Search

Purpose: The aim of this study was to evaluate the potential role of [ 18 F]FDG positron emission tomography/computed tomography (PET/CT) in the characterization of thymic epithelial tumors (TETs). Materials and Methods: A total of 73 patients who underwent preoperative [ 18 F]FDG PET/CT were included in this study. Visual total score (VTS), maximum standard uptake values (SUV max ), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and heterogeneity index (HI) parameters were analyzed to investigate the prediction of histopathologic grade and advanced stage. Results: The cohort included 26 patients with low-grade thymoma (LGT), 36 patients with high-grade thymoma (HGT), and 11 patients with thymic carcinoma (TC). Ninety-one percent of TC had VTS >2, whereas 31% of LGT and 75% of HGT had VTS >2. SUV max , MTV, and TLG were statistically significantly higher in the TC group than in both thymoma and HGT. Using the cutoff value of 7.25 for SUV max , TC was differentiated from thymomas with 91% sensitivity and 74% specificity. TC had significantly lower HI values than thymomas. HI parameters showed good diagnostic ability to differentiate TC from thymoma and TC from HGT. SUV max , MTV, and TLG were significantly higher in advanced-stage disease than in early-stage disease. Conclusions: Visual and quantitative parameters can reliably predict both advanced disease and the grade of primary tumor in TETs. Therefore, as a promising metabolic imaging method, [ 18 F]FDG PET/CT makes important contributions to preoperative evaluation in routine clinical practice.

Purpose: We aimed to investigate the potential of [ 68 Ga]Ga-FAPI-04 PET/CT as an alternative diagnostic and theranostic tool in well-differentiated NETs refractory to [ 177 Lu]Lu-DOTATATE therapy., Methods: Patients who received at least two cycles of [ 177 Lu]Lu-DOTATATE therapy for metastatic NETs and progressed under treatment were included. All patients had performed [ 68 Ga]Ga-DOTATATE and [ 68 Ga]Ga-FAPI-04 PET/CT within 3 weeks. The number of PET-positive lesions related to NETs and tumor sites was documented. Mann-Whitney U and chi-square tests were used to compare SUVmax levels of tracers and the number of detected metastases., Results: Twelve patients (7 male, 5 female) who met the eligibility criteria were included in the study. Ten patients had grade 1-2 NET of various origins, and two had paraganglioma and pheochromocytoma. One hundred ninety-eight of 230 lesions (86%) were SSTR positive with a median SUVmax of 16.6 (2.2-76.5), and 88 of 230 lesions (38.2%) were [ 68 Ga]Ga-FAPI-04 positive with a median SUVmax of 5.1 (2.3-21). Median SUVmax level and detected number of tumors were significantly higher in [ 68 Ga]Ga-DOTATATE PET/CT (p=<0.001). [ 68 Ga]Ga-FAPI-04 PET/CT was completely (n:2) or almost completely (n:3) negative in 5 (42%) patients. Two (17%) patients had flip-flop SSTR/FAPI uptake in tumors. In four patients (33%), tumor uptake or the number of PET-positive lesions was inferior in [ 68 Ga]Ga-FAPI-04 PET/CT. In only one patient (8%), tumor uptakes were higher in [ 68 Ga]Ga-FAPI-04 PET/CT. Low-dose [ 177 Lu]Lu-FAPI-46 dosimetry was performed on the FAPI-dominant patient; absorbed radiation doses per GBq were 1.26 Gy, 0.36 Gy, 0.32 Gy, and 0.2 Gy for kidneys, liver, spleen, and total body, respectively. The mean absorbed dose per GBq was 0.33 Gy for liver mass and 0.41 Gy for metastatic lymph nodes., Conclusion: Our preliminary results demonstrated that [ 68 Ga]Ga-FAPI-04 PET/CT mainly failed in well-differentiated NETs refractory to [ 177 Lu]Lu-DOTATATE therapy and had a limited role as an alternative diagnostic or theranostic agent. Further investigations with a larger patient population are required to determine the impact of [ 68 Ga]Ga-FAPI-04 PET/CT on NETs., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Abstract: A 69-year-old woman with breast cancer underwent 18 F-FDG PET/CT because of the increased CA-15-3 level. 18 F-FDG PET/CT showed multiple hypermetabolic lymph nodes (LNs) in the neck and mediastinum. The patient was also referred for 68 Ga-fibroblast activation protein inhibitor (FAPI) 04 PET/CT for further evaluation. However, 18 F-FDG-avid LNs were FAPI-negative on 68 Ga-FAPI-04 PET/CT. Supraclavicular LN biopsy confirmed the metastasis of breast cancer. Recent reports have focused on the potential of FAPI PET imaging in breast cancer; however, this case highlights that false-negative 68 Ga-FAPI-04-PET/CT findings should also be considered while evaluating metastatic spread., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background and Aim: Gallium-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 68 Ga-PSMA PET/CT on primary LN staging before radical prostatectomy (RP) in intermediate and high risk PCa., Materials and Methods: The retrospectively documented 49 patients with intermediate and high risk non-metastatic PCa who had 68 Ga-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 68 Ga-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., Results: Median 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 68 Ga-PSMA PET/CT. In per patient analysis, the sensitivity, specifity, PPV and NPV of 68 Ga-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 68 Ga-PSMA PET/CT. In per-node analysis, the sensitivity, specificity, PPV and NPV of 68 Ga-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., Conclusion: The use of 68 Ga-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 68 Ga-PSMA PET/CT in individualized treatment era., Competing Interests: Conflict of interest All authors declare that they have no conflict of interest, (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: This study investigates the prognostic value of 68 Ga-Pentixafor PET/CT using PET-derived quantitative in multiple myeloma (MM) patients with suspected recurrence in comparison to 18 F-FDG PET/CT and clinical data., Methods: Twenty-four MM patients with suspicion for relapse who underwent 68 Ga-Pentixafor and 18 F-FDG PET/CT were retrospectively evaluated. Total bone marrow glycolysis for 18 F-FDG (TBM FDG ) and total bone marrow uptake for 68 Ga-Pentixafor PET/CT (TBM CXCR4 ) were calculated using whole-body metabolic tumor burden obtained by dedicated software (MIM 7.0.6). The patients were followed for 19-24 months, and the association of PET-derived quantitative data with overall survival (OS) was analyzed., Results: 68 Ga-Pentixafor PET/CT was positive in 17 patients, of which 13 were also positive on 18 F-FDG PET/CT, whereas 7 patients were negative on both scans. The positive rate of 68 Ga-Pentixafor and 18 F-FDG PET/CT on a patient-based approach was 70.8% and 54.1%, respectively. 68 Ga-Pentixafor positivity was significantly associated with OS (p = 0.009), and 18 F-FDG positivity was at the margin of statistical significance (p = 0.056). TBM CXCR4 and TBM FDG were negatively correlated with OS (r = -0.457, p = 0.025 and r = -0.617, p = 0.001, respectively). The OS was negatively correlated with beta-2-microglobulin levels (r = -0.511, p = 0.01) and CRAB score (r = -0.592, p = 0.002) as an indicator of the end-organ disease, which confirmed these results. Serum beta-2-microglobulin levels and CRAB score were also correlated with TBM CXCR4 (r = 0.442, p = 0.039 and r = 0.573, p = 0.003, respectively) and TBM FDG (r = 0.543, p = 0.009 and r = -0.424, p = 0.003, respectively)., Conclusion: 68 Ga-Pentixafor PET/CT positivity is a negative prognostic factor in the survival outcome of MM patients. Complementary 68 Ga-Pentixafor PET/CT has the potential to overcome 18 F-FDG PET/CT limitations and helps a more precise risk stratification., (© 2021. The Japanese Society of Nuclear Medicine.)

Abstract: We present a case of clear cell renal cell carcinoma, which demonstrates complementary FDG and prostate-specific membrane antigen (PSMA) uptake on metastases in PET/CT, as an example of tumor heterogeneity. The patient had non-FDG-avid lung and bone metastases with PSMA uptake, whereas metastatic cervical and axillary lymph nodes showed vice versa, and skeletal muscle metastasis to vastus lateralis, which is an unusual region for metastasis, showed both PSMA and FDG positivity. In response assessment, mix response was detected. It seems that 68Ga-PSMA and 18F-FDG may have a complementary role in demonstration of metastasis accurately and assessment of treatment response in clear cell renal cell carcinoma., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objection: We aimed to evaluate the role of bone scintigraphy (BS) which has long been the imaging modality of choice in prostate cancer (PCa) and performed a head-to-head comparison between BS, BS + SPECT/CT and 68 Ga-PSMA-PET/CT, for the detection of bone metastasis of PCa., Methods: We evaluated 138 PCa patients who underwent BS and 68 Ga-PSMA PET/CT and SPECT/CT of 102 of 138 patients. Images were interpreted retrospectively and areas of abnormally increased tracer uptake related to PCa were documented as benign, metastatic or equivocal. Equivocal uptakes were finally diagnosed based on a consensus review of correlative imaging. Patient- and lesion-based analysis was performed. Patients with superscan images were excluded from lesion-based analysis., Results: At least one metastatic or equivocal uptake in skeleton was defined in 76 of 138 (55%) BS, in 33 of 102 (32.3%) SPECT/CT, and in 49 of 138 (35.5%) 68 Ga-PSMA PET/CT. 23 (16.7%) patients had also superscan findings on BS and 68 Ga-PSMA PET/CT. For patient-based analysis, sensitivity, specificity, accuracy, PPV, and NPV were calculated as 91.1%, 64.5%, 73.1%, 55.4% and 93.7% for BS; 95.5%, 82.7%, 86.9%, 72.8% and 96.2% for BS + SPECT/CT; 97.7%, 95.7%, 95.6%, 91.6% and 98.8% for 68 Ga-PSMA PET/CT. For lesion-based analysis, sensitivity, specificity, accuracy, PPV, and NPV were 53%, 63.9%, 60.1%, 42.8% and 71.8% for BS; 59.2%, 87.6%, 77.7%, 62.6% and 80% for BS + SPECT/CT; 96.4%, 98.1%, 97.5%, 96.4% and 98.1% for 68 Ga-PSMA PET/CT., Conclusion: This study has shown that 68 Ga-PSMA PET/CT overcomes the limitations of BS and proves superiority in detecting bone metastases, even in patients with SPECT/CT. Our findings present important implications that 68 Ga-PSMA PET/CT can replace BS in future practice.

Peritoneal metastasis of prostate cancer (PC) is unusual site of metastatic disease; only limited case reports are published in literature. Ga-prostate-specific membrane antigen (PSMA) PET/CT is recently used for detection of PC metastasis with high accuracy rates. We present a case of a 68-year-old man with disseminated peritoneal metastases and abdominal metastatic lymph nodes of PC, demonstrated in Ga-PSMA PET/CT with intense PSMA uptake.

Our purpose was to determine whether there is a clinical benefit to add lower-limb imaging in 68 Ga-labeled prostate-specific membrane antigen (PSMA) PET/CT scans for patients with prostate cancer. Methods: In total, 701 patients with prostate cancer who underwent 68 Ga-PSMA PET/CT were evaluated retrospectively. All patients underwent additional lower-limb imaging. Images were reanalyzed by experienced nuclear medicine physicians, and metastatic sites were documented. The prostate-specific antigen (PSA) level and Gleason score were also compared with 68 Ga-PSMA PET/CT findings. Results: In 601 patients (85.7%), at least 1 tumoral lesion was observed on 68 Ga-PSMA PET/CT. The number of patients with bone metastasis in 2 forms was 278 patients (39.6%); 108 (15.4%) were oligometastatic (<4 metastases) and 170 (24.2%) were multimetastatic (≥4 metastases). In lower-limb imaging, bone metastasis was detected in 61 patients (8.7%), the specific locations of which were as follows: middle-distal femur ( n = 54), tibia ( n = 19), fibula ( n = 24), and calcaneus ( n = 1). Lower-limb metastasis was detected mostly in symptom-positive patients (70.1%) but in only 4% of the symptom-negative group. All patients with lower-extremity metastasis also had multiple bone metastases shown on limited whole-body 68 Ga-PSMA PET/CT. The median PSA level was significantly higher in multimetastatic patients with lower-limb metastasis than in those without lower-limb metastasis ( P < 0.001, Mann-Whitney U test), but no statistical differences was found in terms of Gleason score (χ 2 = 0.042, P = 0.837). According to receiver-operating-characteristic analysis, PSA has a good predictive value for detecting lower-limb metastasis, with 76.6% sensitivity and 72% specificity (using a reference cutoff PSA level of 24 ng/mL [area under the curve, 0.81; 95% confidence interval, 0.74-0.87]). Conclusion: Lower-limb imaging did not change the metastatic status of disease or significantly affect the therapeutic approach. However, if multimetastatic patients present relevant symptoms for lower-limb metastasis, it could be beneficial to consider including lower-limb imaging for possible palliative therapies., (© 2019 by the Society of Nuclear Medicine and Molecular Imaging.)

OBJECTIVE. The objective of our study was to investigate the impact of point-spread function (PSF) reconstruction and lesion size on 68 Ga-tetraazacyclododecanetetraacetic acid-DPhe1-Tyr3-octreotate (DOTATATE) PET/CT quantitative parameters. MATERIALS AND METHODS. A total of 38 patients with 42 68 Ga-DOTATATE PET/CT studies and 125 lesions were included. Scans were reconstructed with and without PSF modulation. For each lesion, the maximum standardized uptake value (SUV max ) and peak standardized uptake value (SUVpeak), metabolic tumor volume (MTV), total lesion somatostatin avidity, and tumor somatostatin receptor expression heterogeneity using the AUC method were measured. Intraclass correlation coefficient (ICC) and Bland-Altman analyses were used to compare PSF and non-PSF values. A subgroup analysis was performed to determine the impact of lesion size. RESULTS. Of the 125 lesions, 51 were in the liver, 31 in lymph nodes, 17 in bone, eight in pancreas, four in lung, and 14 in other sites. The ICCs between PSF and non-PSF values were excellent for SUV max , SUVpeak, MTV, and total lesion somatostatin avidity (ICC = 0.97-0.99), and the ICC was good for tumor somatostatin receptor expression heterogeneity (ICC = 0.81). Comparison of PSF with non-PSF values showed a bias (mean percentage change ± SD) of 27.5% ± 14.7% for SUV max , 15.5% ± 9.5% for SUVpeak, -18.6% ± 37.6% for MTV, 0.8% ± 28.1% for total lesion somatostatin avidity, and -7.1% ± 11.0% for tumor somatostatin receptor expression heterogeneity. Comparison of PSF with non-PSF values for lesions less than 2 cm ( n = 75) showed corresponding biases greater than those for lesions 2 cm or larger ( n = 50). CONCLUSION. PSF reconstruction effected higher values for SUV max and SUVpeak, produced decreased values for tumor somatostatin receptor expression heterogeneity, and had a variable effect on MTV and total lesion somatostatin avidity depending on lesion size.

Prostate specific membrane antigen (PSMA) expression has been demonstrated in tumor neovasculature of many solid tumors, including hepatocellular carcinoma (HCC). The purpose of this study is to evaluate PSMA expression in patients with HCC., Materials and Methods: Nineteen HCC patients who underwent F-fluorodeoxyglucose (F-FDG) positron emission tomography (PET) as part of restaging procedure also underwent Ga-PSMA PET. F-FDG PET and Ga-PSMA findings were compared visually as well as quantitatively using maximized standardized uptake values (SUVmax)., Results: FDG was positive in 15 patients while 16 patients demonstrated PSMA expression. The only extrahepatic finding was one metastatic lymph node detected by both tracers. Mean SUVmax of liver lesions on FDG PET/CT was 8.3 ± 2.3 and mean tumor to background ratio was 2.3 ± 1.5. Respective values for Ga-PSMA PET/CT were 17.4 ± 9 and 3.3 ± 2.2. On visual and quantitative evaluation uptake was higher with PSMA in nine patients and higher with FDG in four patients. PSMA and FDG activity were similar in three patients. One of the FDG positive patients was PSMA negative whereas two patients were PSMA positive but FDG negative. Heterogeneous uptake pattern was observed in three patients. Comparison of mean SUVmax and T/B values between PET studies revealed no statistically significant difference (P > 0.1). The mean survival was 25 months (range: 18-32 months) and SUVmax of PSMA (P = 0.05) and FDG (P = 0.012) showed medium strength of correlation with overall survival., Conclusion: PSMA expression in advanced HCC can be demonstrated by Ga-PSMA PET but is not superior to FDG PET however it could be useful for identifying patients with limited therapeutic options.

There are recent advances, namely, a standardized method for reporting therapy response (Hopkins criteria), a multicenter prospective cohort study with excellent negative predictive value of F-FDG PET/CT for N0 clinical neck, a phase III multicenter randomized controlled study establishing the value of a negative posttherapy F-FDG PET/CT for patient management, a phase II randomized controlled study demonstrating radiation dose reduction strategies for human papilloma virus-related disease, and Food and Drug Administration approval of nivolumab for treatment of recurrent head and neck squamous cell carcinoma.

Treatment of high-risk prostate cancer (HRPCa) is challenging. Local staging and metastatic evaluation are important for the patient management. Recently, prostate-specific membrane antigen (PSMA)-based imaging modalities such as PSMA PET/CT and PET/MRI have received significant attention for detection of recurrent prostate cancer sites with elevated prostate-specific antigen levels, after therapy. Current evidence suggests that these imaging modalities may also have a role for the management of patients with HRPCa. In this review, we discuss PSMA-based imaging modalities in the management of patients with HRPCa.

Objective: The purpose of this article is to provide a review of the use of 68 Ga tetraazacyclododecanetetraacetic acid-DPhe1-Tyr3-octreotate (DOTATATE) PET/CT, a functional imaging modality for assessment of well-differentiated neuroendocrine tumors (NETs). It has become the preferred imaging modality for initial diagnosis, selection of patients for peptide receptor radionuclide therapy, and localization of unknown primary tumors. The National Comprehensive Cancer Network guideline has added 68 Ga-DOTATATE PET/CT as an appropriate test in the management of NETs., Conclusion: In combination with FDG PET/CT, 68 Ga-DOTATATE PET/CT can noninvasively assess tumor heterogeneity, especially in G2 and G3 NETs, for personalized management of patients.

Aim: To investigate the relationship between serum PSA level, Gleason score of PCa and the outcomes of Ga 68 -PSMA PET/CT in patients with recurrent PCa., Methods: A total of 109 consecutive patients (median age 71 years; range 48-89 years) who had PSA recurrence after RP and/or hormonotherapy and/or radiotherapy were included in this study. Local recurrences, lymph node metastasis (pelvic, abdominal and/or supradiaphragmatic), bone metastases (oligometastatic/multimetastatic) and other metastatic sites (lung, liver, brain, etc) were documented., Results: In 91(83.4%) patients at least one lesion characteristic for PCa was detected by 68 Ga-PSMA PET/CT. The median serum total PSA (tPSA) was 6.5 (0.2-640) ng/ml.There was a significant difference between 68 Ga-PSMA PET/CT positive and negative patients in terms of serum total PSA value. No statistical significance was found between positive and negative 68 Ga-PSMA PET/CT findings in terms of Gleason score. Local recurrence was detected in 56 patients. whereas lymph node metastases were demonstrated in 46 patients. Pelvic nodal disease was the most frequent presentation followed by abdominal and supradiaphragmaticnodal involvement. Bone metastases [oligometastasis, (n = 20); multimetastasis, (n = 35)⦌ were also detected in 55 patients. In the ROC analysis for the study cohort, the optimal cut-off value of total serum PSA was determined as 0.67 ng/ml for distinguishing between positive and negative 68 Ga-PSMA PET/CT images, with an area under curve of 0.952 (95% CI 0.911-0.993)., Conclusions: 68 Ga-PSMA PET/CT was found to be an effective tool for the detection of recurrent PCa. Even though no relationship was detected between the GS and 68 Ga-PSMA PET/CT findings, serum total PSA values may be used for estimating the likelihood of positive 68 Ga-PSMA PET/CT results.

Objective: Minimizing side effects by using response-adopted therapy strategies plays an important role in the management of pediatric Hodgkin lymphoma (HL); however, the criteria for the definition of adequate or inadequate response are controversial. The aim of this study is to compare different methods of interpretation of 18 F-FDG-PET/CT (PET) in the prediction of disease outcome in order to determine the optimum method in this regard., Methods: Baseline, interim and post-treatment PET scans of 72 children were interpreted according to revised International Harmonization Project criteria (IHP) and Deauville criteria. Cut-off values for changes in interim and post-treatment FDG uptake (ΔSUV max ) in the prediction of progression-free survival (PFS) were measured using ROC analysis. Quantitative and visual data were compared with each other in the prediction of PFS., Results: Mean interim and post-treatment ΔSUV max of the primary lesions were 77.4 ± 19.5 and 68.8 ± 30.4% and respective cut-off values were 82 and 73%. However, only post-treatment ΔSUV max yielded statistically significant results in the prediction of 3-year PFS (p = 0.043). Interim ΔSUV max was further analyzed according to the values reported in the literature (66 and 77%) yet statistically significant results were not reached (p = 0.604 and 0.431). For interim evaluation, IHP criteria was correlated to Deauville criteria (p = 0.002 and p = 0.001) and ΔSUV max (p = 0.03), whereas for post-treatment evaluation, significant correlation with ΔSUV max (p = 0.04) but marginally significant (p = 0.055 and p = 0.058) correlation with Deauville criteria were achieved. Overall, 1, 3 and 5-year PFS were 95.7 ± 0.2, 89.6 ± 0.4 and 80.8 ± 0.7%, respectively. All methods demonstrated comparable performance in the prediction of 3-year PFS; however, interim PET using Deauville criteria and post-treatment PET using IHP criteria were statistically significant. All methods demonstrated high negative-predictive value but substantially low positive-predictive value., Conclusions: Deauville criteria are superior to other methods in the prediction of pediatric HL outcome using interim PET data. On the other hand, quantitative evaluation and visual evaluation by IHP can be used reliably at the end of the treatment. In this regard, we report the optimal cut-off value of SUV max reduction as 73%.

Fluorine-18 fluorodeoxyglucose ( 18 F-FDG) PET-computed tomography (CT) plays a significant role in diagnosis, staging, therapy selection, and therapy assessment of multiple pediatric malignancies and facilitating precision medicine delivery in pediatric patients. In patients with Hodgkin lymphoma, interim fludeoxyglucose 18 F-FDG PET/CT is highly sensitive and specific for predicting survival and multiple trials with FDG PET/CT-based adaptive therapies are currently ongoing. It is superior to iodine-131 metaiodobenzylguanidine ( 131 I-MIBG) scintigraphy and bone scintigraphy for detecting metastases in neuroblastoma patients and sarcoma patients. It may predict histologic differentiation and neoadjuvant therapy assessment in Wilms tumor., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Recent advances in genomic profiling and sequencing of melanoma have provided new insights into the development of the basis for molecular biology to more accurately subgroup patients with melanoma. The development of novel mutation-targeted and immunomodulation therapy as a major component of precision oncology has revolutionized the management and outcome of patients with metastatic melanoma. PET imaging plays an important role in noninvasively assessing the tumor biological behavior, to guide individualized treatment and assess response to therapy. This review summarizes the recent genomic discoveries in melanoma in the era of targeted therapy and their implications for functional PET imaging., (Published by Elsevier Inc.)

Purpose: We aimed to investigate the diagnostic power of 68Ga-PSMA PET/CT in the detection of metastatic spread of newly diagnosed PCa, and evaluate the relationship with modified D'Amico risk classification. Methods: We evaluated newly diagnosed PCa patients who underwent 68Ga-PSMA PET/CT prior to therapy. All images were interpreted retrospectively and areas of abnormally increased tracer uptake were documented according to PSMA-RADS version 1.0 system. Patients were divided into risk groups as low, intermediate, or high risk, according to a modification in D'Amico classification system as ISUP grade 3 tumors were included to high-risk group. 68Ga-PSMA PET/CT findings were compared among risk groups as well as PSA levels, clinical T stages, and ISUP grades. Results: A total of 356 patients were included to the study with a median PSA level was 16.42 (1.29–7013) ng/ml and median Gleason score was 8 (range: 6–10). Of these, 13(3.7%), 54 (15.1%), and 289 (81.2%) were in the low-, intermediate-, and high-risk groups, respectively. Lymph node metastases were detected in 125 (35.1%) patients, and in 48 of them, metastasis was limited to pelvic lymph nodes (PLN). Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated as 71.4%, 100%, 95.9%, 100%, and 95.4%, respectively for the detection of PLN, based on histopathological results of 49 patients. Overall, any metastasis was detected in 47.7% of high-risk patients, while only PLN metastases were defined in 3.7% intermediate-risk patients and none of low-risk patients had any kind of metastasis. Conclusion: This study revealed that 68Ga-PSMA PET/CT should be routinely used in newly diagnosed high-risk PCa patients; whereas it seems to be of limited use for intermediate-risk group and useless for the low-risk group. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the potential role of [18F]FDG positron emission tomography/computed tomography (PET/CT) in the characterization of thymic epithelial tumors (TETs). Materials and Methods: A total of 73 patients who underwent preoperative [18F]FDG PET/CT were included in this study. Visual total score (VTS), maximum standard uptake values (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and heterogeneity index (HI) parameters were analyzed to investigate the prediction of histopathologic grade and advanced stage. Results: The cohort included 26 patients with low-grade thymoma (LGT), 36 patients with high-grade thymoma (HGT), and 11 patients with thymic carcinoma (TC). Ninety-one percent of TC had VTS >2, whereas 31% of LGT and 75% of HGT had VTS >2. SUVmax, MTV, and TLG were statistically significantly higher in the TC group than in both thymoma and HGT. Using the cutoff value of 7.25 for SUVmax, TC was differentiated from thymomas with 91% sensitivity and 74% specificity. TC had significantly lower HI values than thymomas. HI parameters showed good diagnostic ability to differentiate TC from thymoma and TC from HGT. SUVmax, MTV, and TLG were significantly higher in advanced-stage disease than in early-stage disease. Conclusions: Visual and quantitative parameters can reliably predict both advanced disease and the grade of primary tumor in TETs. Therefore, as a promising metabolic imaging method, [18F]FDG PET/CT makes important contributions to preoperative evaluation in routine clinical practice. [ABSTRACT FROM AUTHOR]

Background and Aim: Gallium-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 Methods: The 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.Results: Median 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.Conclusion: The 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. [ABSTRACT FROM AUTHOR]