumor by either high-dose rate or low-dose rate brachytherapy, as well as by external beam techniques such as intensity modulated radiotherapy (IMRT).

Follow-up ProstaScint scans verify detection of occult soft-tissue recurrence after failure of primary prostate cancer therapy.

A reliable imaging modality is required to uncover occult soft- tissue recurrence after failure of primary prostate cancer therapy. This retrospective study was done to evaluate the ability of the (111)Indium-labeled monoclonal antibody (ProstaScint(R)) scan in detection of prostatic bed recurrence and/or metastases to regional and/or distant lymph nodes. One hundred sequential patients were evaluated with repeated ProstaScint(R) scans because of evidence of recurrence during the course of their disease. These 100 patients were followed closely 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. 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 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. 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(R) 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.

Evaluation of prostate cancer patients receiving multiple staging tests, including ProstaScint scintiscans.

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. Data 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. 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 (N)-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. 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.

ProstaScint scan may enhance identification of prostate cancer recurrences after prostatectomy, radiation, or hormone therapy: analysis of 136 scans of 100 patients.

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. We evaluated 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.The 111indium-labeled monoclonal antibody (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.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.

ProstaScint scan may enhance identification of prostate cancer recurrences after prostatectomy, radiation, or hormone therapy: analysis of 136 scans of 100 patients.

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. We evaluated 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. The 111indium-labeled monoclonal antibody (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. 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.

Comparison of serum PSMA, PSA levels with results of cytogen-356 ProstaScint® scanning in prostatic cancer patients

Stored serum from clinical trial cases undergoing ProstaScint (CYT-356) scanning were available for Prostate Specific Membrane Antigen (PSMA) assay. Prostate Specific Antigen (PSA) levels had already been determined. This provided an opportunity to see what correlations existed between the serum markers and the ProstaScint scan. A group of patients had the studies preprostatectomy, whereas another group had the studies postprostatectomy. The scan results, serum PSA, serum PSMA, and clinical data were separately analyzed. PSMA serum levels were determined by Western blot. Preoperatively, radical prostatectomy patients showed a correlation between serum PSA or PSMA levels and the ProstaScint scan in the total group (n = 86), or in an untreated group (n = 38). Preoperatively, PSMA correlated with the pathological stage, whereas PSA correlated with the scan. Postoperatively, only PSMA serum levels correlated with the scan in an untreated group (n = 40). Preoperatively or postoperatively, Western blot PSMA serum levels predict the stage of disease or local, regional, or distant metastases, as shown by ProstaScint scan. Both the scan and the serum tests provide prognostic information and evaluate the extent of disease to a more significant degree than previously possible.