68Ga-prostate-specific membrane antigen positron emission tomography/computed tomography for patients with favorable intermediate-risk prostate cancer

IntroductionCurrent guidelines do not support the use of pretreatment imaging in patients with favorable intermediate-risk prostate cancer. ⁶⁸Ga-prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) is more accurate than conventional imaging for preoperative staging. We aimed to evaluate whether pretreatment ⁶⁸Ga-PSMA PET/CT is beneficial for identifying pathological lymph node involvement (LNI) and adverse pathology among patients with favorable intermediate-risk prostate cancer.MethodsWe reviewed 88 patients with favorable intermediate-risk prostate cancer who underwent ⁶⁸Ga-PSMA PET/CT prior to radical prostatectomy and lymph node dissection from 2016–2020. The primary endpoint was the presence of pathological LNI. Association between pretreatment characteristics and outcomes were evaluated.ResultsPreoperative ⁶⁸Ga-PSMA PET/CT showed suspicious uptake in lymph nodes in 4/88 patients (5%), hence, 20 patients would need to be scanned to identify a patient with a positive lymph node on imaging. Two patients had pathological LNI, only one of whom showed ⁶⁸Ga-PSMA PET/CT uptake prior to surgery. The sensitivity, specificity, positive predictive value, and negative predictive values of ⁶⁸Ga-PSMA PET/CT for identifying LNI were 50%, 97%, 25%, and 99%, respectively. After surgery, four patients had evidence of prostate-specific antigen (PSA) persistence. The rate of PSA persistence was higher among patients with LNI on preoperative ⁶⁸Ga-PSMA PET/CT (2/4, 50% vs. 2/84, 2%, p=0.009).ConclusionsPreoperative imaging of favorable intermediate-risk prostate cancer patients using ⁶⁸Ga-PSMA PET/CT showed a low yield for identifying patients at higher risk. Consistent with current guidelines, our findings do not support the routine use of PET/CT in this group of patients. Future prospective studies are needed to validate our findings.     

How accurate is 68Gallium-prostate specific membrane antigen positron emission tomography / computed tomography (68Ga-PSMA PET/CT) on primary lymph node staging before radical prostatectomy in intermediate and high risk prostate cancer? A study of patient- and lymph node- based analyses

Background and aimGallium-68 (68Ga)-Prostate Membrane Specific Antigen Positron Emission Tomography/Computed Tomography (68Ga-PSMA PET/CT) is an emerging diagnostic modality which is gaining importance in individualized prostate cancer (PCa) management era. This study aimed to investigate the diagnostic accuracy of ⁶⁸Ga-PSMA PET/CT on primary LN staging before radical prostatectomy (RP) in intermediate and high risk PCa.Materials and MethodsThe retrospectively documented 49 patients with intermediate and high risk non-metastatic PCa who had ⁶⁸Ga-PSMA PET/CT before RP were enrolled into this study. The histopathology of dissected LNs was used as reference standard to evaluate the accuracy of ⁶⁸Ga-PSMA PET/CT on primary LN staging, both in per-patient (n = 49) and in per-node (n = 454) analyses. The diagnostic accuracy was investigated using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), and by area under the curve (AUC) provided using receiver operating curve (ROC) analysis.ResultsMedian age was 64 (48-79) years and, median and mean PSA values were 10 (1.31–138) ng/ml and 16.2 (±19.8) ng/ml, respectively. 22 (44.9%) and 27 (55.1%) of patients had intermediate and high risk PCa, respectively. A total of 5 (10.2%) patients had histopathologically proven LN metastasis and 3 (60%) of them was detected in ⁶⁸Ga-PSMA PET/CT. In per patient analysis, the sensitivity, specifity, PPV and NPV of ⁶⁸Ga-PSMA PET/CT on primary LN staging were 0.60, 0.96, 0.60 and 0.96, respectively. Among overall 454 LNs, 16 (3.5 %) of them were reported as metastatic in histopathology and, 13 (2.9%) of these metastatic LNs were detected in ⁶⁸Ga-PSMA PET/CT. In per-node analysis, the sensitivity, specificity, PPV and NPV of ⁶⁸Ga-PSMA PET/CT on primary LN staging were 0.82, 0.99, 0.87 and 0.99, respectively. The ROC analyses found AUCs for primary LN staging as 0.777 (95%CI:0.508–1.0) in per patient analysis and, as 0.904 (95%CI:0.790 – 1.0) in per node analysis, respectively.ConclusionThe use of ⁶⁸Ga-PSMA PET/CT has promising diagnostic accuracy on primary LN staging before RP in intermediate and high risk PCa. However, the efforts should be taken to increase sensitivity of ⁶⁸Ga-PSMA PET/CT in individualized treatment era.     

Systematic review & meta-analysis of positron emission tomography/computed tomography and bone scan in the diagnosis of prostate lesions

BackgroundTo date, the results of studies into the effectiveness of positron emission tomography (PET) combined with computed tomography (CT) and bone scan (BS) in the diagnosis of malignant prostate lesions have been inconsistent, and the advantages and disadvantages of the two methods cannot be accurately judged.MethodsArticles were retrieved from the China National Knowledge Infrastructure (CNKI) database, Wan Fang Medical Network, PubMed, Excerpta Medica data BASE (EMBASE), Medline, and Cochrane database. The keywords used in the search were: ⁶⁸Ga-prostate specific membrane antibody (⁶⁸Ga-PSMA), PET/CT, prostate lesions, prostate adenocarcinoma, bone metastasis, and BS.ResultsUltimately, 3 publications were selected for inclusion in the meta-analysis. A total of 215 patients were considered in the 3 articles that met the inclusion criteria. All of the included articles were small sample studies, with sample sizes ranging from 28 to 113 cases. In this study, from the 3 randomized controlled trials, only 2 (66.67%) randomized controls described the correct randomized allocation method, and only 1 (33.33%) described the hidden allocation scheme in detail. The highest sensitivity for ⁶⁸Ga-PSMA PET/CT was 0.96, with 95% CI: 0.87, 1.00, and the highest specificity was 1.00, with 95% CI: 0.96, 1.00. The highest sensitivity and specificity of BS were 0.92 with 95% CI: 0.81, 0.98 and 0.96 with 95% CI: 0.78, 1.00, respectively. The results of meta-analysis of ⁶⁸Ga-PSMA PET/CT diagnosis with confirmation by surgical and histopathological examination showed that the area under the summary receiver operating characteristics (SROC) curve (AUC) =0.826 and standard error (SE) (AUC) =0.0425. The results of meta-analysis of BS diagnosis with confirmation by surgical and histopathological examination showed that the area under the SROC curve (AUC) =0.714 and SE (AUC) =0.0034.DiscussionThe meta-analysis showed that ⁶⁸Ga-PSMA PET/CT has clear advantages over BS in the diagnosis of bone metastases of malignant prostate tumors, and could improve the diagnostic accuracy of bone metastases.     

Prospective Analysis of Accuracy of Positron Emission Tomography,Computed Tomography,and Endoscopic Ultrasonography in Staging of Adenocarcinoma of the Esophagus and the Esophagogastric Junction

Background: Exact preoperative staging of esophageal cancer is essential for accurate prognosis and selection of appropriate treatment modalities.Methods: Forty-two patients with adenocarcinoma of the esophagus or the esophagogastric junction suitable for radical esophageal resection were staged with positron emission tomography (PET), spiral computed tomography (CT), and endoscopic ultrasonography (EUS).Results: Diagnostic sensitivity for the primary tumor was 83% for PET and 67% for CT; for local peritumoral lymph node metastasis, it was 37% for PET and 89% for EUS; and for distant metastasis, it was 47% for PET and 33% for CT. Diagnostic specificity for local lymph node metastasis was 100% with PET and 54% with EUS, and for distant metastasis, it was 89% for PET and 96% for CT. Accuracy for locoregional lymph node metastasis was 63% for PET, 66% for CT, and 75% for EUS, and for distant metastasis, it was 74% with PET and 74% with CT. Of the 10 patients who were considered inoperable during surgery, PET identified 7 and CT 4. The false-negative diagnoses of stage IV disease in PET were peritoneal carcinomatosis in two patients, abdominal para-aortic cancer growth in one, metastatic lymph nodes by the celiac artery in four, and metastases in the pancreas in one. PET showed false-positive lymph nodes at the jugulum in three patients.Conclusions: The diagnostic value of PET in the staging of adenocarcinoma of the esophagus and the esophagogastric junction is limited because of low accuracy in staging of paratumoral and distant lymph nodes. PET does, however, seem to detect organ metastases better than CT.     

<Superscript>99m</Superscript>Tc-HDP bone scintigraphy and <Superscript>18</Superscript>F-sodiumfluoride PET/CT in primary staging of patients with prostate cancer

Introduction/Aim

Correct staging of patients with prostate cancer is important for treatment planning and prognosis. Although bone scintigraphy with ^99mTc-phosphonates (BS) is generally advised for staging by guidelines in high risk prostate cancer, this imaging technique is hampered by a high rate of inconclusive results and moderate accuracy. Potentially better imaging techniques for detection of bone metastases such as ¹⁸F-sodiumfluoride PET/CT (NaF PET/CT) are therefore being evaluated. In this observational cohort study we evaluate the performance and clinical impact of both BS and NaF PET/CT in primary staging of patients with prostate cancer.

Methods

The first of two cohorts consisted of patients who received a BS while the second included patients who received a NaF PET/CT for primary staging of prostate cancer. For both cohorts the number of positive, negative and equivocal findings, calculated diagnostic performance of the imaging modality in terms of sensitivity and specificity, as well as the impact on clinical management were studied. The ranges of the diagnostic performance were calculated both assuming that equivocal findings were positive and assuming that they were negative for bone metastases. For the NaF PET/CT cohort the number of patients with signs of lymph node metastases on low dose CT were also recorded, including the impact of these findings on clinical management.

Results

One-hundred-and-four patients underwent NaF PET/CT, whereas 122 patients underwent BS. Sensitivities of 97–100 and 84–95% and specificities of 98–100 and 72–100% were found on a patient basis for detection of bone metastases with NaF PET/CT and BS, respectively. Equivocal findings warranted further diagnostic procedures in 2% of the patients in the NaF cohort and in 16% in the BS cohort. In addition NaF PET/CT demonstrated lymph node metastases in 50% of the included patients, of which 25% showed evidence of lymph node metastases only.

Conclusion

Our data indicate better diagnostic performance of NaF PET/CT compared to BS for detection of bone metastases in primary staging of prostate cancer patients. Less equivocal findings are encountered with NaF PET/CT. Moreover, NaF PET/CT has additional value over BS since lymph node metastases are encountered frequently.

     

Diagnostic performance of 18F-DCFPyL positron emission tomography/computed tomography for biochemically recurrent prostate cancer and change-of-management analysis

IntroductionConventional imaging (CI) performs poorly to identify sites of disease in biochemically recurrent prostate cancer. ⁶⁸Ga-PSMA-11 positron emission tomography/computed tomography (PET/CT) is most studied but has a very short half-life. This study reports the diagnostic performance of the novel prostate-specific membrane antigen (PSMA) radiotracer ¹⁸F-DCFPyL using real-life data and tumor board simulation to estimate the impact of ¹⁸F-DCFPyL PET on patient management.MethodsNinety-three ¹⁸F-DCFPyL PET/CT scans performed for patients previously treated for prostate cancer with a rising prostate-specific antigen (PSA) were retrospectively compared to contemporary CI and clinical imaging and PSA followups. A chart review was performed to document prior imaging, pathology results, serial serum PSA measurements, and other pertinent clinical data. Clinical utility of ¹⁸F-DCFPyL PET was measured using a simulated tumor board formed by three physicians with extensive prostate cancer experience deciding on management with and without knowledge of PET/CT results.ResultsAt median PSA 2.27 (interquartile rage [IQR] 5.27], 82% of ¹⁸F-DCFPyL PET/CT demonstrated at least one site of disease: non-regional lymph nodes (37% of scans), regional lymph node metastases (28%), local recurrence (27%), and bone metastases (20%), with higher PET positivity at higher PSA. Compared to ¹⁸F-DCFPyL PET/CT, CI showed overall poor performance, with accuracy below 20% for all extent of disease. PET/CT changed management in 44% of cases. The most frequent scenario was a radical change from initiating androgen deprivation therapy (ADT) to stereotactic body radiotherapy (SBRT) of oligo-lesional disease. In univariate and multivariate analysis, no patient characteristic could predict change of management by PET/CT results.Conclusions¹⁸F-DCFPyL significantly outperforms CI in recurring prostate cancer and is likely to impact management.     

18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is accurate for high-grade prostate cancer bone staging when compared to bone scintigraphy

IntroductionIn this study, we compared ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG)-positron emission tomography/computed tomography (PET/CT) and bone scintigraphy accuracies for the detection of bone metastases for primary staging in high-grade prostate cancer (PCa) patients to determine if ¹⁸F-FDG-PET/CT could be used alone as a staging modality.MethodsMen with localized high-grade PCa (n=256, Gleason 8–10, International Society of Urological Pathology [ISUP] grades 4 or 5) were imaged with bone scintigraphy and ¹⁸F-FDG-PET/CT. We compared, on a per-patient basis, the accuracy of the two imaging modalities, taking inter-modality agreement as the standard of truth (SOT).Results¹⁸F-FDG-PET/CT detected at least one bone metastasis in 33 patients compared to only 26 with bone scan. Of the seven false-negative bone scintigraphies, four (57.1%) were solitary metastases (monometastatic), three (42.9%) were oligometastatic (2–4 lesions), and none were plurimetastatic (>4 lesions). Compared to SOT, ¹⁸F-FDG-PET/CT showed higher sensitivity and accuracy than bone scintigraphy (100% vs. 78.8%, and 98.7% vs. 98.2%) for the detection of skeletal lesions.Conclusions¹⁸F-FDG-PET/CT appears similar or better than conventional bone scans to assess for bone metastases in patients newly diagnosed with high-grade PCa. Since intraprostatic FDG uptake is also a biomarker for failure of radical prostatectomy and that FDG-PET/CT has been shown to be accurate in detecting PCa lymph node metastasis, FDG-PET/CT has the potential to be used as the sole preoperative staging modality in high-grade PCa.     

Gallium-68 Prostate-specific Membrane Antigen Positron Emission Tomography in Advanced Prostate Cancer—Updated Diagnostic Utility,Sensitivity, Specificity,and Distribution of Prostate-specific Membrane Antigen-avid Lesions: A Systematic Review and Meta-analysis

ContextAccurate staging of high-risk localised, advanced, and metastatic prostate cancer is becoming increasingly more important in guiding local and systemic treatment. Gallium-68 prostate-specific membrane antigen (PSMA) positron emission tomography (PET) has increasingly been utilised globally to assess the local and metastatic burden of prostate cancer, typically in biochemically recurrent or advanced disease. Following our previous meta-analysis, a high-volume series has been reported highlighting the utility of ⁶⁸Ga-PSMA PET in this setting.ObjectiveTo perform a systematic review and meta-analysis to update reported predictors of positive ⁶⁸Ga-PSMA PET according to prior therapy and proportion of positivity in various anatomical locations with sensitivity and specificity profiles.Evidence acquisitionWe performed critical reviews of MEDLINE, EMBASE, ScienceDirect, Cochrane Libraries, and Web of Science databases in July 2018 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. Quality assessment was performed using Quality Assessment if Diagnostic Accuracy Studies-2 tool. Meta-analyses of proportions were performed using a random-effect model. Summary sensitivity and specificity values were obtained by fitting bivariate hierarchical regression models.Evidence synthesisA total of 37 articles including 4790 patients were analysed. For patients with biochemical recurrence, positive ⁶⁸Ga-PSMA PET scans increased with higher pre-PET prostate-specific antigen (PSA) levels. For PSA categories 0–0.19, 0.2–0.49, 0.5–0.99, 1–1.99, and ≥2 ng/ml, the percentages of positive scans were 33%, 45%, 59%, 75%, and 95%, respectively. No significant differences in positivity were noted between Gleason sums ≤7 and ≥8. Significant differences in positivity after biochemical recurrence in the prostate bed were noted between radical prostatectomy (22%) and radiotherapy (52%) patients. On per-node analysis, high sensitivity (75%) and specificity (99%) were observed.ConclusionsGa-68-PSMA PET improves detection of metastases with biochemical recurrence, particularly at low pre-PET PSA levels of >0.2 ng/ml (33%) and 0.2–0.5 ng/ml (45%). Ga-68-PSMA-PET produces favourable sensitivity and specificity profiles on meta-analysis of pooled data. This analysis highlights different anatomic patterns of metastatic spread according to PSMA PET in the primary and biochemically recurrent settings.Patient summaryGallium-68 prostate-specific membrane antigen positron emission tomography is now an established imaging technique that has been developed in response to inadequacies in standard of care imaging modalities to improve the detection of metastatic disease in prostate cancer, particularly in the setting of disease recurrence. To date, this imaging modality in the setting of primary staging is controversial, given the paucity of data. In light of the growing body of evidence, we summarised the data to date to provide clinicians with an overview of this imaging modality.     

MRI/PET Imaging in elevated PSA and localized prostate cancer: a narrative review

ObjectiveTo review the recent milestones in MRI and PET based imaging and evaluate their evolving role in the setting of elevated PSA as well as localized prostate cancer.BackgroundThe importance of multiparametric MRI (mpMRI) and PET based imaging for the diagnosis and staging of prostate cancer cannot be understated. Accurate staging has become another significant milestone with the use of PET scans, particularly with prostate specific radiotracers like 68-Gallium Prostate Specific Membrane Antigen (68Ga-PSMA). Integrated PET/MRI systems are commercially available and can be modulated to evaluate the unique needs of localized as well as recurrent prostate cancer.MethodsA literature search was performed using PubMed and Google Scholar using the MeSH compliant and other keywords that included prostate cancer, PSA, mpMRI, PET CT, PET/MRI.ConclusionsmpMRI has now established itself as the gold-standard of local prostate imaging and has been incorporated into international guidelines as part of the diagnostic work-up of prostate cancer. PSMA PET/CT has shown superiority over conventional imaging even in staging of localized prostate cancer based on recent randomized control data. Imaging parameters from PET/MRI have been shown to be associated with malignancy, Gleason score and tumour volume. As mpMRI and PSMA PET/CT become more ubiquitous and established; we can anticipate more high-quality data, cost optimization and increasing availability of PET/MRI to be ready for primetime in localized prostate cancer.     

18F-fluorocholine PET/CT compared with extended pelvic lymph node dissection in high-risk prostate cancer

Purpose

To compare ¹⁸F-fluorocholine positron-emission tomography/computed tomography (PET/CT) with extended pelvic lymph node dissection (ePLND) for the detection of lymph node metastases in a large cohort of patients with high-risk prostate cancer.

Materials and methods

Patients with prostate-specific antigen levels between 20 and 99 ng/mL and/or Gleason score 8–10 cancers, planned for treatment with curative intent following a negative or inconclusive standard bone scan, were investigated with ¹⁸F-fluorocholine PET/CT followed by an ePLND. None of the patients received hormonal therapy prior to these staging procedures. Results for PET/CT were compared on a per-patient basis with histopathology from ePLND. Sensitivity, specificity, positive and negative predictive values were calculated.

Results

PET/CT detected a total of 76 suspected lymph node metastases and four suspected bone metastases in 33 (29 %) of the 112 included patients. Of these, 35 suspected lymph node metastases, only within the anatomical template area of an ePLND, were found in 21 of the patients. Histopathology of the ePLND specimens detected 117 lymph node metastases in 48 (43 %) of the 112 patients. Per-patient sensitivity, specificity, positive and negative predictive values for ¹⁸F-fluorocholine PET/CT for lymph node metastases within the ePLND template were 0.33, 0.92, 0.76 and 0.65, respectively. Only 11 patients had lymph nodes larger than 10 mm that would have been reported by CT alone.

Conclusions

¹⁸F-fluorocholine PET/CT detects lymph node metastases in a significant proportion of patients with high-risk prostate cancer with a high specificity, but low sensitivity.     

[18F]‐fluorocholine positron‐emission/computed tomography for lymph node staging of patients with prostate cancer: preliminary results of a prospective study

Study Type – Diagnostic (case series)
Level of Evidence 4

OBJECTIVES

To evaluate prospectively [¹⁸F]‐fluorocholine positron‐emission/computed tomography (FCH PET/CT) for lymph node staging of prostate cancer before intended curative therapy, and to determine whether imaging 15 or 60 min after radiotracer injection is preferable.

PATIENTS AND METHODS

In all, 25 consecutive patients with newly diagnosed prostate cancer (Gleason score >6, and/or a prostate‐specific antigen level of >10 ng/mL, and/or T3 cancer) were scanned before lymphadenectomy. Each patient was assessed twice with imaging, at 15 and 60 min after the injection with FCH. Images were compared with the results of histopathological examination of the surgically removed lymph nodes. Maximum standardized uptake values (SUV_max) at 15 and 60 min were also compared.

RESULTS

Histopathologically, metastases were present in removed lymph nodes from three patients. FCH PET/CT showed a high radiotracer uptake in four patients, the former three and a fourth. The sensitivity, specificity, positive and negative predictive value of FCH PET/CT for patient based lymph node staging of prostate cancer were 100%, 95%, 75% and 100%, respectively; the corresponding 95% confidence intervals were 29.2–100%, 77.2–99.9%, 19.4–99.4% and 83.9–100%, respectively. Values of SUV_max at early and late imaging were not significantly different.

CONCLUSIONS

This small series supports the use of FCH PET/CT as a tool for lymph node staging of patients with prostate cancer. Values of SUV_max at early and late imaging did not differ. However, larger prospective studies are needed to validate these findings.     

18F-FDG PET/CT在胆道系统恶性肿瘤中的应用

目的探讨~(18)F-FDG PET/CT诊断胆道系统恶性肿瘤的价值。方法回顾性分析34例临床疑似胆道恶性肿瘤患者的PET/CT影像资料,均获得术后病理结果,其中12例经手术切除淋巴结或淋巴结穿刺活检对18枚淋巴结获得病理诊断;与病理结果对照,计算PET/CT对胆道恶性病变原发灶、淋巴结转移的灵敏度、特异度、阳性预测值、阴性预测值及准确率。结果 34例中,31例为恶性病变,3例为良性病变。PET/CT诊断胆道恶性肿瘤原发灶的灵敏度100%(31/31),特异度66.67%(2/3),阳性预测值96.88%(31/32),阴性预测值100%(2/2),准确率97.06%(33/34)。胆道恶性病变原发灶最大标准摄取值(SUV_(max))为8.42±4.27;3例胆道良性疾病SUV_(max)分别为12.90、2.00及1.90。共18枚淋巴结获得病理结果,包括转移性淋巴结13枚,良性增生5枚。PET/CT诊断淋巴结转移的灵敏度76.92%(10/13),特异度60.00%(3/5),阳性预测值83.33%(10/12),阴性预测值50.00%(3/6),准确率72.22%(13/18)。结论 PET/CT对胆道系统恶性肿瘤的诊断具有重要价值。     

Rektummukosametastase beim Prostatakarzinomrezidiv

This article presents for the first time a case of rectal mucosa metastasis of recurrent prostate cancer that was diagnosed with ⁶⁸Ga-PSMA PET/CT. After histological confirmation, the patient was treated with salvage radiotherapy. This case report underlines the specificity and efficacy of PSMA-based PET imaging. In case of biochemical relapse, it can be used even at low PSA levels to detect prostate cancer metastases that might also be in atypical locations. Thus, ⁶⁸Ga-PSMA PET/CT may allow new options for salvage therapy.     

Detecting metastatic pelvic lymph nodes by 18F-2-deoxyglucose positron emission tomography in patients with prostate-specific antigen relapse after treatment for localized prostate cancer

AIM: To evaluate whether positron emission tomography (PET) with (18)F-2-deoxyglucose (FDG) can detect pelvic lymph node metastases in prostate cancer patients who had elevated serum prostate-specific antigen (PSA) levels after treatment. METHODS: Twenty-four patients with a rising serum PSA level after treatment for localized prostate cancer were examined with FDG-PET before pelvic lymph node dissection. All patients had negative findings on whole body bone scan and equivocal pelvic computed tomography (CT) results. The results of FDG-PET were then compared to the histology of the pelvic lymph nodes obtained at surgery. RESULTS: Lymph node metastases were detected by histopathological examination in 16/24 (66.7%) patients. At the sites with histopathologically proven metastases, increased FDG uptake was found in 12/16 (75.0%) patients. In addition, there were 4 patients with false-negative results, but no patient with a false-positive result on FDG-PET images. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG-PET in detecting metastatic pelvic lymph nodes were 75.0, 100.0, 83.3, 100.0, and 67.7%, respectively. CONCLUSIONS: These results suggest that FDG-PET may be a valuable diagnostic tool in the staging of pelvic lymph nodes in patients with PSA relapse after treatment of localized prostate cancer when the whole body bone scan is negative and pelvic CT findings are equivocal.     

68Ga-PSMA-11 PET/TC en la recidiva bioquímica oculta del carcinoma de próstata,con 18F-Colina PET/TC negativa. Valoración preliminar de su uso clínico

ObjectiveTo assess the clinical usefulness of ⁶⁸Ga-PSMA PET/CT studies in patients with occult biochemical recurrence of prostate carcinoma, with negative or inconclusive radiologic and 18F-Choline PET/CT imaging studies.Material and methodsRetrospective observational and diagnostic accuracy. The first 14 patients with a history of prostate carcinoma, treated with curative intent and presenting suspicion of biochemical recurrence with low PSA values (< 3 ng/ml) were selected. Imaging studies, prostate ultrasound, pelvic CT and/or MRI were negative, and all of them had a negative or inconclusive 18F-Choline PET/CT.All patients were referred to ⁶⁸Ga-PSMA-11 PET/CT. Protocol: Dose 2.2 MBq/kg. 20 mg furosemide at start. PET/CT images from skull base to proximal third of thighs at 60 min, and late images at 3 hours if needed.ResultsThe ⁶⁸Ga-PSMA-11 PET/CT was able to localize the occult biochemical recurrence in 9 of the 14 patients (64.2%), and it affected the therapeutic attitude in all of them.Four patients (28.5%) obtained a negative or inconclusive ⁶⁸Ga-PSMA-11 PET/CT and continued under vigilant approach with PSA controls and imaging studies according to the clinical guidelines. These patients had the lowest PSA values (less than 1 ng/ml).One of the ⁶⁸Ga-PSMA-11 PET/CT studies was inconclusive, reporting the presence of a doubtful right iliac adenopathy.Conclusión⁶⁸Ga-PSMA-11 PET/CT allows an early diagnosis, with low PSA values, of occult biochemical recurrence of prostate carcinoma, even in patients with negative 18F-Choline PET/CT.     

Detection of inguinal lymph node involvement in penile squamous cell carcinoma by 18F-fluorodeoxyglucose PET/CT: A prospective single-center study

BackgroundThe extent of lymph node involvement is the most relevant prognostic factor in patients with penile cancer.ObjectiveTo prospectively analyze the diagnostic accuracy of 18F-FDG-PET/CT-scan in the assessment of inguinal lymph node involvement in patients with invasive penile carcinoma.Patients and methodsThirty-five patients with invasive penile carcinoma were staged prospectively by 18F-FDG-PET/CT-scan, and blindly evaluated by 2 nuclear medicine physicians. In total, lymph node involvement was assessed in 70 inguinal groins. Reference standard was either histology or clinical follow-up with a minimum of 31 months (mean: 48.4 months; range: 31–68 months).Results18-FDG-PET/CT showed a sensitivity of 88.2% and a specificity of 98.1%. Positive predictive value (PPV) was 93.8%, while negative predictive value (NPV) was 96.3%. In two groins, metastasis of 5 and 7 mm were missed by PET/CT scan.Conclusion18F-FDG-PET/CT is a promising staging tool in assessing the inguinal lymph node involvement of patients with penile carcinoma. Integration of PET/CT scanning into preoperative staging algorithms may avoid surgical staging in selected patients.     

PET—CT在前列腺癌诊断与临床分期的应用

目的探讨PET—CT应用于前列腺癌诊断及分期的临床价值。方法2008年1月至2011年1月新疆自治区人民医院泌尿外科收治前列腺肿瘤病例中,病理类型最终确诊为前列腺癌者有47例接受了全身PET—CT检查。检查范围包括前列腺原发肿瘤、区域淋巴结及全身脏器,将PET—CT结果参照手术／病理结果进行评价分析。结果47例患者中1例未发现原发病灶,此外PET—CT与常规检查各有1例假阴性,准确性均高达95．7％,差异无统计学意义。35例I、Ⅱ期患者中18例髂血管淋巴结转移,PET-CT检查的敏感性59．6％、特异性81％、准确性70．3％,优于B超、磁共振检查;PET—CT发现4例患者合并远处转移并经穿刺证实,准确性100％。结论PET—CT对于发现前列腺癌原发肿瘤、区域淋巴结转移均优于B超、磁共振检查,且对于远处转移具有较精确的检测能力,对于前列腺癌术前诊断及分期有较好的临床价值。     

Significance of metabolic tumor volume and total lesion uptake measured using Ga-68 labelled prostate-specific membrane antigen PET/CT in primary staging of prostate cancer

ObjectiveTo evaluate the accuracy of Ga-68 prostate-specific membrane antigen positron-emission-tomography and computed-tomography(PSMA-PET/CT) in primary nodal staging of prostate cancer (PCa), and the predictive value of volumetric parameters derived from Ga-68- PSMA-PET/CT data in lymph node(LN) metastasis and correlation with histopathological and surgical outcomes.Materials and methodsSeventy-seven patients with newly diagnosed, biopsy-proven PCa who underwent Ga-68-PSMA-PET/CT for primary staging of disease and underwent radical prostatectomy with extendend pelvic LN dissection were evaluated retrospectively. 2 experienced nuclear medicine specialists have retrospectively reviewed PET/CT images blinded to all histopathological and clinical data. Sensitivity, specificity, positive predictive value(PPV), and negative predictive value(NPV) for the detection of LN metastases were analyzed per-patient. Volumetric and semiquantitative PET parameters of the primary prostate lesions including SUVmax,metabolic tumor volume(MTV), and total lesion uptake(TLU) were measured and recorded.ResultsPrimary tumor SUVmax, MTV and TLU were found significantly higher in patients who were in higher ISUP Grade groups 3,4,5 after surgical treatment (P = 0.021,P = 0.049,P = 0.032, respectively). The sensitivity, specificity, PPV and NPV on LN metastasis detection of Ga-68-PSMA-PET/CT was found 60%, 91%, 82% and 78% respectively. Although the distribution of the measured primary tumor MTV and TLU values were higher in histopathologically proven LN metastasis positive patients compared to negative patients, only TLU was statistically significant(P = 0.023). Increase in primary tumor TLU values were correlated with higher pT stages and surgical margin positivity(P = 0.034).ConclusionGa-68-PSMA-PET/CT is of clinically valuable for primary staging. Measuring and adding these 2 parameters in routine clinical evaluation may increase the prediction power of high-grade disease confirmed by surgery.     

Comparison of Integrated Positron Emission Tomography/Computed Tomography and Mediastinoscopy in Mediastinal Staging of Non-Small Cell Lung Cancer: Analysis of 212 Patients

Background : Mediastinal staging is crucial to determine the prognosis and treatment options for patients with non-small cell lung cancer (NSCLC). In this study, we compared the results of integrated positron emission tomography-computerised tomography (PET/CT) with those of mediastinoscopy in mediastinal staging of NSCLC patients. Methods : PET/CT and mediastinoscopy was performed on 250 consecutive patients diagnosed with NSCLC between September 2005 and March 2008. Thirty-eight patients were excluded from the study. Standard cervical mediastinoscopy was performed in all patients, and simultaneous extended cervical mediastinoscopy was performed in 52 patients with left sided lesions. Patients with negative mediastinoscopy underwent resection. The pathological results were correlated with PET/CT findings.

Results : A total of 212 patients (199 male, 13 female; mean age: 58.3 years) were evaluated. In PET/CT analysis 60 true-positive, 45 false-positive, 103 true-negative and 4 false-negative patients were found. The rate of PET/CT positivity of mediastinal lymph nodes was 49.5%. The sensitivity, specificity, positive and negative predictive values and accuracy for PET/CT were 93.8%, 69.6%, 57.1%, 96.3% and 76.9% respectively. The incidence of N2 disease in NSCLC patients with negative mediastinal lymph node uptake on PET/CT was 3.7% (4 of 107). In univariate analysis, right upper lobe tumours were significantly (p < 0.05) more associated with occult N2 disease.

Conclusions : In patients with positive mediastinal lymph node uptake on PET/CT invasive mediastinal staging appears necessary for exact staging. Mediastinoscopy can be omitted in NSCLC patients with negative mediastinal uptake on PET/CT in regions where the rate of PET/CT positivity of mediastinal lymph nodes is high.