Diagnostic efficacy of [11C]choline positron emission tomography/computed tomography compared with conventional computed tomography in lymph node staging of patients with bladder cancer prior to radical cystectomy

Background

Current imaging techniques are of limited value for lymph node (LN) staging in bladder cancer (BCa) patients scheduled for radical cystectomy (RC).

Objective

Evaluate the diagnostic efficacy of [11C]choline positron emission tomography in combination with computed tomography (PET/CT) for LN staging of patients with BCa scheduled for RC and compare that efficacy with the diagnostic efficacy of CT and the gold standard of histopathologic evaluation.

Design, setting, and participants

From June 2004 to May 2007, 44 patients with localized BCa were staged with [11C]choline PET with low-dose CT for attenuation correction and simultaneous intravenous and rectal contrast-enhanced diagnostic CT before RC and pelvic lymph node dissection (PLND). LNs were dissected from the internal and external iliac arteries up to the origin of the inferior mesentery artery according to a template with 14 predefined anatomic fields.

Intervention

Diagnostic [11C]choline PET/CT before RC and regional LN dissection.

Measurements

Histopathologic findings of resected LN were correlated with the results of [11C]choline PET/CT and CT alone in a patient- and field-based manner. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of [11C]choline PET/CT and CT were assessed.

Results and limitations

LN metastases were found in 12 of 44 patients (27%). On patient-based analysis, sensitivity, specificity, PPV, NPV, and accuracy for [11C]choline PET/CT were calculated as 58%, 66%, 39%, 81%, and 64%, respectively; and for CT the calculated percentages were 75%, 56%, 39%, 86%, and 61%, respectively. Twenty-five of 471 dissected LN fields (5%) showed metastases. On field-based analysis, sensitivity, specificity, PPV, NPV, and accuracy for [11C]choline PET/CT were 28%, 95%, 21%, 96%, and 91%, respectively; for CT, the calculated percentages were 39%, 92%, 20%, 96%, and 90%, respectively. Limitations of this study are small patient number and the fact that not all patients underwent extensive PLND.

Conclusions

In patients with BCa who were scheduled for RC, preoperative LN staging with [11C]choline PET/CT was not able to improve diagnostic efficacy compared with conventional CT alone.     

The diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography and computed tomography in staging bladder cancer: a single-institution study and a systematic review with meta-analysis

Purpose

The purpose of this study was to assess the diagnostic accuracy of 18F-fluorodeoxyglucose with positron emission tomography and computed tomography (FDG–PET–CT) to predict nodal metastases in patients with bladder cancer (BC) scheduled to undergo radical cystectomy (RC).

Methods

We retrospectively reviewed records of patients diagnosed with BC and scheduled to undergo RC at our center from January 2011 through February 2015, who also underwent FDG–PET–CT at the time of diagnosis. All patients underwent RC and an extended pelvic lymph node dissection as the reference standard. The primary endpoints were the sensitivity, specificity and overall accuracy of FDG–PET–CT in detecting lymph node metastasis. We also examined its accuracy in identifying distant metastasis. In addition, we conducted a protocol-driven systematic review and meta-analysis of accuracy of FDG–PET–CT for preoperative staging of BC, as compared to CT alone, as reported in individual studies. To assess the methodological quality of eligible studies, we used the QUADAS-2 tool (a revised tool for the Quality Assessment of Diagnostic Accuracy Studies) and pooled diagnostic accuracy measures using Meta-DiSc statistical software.

Results

For detecting nodal metastases in 78 patients, the sensitivity of FDG–PET–CT was 0.56 (95 % CI 0.29–0.80) and the specificity, 0.98 (95 % CI 0.91–1.00). Pooled sensitivity and specificity for detecting lymph node metastasis were 0.57 and 0.95, respectively. Positive likelihood ratio was 9.02. All lesions that were suspicious for distant metastasis were found to be positive on biopsy.

Conclusion

FDG–PET–CT was more accurate than CT alone in staging BC in patients undergoing surgery. Standardization of FDG–PET–CT protocol and cost-effectiveness analysis are required before widespread implementation of this technology.

     

Primary lymph-node staging with 68Ga-PSMA PET in high-risk prostate cancer: pathologic correlation with extended pelvic lymphadenectomy specimens

Aim of the studyThis study aims to assess the diagnostic efficacy of Gallium-68-prostate-specific membrane antigen positron emission tomography (PET)/computed tomography (CT) (68Ga PSMA PET-CT) in primary nodal staging of high-risk prostate cancer (PCa) when compared to pathologic findings of extended pelvic lymph-node dissection (eLND).Materials and methodsThe records of high-risk PCa patients who were preoperatively staged through 68Ga PSMA PET-CT and who underwent robot-assisted radical prostatectomy with eLND either alone or as part of multimodal definitive therapy between August 2016 and November 2019 were retrospectively reviewed. Surgeons were not blinded to the results of the 68Ga PSMA PET-CT scan. Pathologic uptake was defined as any anomalous uptake which was not better explained by another cause and was suggestive of PCa. The reference standard for this study was the pathologic confirmation using a node-based analysis. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for 68Ga PSMA PET-CT were calculated in a per-patient analysis using IBM SPSS Statistics version 25.ResultsSeventeen patients met the selection criteria. Mean age was 63 years (range 44–77) and mean and median preoperative serum prostate specific antigen was 19.25 and 9 ng/ml (range 6–131), respectively. The most common pathologic Gleason score was 8 (52.9% of cases). Seven patients (41%) had positive surgical margins and were submitted to adjuvant radiotherapy. Mean number of per patient removed lymph-nodes was 13 (±2.19). 68Ga PSMA PET-CT showed findings compatible with lymph node metastases in 4/17 patients and with locally-confined disease in 13/17 patients. Following pathologic confirmation, the per-patient sensibility of the 68Ga PSMA PET-CT was calculated at 75% (1 false negative) and the specificity at 92.3% (1 false positive) for detection of lymph node metastasis on primary staging of high-risk PCa patients. Positive and negative predictive value were 75% and 92.3%, respectively; accuracy of the test was calculated at 88.2%. All patients were submitted to 68Ga PSMA PET-CT re-evaluation 6 months after surgery and tested negative for local, nodal, or distant recurrence of disease.Conclusions68Ga PSMA PET-CT appears to have a high negative predictive value for local lymph node metastases in high-risk primary PCa when compared to pathologic findings of eLND. Its role in the primary nodal staging of high-risk PCa patients worths further evaluation.     

Final analysis of a prospective trial on functional imaging for nodal staging in patients with prostate cancer at high risk for lymph node involvement

PurposeAccurate staging modalities to diagnose lymph node involvement in patients with prostate cancer (PCa) are lacking. We wanted to prospectively assess sensitivity, specificity, and positive predictive value (PPV) and negative predictive value of ¹¹C-choline positron emission tomography (PET)-computed tomography (CT) and diffusion-weighted (DW) magnetic resonance imaging (MRI) for nodal staging in patients with PCa at high risk for lymph node involvement.Material and methodsIn total, 75 patients with a risk≥10% but<35% for lymph node (LN) metastases (Partin tables) who had N0 lesions based on the findings of contrast-enhanced CT scans were included. Patients underwent ¹¹C-choline PET-CT and DW MRI before surgery, which consisted of a superextended lymph node dissection followed by radical prostatectomy. LNs were serially sectioned and histopathologically examined after pankeratin staining. These results were used as the gold standard to compare with the imaging results.ResultsOf 1,665 resected LNs (median = 21, range: 7–49), 106 affected LNs (median = 2, range: 1–10) were found in 37 of 75 patients (49%). On a region-based analysis, we found a low sensitivity of 8.2% and 9.5% and a PPV of 50.0% and 40.0% for ¹¹C-choline PET-CT and DW MRI, respectively. The patient-based analysis showed a sensitivity of 18.9% and 36.1% for and a PPV of 63.6% and 86.7% ¹¹C-choline PET-CT and DW MRI, respectively. Even when both imaging modalities were combined, sensitivity values remained too low to be clinically useful.ConclusionsBecause of the low sensitivity, there is no indication for routine clinical use of either ¹¹C-choline PET-CT or DW MRI for LN staging in patients with PCa, in whom CT scan findings were normal.     

Do patients who undergo multiparametric MRI for prostate cancer benefit from additional staging imaging? Results from a statewide collaborative

ObjectivesProstate cancer (CaP) staging traditionally includes computed tomography (CT) and technetium-99m bone scintigraphy (BS) for assessment of lymph node (LN) and bone metastases, respectively. In recent years, multiparametric magnetic resonance imaging (mpMRI) has been used in diagnostic assessment of CaP. We sought to compare the accuracy of mpMRI to CT and BS for pretreatment staging.Materials and methodsUsing the Michigan Urological Surgery Improvement Collaborative registry, we identified men undergoing pretreatment mpMRI in addition to CT and/or BS in 2012 to 2018. Imaging reports were classified as positive, negative, or equivocal for detection of LN and bone metastases. A best value comparator (BVC) was used to adjudicate metastatic status in the absence of pathologic data. mpMRI accuracy was calculated using pessimistic (equivocal=positive) and optimistic (equivocal = negative) interpretations. We compared the diagnostic performance of mpMRI, CT, and BS in detecting metastases.ResultsIn total, 364 men underwent CT and mpMRI, and 646 underwent BS and mpMRI. Based on the BVC, 52 men (14%) harbored LN metastases and 38 (5.9%) harbored bone metastases. Sensitivity of mpMRI for LN metastases was significantly higher than CT (65–73% vs 38%, P < 0.005), and specificity of mpMRI and CT were 97% to 99% and 99% (P = 0.2–0.4), respectively. For bone metastases, BS sensitivity was 68% as compared to 42% to 71% (P = 0.02–0.83) for mpMRI. Specificity for bone metastases was 95% to 99% across all modalities.ConclusionsUsing statewide data, mpMRI appears superior to CT and comparable to BS for detection of LN and bone metastases, respectively. Pretreatment mpMRI may obviate the need for additional staging imaging.     

Diagnostic accuracy of preoperative lymph node staging of bladder cancer according to different lymph node locations: A multicenter cohort from the European Association of Urology – Young Academic Urologists

BackgroundThe preoperative lymph node (LN) staging of bladder cancer (BCa) addresses the subsequent therapeutic strategy and influences patient's prognosis. However, sparce evidence exists regarding the accuracy of conventional cross-sectional imaging, such as computed tomography or magnetic resonance imaging, in correctly detect LN status. We aimed to assess the diagnostic accuracy of conventional cross-sectional imaging in detecting preoperative LN involvement among BCa patients treated with radical cystectomy and pelvic lymph node dissection.MethodsWe retrospectively analyzed data of 1,104 patients who underwent preoperative LN staging with computed tomography or magnetic resonance imaging and subsequent radical cystectomy with pelvic lymph node dissection for BCa between 1997 and 2017 at three tertiary referral centers. Patients receiving neoadjuvant chemotherapy were excluded. We assessed the concordance between clinical (cN) and pathological LN (pN) status, defined as the accuracy of imaging in detecting LN involvement using pathological specimen as reference; concordance was expressed according to Cohen's kappa coefficient. Location-based sub-analyses were performed, distinguishing among external iliac, intern iliac, obturator, common iliac, presacral and paraaortic LNs.ResultsAmong 870 cN0 patients, 68.9% were confirmed pN0 at pathological report; while among 234 cN+ patients, 50.5% were found with LN metastases at pathological specimen. Overall, conventional imaging showed slight concordance (64.9%) between cN and pN stages (sensitivity: 30%; specificity: 84%). At sub-analysis, no agreement between cN and pN status was found in each LN location, with the only exception of common iliac LNs with slight concordance (37.5%). Common iliac LNs achieved the highest sensitivity and positive likelihood ratio (15% and 2.4, respectively) compared to other LN locations.ConclusionsOverall, preoperative cross-sectional imaging exhibited a slight concordance between cN and pN status. Our location-based sub-analyses showed unsatisfactory results in each LN location- Thus, nomograms combining morphological patterns with serological and clinicopathological features are urgently required.     

Prospective evaluation of 11C-choline positron emission tomography/computed tomography and diffusion-weighted magnetic resonance imaging for the nodal staging of prostate cancer with a high risk of lymph node metastases

Background

Contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging for lymph node (LN) staging of prostate cancer (PCa) are largely inadequate.

Objective

Our aim was to assess prospectively the sensitivity, specificity, and positive and negative predictive values for the LN staging by ¹¹C-choline positron emission tomography (PET)-CT and MR diffusion-weighted imaging (DWI) of the pelvis before retropubic radical prostatectomy (RRP) with extended pelvic LN dissection (PLND).

Design, setting, and participants

From February 2008 to August 2009, 36 patients with histologically proven PCa and no pelvic LN involvement on contrast-enhanced CT with a risk ≥10% but ≤35% at LN metastasis according to the Partin tables were enrolled in this study.

Intervention

Patients preoperatively underwent ¹¹C-choline PET-CT and DWI. Subsequently all patients underwent a wide RRP and an extended PLND.

Measurements

Sensitivity, specificity, and positive and negative predictive values (PPV and NPV) for LN status of ¹¹C-choline PET-CT and DWI were calculated with the final histopathology of the LNs as comparator.

Results and limitations

Seventeen patients (47%) had a pN1 stage, and 38 positive LNs were identified. On a LN region-based analysis, sensitivity, specificity, PPV, NPV, and the number of correctly recognised cases at ¹¹C-choline PET-CT were 9.4%, 99.7%, 75.0%, 91.0%, and 7.9%, respectively, and at DWI these numbers were 18.8%, 97.6%, 46.2%, 91.7%, and 15.8%, respectively. Twelve LN regions containing macrometastases, of which 2 had capsular penetration, were not detected by ¹¹C-choline PET-CT; 11 LNs, of which 2 had capsular penetration, were not detected by DWI. This is a small study with 36 patients, but we intend to recruit more patients.

Conclusions

From this prospective histopathology-based evaluation of ¹¹C-choline PET-CT and DWI for LN staging in high-risk PCa patients, it is concluded that these techniques cannot be recommended at present to detect occult LN metastases before initial treatment.     

PET-CT and diagnostic CT: The synergy of metabolic and morphological data in onco-haematology

PurposeOur goal was to determine how interpreting diagnostic CT together with PET-CT could improve the assessment of morphology in onco-haematology.Patients and methodsFifty-nine patients with aggressive lymphoma were retrospectively included. The diagnostic CT scan was interpreted by two radiologists, followed by a combined analysis of the CT and the PET-CT carried out by two specialists in metabolic and morphological imaging. The diagnostic performances were assessed in terms of sensitivity and specificity, then concordance and discordance rates (kappa) were studied.ResultsA combined interpretation of CT and PET-CT showed better diagnostic performances than those of interpretations of CT only in the assessment of nodal sites (826 sites, sensitivity of 99% versus 85%, P < 0.05), extranodal sites (649 sites, sensitivity of 88% versus 78%) and bone sites (one analysed per patient, sensitivity of 50% versus 27%). The combined interpretation also improved inter-observer agreement and led to an upgraded Ann Arbor staging in 15% of patients, with a change of treatment in 10%.ConclusionInterpretation of diagnostic CT in onco-haematology can be improved by combining it with an assessment of PET-CT. The synergy between metabolic and morphological information leads to improved diagnostic capabilities and renders interpretations more reproducible.     

Utility of [11C]choline PET/CT in guiding lesion-targeted salvage therapies in patients with prostate cancer recurrence localized to a single lymph node at imaging: Results from a pathologically validated series

ObjectivePositron emission tomography (PET)/computed tomography (CT) has been shown to be a valid tool in detecting lymph node (LN) metastases in men with biochemical recurrence after radical prostatectomy. We assessed its validity in detecting a single positive LN at pathologic examination in regard to an increasing interest in lesion-targeted salvage therapies.Methods and materialsWe included 46 patients with biochemical recurrence after radical prostatectomy and a single positive spot at [¹¹C]choline PET/CT who underwent pelvic or pelvic and retroperitoneal LN dissection. The ability of [¹¹C]choline PET/CT in identifying the exact positive LN was assessed with the positive predictive value (PPV) in the overall population and according to androgen deprivation therapy, prostate-specific antigen value, and site of PET/CT positivity.ResultsOverall, 30 patients (65%) had positive LNs at pathologic examination. Of these, only 16 (35%) had pathologically confirmed metastases in the same lymphatic region and 11 (24%) had involvement of 1 single LN. Conversely, 28 patients had positive LNs in other areas and 8 had no evidence of metastases. The overall PPV of PET/CT was 34.8% and 23.9% when exact concordance was defined according to the lymphatic landing site and single positive LN, respectively. The PPV ranged from 33.3% to 44.4% and from 17.9% to 28.6%, in men with and without androgen deprivation therapy, respectively.ConclusionsThe PPV [¹¹C]choline of PET/CT in correctly identifying patients with a single positive LN at salvage LN dissection is poor (24%). Therefore, extensive salvage treatment approaches are needed to maximize the chance of cure.     

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.     

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.     

The role of FDG-PET-CT is limited in initial staging of nodal metastasis for thin cutaneous melanoma

IntroductionPositron emission tomography computed tomography (PET-CT) is often used to stage nodal metastases in thin cutaneous melanoma, with limited evidence.MethodsA retrospective review of patients with cutaneous malignant melanoma treated at our institution was performed from 2005 to 2015, identifying those who received a PET-CT prior to lymphadenectomy. Biopsy features, lymph node status, and PET-CT results were collected. We calculated the overall sensitivity, specificity, accuracy, likelihood ratios, and positive predictive value of PET-CT in identifying nodal metastases. Results were stratified by initial biopsy tumor depth.ResultsWe identified 367 cases; 95 obtained a PET-CT prior to lymphadenectomy. Overall, sensitivity and specificity of PET-CT was 34.6% and 95.4%, respectively. The positive likelihood ratio and negative likelihood ratio were 7.62 and 0.68, respectively. The accuracy was 78.2%. The positive predictive value for T3 and T4 melanomas were 100% and 81.4%, respectively. For thin melanomas, specificity and accuracy was 88.2% and 88.2%, respectively.ConclusionsPET-CT has low specificity and its use alone is not recommended for initial staging of nodal metastases in thin cutaneous malignant melanoma.     

Scanning with 18F-FDG-PET/CT for Detection of Pelvic Nodal Involvement in Inguinal Node-Positive Penile Carcinoma

Background

Penile carcinoma patients with inguinal lymph node involvement (LNI) have an increased risk for pelvic nodal involvement with or without distant metastases.

Objective

To evaluate the diagnostic accuracy of fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) with computed tomography (CT; 18F-FDG PET/CT) scanning in determining further metastatic spread in patients with tumour-positive inguinal nodes.

Design, setting, and participants

Eighteen patients with penile squamous cell carcinoma with unilateral or bilateral cytologically tumour-positive inguinal disease underwent whole-body 18F-FDG-PET/CT scanning for tumour staging.

Measurements

Images were blindly assessed by two nuclear medicine physicians. All scans were evaluated for pelvic nodal involvement per basin and for distant metastases. Histopathology (when available), radiologic imaging, and clinical follow-up (with a minimum of 1 yr) served as a reference standard. The diagnostic value of PET/CT scanning for predicting pelvic nodal involvement was evaluated using standard statistical methods.

Results and limitations

The reference was available in 28 of the 36 pelvic basins. Of the 11 tumour-positive pelvic basins, 10 were correctly predicted by PET/CT scan, as were all 17 tumour-negative pelvic basins. PET/CT scan showed a sensitivity of 91%, a specificity of 100%, a diagnostic accuracy of 96%, a positive predictive value of 100%, and a negative predictive value of 94% in detecting pelvic nodal involvement. Additionally, PET/CT scans showed distant metastases in five patients. In four patients, the presence of distant metastases could be confirmed, while in one patient, no radiologic confirmation was found for that particular lesion. A potential limitation is that the diagnostic accuracy of PET/CT scanning was calculated on 28 pelvic basins only. Furthermore, no comparison was made with conventional CT scans, as not all patients had undergone contrast-enhanced CT scans.

Conclusions

PET/CT scanning appears promising for detecting pelvic lymph node metastases with great accuracy, and it identifies distant metastases in penile carcinoma patients with inguinal LNI. In our practice, PET/CT scanning has become part of routine staging in such patients.     

Comparison of Linear Array Endoscopic Ultrasound and Helical Computed Tomography for the Staging of Periampullary Malignancies

Background: The purpose of this study was to compare linear array endoscopic ultrasound (EUS) and helical computed tomography (CT) scan in the preoperative local staging evaluation of patients with periampullary tumors.Methods: Patients evaluated with EUS and CT for suspected periampullary malignancies from 1996 to 2000 were analyzed. Surgical/pathology staging results were the reference standard.Results: Forty-eight patients (28 men and 20 women; mean age, 62 ± 4.9 years; range, 18–90 years) were identified. Malignancy was histologically confirmed in 44 patients. Parameters evaluated included tumor size, lymph node metastases, and major vascular invasion. EUS was significantly more sensitive (100%), specific (75%), and accurate (98%) than helical CT (68%, 50%, and 67%, respectively) for evaluation of the periampullary mass (P < .05). In addition, EUS detected regional lymph node metastases in more patients than helical CT. Sensitivity, specificity, and accuracy of EUS were 61%, 100%, and 84%, in comparison to 33%, 92%, and 68%, respectively, with CT. Major vascular involvement was noted in 9 of 44 patients. EUS correctly identified vascular involvement in 100% compared with 45% with CT (P < .05).Conclusions: Linear array EUS was consistently superior to helical CT in the preoperative local staging of periampullary malignancies.Presented in part at the Society of Surgical Oncology Parallel Session, Washington, DC, March 2001.     

Role of C11-FDG dual-tracer PET-CT scan in metastatic screening of hepatocellular carcinoma—a cost-effectiveness analysis

BackgroundWe aimed to identify predictive factors for positron emission tomography (PET)-detected hepatocellular carcinoma (HCC) metastasis and a cost-effective approach to preoperative PET-computed tomography (CT) for detecting metastasis.MethodsClinicopathological and survival data of HCC patients having PET-CT with 18F-fludeoxyglucose (FDG) and 11C-acetate (ACT) following contrast-enhanced CT/magnetic resonance imaging (MRI) for preoperative tumor staging were reviewed. Binary logistic regression was performed to identify predictive factors for PET-detected metastasis. A cost-benefit analysis model was built for the incurred costs and the impact of PET-CT findings on treatment strategy was studied.ResultsTotally 152 patients were analyzed. Dual-tracer PET-CT detected metastasis in 17 patients (11%). By multivariate analysis, alpha-fetoprotein (AFP) ≥400 ng/mL [relative risk (RR): 4.30, 95% confidence interval (CI): 1.41–13.15, P=0.011] and bilobar disease (RR: 3.94, 95% CI: 1.24–12.52, P=0.014) were independent predictive factors for PET-detected metastasis. PET-CT findings altered the treatment strategy for 12 patients (7.9%); three partial hepatectomies, eight episodes of transarterial chemoembolization (TACE) and one episode of ablation were avoided, with an estimated cost-saving of US $91,000, $150,000 and $10,600 respectively. Had the PET-CT been performed only for patients with AFP ≥400 ng/mL or bilobar disease (n=74), metastasis would have been confirmed in 14 patients (18.9%), and the cost-saving per patient was estimated at US $1,070.ConclusionsDual-tracer PET-CT is cost-effective and useful for preoperative HCC staging in patients with AFP ≥400 ng/mL or bilobar disease. Its routine use in preoperative workup for all HCC patients is not recommended. Unilobar disease with AFP <400 ng/mL can achieve good negative predictive value for PET-detected metastasis. Screening patients with either factor can avoid unnecessary procedures and is thus cost-effective for preoperative HCC workup.     

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.     

Good quality white-light transurethral resection of bladder tumours (GQ-WLTURBT) with experienced surgeons performing complete resections and obtaining detrusor muscle reduces early recurrence in new non-muscle-invasive bladder cancer: validation across time and place and recommendation for benchmarking

Study Type – Diagnostic (exploratory cohort) Level of Evidence 2a What's known on the subject? and What does the study add? Staging of patients with prostate cancer is the cornerstone of treatment. However, after curative intended therapy a high portion of patients relapse with local and/or distant recurrence. Therefore, one may question whether surgical lymph node dissection (LND) is sufficiently reliable for staging of these patients. Several imaging methods for primary LN staging of patients with prostate cancer have been tested. Acceptable detection rates have not been achieved by CT or MRI or for that matter with PET/CT using the most common tracer fluoromethylcholine (FCH). Other more recent metabolic tracers like acetate and choline seem to be more sensitive for assessment of LNs in both primary staging and re‐staging. However, previous studies were small. Therefore, we assessed the value of [¹⁸F]FCH PET/CT for primary LN staging in a prospective study of a larger sample and with a ‘blinded’ review. After a study period of 3 years and >200 included patients, we concluded that [¹⁸F]FCH PET/CT did not reach an optimal detection rate compared with LND, and, therefore, it cannot replace this procedure. However, we did detect several bone metastases with [¹⁸F]FCH PET/CT that the normal bone scans had missed, and this might be worth pursuing.

OBJECTIVES

• ? To assess the value of [¹⁸F]fluoromethylcholine (FCH) positron emission tomography/computed tomography (PET/CT) for lymph node (LN) staging of prostate cancer.
• ? To evaluate if FCH PET/CT can replace LN dissection (LND) for LN staging of prostate cancer, as about one‐third of patients with prostate cancer who receive intended curative therapy will have recurrence, one reason being undetected LN involvement.

PATIENTS AND METHODS

• ? From January 2008 to December 2010, 210 intermediate‐ or high‐risk patients had a FCH PET/CT scan before regional LND.
• ? After dissection, the result of histological examination of the LNs (gold standard) was compared with the result of FCH PET/CT obtained by ‘blinded review’.
• ? Sensitivity, specificity, positive (PPV), and negative predictive values (NPV) of FCH PET/CT were measured for detection of LNe metastases.

RESULTS

• ? Of the 210 patients, 76 (36.2%) were in the intermediate‐risk group and 134 (63.8%) were in the high‐risk group. A medium (range) of 5 (1–28) LNs were removed per patient.
• ? Histological examination of removed LNs showed metastases in 41 patients. Sensitivity, specificity, PPV, and NPV of FCH PET/CT for patient‐based LN staging were 73.2%, 87.6%, 58.8% and 93.1%, respectively.
• ? Corresponding values for LN‐based analyses were 56.2%, 94.0%, 40.2%, and 96.8%, respectively.
• ? The mean diameter of the true positive LN metastases was significantly larger than that of the false negative LNs (10.3 vs 4.6 mm; P < 0.001).
• ? In addition, FCH PET/CT detected a high focal bone uptake, consistent with bone metastases, in 18 patients, 12 of which had histologically benign LNs.

CONCLUSIONS

• ? Due to a relatively low sensitivity and a correspondingly rather low PPV, FCH PET/CT is not ideal for primary LN staging in patients with prostate cancer.
• ? However, FCH PET/CT does convey important additional information otherwise not recognised, especially for bone metastases.

     

Is pelvic MRI imaging sufficient cross-sectional imaging for staging intermediate and high-risk prostate cancer?

ObjectivesThe American Urological Association's (AUA) and National Comprehensive Cancer Network's (NCCN) provide highly recognized guidelines for staging prostate cancer (CaP). However, both are vague as to specific type of cross-sectional imaging (CT vs. MRI) and extent (abdominal vs. pelvis), thereby raising concern for overlapping imaging. We investigated if current AUA and NCCN CaP staging guidelines can become more specific yet maintain sufficient staging.MethodsWe identified 493 patients diagnosed with CaP between 2011 and 2017 and focused analysis on those with AUA and NCCN Intermediate risk (IR) and High risk (HR) groups. Type of staging imaging was recorded and frequency of overlapping (CT + MRI) and abdominal imaging determined. Significance of radiologist findings, for both overlapping and abdominal imaging, were classified as nonurologic, nonsignificant urologic, and CaP significant.ResultsAmong IR and HR AUA and NCCN risk groups, 82 (35.7%) and 95 (37.3%) patients, respectively, experienced overlapping imaging, of which only 7 patients in AUA and 9 patients in NCCN risk groups had an abnormal CT with normal MRI. However, only 3 of these CTs had CaP significant findings, of which 2 identified bone metastases, which were subsequently detected on bone scan. In regard to the extent of imaging, a total of 157 (68.2%) AUA and 178 (69.8%) NCCN IR and HR patients received abdominal scans, of which only 46 (20.0%) and 49 (19.2%) were abnormal among AUA and NCCN risk groups, respectively. Among these abnormal abdominal scans, only 10 showed CaP significant findings, of which half were suspected bone metastases, and confirmed on recommended bone scan.ConclusionsDue to nonspecific staging guidelines in IR and HR CaP regarding type and extent of cross-sectional imaging, patients are frequently receiving imaging of overlapping locations. Based on low occurrences of unique CaP significant findings on CT and abdominal imaging, our exploratory analysis suggests that narrowing cross-sectional imaging recommendations to pelvic MRI may reduce imaging overlap while maintaining sufficient staging.     

Computed tomography in evaluation of patients with stage III melanoma

Background: Metastatic disease is detected infrequently by computed tomography (CT) in early stage melanoma. The diagnostic yield of routine CT for stage III melanoma is less established, despite extensive use in clinical practice. Methods: Charts from 347 asymptomatic patients with stage III melanoma were reviewed. Findings suggestive of metastatic melanoma identified by head or body CT, chest radiography, bone scan, or liver function studies were confirmed histologically or by progression of disease. Results: Individual CT scans identified 33/788 (4.2%) instances of metastatic melanoma, with 66/788 (8.4%) false positive studies. No metastases were identified among 104 head CT scans. Chest CT had the highest yield in patients with cervical adenopathy (7/35, 20%), and the lowest yield with groin adenopathy (1/50, 2%). Pelvic CT diagnosed metastases in 7/94 (7.4%) patients with groin adenopathy, but no patients with palpable axillary (n=76) or cervical (n=21) nodes. Metastatic melanoma was diagnosed in 11/136 (8.1%) patients having complete body CT imaging (chest, abdomen, and pelvis), including six patients (4.4%) identified by CT alone. Conclusions: Routine CT in patients with clinical stage III melanoma infrequently identifies metastatic disease. Head CT in the asymptomatic patient, chest CT in patients with groin adenopathy, and pelvic CT in the presence of axillary or cervical adenopathy are not indicated. Selective use of chest CT in patients with cervical adenopathy or pelvic CT in the presence of groin disease may be useful. Presented at the 49th Annual Cancer Symposium of The Society of Surgical Oncology, Atlanta, Georgia, March 21–24, 1996.