[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.     

Evaluation of fluorodeoxyglucose positron‐emission tomography with computed tomography for staging of urothelial carcinoma

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

OBJECTIVE

To investigate the role of ¹⁸F‐fluorodeoxyglusose positron‐emission tomography (FDG‐PET), combined with computed tomography (CT) and forced diuresis, in the staging and follow‐up of urothelial carcinoma (UC).

PATIENTS AND METHODS

We recruited 44 patients with muscle‐invasive urothelial bladder cancer (UBC) before radical cystectomy (RC), 19 under follow‐up after RC and seven after systemic chemotherapy. For those who had RC, histopathology was used as the reference standard to compare the sensitivity and specificity of FDG‐PET/CT and standard CT in detecting UBC and pelvic lymph node metastasis. Furthermore, 36 patients with ≥6 months of follow‐up imaging were considered to describe the progression of UC and extrapelvic positive FDG‐PET/CT images.

RESULTS

For the detection of primary UBC, FDG‐PET/CT was slightly more sensitive than CT (85% vs 77%) but less specific (25% vs 50%). For the detection of pelvic node metastasis FDG‐PET/CT was more sensitive than CT (57% vs 33%) with a specificity of 100% for both imaging techniques. In 20 patients, extrapelvic FDG‐PET/CT images showed suspected disease at the first evaluation. UC progressed in nine of the 10 patients who had synchronous multiple PET‐positive retroperitoneal or mediastinal lymph nodes, and in only two of the nine with unique hyperactive lesions in the lung. FDG‐PET/CT also detected a pT1G3 UC of the renal pelvis and all bone metastases detected by bone scintigraphy.

CONCLUSIONS

FDG‐PET/CT could replace standard CT and bone scintigraphy in the presurgical staging and monitoring of patients with UC after surgery or chemotherapy.     

Preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer: accuracy of integrated positron emission tomography and computed tomography

Objective: To evaluate the accuracy of integrated positron emission tomography with ¹⁸F-fluoro-2-deoxy-d-glucose (FDG) and computed tomography (PET/CT) in preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer (NSCLC) and to ascertain the role of invasive staging in verifying positron emission tomography (PET)/computed tomography (CT) results. Methods: Retrospective, single institution study of consecutive patients with suspected or pathologically proven, potentially resectable NSCLC undergoing integrated PET/CT scanning in the same PET centre. Lymph node staging was pathologically confirmed on tissue specimens obtained at mediastinoscopy and/or thoracotomy. Statistical evaluation of PET/CT results was performed on a per-patient and per-nodal-station bases. Results: A total of 1001 nodal stations (723 mediastinal, 148 hilar and 130 intrapulmonary) were evaluated in 159 patients. Nodes were positive for malignancy in 48 (30.2%) out of 159 patients (N1 = 17; N2 = 30; N3 = 1) and 71 (7.1%) out of 1001 nodal stations (N1 = 24; N2 = 46; N3 = 1). At univariate analysis, lymph node involvement was significantly associated (p < 0.05) with the following primary tumour characteristics: increasing diameter, maximum standardised uptake value >9, central location and presence of vascular invasion. PET/CT staged the disease correctly in 128 out of 159 patients (80.5%), overstaging occurred in nine patients (5.7%) and understaging in 22 patients (13.8%). The overall sensitivity, specificity, positive and negative predictive values, and accuracy of PET/CT for detecting metastatic lymph nodes were 54.2%, 91.9%, 74.3%, 82.3% and 80.5% on a per-patient basis, and 57.7%, 98.5%, 74.5%, 96.8% and 95.6% on per-nodal-station basis. With regard to N2/N3 disease, PET/CT accuracy was 84.9% and 95.3% on a per-patient basis and on per-nodal-station basis, respectively. Referring to nodal size, PET/CT sensitivity to detect malignant involvement was 32.4% (12/37) in nodes <10 mm, and 85.3% (29/34) in nodes ≥10 mm. Conclusion: Our data show that integrated PET/CT provides high specificity but low sensitivity and accuracy in intrathoracic nodal staging of NSCLC patients and underscore the continued need for surgical staging.     

Prostate cancer localization with 18fluorine fluorocholine positron emission tomography

PURPOSE: We evaluated positron emission tomography (PET) with fluorine fluorocholine (F FCH) for the pretreatment localization of prostate cancer. MATERIALS AND METHODS: A total of 17 patients with prostate cancer who had not yet received treatment for the disease underwent whole body PET following intravenous administration of 3.3 to 4 MBq/kg F FCH. PET findings were compared with the results of prostate sextant biopsy and other imaging studies, and the clinical course. Tracer uptake in prostate sextants was measured as a maximum standardized uptake value (SUVmax) and evaluated as a predictor of the prostate sextant biopsy result by ROC analysis. RESULTS: Prostate sextants positive for malignancy on biopsy demonstrated significantly higher SUVmax than biopsy negative sextants (mean 5.5 vs 3.3, p <0.001). In all 6 cases in which biopsy identified malignancy on only 1 side of the prostate it was possible to identify correctly the affected side based on higher SUVmax. Area under the ROC curve for SUVmax as a discriminator of biopsy positive sextants was 0.86. In 2 patients PET demonstrated areas of abnormal uptake in the retroperitoneum. Computerized tomography confirmed the presence of retroperitoneal lymphadenopathy in these areas. In the 2 patients these lesions regressed following hormonal treatment for prostate cancer. CONCLUSIONS: Malignant tumors in the prostate gland can be localized based on a standardized regional measurement of F FCH uptake. PET with F FCH is potentially useful for staging and localizing prostate cancer.     

Detection of incidental colorectal tumours with 18F‐labelled 2‐fluoro‐2‐deoxyglucose positron emission tomography/computed tomography scans: results of a prospective study

Aim This study assessed the clinical significance of incidental colorectal 2‐fluoro‐2‐deoxyglucose (FDG) uptake using ¹⁸F‐FDG positron emission tomography/computed tomography (PET/CT) scans and evaluated the importance of colonoscopy when incidental colorectal FDG uptake was observed. Method A prospective study was designed and conducted at a single institution over a 2‐year period. In patients undergoing PET/CT scans, all with FDG uptake in the colorectum were assigned to have colonoscopy and biopsy. The value of PET/CT scanning was studied by comparison with the colonoscopy and biopsy results. Results Among 10 978 PET/CT scans, one or more focal uptakes of FDG in the colorectum were observed in 148 (1.35%) patients. In 136 valid patients, malignant colorectal tumours and polyps were found in 23.5% and 20.5%, respectively,, while the colon in the other 56% was normal. A higher false‐positive rate was found in the right colon compared with the distal colorectum (66.2%vs 36.7%, P = 0.004). A significant increase of the maximum standardized uptake (SUVmax) value was found among normal, polyps and cancer groups. Multivariate analysis revealed that SUVmax was the risk factor for predicting colorectal cancer or polyps and FDG uptake in the right colon was a negative predictive factor for finding cancers or polyps. Conclusions Our study proves the necessity of colonoscopy when incidental FDG uptake is found on PET/CT imaging. The false‐positive FDG uptake is more commonly observed in the right colon. Although the SUVmax value is higher in cancer patients, a high SUVmax value does not necessarily result in malignancies.     

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.     

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.     

PET/CT检查注射~(18)F-FDG方法研究

目的比较PET/CT检查经留置针和头皮针注射~(18)F-2-氟-2-脱氧-D-葡萄糖(~(18)F-FDG)的差异,探讨预置留置针用于PET/CT检查的可行性。方法将120例行PET/CT检查患者按检查时间段分为对照组、模型1组和模型2组,对照组按常规方法采用头皮针注射18F-FDG,模型1组和模型2组采用留置针注射~(18)F-FDG,注射前生理盐水冲洗量均为3 mL,注射后分别为5 mL、5mL、10mL,比较三组残留放射性活度;同期选择45例已预置留置针的患者为实验组,采用留置针注射并不拔除留置针,注射前后生理盐水冲冼量分别为5mL、10mL,与对照组比较放射性浓聚、药物污染、受辐射时间的差异。结果对照组与实验组放射性浓聚及药物污染发生率、受辐射时间比较,差异无统计学意义(均P0.05);模型1组残留放射性活度显著高于对照组(P0.05)。结论 PET/CT检查可经预置留置针注射18F-FDG,使用时须增加冲洗管道的生理盐水量。     

Staging fluorodeoxyglucose positron emission tomography/computed tomography for muscle-invasive bladder cancer: a nationwide population-based study

Objective

To provide insight into the use and staging information on lymph-node involvement added by fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in patients with muscle-invasive bladder cancer (MIBC), based on a nationwide population-based cohort study.

Patients and methods

We analysed a nationwide cohort of patients with MIBC without signs of distant metastases, newly diagnosed in the Netherlands between November 2017 and October 2019. From this cohort, we selected patients who underwent pre-treatment staging with CT only or CT and FDG-PET/CT. The distribution of patients, disease characteristics, imaging findings, nodal status (clinical nodal stage cN0 vs cN+) and treatment were described for each imaging modality group (CT only vs CT and FDG-PET/CT).

Results

We identified 2731 patients with MIBC: 1888 (69.1%) underwent CT only; 606 (22.2%) underwent CT and FDG-PET/CT, 237 (8.6%) underwent no CT. Of the patients who underwent CT only, 200/1888 (10.6%) were staged as cN+, vs 217/606 (35.8%) who underwent CT and FDG-PET/CT. Stratified analysis showed that this difference was found in patients with clinical tumour stage (cT)2 as well as cT3/4 MIBC. Of patients who underwent both imaging modalities and were staged with CT as cN0, 109/498 (21.9%) were upstaged to cN+ based on FDG-PET/CT. Radical cystectomy (RC) was the most common treatment within both imaging groups. Preoperative chemotherapy was more frequently applied in cN+ disease and in FDG-PET/CT-staged patients. Concordance of pathological N stage after upfront RC was higher among patients staged as cN+ with CT and FDG-PET/CT (50.0% pN+) than those staged as cN+ with only CT (39.3%).

Conclusion

Patients with MIBC who underwent pre-treatment staging with FDG-PET/CT were more often staged as lymph node positive, regardless of cT stage. In patients with MIBC who underwent CT and FDG-PET/CT, FDG-PET/CT led to clinical nodal upstaging in approximately one-fifth. Additional imaging findings may influence subsequent treatment strategies.     

Risk of metastatic disease on 68gallium-prostate-specific membrane antigen positron emission tomography/computed tomography scan for primary staging of 1253 men at the diagnosis of prostate cancer

In an effort to improve the quality of statistics in the clinical urology literature, statisticians at European Urology, The Journal of Urology, Urology and BJU International came together to develop a set of guidelines to address common errors of statistical analysis, reporting, and interpretation. Authors should ‘break any of the guidelines if it makes scientific sense to do so’, but would need to provide a clear justification. Adoption of the guidelines will in our view not only increase the quality of published papers in our journals but improve statistical knowledge in our field in general.     

The influence of 18F-fluorodeoxyglucose positron emission tomography/computed tomography on the N- and M-staging and subsequent clinical management of intrahepatic cholangiocarcinoma

BackgroundIntrahepatic cholangiocarcinoma (ICC) is a highly metastatic cancer. ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) enables sensitive tumor and metastasis detection. Our aim is to evaluate the influence of pre-treatment PET/CT on the N- and M-staging and subsequent clinical management in ICC patients.MethodsBetween August 2010 and August 2018, 660 consecutive ICC patients, without prior anti-tumor treatments nor other malignancies, were enrolled. The diagnostic performance of PET/CT on the N- and M-staging was compared with conventional imaging, and the preoperative staging accuracy and treatment re-allocation by PET/CT were retrospectively calculated. Survival difference was compared between patients receiving PET/CT or not after propensity score matching.ResultsPatients were divided into group A (n=291) and group B (n=369) according to whether PET/CT was performed. Among 291 patients with both PET/CT and conventional imaging for staging in group A, PET/CT showed significantly higher sensitivity (83.0% vs. 70.5%, P=0.001), specificity (88.3% vs. 74.9%, P<0.001) and accuracy (86.3% vs. 73.2%, P<0.001) than conventional imaging in diagnosing regional lymph node metastasis, as well as higher sensitivity (87.8% vs. 67.6%, P<0.001) and accuracy (93.5% vs. 89.3%, P=0.023) in diagnosing distant metastasis. Overall, PET/CT improved the accuracy of preoperative staging from 60.1% to 71.8% (P<0.001), and modified clinical treatment strategy in 5.8% (17/291) of ICC patients, with unique roles in different tumor-node-metastasis (TNM) stages. High tumor-to-non-tumor ratio (TNR) predicted poor overall survival [hazard ratio (HR) = 2.17; 95% confidence interval (CI): 1.49–3.15; P<0.001]. Furthermore, patients performing PET/CT had longer overall survival compared with those without PET/CT (HR =0.74; 95% CI: 0.58–0.93; P=0.011) after propensity score matching.ConclusionsPET/CT was valuable for diagnosing regional lymph node metastasis and distant metastasis in ICC patients, and facilitated accurate tumor staging and optimal treatment allocation.