Staging of pelvic lymph nodes in neoplasms of the bladder and prostate by positron emission tomography with 2-[(18)F]-2-deoxy-D-glucose

OBJECTIVES: The aim of this study was to evaluate whether pelvic lymph node metastases in patients with neoplasms of the bladder or prostate can be detected applying positron emission tomography with 2-[(18)F]-2-deoxy-D-glucose (FDG-PET). METHODS: Eight patients with bladder cancer and 17 patients with prostate cancer were examined with FDG-PET before pelvic lymph node dissection. Results of PET were then compared to histology of pelvic lymph nodes obtained at surgery. RESULTS: Lymph node metastases were detected by histopathological examination in 3 patients with bladder cancer and in 6 patients with prostate cancer. At the sites with histologically proven metastases, increased FDG uptake suspicious of metastatic disease was found in 2/3 and 4/6 patients, respectively. The smallest detected metastasis was a micrometastasis with a diameter of 0.9 cm. In 3 additional patients who all had histopathologically proven micrometastases ( 相似文献   

Detection of pelvic lymph node metastases in patients with clinically localized prostate cancer: comparison of [18F]fluorocholine positron emission tomography-computerized tomography and laparoscopic radioisotope guided sentinel lymph node dissection

PURPOSE: Accurate detection of lymph node metastases in prostate cancer has important implications for prognosis and approach to treatment. We investigated whether preoperative [18F]fluorocholine combined in-line positron emission tomography-computerized tomography and intraoperative laparoscopic radioisotope guided sentinel pelvic lymph node dissection can detect pelvic lymph node metastases in patients with clinically localized prostate cancer as reliably as extended pelvic lymph node dissection. MATERIALS AND METHODS: A total of 20 patients (mean age 63.9 +/- 6.7 years, range 52 to 75) with clinically localized prostate cancer, prostate specific antigen greater than 10 ng/ml, and/or a Gleason score sum of 7 or greater and negative bone scan were enrolled in the study. [18F]fluorocholine combined in-line positron emission tomography-computerized tomography was performed before surgery. Sentinel pelvic lymph node dissection preceded extended pelvic lymph node dissection including the area of the obturator fossa, external iliac artery/vein and internal iliac artery/vein up to the bifurcation of the common iliac artery. Laparoscopic radical prostatectomy was performed afterward. RESULTS: In 10 of the 20 patients (50%) lymph node metastases were detected, and were exclusively found outside the obturator fossa in 62%. These metastases would not have been identified with standard lymph node dissection of the obturator fossa only. [18F]fluorocholine combined in-line positron emission tomography-computerized tomography was true positive in 1, false-positive in 2, false-negative in 9 and true negative in 8 patients. The largest lymph node metastasis not seen with [18F]fluorocholine combined in-line positron emission tomography-computerized tomography was 8 mm. Laparoscopic sentinel guided lymph node dissection revealed lymph node metastases in 8 of 10 patients. In the other 2 patients sentinel lymph node dissection was not conclusive. In 1 patient normal nodal tissue was completely replaced by cancer and, therefore, there was no tracer uptake in the involved pelvic sidewall/node, and the other patient had no tracer activity at all in the involved pelvic sidewall. Extended pelvic lymph node dissection missed 1 lymph node metastasis (2 mm diameter near pudendal artery) which was detected by sentinel pelvic lymph node dissection only. CONCLUSIONS: Extended pelvic lymph node dissection reveals a higher number of lymph node metastases as described for obturator fossa dissection only. [18F]fluorocholine combined in-line positron emission tomography-computerized tomography is not useful in searching for occult lymph node metastases in clinically localized prostate cancer. Sentinel guided pelvic lymph node dissection allows the detection of even small lymph node metastases. The accuracy of sentinel pelvic lymph node dissection is comparable to that of extended pelvic lymph node dissection when the limitations of the method are taken into consideration.     

Laparoscopic pelvic lymph node dissection allows significantly more accurate staging in "high-risk" prostate cancer compared to MRI or CT

OBJECTIVE: To compare the accuracy of lymph node staging using pelvic MRI or CT to that of laparoscopic pelvic lymph node dissection (LPLND) in prostate cancer patients prior to radical radiotherapy. MATERIAL AND METHODS: A total of 55 consecutive patients at high risk of locally advanced disease [prostate-specific antigen (PSA) > 10 ng/ml, Gleason score 7 or worse on biopsy, normal (99m) Tc bone scan] underwent either a pelvic MRI (n = 42) or CT (n = 13) scan and subsequent LPLND. Preoperative staging was compared to the histology of the lymph node specimens obtained. RESULTS: A total of 20/55 (36.4%) patients had pelvic lymph node metastases confirmed by LPLND. MRI identified three patients (27.3%) with pelvic lymph node metastases and missed eight (72.7%) whilst CT identified none of nine patients with pelvic lymph node metastases. The groups with histologically-positive and -negative nodes had similar mean ages (63 vs 65 years; p = 0.52), Gleason scores (6.8 vs 6.5; p = 0.41) and PSA levels (43.1 vs 31.4 ng/ml; p = 0.56). CONCLUSION: The presence or absence of lymph node metastases has critical implications for the prognosis and treatment of prostate cancer. In this study both MRI and CT missed many cases of lymph node metastases in "high-risk" patients. While a positive scan seems likely to indicate nodal metastases, the low sensitivity in high-risk patients seems unacceptable if treatment decisions are to be based on accurate staging, and LPLND offers an alternative.     

前列腺癌根治术前盆腔淋巴结微转移检测的研究

目的 明确新辅助治疗后前列腺癌根治术前,real-time PCR检测盆腔淋巴结微转移的意义.方法 2007年8月至2010年3月对21例临床局限性前列腺癌病例,根据病理检查阳性(A组)、real-time PCR检查前列腺特异性抗原(PSA)mRNA和前列腺特异性膜抗原(PSMA)mRNA阳性(B组)、病理检查及real-time PCR检查PSA mRNA及PSMA mRNA均阴性(C组)进行分组,D组为对照组.术前行淋巴管造影显示盆腔淋巴结,对可疑淋巴结在X线定位下穿刺抽吸淋巴液,用real-time PCR方法检测淋巴液中PSA mRNA和PSMA mRNA的表达,阳性表达提示淋巴结转移的存在,术后对淋巴结组织切片进行免疫组化检查.结果 对术前盆腔淋巴结穿刺抽吸淋巴液用real-time PCR方法检测PSA mRNA和PSMA mRNA的表达,证实有14例淋巴结存在微转移,术后对清扫淋巴结进行免疫组化检查有3例存在淋巴结转移,A组与B组PSA mRNA和PSMA mRNA的表达存在明显的差异;A、B组淋巴液中PSA mRNA及PSMA mRNA的表达明显高于淋巴结(P＜0.01).结论 采用real-time PCR方法检测淋巴液中PSA和PSMA mRNA的表达有利于探测到淋巴结微转移的存在,术前穿刺淋巴结抽吸淋巴液提高了术前前列腺癌分期的准确性.     

A preoperative nomogram identifying decreased risk of positive pelvic lymph nodes in patients with prostate cancer

PURPOSE: We developed a preoperative nomogram for prediction of lymph node metastases in patients with clinically localized prostate cancer. MATERIALS AND METHODS: The study was a retrospective, nonrandomized analysis of 7,014 patients treated with radical prostatectomy at 6 institutions between 1985 and 2000. Exclusion criteria consisted of preoperative androgen ablation therapy, salvage radical prostatectomy and pretreatment prostate specific antigen (PSA) greater than 50 ng/ml. Preoperative predictors of lymph node metastases consisted of pretreatment PSA, clinical stage (1992 TNM) and biopsy Gleason sum. These predictors were used in logistic regression analysis based nomograms to predict the probability of lymph node metastases. RESULTS: Overall 5,510 patients with complete clinical and pathological information were included in the study. Lymph nodes metastases were present in 206 patients (3.7%). Pretreatment PSA, biopsy Gleason sum, clinical stage and institution represented predictors of lymph node status (p <0.001). Bootstrap corrected predictive accuracy of the 3-variable nomogram (clinical stage, Gleason sum and PSA) was 0.76. Inclusion of a fourth variable, which accounts for institutional differences in lymph node metastases, yielded an area under the receiver operating characteristics curve of 0.78. The negative predictive value of our nomograms was 0.99 when they predicted 3% or less chance of positive lymph nodes. CONCLUSIONS: Using clinical information, we produced 2 calibrated and validated nomograms, which accurately predict pathologically negative lymph nodes in men with localized prostate cancer who are candidates for radical prostatectomy.     

Fluorodeoxyglucose positron emission tomography studies in the diagnosis and staging of clinically advanced prostate cancer

OBJECTIVE: To determine the value of 18F-fluoro-2-deoxyglucose (FDG) positron-emission tomography (PET) studies in evaluating patients with advanced prostate cancer. PATIENTS AND METHODS: FDG-PET scans were taken in 30 patients with advanced prostate cancer 1 h after an injection with 555 MBq of FDG. Patients were scanned from the base of the skull to the inguinal region (including the pelvis). They were also assessed by computed tomography (CT) of the abdomen and pelvis, and bone scintigraphy, to evaluate them for metastases. RESULTS: Thirteen patients had locally extensive prostate cancer and 17 had metastatic disease. Twenty of the 30 patients were positive for radioisotope uptake in the prostate or extraprostatically. The patients with PET-detected prostate cancer were untreated (seven), treated hormonally while they had rising PSA levels (eight), or treated hormonally with a detectable but stable PSA (five). The remaining 10 patients were negative for FDG uptake in the prostate or any metastatic sites; these 10 patients were receiving hormone therapy, with undetectable PSA levels. CONCLUSION: FDG-PET imaging is not a useful test in evaluating advanced prostate cancer in patients being treated and who have an undetectable PSA level. Staging of advanced prostate cancer may be enhanced by FDG-PET imaging in patients who are untreated, who have had an incomplete response to therapy, or who have a rising PSA level despite treatment.     

Evaluation of prostate cancer using FDG-PET

The clinical usefulness of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was examined in 54 patients with prostate cancer. FDG accumulation was positive in 38 of 54 the prostates (70%), 3 of 8 the lymph node metastases (38%) and 10 of 16 the bone metastases (63%), which suggested that FDG-PET is not superior to other conventional imaging methods as a tool for tumor detection. On the other hand, a quantitative value for FDG uptake in the prostate, expressed as a standardized uptake value (SUV), significantly correlated to the histological grade, clinical stage and serum PSA of the patients. A decrease of SUV was observed in all the patients who responded to endocrine treatment, and the patients with high pre-treatment SUV were shown to be at the risk for disease progression after initial treatment. The present results indicated that FDG-PET could provide us with useful prognostic information for the patients with prostate cancer by evaluating the malignant potential of the tumor.     

Extended pelvic lymphadenectomy in patients undergoing radical prostatectomy: high incidence of lymph node metastasis

PURPOSE: Lymphadenectomy for prostate cancer is limited to obturator and external iliac lymph nodes, although the internal lymph nodes represent the primary landing zone of lymphatic drainage. We performed anatomically adequate extended pelvic lymphadenectomy to assess the incidence of lymph node metastasis in cases of clinically localized prostate cancer. MATERIALS AND METHODS: A total of 103 consecutive patients underwent extended pelvic lymphadenectomy at radical retropubic prostatectomy comprising 9 selective fields, namely the external iliac, internal iliac, obturator and common iliac lymph nodes bilaterally, and the presacral lymph nodes. Histopathological findings were compared with serum prostate specific antigen (PSA), histopathological stage, preoperative biopsy and postoperative prostatectomy Gleason score. Extended pelvic lymphadenectomy was compared with radical retropubic prostatectomy and standard lymphadenectomy in 100 consecutive patients in terms of complications, the number of lymph nodes dissected and operative time. RESULTS: There were no significant differences in age, preoperative PSA or mean biopsy Gleason score in patients who underwent extended pelvic and standard lymphadenectomy. Metastases were diagnosed in 27 of the 103 patients (26.2%) who underwent the extended procedure. A mean of 28 lymph nodes (range 21 to 42) were dissected. Metastases were identified in the internal iliac and presacral regions despite negative obturator lymph nodes. Of the 27 patients 1 to 3 lymph nodes involved with metastasis were detected in 15, 9 and 1, respectively. In 26 of the 27 patients (95.8%) with lymph node metastasis PSA was greater than 10.5 ng./ml. and preoperative biopsy Gleason sum was 7 or greater. A low risk of 2% for lymph node disease was noted in patients with serum PSA less than 10.5 ng./ml. and biopsy Gleason sum less than 7. There were no significant differences in regard to intraoperative and postoperative complications, lymphocele formation or blood loss in the 2 groups. CONCLUSIONS: Extended pelvic lymphadenectomy is associated with a high rate of lymph node metastasis outside of the fields of standard lymphadenectomy in cases of clinically localized prostate cancer. Lymphadenectomy including the internal iliac lymph nodes should be performed in all patients with prostate cancer who are at high risk for lymph node involvement, as indicated by PSA greater than 10.5 ng./ml. and biopsy Gleason sum 7 or greater. In the low risk group pelvic lymphadenectomy can be omitted.     

F-18-fluorodeoxyglucose positron emission tomography as a presurgical evaluation modality for I-131 scan-negative thyroid carcinoma patients with local recurrence in cervical lymph nodes

BACKGROUND: F-18-labeled fluorodeoxyglucose-positron emission tomography (FDG-PET) has a supplementary role in localizing recurrent sites of differentiated thyroid carcinoma. We evaluated whether FDG-PET is feasible as a presurgical evaluation modality for I-131 scan-negative thyroid carcinoma patients. METHODS: Preoperative FDG-PET results were compared with the pathologic findings of lymph nodes specimens of 22 papillary thyroid patients. All patients had thyroidectomy and I-131 ablation therapy beforehand and showed negative I-131 scans on follow-up studies. RESULTS: In 85 cervical lymph node groups dissected, 56 lymph node groups revealed metastasis. The sensitivity and specificity of FDG PET for metastasis were 80% (45 of 56) and 83% (24 of 29), respectively. Among the pathologically positive 33 lymph nodes with normal size(< or =1 cm), FDG-PET detected 23 nodes. Serum thyroglobulin levels were elevated in 12 patients (sensitivity, 55%). CONCLUSION: FDG-PET accurately detected the recurred cervical lymph nodes of differentiated thyroid carcinoma patients who showed negative I-131 scan. FDG-PET is suitable for the presurgical evaluation of these patients.     

The immunohistochemical assessment of occult regional lymph node metastases in patients with T3pN0M0 prostate cancer before definitive radiotherapy

OBJECTIVE: To detect occult regional lymph node metastases in patients with T3pN0M0 prostate cancer not recognized by routine haematoxylin and eosin staining, and to evaluate the clinical relevance of this finding. PATIENTS AND METHODS: Formalin-fixed and paraffin-embedded pelvic lymph nodes (1118) from 92 patients were evaluated by immunohistochemistry using antibodies for prostate specific antigen (PSA) and pancytokeratin (AE1/AE3). Of the tumours, 14% were well, 69% moderately and 17% poorly differentiated. The extent of tumour was categorized as T3pN0M0 in all patients, who were referred for definitive radiotherapy after pelvic staging lymphadenectomy. The median (range) serum PSA value before treatment was 18.5 (0.4-342) microg/L. After radiotherapy, the patients were followed by assessing biochemical progression, pelvic recurrence and/or development of distant metastases. The median (range) observation time for all patients was 61 (16-136) months. RESULTS: Occult lymph node metastases were detected in four (4.4%) of the 92 patients. Patients with or without occult metastases had similar serum PSA levels and histological grades. None of the four patients with occult metastases progressed, compared with 37 of the 88 (42%) with no such metastases. CONCLUSION: Using immunohistochemistry the detection rate of occult lymph node metastases in patients with T3pN0M0 prostate cancer is low. The occurrence of such metastases is probably unrelated to the serum PSA value before treatment. The short-term outcome of patients subsequently treated with definitive radiotherapy does not seem to be associated with the finding of occult lymph node metastases, but long-term follow-up is needed. So far, the results do not justify the search for occult lymph node metastases as a routine procedure in these patients     

Die extendierte Sentinel-Lymphadenektomie im Rahmen der radikalen Prostatektomie?

Extended lymph node dissection during radical prostatectomy for prostate cancer remains a disputed area. Sentinel lymph scans help identify the first lymph node stages in the lymph drainage of the prostate. This study was designed to investigate the detection rate of lymph node metastasis by extended lymph node dissection and sentinel lymph node scanning in patients undergoing radical retropubic prostatectomy (RRP) for localized prostate cancer.In this study at our department from 2005 to 2006, a total of 108 patients with localized prostate carcinoma were treated with radical prostatectomy including extended lymph node dissection. A sentinel lymph node scan with 160 MBq of technetium-99m-Nanocoll (Tc) was performed 1 day before surgery. A C-Trak gamma probe (AEA Technologies, Morgan Hills, CA, USA) was used intraoperatively to detect the sentinel lymph nodes. Scan findings were correlated with tumor stage, Gleason score, prostate-specific antigen (PSA) level, and histological lymph node status.Scans revealed sentinel lymph nodes on the film 2 h after Tc administration in 98 of 108 patients (91%). Histologically proven lymph node metastases were detected in 15 of those 98 patients (15%) with a positive sentinel scan. Those 15 patients had a PSA level greater than 10 ng/ml or a Gleason score greater than 6 and at least a pT2 tumor. Specifically, six patients had a pT2 tumor, and nine patients had a pT3 tumor. Of patients placed in a risk group defined as PSA above 10 ng/ml or Gleason score greater than 6, 15 out of 50 patients (30%) had sentinel positive lymph nodes with metastasis.These data suggest that extended sentinel lymph node dissection helps identify lymph node metastasis in patients with PSA above 10 ng/ml or a Gleason score above 6 in 30% of cases. Further studies will show whether these numbers will hold true in patients undergoing radical prostatectomy for prostate cancer.     

Targeted salvage lymphadenectomy in patients treated with radical prostatectomy with biochemical recurrence: complete biochemical response without adjuvant therapy in patients with low volume lymph node recurrence over a long-term follow-up

Background

Choline positron emission tomography/computed tomography (PET/CT) represents an option in restaging of prostate cancer patients with disease relapse after local treatment. The present study assess whether salvage resection of lymph node metastases detected on choline PET/CT imaging in prostate cancer patients with biochemical recurrence after radical prostatectomy can result in a long-term complete biochemical remission, without adjuvant therapy.

Methods

We analysed 13 patients with prostate specific antigen (PSA) recurrence (PSA median 1.64 ng/ml, range 0.5-9.55) after radical prostatectomy and suspicious lymph nodes (median 1; range 1–3) detected on [11C]choline and [18F]fluoroethylcholine PET/CT scans. An open salvage lymphadenectomy of positive lymph nodes in a PET/CT scan and nearby lymph nodes was carried out. We examined PSA outcome without adjuvant therapy; defined complete biochemical remission as PSA <0.01 ng/ml. Histological and PET/CT findings were compared.

Results

Ten of 11 patients with histologically confirmed lymph node metastases showed a PSA response. Three of ten patients with single lymph node metastases had a complete biochemical remission (median follow-up 72 months, range 31.0-83). In five cases with single lymph node metastasis PSA decreased <0.02 ng/ml. Histologically confirmed 13 of 16 metastasis suspicious lymph nodes. No lymph node metastases were detected in two patients. All of the additionally removed 30 lymph nodes were correctly negative.

Conclusions

This is the first confirmation of a complete biochemical remission after PET/CT guided secondary resection of a single lymph node metastasis in prostate cancer patients with biochemical recurrence after radical prostatectomy, over the long-term (>6.5 years), without adjuvant therapy. In order to improve these promising results, longer-term studies with more patients are required.     

Limitations of radioguided surgery in high-risk prostate cancer

OBJECTIVES: To determine how many men with high-risk prostate cancer (prostate-specific antigen [PSA]>20 ng/ml or biopsy Gleason score 8-10) have positive lymph nodes (sentinel lymph nodes [SLNs] and nonsentinel lymph nodes [NSLNs]) and whether these positive nodes are localised in the region of SLN dissection or in other regions, too. METHODS: In 228 men with high-risk prostate cancer radical retropubic prostatectomy combined with radioguided pelvic lymph node dissection and extended lymphadenectomy were performed. Serial sections of the SLNs were analysed immunohistochemically. RESULTS: A median of 7 SLNs (mean, 7) and 11 NSLNs (mean, 11) were dissected per patient. Ninety-six of 228 men (42.1%) had lymph node metastases. Most men had positive lymph nodes along the internal iliac artery alone or in combination with other regions. Twenty-two men had only micrometastatic disease. In 94 of 96 men the SLNs were positive. Twenty-six of 96 men had also positive NSLNs. When SLNs and NSLNs were positive, in more than half the patients the NSLNs were localised outside the region of sentinel lymphadenectomy. CONCLUSIONS: The dissection of SLNs in prostate cancer has a high sensitivity in detecting positive nodes. When SLNs are negative, the other pelvic lymph nodes are also negative in a high percentage of men (sensitivity 97.1%). When the SLNs are positive, patients with high-risk disease also have a high incidence of positive NSLNs. Therefore, when it is aspired to remove all pelvic lymph node metastases sentinel and extended lymphadenectomy should be performed.     

Reliability of preoperative values to determine the need for lymphadenectomy in patients with prostate cancer and meticulous lymph node dissection

INTRODUCTION: The only definite way to determine lymph node metastasis, an unfavorable prognostic factor in prostate cancer is lymphadenectomy. Due to increased morbidity and the increasing trend towards minimally invasive surgery, ways to avoid or at least limit lymphadenectomy are being sought. We routinely performed a meticulous lymphadenectomy in all patients and the goal of this study was to evaluate which of the previously proposed criteria determining who needs a lymphadenectomy can be applied in our patients.PATIENTS AND METHODS: Patients with clinically localized prostate cancer confirmed by fine needle aspiration cytology, without neoadjuvant hormone therapy, negative pelvic and abdominal CT scans and negative bone scan underwent a radical prostatectomy with simultaneous bilateral extended lymphadenectomy.RESULTS: Between 1989 and 1999, 463 patients were included in this study. The median age was 64 (range 44-76) years and the median PSA was 11.0 (range 0.42-172) ng/ml. A median of 21 nodes were removed per patient. One hundred and nine (24%) had lymph node metastasis: 17% of patients with a PSA value < or =20 ng/ml and 12% with a PSA value < or = 10 ng/ml. None of the patients with a preoperative grading of 1 and a PSA value < or =10 ng/ml and 10% of the "low-risk patients" with a PSA value < or = 10 ng/ml and a preoperative grading <3 had lymph node metastases. Seven percent with a PSA value < or = 10 ng/ml and a prostatectomy Gleason score under 7 were found to be node positive.CONCLUSIONS: A significant number of patients would have been understaged and left with diseased nodes when applying preoperative PSA value < or = 10 ng/ml and grading <3/Gleason <7 as criteria for omitting lymphadenectomy. Therefore we consider meticulous lymphadenectomy a must for correct staging in all patients undergoing radical prostatectomy for prostate cancer, with the exception of patients with a grading of 1 and a PSA < or = 10 ng/ml.     

Evaluation of Fluorodeoxyglucose Positron Emission Tomography in the Detection of Axillary Lymph Node Metastases in Patients With Early-Stage Breast Cancer

Background: The aim of this study was to assess the capacity of positron emission tomography (PET) with fluorodeoxyglucose (FDG) to determine axillary lymph node status in patients with breast cancer undergoing sentinel node (SN) biopsy.Methods: Thirty-two patients with breast cancer and clinically negative axillary nodes were recruited. All patients underwent FDG-PET before SN biopsy. After SN biopsy, all patients underwent complete axillary lymph node (ALN) dissection.Results: The SNs were identified in all patients. Fourteen patients (43.8%) had metastatic SNs (macrometastatic in seven, micrometastatic in six, and isolated tumor cells in one). The false-negative rate of SN biopsy was 6.6% (1 in 15). FDG-PET identified lymph node metastases in 3 of the 14 patients with positive SNs. The overall sensitivity, specificity, and positive and negative predictive values of FDG-PET in the diagnosis of axillary metastasis were 20%, 100%, 100%, and 58.6%, respectively. No false-positive findings were obtained with FDG-PET.Conclusions: This study demonstrates the limitations of FDG-PET in the detection of ALN metastases in patients with early breast cancer. In contrast, FDG-PET seems to be a specific method for staging the axilla in breast cancer. SN biopsy can be avoided in patients with positive FDG-PET, in whom complete ALN dissection should be the primary procedure.     

Evaluation of preoperative ProstaScint scans in the prediction of nodal disease

Diagnostic methods are limited for detecting microscopic soft tissue metastases in patients with prostate cancer. Previous studies using (111)Indium Capromab Pendetide (ProstaScint scan) analyzed patients with extensive localized tumor (prostate specific antigen (PSA) >20 ng/ml) not optimal for surgical therapy. We evaluated the role of the ProstaScint trade mark scan in a preoperative population to provide histological documentation and to assess its utility in a surgical population. A total of 22 preoperative patients, underwent a ProstaScint scan. The mean preoperative PSA was 16.0 ng/ml (range 3.9-33 ng/ml). The mean Gleason score at biopsy was 6.9 (range 6-9). Each patient underwent a radical retropubic prostatectomy and bilateral pelvic lymph node dissection, which included resection of both obturator and common iliac lymph nodes. Histologic analysis of the resected lymph nodes provided the standard of comparison with the ProstaScint scan. The results of the scan and pathology for all 22 patients were compared with the bilateral obturator and iliac nodes, creating 88 data points. Nine areas (10%) were positive on the scan. One of these (11%) was a true positive while the other eight (89%) were false positives. Seventy-nine areas (90%) were negative on scan results. Of these, five areas (6%) were false negatives and 74 areas (94%) were true negatives. The scan yielded a sensitivity of 17%, specificity of 90%, negative predictive value (NPV) of 94% and a positive predictive value (PPV) of 11%. The high false positive rate and low PPV of ProstaScint scans overestimates metastatic lymph nodes disease, and is not useful when used preoperatively.     

Routine frozen section of pelvic lymph node specimens prior to radical retropubic prostatectomy is unnecessary in patients with prostate specific antigen

Our prospective study was designed to evaluate the routine use of frozen section of pelvic lymph node specimens prior to radical prostatectomy in patients with pre-biopsy prostate specific antigen (PSA) levels less than 20 ng/ml. Included in our study were 241 patients who had clinically localized disease on digital rectal examination, a negative preoperative metastatic work-up, and a pre-biopsy serum PSA of less than 20 ng/ml. If a palpable abnormality of pelvic lymph nodes was detected at the time of surgery, specimens were sent for frozen section analysis. Lymphatic specimens that were palpably normal were sent for permanent section only. Ten (4.1%) of the 241 patients had pelvic lymph node metastases demonstrated by permanent section. Of the patients with lymph node metastasis, 50% had Gleason scores of 8-10 on their needle biopsy specimens. None of these patients had frozen section analysis of their lymph nodes. Frozen section failed to detect lymph node metastasis in all cases analyzed. Routine frozen section analysis of pelvic lymphadenectomy specimens in patients with clinically localized prostate cancer, Gleason score 2-7 on the needle biopsy, and prebiopsy PSA of less than 20 ng/ml is unnecessary.     

Clinical use of fluorodeoxyglucose F 18 positron emission tomography for detection of renal cell carcinoma

PURPOSE: We evaluate the role of fluorodeoxyglucose F 18 positron emission tomography (PET) in patients with renal cell carcinoma (RCC) by retrospective review. To our knowledge this series is the largest reviewing the use of PET in patients with RCC. MATERIALS AND METHODS: A total of 66 patients who underwent 90 PET scans for suspected or known RCC were identified. Dictated reports of PET, chest computerized tomography (CT), abdominal/pelvic CT and bone scan were examined with confirmation of results by histopathology or followup of at least 1 year. The accuracies of PET and conventional imaging modalities were compared. RESULTS: PET exhibited a sensitivity of 60% and specificity of 100% for primary RCC tumors (abdominal CT demonstrated 91.7% sensitivity and 100% specificity). For retroperitoneal lymph node metastases and/or renal bed recurrence, PET was 75.0% sensitive and 100.0% specific (92.6% sensitivity and 98.1% specificity for abdominal CT). PET had a sensitivity of 75.0% and a specificity of 97.1% for metastases to the lung parenchyma compared to 91.1% and 73.1%, respectively, for chest CT. PET had a sensitivity of 77.3% and specificity of 100.0% for bone metastases, compared to 93.8% and 87.2% for combined CT and bone scan. In 39 scans (32 patients) PET failed to detect RCC lesions identified by conventional imaging. CONCLUSIONS: The role of fluorodeoxyglucose F 18 PET in the detection of RCC is limited by low sensitivity. With superior specificity PET may have a complementary role as a problem solving tool in cases that are equivocal on conventional imaging.     

Lymph node staging in non-small cell lung cancer: evaluation by [18F]FDG positron emission tomography (PET)

BACKGROUND: A study was undertaken to investigate the accuracy of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D- glucose (FDG) in the thoracic lymph node staging of non-small cell lung cancer (NSCLC). METHODS: Forty six patients with focal pulmonary tumours who underwent preoperative computed tomographic (CT) and FDG- PET scanning were evaluated retrospectively. Thirty two patients had NSCLC and 14 patients had a benign process. The final diagnosis was established by means of histopathological examination at thoracotomy, and the nodal classification in patients with lung cancer was performed by thorough dissection of the mediastinal nodes at surgery. RESULTS: FDG-PET was 80% sensitive, 100% specific, and 87.5% accurate in staging thoracic lymph nodes in patients with NSCLC, whereas CT scanning was 50% sensitive, 75% specific, and 59.4% accurate. The absence of lymph node tumour involvement was identified by FDG-PET in all 12 patients with NO disease compared with nine by CT scanning. Lymph node metastases were correctly detected by FDG-PET in three of five patients with N1 disease compared with two by CT scanning, in nine of 11 with N2 disease compared with six by CT scanning, an in all four with N3 nodes compared with two by CT scanning. CONCLUSIONS: FDG-PET provides a new and effective method for staging thoracic lymph nodes in patients with lung cancer and is superior to CT scanning in the assessment of hilar and mediastinal nodal metastases. With regard to resectability, FDG-PET could differentiate reliably between patients with N1/N2 disease and those with unresectable N3 disease.