Investigation of Clinical, Laboratory, Imaging Findings and Histopathological Features of Patients with Gastric Neuroendocrine Cell Hyperplasia.

BACKGROUND/AIMS: Neuroendocrine cell hyperplasia is a non-neoplastic proliferation of enterochromaffin-like cells and is considered a premalignant lesion because of their potential to progress to neuroendocrine tumor. In this study, we aimed to evaluate the demographic and clinical features, laboratory, radiological and endoscopic findings, gastric biopsy histopathological features, follow-up frequency, and histopathological findings of patients diagnosed with gastric neuroendocrine cell hyperplasia as well as to investigate the factors that play a role in the development of neuroendocrine tumors on the basis of neuroendocrine cell hyperplasia. MATERIALS AND METHODS: The study has been conducted in 2 centers with 282 patients that were grouped as those with and without neuroendocrine tumor. Individuals with control endoscopy were separated as those with regression of neuroendocrine cell hyperplasia and those without regression, and the determined parameters were evaluated between the groups. RESULTS: The most common histological subtype of neuroendocrine cell hyperplasia was linear+micronodular (50.4%). Neuroendocrine tumor developed in 4.3% (12/282) of the patients with neuroendocrine cell hyperplasia after a mean of 36 months. The presence of polyps as confirmed via endoscopy and dysplasia as confirmed via histopathological examination was significantly higher in favor of the group with neuroendocrine tumor (P = .01). In patients with neuroendocrine cell hyperplasia regressed and patients in whom it did not regress were examined, the rate of asymptomatic patients and increased sedimentation rate were found in favor of the group that did not regress (P = .02 and P = .02), but no difference was found in other parameters. CONCLUSION: Neuroendocrine tumor development rate was found to be 4.3% in the background of neuroendocrine cell hyperplasia. Two factors predicting progression from neuroendocrine cell hyperplasia to neuroendocrine tumor can be elaborated as the presence of polypoid appearance due to neuroendocrine cell hyperplasia as confirmed via endoscopy and dysplasia as confirmed via histopathological examination.

Contribution of F-18 fluorodeoxyglucose PET/CT and contrast-enhanced thoracic CT texture analyses to the differentiation of benign and malignant mediastinal lymph nodes.

BACKGROUND: Texture analysis and machine learning methods are useful in distinguishing between benign and malignant tissues. PURPOSE: To discriminate benign from malignant or metastatic mediastinal lymph nodes using F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and contrast-enhanced computed tomography (CT) texture analyses with machine learning and determine lung cancer subtypes based on the analysis of lymph nodes. MATERIAL AND METHODS: Suitable texture features were entered into the algorithms. Features that statistically significantly differed between the lymph nodes with small cell lung cancer (SCLC), adenocarcinoma (ADC), and squamous cell carcinoma (SCC) were determined. RESULTS: The most successful algorithms were decision tree with the sensitivity, specificity, and area under the curve (AUC) values of 89%, 50%, and 0.692, respectively, and naive Bayes (NB) with the sensitivity, specificity, and AUC values of 50%, 81%, and 0.756, respectively, for PET/CT, and NB with the sensitivity, specificity, and AUC values of 10%, 96%, and 0.515, respectively, and logistic regression with the sensitivity, specificity, and AUC values of 21%, 83%, and 0.631, respectively, for CT. In total, 13 features were able to differentiate SCLC and ADC, two features SCLC and SCC, and 33 features ADC and SCC lymph node metastases in PET/CT. One feature differed between SCLC and ADC metastases in CT. CONCLUSION: Texture analysis is beneficial to discriminate between benign and malignant lymph nodes and differentiate lung cancer subtypes based on the analysis of lymph nodes.

Volumetric Evaluation of Staging 18F-FDG PET/CT Images in Patients with Esophageal Cancer.

Objectives: The aim of this study was to evaluate the metastatic potential of primary tumor and survival in esophageal cancer (EC) patients by using metabolic tumor volume (MTV) and total lesion glycolysis (TLG) from the staging 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) images. Another aim is to determine a tumor volume-based cut-off value to predict long-term survival. Methods: Medical records of EC patients were retrospectively evaluated. Sixty-two patients with staging 18F-FDG PET/CT and at least five years of follow-up were included in the study. The region of interest to the primary tumor and all metastatic sites was created and MTV and TLG values of the primary tumor (MTVp, TLGp) and total tumor volume (MTVt and TLGt) values were obtained. The relationship between the obtained MTV and TLG values and short-time (one-year) and long time (five-year) survival was investigated. Results: Significant factors on survival were determined as lymph node or distant metastasis (p=0.024, 0.008, respectively) at the staging PET/CT. A significant relationship between volumetric parameters of the primary tumor and total tumor burden (MTVp, TLGp, MTVwb and TLGwb) between survivors and non-survivors for one-year and five-year was detected. In receiver operating characteristics analysis, the most significant volumetric parameter was MTVwb, with area under curve 0.771 in estimated five-year survival. The best cut-off value was detected as 36.1 mL with 78% sensitivity and 75% specificity for MTVwb in determining long-term survivors. Conclusion: Tumor burden in 18F-FDG PET/CT images at the time of staging of patients with EC will contribute to the prediction of long-term survivors.

The role of volumetric and textural analysis of pretreatment 18F-fluorodeoxyglucose PET/computerized tomography images in predicting complete response to transarterial radioembolization in hepatocellular cancer.

OBJECTIVE: This study evaluates the role of pretreatment 18F-FDG PET/CT in predicting the response to treatment in patients with hepatocellular cancer (HCC) who applied transarterial radioembolization (TARE) via the volumetric and texture features extracted from 18F-FDG PET/CT images. METHODS: Thirty-three patients with HCC who had applied TARE [lobar (LT) or superselective (ST)] after 18F-FDG PET/CT were included in the study. Response to the treatment was evaluated from posttherapy magnetic resonance (MR). Patients were divided into two groups: the responder group (RG) (complete responders) and non-RG (NRG) (including partial response, stabile, and progressive). Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) and texture features were extracted from PET/CT images. The differences among MTV, TLG, and texture features between response groups were analyzed with the Mann-Whitney U test. ROC analysis was performed for features with P < 0.05. Spearman correlation analysis was used, and features with correlation coefficient < 0.8 were evaluated with the logistic regression analysis. RESULTS: Significant differences were detected in TLG, MTV, SHAPE_compacity, GLCM_correlation, GLRLM_GLNU, GLRLM_RLNU, NGLDM_coarseness, NGLDM_busyness, GLZLM_LZHGE, GLZLM_GLNU, and GLZLM_ZLNU between RG and NRG. Multivariate analysis demonstrated that MTV was the only meaningful parameter with an AUC of 0.827 (P = 0.002; 95% CI, 0.688-0.966). The best cutoff value was determined as 74.11 ml with 78.9% sensitivity and 78.6% specificity in discriminating nonresponders. CONCLUSION: In predicting the curative effect of TARE, multivariate analysis results demonstrated that MTV was the only independent predictor, and MTV higher than 74.11 ml were determined the best predictor of nonresponders.

Dual time point imaging of staging PSMA PET/CT quantification; spread and radiomic analyses.

OBJECTIVE: The aims were to evaluate the performance of models that predict Gleason Grade (GG) groups with radiomic data obtained from the prostate gland in dual time 68Ga-Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography/Computerized Tomography (PET/CT) images for prostate cancer (PCa) staging, and to analyze the contribution of late imaging to the radiomic model and to evaluate the relationship of the distance between tumor foci in the body (Dmax) obtained in early PET images with histopathology and prostate specific antigen (PSA) value. METHODS: Between October 2020 and August 2021, 41 patients who underwent 68Ga-PSMA PET/CT for staging of PCa were retrospectively analyzed. Volumetric and radiomics data were obtained from early and late PSMA PET images. The differences between age, metastasis status, PSA, standard uptake value (SUV), volumetric and radiomics parameters between GG groups were analyzed. Early and late PET radiomic models were created, area under curve (AUC), sensitivity, specificity and accuracy values of the models were obtained. In addition, the correlation of Dmax values with total PSMA-tumor volume (TV), Total lesion (TL)-PSMA and PSA values was evaluated. In metastatic patients, the difference in Dmax between GG groups was analyzed. RESULTS: There was a significant difference between patients with GG ≤ 3 and > 3 in 35 of the early PET radiomic features. In the early PET model, multivariate analyses showed that GLRLM_RLNU and PSA were the most meaningful parameters. The AUC, sensitivity, specificity and accuracy values of the early model in detecting patients with GG > 3 were calculated as 0.902, 76.2%, 84% and 78.1%, respectively. In 36 late PET radiomic features, there was a significant difference between patients with GG ≤ 3 and > 3. In multivariate analyses; SHAPE_compacity and PSA were obtained as the most meaningful parameters. The AUC, sensitivity, specificity and accuracy values of the late model in detecting patients with GG > 3 were calculated as 0.924, 85.7%, 85% and 85.4%. There was a strong correlation between Dmax and PSA values (p < 0.001, rho: 0.793). Dmax showed strong correlation with PSMA-TVtotal and TL-PSMAtotal (p < 0.001, rho: 0.797; p < 0.001, rho: 0.763, respectively). In patients with metastasis, median Dmax values of the GG > 3 group were higher than GG ≤ 3 group; A statistically significant difference was obtained between these two groups (p = 0.023). CONCLUSIONS: Model generated from the late PSMA PET radiomic data had better performance in the current study. Without the use of invasive methods, the heterogeneity and aggressiveness of the primary tumor and the prediction of GG groups may be possible with 68Ga-PSMA PET/CT images obtained for diagnostic purposes especially with late PSMA PET/CT imaging.

Prediction of early biochemical response after 177Lu-PSMA radioligand therapy with 68Ga-PSMA PET, a different perspective with quantitative parameters.

OBJECTIVE: In this study, our aim was to evaluate the relationship of the quantitative data obtained from pretreatment 68Ga prostate-specific membrane antigen (PSMA) PET-computerized tomography (PET/CT) with treatment response of the patients with the diagnosis of metastatic castrationresistant prostate cancer (mCRPC) who received 177Lu-PSMA radioligand therapy (RLT). METHODS: The patients who were given three or four cycles of 177Lu-PSMA RLT between January 2016 and June 2018 were evaluated retrospectively. Volumetric data; PSMA tumor volume (TV) and total lesion (TL) PSMA, were obtained from 68Ga-PSMA PET/CT for whole (PSMA-TVT and TL-PSMAT). The distance between the two furthest lesions (Dmax) was calculated. Posttreatment early prostate-specific antigen (PSA) values on the fourteenth day after treatment were obtained. According to the PSA responses, the patients were divided into two groups as progressed and nonprogressed. In univariate analysis, the relationship of PET quantitative data with biochemical response groups was evaluated with Mann-Whitney U test. Logistic regression was used in multivariate analysis. RESULTS: A total of 38 patients were included in the study. In univariate analysis, Dmax, PSMA-TVT and TL-PSMAT values were obtained at lower levels in the progressed group. In multivariate analysis, only Dmax was found to be a prognostic factor in predicting early biochemical response. CONCLUSION: Dmax is the most prognostic parameter in predicting the early biochemical response in patients with mCRPC; high total tumor volume and burden are also parameters that give us an idea about the response to treatment. The success rate will be higher if 177Lu-PSMA RLT treatment is planned for patients with higher tumor volume and spread.

Interreader agreement in evaluation of 68Ga-PSMA PET/CT at the time of initial staging: comparison of the three evaluation criteria in the pretreatment risk groups.

OBJECTIVE: The aim of this study was to assess the interreader agreement in evaluation 68Ga-prostate-specific membrane antigen (PSMA) PET/CT according to three current criteria European association of nuclear medicine, PROMISE with miTNM, and PSMA-RADS in newly diagnosed prostate cancer (PC) patients. METHODS: The images of 101 patients who had been diagnosed with PC and underwent 68Ga-PSMA PET/CT at the time of initial staging were evaluated according to the three interpretation criteria by two nuclear medicine specialists. Local tumor, pelvic lymph node metastasis and distant metastasis were evaluated separately. Abdominal lymph nodes, bone and visceral organ metastases were additionally evaluated as subregions of distant metastatic sites. Patients were evaluated in subgroups Gleason score ≥8 or prostate-specific antigen ≥20 ng/mL as the high-risk group (HR) and prostate-specific antigen ≤ 20 ng/mL and Gleason score <8 as the low-risk group (LR). To measure interreader agreement for each judgment site Cohen's Kappa statistic coefficient (κ) was calculated. RESULTS: All three criteria European association of nuclear medicine, PROMISE with miTNM and PSMA-RADS exhibit substantial and almost perfect agreement between the readers in all sites except for PSMA-RADS in bone and visceral metastasis (κ = 0.495, κ = 0.506, respectively). According to the risk groups, a remarkable difference in interreader agreement for bone metastasis for all three criteria (especially in PSMA-RADS) between the HR and LR patients was detected. CONCLUSIONS: In low-risk patients especially PSMA-RADS criteria leads to increased interreader reporting differences. While evaluating 68Ga-PSMA PET/CT images it should be considered that pretreatment risk levels of PC patients could affect the interreader agreement.

The position of transarterial chemoembolization with drug-eluting beads and yttrium-90 transarterial radioembolization in patients with hepatocellular carcinoma: Consensus statements from a Delphi-method expert panel in Turkey.

PURPOSE: Clinical studies conducted in different geographic regions using different methods to compare transarterial chemoembolization (TACE) and transarterial radioembolization (TARE) have demonstrated discordant results. Meta-analyses in this field indicate comparable overall survival (OS) with TACE and TARE, while reporting a longer time to progression and a higher downstaging effect with TARE treatment. In terms of isolated procedure costs, treatment with TARE is 2 to 3 times more, and in some countries even more, expensive than TACE. However, relevant literature indicates that TARE is more advantageous compared to TACE regarding the need for repeat procedures, costs of complication management, total hospital stay and quality of life. Heterogeneity of hepatocellular carcinoma (HCC) patients as well as the shortcomings of clinical classifications, randomized clinical trials and cost-effectiveness studies make it difficult to choose between treatment alternatives in this field. As in other countries, these challenges lead to differences in treatment choice across different centers in Turkey. METHODS: The present expert panel used two round modified Delphi method to investigate the resources and clinical parameters referenced while selecting patients for drug-eluting beads (DEB)-TACE and TARE treatment modalities in Turkish clinical practice. The cost-effectiveness parameters and comparisons of these treatments have also been evaluated at a prediction level. RESULTS: The panelists stated that they most commonly use the BCLC staging system for the management of HCC patients in Turkey. However, they did not find any of the staging systems or treatment guidelines sufficient enough for their clinical practice in terms of covering the down-staging intent of treatments. Since living donor transplant preference is higher in Turkey than the rest of the Western countries, down-staging treatments are thought to be more prioritized in Turkey than that in other Western countries. The panelists reached a consensus that TARE may provide improved OS and reduce the number of repeat procedures compared to DEB-TACE in intermediate-stage patients with a single tumor spanning a diameter above 5 cm who experience recurrence after previous treatment with TACE and most TACE-naïve patient groups in intermediate stage. CONCLUSION: Based on the consensus on OS and the number of procedures, the panelists assumed that TARE would be more cost-effective than DEB-TACE in most groups of TACE-naïve patients in intermediate stage and in those with a single tumor spanning a diameter above 5 cm. It was also stated that the predicted cost-effectiveness advantage of TARE could be more pronounced in patients with a tumor diameter greater than 7 cm.

Is SUV Corrected for Lean Body Mass Superior to SUV of Body Weight in 68Ga-PSMA PET/CT?

Objectives: This study aimed to investigate the relationship between the standard uptake value (SUV) of body weight and SUV corrected for lean body mass (SUL) parameters obtained from the prostate gland in gallium-68 (68Ga)-prostate-specific membrane antigen (PSMA) positron emission tomography-computed tomography (PET/CT) with Gleason grade (GG) groups, D'Amico risk groups, and presence of metastases. Methods: Patients with prostate adenocarcinoma who underwent 68Ga-PSMA PET/CT for staging at our center between February 2017 and October 2018 were evaluated retrospectively. Maximum SUV (SUVmax), SUVpeak, SULmax, SULpeak, SUVmean, and SULmean values of the prostate tumor were obtained. The difference in these values between GG groups (≥3, <3) and D'Amico risk (low-moderate/high) groups was evaluated with the Mann-Whitney U test. The area under the curve values of SUV and SUL parameters were compared. In addition, SUVmean and SULmean values were obtained from the right liver lobe, and their correlation with body weight was evaluated. Results: A total of 79 patients were included in the study. Significant differences were found in the prostate SUVmax, SULmax, SUVpeak, SULpeak, SUVmean, and SULmean values between the GG (≥3 and <3) groups and between D'Amico risk (low-moderate and high) groups. However, no significant difference was found in the discriminative power of any SUV or SUL parameter when compared with each other. A significant difference in any SUV and SUL parameters was found in patients with and without metastasis. Neither liver SUVmean value nor SULmean value correlated with the body weight. Conclusion: The superiority of SUL values obtained from 68Ga-PSMA PET to SUV was not determined in our study. SUV parameters can also be used for quantitative analysis in 68Ga-PSMA PET.

A different overview of staging PET/CT images in patients with esophageal cancer: the role of textural analysis with machine learning methods.

OBJECTIVE: This study evaluates the ability of several machine learning (ML) algorithms, developed using volumetric and texture data extracted from baseline 18F-FDG PET/CT studies performed initial staging of patient with esophageal cancer (EC), to predict survival and histopathology. METHODS: The initial staging 18F-FDG PET/CT images obtained on newly diagnosed EC patients between January 2008 and June 2019 were evaluated using LIFEx software. A region of interest (ROI) of the primary tumor was created and volumetric and textural features were obtained. A significant relationship between these features and pathological subtypes, 1-year, and 5-year survival was investigated. Due to the nonhomogeneity of the data, nonparametric test (The Mann-Whitney U test) was used for each feature, in pairwise comparisons of independent variables. A p value of < 0.05 was considered significant. Receiver operating curve (ROC) analysis was performed for features with p < 0.05. Correlation between the significant features was evaluated with Spearman correlation test; features with correlation coefficient < 0.8 were evaluated with several ML algorithms. RESULTS: In predicting survival in a 1-year follow-up J48 was obtained as the most successful algorithm (AUC: 0.581, PRC: 0.565, MCC: 0.258, acc: 64.29%). 5-year survival results were more promising than 1-year survival results with (AUC: 0.820, PRC: 0.860, MCC: 271, acc: 81.36%) by logistic regression. It is revealed that the most successful algorithm was naive bayes (AUC: 0.680 PRC: 0.776, MCC: 0.298, acc: 82.66%) in the histopathological discrimination. CONCLUSION: Texture analysis with ML algorithms could be predictive of overall survival and discriminating histopathological subtypes of EC.

Evaluation of 68Ga-PSMA PET/CT with volumetric parameters for staging of prostate cancer patients.

BACKGROUND: The aim of this study was to investigate the relationship between volumetric data obtained from staging 68Ga-prostate-specific membrane antigen (PSMA) PET computerized tomography (CT) images with prostate-specific antigen (PSA), risk groups, Gleason Grade (GG) groups and presence of metastasis. METHODS: We performed a retrospective analysis of 68Ga-PSMA PET-CT images from 88 patients undergoing initial staging of prostate adenocarcinoma between January 2015 and September 2018. Images were evaluated in LIFEx software; PSMA involvement above the background activity in prostate gland, lymph node and other distant metastases was plotted with 40% SUVmax threshold, SUVmax, PSMA tumor volume (PSMA-TV) and total lesion PSMA (TL-PSMA) values were obtained. RESULTS: In all patients, there was a moderate correlation between PSA and PSMA-tumor volume whole-body (PSMA-TVwb) (P < 0.001, r = 0.580) and a high correlation between total lesion-PSMAwb (TL-PSMAwb) (P < 0.001, r = 0.636). Prostate PSMA-TV (PSMA-TVp) and TL-PSMA (PSMA-TVp) values were different in local and locally advanced/metastatic patients (P = 0.020 and 0.006, respectively). PSMA-TVp and TL-PSMAp values were significantly different in low-moderate and high-risk patients (P = 0.003 and <0.001, respectively), and in patients with and without metastasis (P = 0.008 and <0.001, respectively). PSMA-TVp, PSMA-TVwb, TL-PSMAp and TL-PSMAwb values were significantly different in patients with GG ≤3 and >3 (P = 0.030, 0.002, <0.001 and <0.001, respectively). CONCLUSION: Pretreatment 68Ga-PSMA PET/CT volumetric parameters provides unique data to use in the clinical decision-making process of patients with adenocarcinoma of the prostate.

Evaluating Focal 18F-FDG Uptake in Thyroid Gland with Radiomics.

PURPOSE: The aim of this study was to evaluate the ability of 18F-FDG PET/CT texture analysis to predict the exact pathological outcome of thyroid incidentalomas. METHODS: 18F-FDG PET/CT images between March 2010 and September 2018 were retrospectively reviewed in patients with focal 18F-FDG uptake in the thyroid gland and who underwent fine needle aspiration biopsy from this area. The focal uptake in the thyroid gland was drawn in 3D with 40% SUVmax threshold. Features were extracted from volume of interest (VOI) using the LIFEx package. The features obtained were compared in benign and malignant groups, and statistically significant variables were evaluated by receiver operating curve (ROC) analysis. The correlation between the variables with area under curve (AUC) value over 0.7 was examined; variables with correlation coefficient less than 0.6 were evaluated with machine learning algorithms. RESULTS: Sixty patients (70% train set, 30% test set) were included in the study. In univariate analysis, a statistically significant difference was observed in 6 conventional parameters, 5 first-, and 16 second-order features between benign and malignant groups in train set (p < 0.05). The feature with the highest benign-malignant discriminating power was GLRLMRLNU (AUC:0.827). AUC value of SUVmax was calculated as 0.758. GLRLMRLNU and SUVmax were evaluated to build a model to predict the exact pathology outcome. Random forest algorithm showed the best accuracy and AUC (78.6% and 0.849, respectively). CONCLUSION: In the differentiation of benign-malignant thyroid incidentalomas, GLRLMRLNU and SUVmax combination may be more useful than SUVmax to predict the outcome.

The use of molecular volumetric parameters for the evaluation of Lu-177 PSMA I&T therapy response and survival.

PURPOSE: The primary aim of this study was to evaluate the volumetric therapy response via Ga-68 PSMA I&T PET/CT in patients treated with Lu-177 PSMA I&T therapy. The secondary purpose was to determine the impact of volumetric parameter responses to overall survival. METHODS: PSMA tumor volumes (PSMA-TV) and tumor lesion PSMA expressions (TL-PSMA) were calculated with a semi-automatic program on Ga-68 PSMA I&T PET/CT images that were obtained before and after Lu-177 PSMA I&T therapies with 19 patients. The median overall survival was compared with PSMA-TV, TL-PSMA, SUVmax, PSA, and alteration in PERCIST criteria. RESULTS: PSMA-TV values were decreased in 12 patients (63%), and TL-PSMA values were decreased in 15 patients (79%) following the therapy. The SUVmax and the PSA values were also decreased in 14 (74%) and 10 (53%) patients, respectively. The complete remission (CR) was observed in two patients (10%). The partial response (PR) and progressive disease were observed in 6 (32%) and 11 (58%) patients, respectively, according to PRECIST criteria. The survival rates were statistically significant in patients with a decrease in PSMA-TV and TL-PSMA values than patients without any decrease (p 0.001, p < 0.001, respectively). However, the survival rates did not differ in responders (PR or CR) and non-responders according to the PERCIST criteria (p 0.232). The survival rates did not also differ in responders and non-responders according to the SUVmax and PSA values (p 0.140, p 0.206, respectively). CONCLUSIONS: Molecular and volumetric parameters are beneficial in the assessment of Lu-177 PSMA I&T therapy response. Although the number of patients is small, TL-PSMA response, which includes both the tumor volume and PSMA expression in tumor, may be considered as the most valuable parameter for the evaluation of the therapy response and the prediction of survival rate.

Does lymph node localization affect prostate-specific membrane antigen uptake?

OBJECTIVE: To investigate the relationship between lymph node (LN) size and localization and prostate-specific membrane antigen (PSMA) uptake in patients with prostate cancer. PATIENTS AND METHODS: Between February 2015 and February 2017, a total of 178 patients diagnosed with prostate adenocarcinoma by gallium-68 PSMA PET/computed tomography were evaluated. Seventy-eight patients with LN PSMA uptake were included in the study.The short-axis diameter and maximum and mean standardized uptake values (SUV) were measured from axial images of LNs with PSMA uptake. LN conglomerates were considered a single lesion. Patients were divided into two groups according to the presence (group 1) or absence (group 2) of bone uptake in addition to the LN uptake; subgroups were constituted according to the short-axis diameter and PSMA-positive LN region for each group. LNs were classified according to their localization as pelvic, abdominal, or cervical/thoracic. RESULTS: In both groups, the SUV were significantly higher in LNs with short-axis diameters more than 8 mm than those with diameters up to 8 mm (P < 0.001 and < 0.001, respectively). Also, both groups showed a moderate correlation between the LN size and SUV.When the analysis was carried out according to the localization, but after excluding the LN conglomerates, the correlation between the pelvic and abdominal LNs was higher in the second group. CONCLUSION: The highest significant positive correlation between LN size and SUV was in patients with pelvic and abdominal LN metastases without bone involvement according to the gallium-68 PSMA PET/computed tomography images in our study.

Hepatopulmonary Shunt Reduction With 177Lu-DOTATATE Therapy.

A 72-year-old man was diagnosed with well-differentiated neuroendocrine tumor of unknown primary with liver metastasis. All liver lesions were detectable only on Ga-DOTATATE PET/CT and were negative on F-FDG PET/CT. Intrahepatic Y radioembolization therapy was planned, but the hepatopulmonary shunt fraction was found to be 31.6%. Because the hepatopulmonary shunt fraction greater than 20% is an absolute contraindication to radioembolization, we decided to give him Lu-DOTATATE therapy. He received 4 courses of Lu-DOTATATE and showed regression in posttherapy Ga-DOTATATE PET/CT imaging. The hepatopulmonary shunt fraction was reduced to 8% after Lu-DOTATATE therapy.

Does cisplatin chemotherapy decrease the MDP uptake of normal bone? An experimental study.

OBJECTIVE: Bone scan is the accepted initial imaging modality for skeletal metastases. Cisplatin is a cell-cycle nonspecific antineoplastic agent used in some chemotherapy regimens. Knowing that platinum reacts with phosphate compounds such as methylenediphosphonic acid (MDP), decreases bone resorption and new bone formation, it can be proposed that cisplatin chemotherapy may decrease Tc-99m MDP bone uptake. We aimed to demonstrate, if present, the decrease in bone uptake and to determine the duration of this effect. METHODS: Thirty male Wistar rats were randomized into five groups, namely, placebo group (G1) and cisplatin groups (G2, G3, G4, G5). Pre-therapy bone scintigraphies were obtained in all the groups. Cisplatin chemotherapy was given as infusion. Post-therapy bone scintigraphies were obtained 10 min, 1 h, 24 h, and 72 h after chemotherapy in groups G2-G5, respectively. A placebo bone scintigraphy was obtained 10 min after infusion of serum physiologic in G1. Plasma samples for cisplatin plasma values were obtained. The graphite furnace atomic absorption spectrophotometry technique was used for cisplatin analysis. Quantitative analysis (bone uptake ratios) was performed by drawing regions of interest on the right femur, vertebral column, and adjacent soft tissues. The injection/examination time delay and the net injected MDP doses were also noted. RESULTS: There was no statistically significant difference in bone uptake values, injected MDP doses or injection/examination time delay in any group. Cisplatin plasma values were significantly different in G2, G3, G4, and G5 (P < 0.05) but not in G1. CONCLUSIONS: Cisplatin chemotherapy seems to have no effect on the Tc-99m MDP uptake of normal bone.