Adipose tissue indices predict prognosis in hodgkin lymphoma.

INTRODUCTION BACKGROUND: This study evaluated the impact of adipose tissue indices on prognosis of HL. METHODS: Fifty-five patients with newly diagnosed Hodgkin Lymphoma were evaluated retrospectively for association with adipose tissue indices (total abdominal tissue volume, radiodensity, subcutaneous and visceral adipose tissue SUVmax value and prognostic factors for Hodgkin Lymphoma such as IPS-3, IPS-7, stage, sedimentation, progression free and overall survival. RESULTS: For IPS-3, SAT SUVmax and TAAT radiodensity were significantly increased in high-risk patients (2and 3) compared to group 0 and 1. For IPS-7, total abdominal adipose volume was significantly decreased in high-risk patients, SAT SUVmax significantly increased in high-risk patients and decreased in low-risk patients. In addition, SAT SUVmax was significantly increased in patients with high sedimentation rate, with B symptoms and who passed away during follow-up. SAT SUVmax showed moderate positive correlation with sedimentation, IPS-3, IPS-7, and stage. In addition, it was observed that TAAT radiodensity and SAT SUVmax were significantly better for determining prognosis than other adipose tissue indices. Roc analysis showed that the diagnostic value of all adipose tissue indices in predicting IPS-3 and IPS-7 prognoses were statistically significant. CONCLUSION: SAT SUVmax and TAAT radiodensity were two new and independent markers with diagnostic value in predicting prognosis.

Prognostic value of computed tomography associated body composition measurement changes in metastatic colorectal cancer patients.

BACKGROUND: Sarcopenia is associated with poor prognosis in metastatic colorectal cancer (mCRC) patients. PURPOSE: To investigate the prognostic value of body composition measurement changes measured by computed tomography (CT) in mCRC patients. MATERIAL AND METHODS: The abdominal skeletal muscle density (SMD) and skeletal muscle (SMI) indices, as well as the visceral (VATI) and subcutaneous fat tissue (SATI) indices, were calculated by automatic segmentation method on the abdominal CT images obtained before (n = 71) and after chemotherapy (n = 52). Skeletal muscle gauge (SMG = SMD × SMI) was calculated. We calculated the percentage change of body composition measurements with respect to the first measurements. The cutoff value for the change in SMG was calculated by receiver operating characteristic analysis. Kaplan-Meier and Cox regression analyses were performed to calculate the prognostic value of age, gender, tumor location, metastasis site and carcinoembriogenic antigen (CEA) elevation, hypoalbuminemia, body mass index classification, presence of sarcopenia and SMG changes in terms of overall survival. RESULTS: There was a significant association between SMG change and mortality (P = 0.037). According to survival analyses, highly decreased SMG, hypoalbuminemia and CEA variables of the patients were the significant factors (P < 0.001, P = 0.015 and P = 0.019, respectively). According to multivariate regression analysis, hypoalbuminemia (P = 0.004, hazard ratio = 3.60) and highly decreased SMG (P < 0.001, hazard ratio = 14.98) were found to be significant prognostic factors together. CONCLUSION: In mCRC patients, hypoalbuminemia and highly decreased SMG are significant prognostic factors for overall survival. Therefore, we suggest that the change in SMG calculated in follow-up images should also be evaluated in the prognosis estimation of this patient group.

The Role of Metabolic Volumetric Parameters in Predicting Malignancy in Incidental Thyroid Nodules Detected in 18F-FDG PET/CT Scans

Objectives: The metabolic activities of tumors can be calculated volumetrically during positron emission tomography/computed tomography (PET/CT) imaging using metabolic tumor volume (MTV) and total lesion glycolysis (TLG). This study aimed to evaluate the roles of MTV and TLG in predicting the malignancy risk of incidental thyroid nodules detected by PET/CT imaging. Methods: Active metabolic areas of each section were manually drawn by region of interest to calculate the MTV of nodules, and all obtained values were then summed. TLG, the product of mean standardized uptake value and MTV, was calculated by multiplying two values. All participants underwent thyroid ultrasonography imaging. All nodules were divided into risk classes according to the European Thyroid Image Reporting and Data System (EU-TIRADS) that was developed by the European Thyroid Association. The American Thyroid Association Guidelines were used to determine which thyroid nodules would undergo thyroid fine-needle biopsy (FNAB). Results were classified according to the Bethesda scoring system. Results: TLG levels were significantly higher in malignant or malignant-suspicious nodules than in benign nodules (p=0.013). Although MTV levels were high in malignant or malignant-suspicious nodules than in benign and non-diagnostic nodules, it was statistically insignificant at limit values (p=0.079). Areas under curve (AUC) were 0.726 (p=0.005) and AUC: 0.668 (p=0.039) for TLG and MTV, respectively. The 2.3 g cut-off value of TLG has a sensitivity of 85.7% and specificity of 59.0%. The 1.7 mL cut-off value of MTV has a sensitivity of 78.6% and specificity of 60.4%. Conclusion: We believe that TLG evaluation will be useful in predicting high-risk malignancy or malignancy suspicion based on EU-TIRADS risk classification of incidental thyroid nodules detected in PET/CT images. We believe that unnecessary thyroid FNABs can be avoided for thyroid incidental nodules if such relation and cut-off values are determined and that it will be useful in hastening the operation of the necessary patients.

Correlation of 18F-FDG/PET SUVmax, SUVmean, MTV, and TLG with HIF-1α in Patients with Colorectal Cancer

Objectives: Post-hypoxia hypoxia-inducible factor (HIF)-1α activation plays a vital role in colorectal cancer (CRC) angiogenesis. Although glucose metabolism is induced in some cancer types via HIF-1α, the prognostic significance of HIF-1α in CRC and its correlation with 18fluorinefluorodeoxyglucose (18F-FDG) uptake in positron emission tomography (PET) remain controversial. This study aims to investigate the association between 18F-FDG/PET parameters and HIF-1α expression in CRC. Methods: Thirty-six histopathologically confirmed patients with CRC who had 18F-FDG/PET scans before surgery were enrolled in the study. The correlations between the maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume (MTV), total lesion glycolysis, HIF-1α overexpression, and histopathological features were evaluated. Results: The tumor location, tumor diameter, perineural invasion, lymphovascular invasion, T and N stage were not significantly correlated with HIF-1α overexpression. In contrast, the tumor differentiation was negatively correlated with HIF-1α expression (r=-0.332, p=0.048). None of the 18F-FDG/PET parameters was significantly correlated with HIF-1α overexpression. A significant relationship was found between tumor differentiation, tumor necrosis percentage, and MTV (p=0.030, p=0.020). Conclusion: The expected association between HIF-1α overexpression and 18F-FDG/PET parameters was not found in this study. However, there was a relationship between MTV, tumor differentiation, and tumor necrosis percentage. Hence, further studies are required to predict the pathological and prognostic courses of CRC using a diagnostic 18F-FDG/PET evaluation.

The Role of Ga-68 PSMA PET/CT Scan on Differentiating of Oligometastatic and High Risk Prostate Cancer

Objectives: In this study, we aimed to investigate whether Ga-68 prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) scanning is adequate to predict intermediate risk, high risk, or oligometastatic prostate cancer (PCa) as an initial staging modality. Methods: The Ga-68 PSMA PET/CT scan images of 50 PCa patients pathologically proven by transrectal ultrasound guided biopsy were evaluated retrospectively. The association of standard uptake value maximum (SUVmax) value of the area with the highest PSMA expression within the primary tumor with the risk groups and metastatic burden is investigated. Results: The SUVmax value was 6.18 in oligometastatic patients where it was measured as 10.93 in patients with higher metastatic burden (p=0.037). The cut-off SUVmax value for multiple metastases was 7.96 (p=0.047). According to the regression model, SUVmax value has a positive influence [odds ratio (OR)=1.42], which was statistically significant (p=0.038). SUVmax values for intermediate and high risk patients were 6.91 and 11.44, respectively (p=0.014). The cut-off SUVmax value for the high risk group was 10.55 (p=0.006). In the regression model, SUVmax value has a positive influence (OR=1.198), which was statistically significant (p=0.021). Conclusion: In this paper, we demonstrated the association between SUVmax value of primary tumor and Gleason score. Our results also allowed us to suggest that primary tumor SUVmax is a sufficiently accurate predictor of D'Amico risk groups in newly diagnosed PCa cases. Additionally, Ga-68 PSMA PET/CT turns out to be a useful tool in determining oligometastatic PCa, which requires a different treatment approach.

Solitary Pulmonary Nodule: Morphological Effects on Metabolic Activity Assessment

Objectives: We aimed to evaluate the effects of morphological characteristics of the solitary pulmonary nodules (SPN) on metabolic activity assessment. To the best of our knowledge, this is the first study to compare the volumetric metabolic activity parameters according to the morphologic parameters of the nodules. Methods: In this retrospective study, 18F-FDG positron emission tomography and computed tomography scans performed between 2011 and 2018 were evaluated by a nuclear and diagnostic radiologist. One hundred thirteen patients with SPNs with biopsy-proven diagnosis were included. SPNs were classified as solid, partially solid (PS), and ground glass opacity (GGO). Results: SPN diameter, SUVmax, metabolic tumor volume (MTV), total lesion glycolysis (TLG), and density were significantly higher in the malignant group. SUVmax, MTV, TLG increased in direct proportion to the diameter. There was no a significant difference between GGO, PS, and solid nodules in terms of SUVmax values. MTV and TLG values increased in parallel with the density of the nodules, but this increase was only significant in the malignant group. There was a significant difference between SPNs <2 cm and SPNs ≥2 cm in terms of MTV, while there was no difference in terms of SUVmax. The cut-off value determined by the ROC curve was found to be 4.39 for SUVmax, 7.33 mL for MTV and 31.88 g for TLG. The cut-off values for SUVmax of solid and subsolid nodules were close to each other, but cut-off values for MTV and TLG were higher in solid nodules. Conclusion: SUVmax, MTV, and TLG are affected by diameter and attenuation. We suggest using different MTV and TLG cut-off values for solid and subsolid nodules, but we suggest using same SUVmax values. MTV can be a more reliable parameter than SUVmax in prediction of malignancy in smaller nodules.