68 Ga-PSMA Uptake in the Testis : Two Different Patients With Two Different Diagnosis.

ABSTRACT: Although abnormal 68 Ga-PSMA uptake in the prostate and its metastases can be seen in a variety of diseases, it is rare to see in the testis. In these 2 cases, 68 Ga-PSMA PET/CT revealed unilateral 68 Ga-PSMA uptake in the testis of 2 patients. One of these patients was diagnosed with testis metastases from prostate cancer after an orchiectomy. The other patient was diagnosed with an orchitis. 68 Ga-PSMA uptake should be considered as an infection, as well as a malignancy in the initial differential diagnosis.

68 Ga-PSMA Uptake in Solar Elastosis.

ABSTRACT: 68 Ga-prostate specific membrane antigen (PSMA) PET/CT scan for staging revealed increased 68 Ga-PSMA uptake in solar elastosis in a patient with prostate cancer. Solar elastosis is a degenerative condition of elastic tissue in the dermis caused by prolonged sun exposure. A few studies have demonstrated 68 Ga-PSMA uptake in cutaneous lesions. This case illustrates another instance of a benign cutaneous lesion accompanied by increased 68 Ga-PSMA uptake.

The role of myocardial perfusion imaging in predicting myocardial ischemia in patients diagnosed with long COVID.

OBJECTIVE: Incomplete recovery with long-term complications weeks beyond the acute coronavirus disease 2019 (COVID-19) infection is referred to as long COVID. Among the well-known long-term complications of COVID-19, myocardial damage is a frequently encountered side effect. Yet there is a lack of data for identifying high-risk patients who are more likely to develop long-term cardiovascular complications following COVID-19. Myocardial perfusion imaging (MPI) is the primary functional imaging modality in evaluating myocardial ischemia This study aimed to investigate the role of MPI in predicting myocardial ischemia in patients diagnosed with long COVID. METHODS: Subjects were selected from eligible long COVID patients and control subjects without a prior history of COVID-19 who were referred to the nuclear medicine department for stress and rest single-photon emission computed tomography (SPECT) MPI. All participants' past medical records and clinical, and demographic characteristics were scanned. In addition, patients undergoing coronary angiography (CAG) following SPECT MPI were documented and patients with critical coronary stenosis were identified. RESULTS: Our results revealed that long COVID patients had higher rates of abnormal summed stress scores compared to the control subjects (p < 0.05). Additionally, serum CRP level, SPECT lung-to-heart ratio (LHR), and the presence of long COVID were independent predictors of ischemia. The presence of long COVID was the best predictor of ischemia among the aforementioned parameters (p < 0.001). CONCLUSION: Our data indicate that SPECT MPI provides comprehensive information on myocardial perfusion and left ventricular function in long COVID patients.

Comparison of prognostic value of different metabolic response criteria determined by PET/CT in patients with metastatic breast cancer under CDK 4/6 inhibitor treatment.

PURPOSE: This study evaluates the prognostic role of different [18F]FDG PET/CT metabolic response criteria in metastatic breast cancer (MBC) patients treated with cyclin-dependent kinase 4/6 inhibitors (CDK 4/6). MATERIALS AND METHODS: We retrospectively evaluated the data of MBC patients treated with CDK 4/6 inhibitors who underwent an [18F]FDG PET/CT scan before starting and during treatment. [18F]FDG PET/CT response was assessed with the European Organization for Research and Treatment of Cancer (EORTC), PET Response Criteria in Solid Tumors (PERCIST), and whole-body total lesion glycolysis (WBTLG) criteria. Fleiss kappa was computed to assess the agreement between metabolic response criteria. The endpoint of the study was progression-free survival (PFS). PFS data were analyzed by the Kaplan-Meier method and compared using the log-rank test. RESULTS: The study included sixteen MBC patients who received CDK 4/6 inhibitors therapy. According to PERCIST, partial metabolic response (PMR) was found in seven patients, stable metabolic disease (SMD) in seven patients, and progressive metabolic disease (PMD) in two patients. According to EORTC, PMR was detected in eight patients, SMD in seven patients, and PMD in one patient. According to WBTLG, PMR was found in 10 patients, SMD in four patients, and PMD in two patients. There was a fair agreement between the three criteria. While progression was detected in seven of the patients during follow-up, no progression was detected in nine of them. Kaplan-Meier analysis revealed that the responders according to WBTLG showed significantly longer PFS than non-responders. CONCLUSION: Treatment response according to WBTLG criteria during treatment appears to be associated with prolonged PFS in patients treated with CDK 4/6 inhibitors for MBC.

Characteristics of Radiopharmaceutical Uptake in Primary Tumor and Metastatic Lesions of Prostate Carcinoma: Comparison of Oligometastatic with Multimetastatic Disease.

Objectives: Oligometastases may generate secondary to indolent tumor biology. In this study, we investigated whether semiquantitative measures of 18F-fluorodeoxyglucose (FDG) and gallium-68 (68Ga) prostate-specific membrane antigen (PSMA) uptake of metastatic lesions and prostatic sites are different between oligometastatic (OM) and multimetastatic (MM) disease of prostate carcinoma (PC). Methods: Patients with PC, who underwent positron emission tomography/computed tomography (PET/CT) from October 2012 to February 2020 were retrospectively reviewed. Patients, whose reports were consistent with metastatic diseases were selected. Patients classified as with MM or OM disease. Maximum standardized uptake values (SUVmax) were calculated from metastatic lesions and the prostatic site. The median of the SUVmax results between patients with OM and MM disease were compared. Results: A totally 145 patients with a mean age of 71.46±9.26, were evaluated. In 59 of 145 patients, 18F-FDG PET/CT was performed;86 patients had gone through 68Ga PSMA PET/CT. Thirty-seven of 145 patients were OM, whereas 108 patients were MM. The median of the SUVmax of metastatic lesions in patients with OM and MM disease in the 18F-FDG group were 5.60 and 9.51, respectively. The results of the calculated median SUVmax values in OM and MM disease in the Ga-68 PSMA group were 13.44 and 29.84, respectively. A significant difference was observed in the median SUVmax results of metastatic lesions between OM and MM disease (p<0.05). Median values of SUVmax calculated from the prostatic site in OM and MM disease were 7.83 and 12.29 respectively in 18F-FDG; 26.23 and 26.74 in the 68Ga PSMA group. No significant difference was found in the SUVmax results of the prostatic site between OM and MM disease (p>0.05). Conclusion: SUVmax results of metastatic lesions are significantly higher in patients with MM than in patients with OM disease in patients with PC, which may be secondary to their different biological contents in terms of aggressiveness.

Isolated Liver Metastasis Detected by 68 Ga-PSMA PET/CT in Newly Diagnosed Prostate Cancer.

ABSTRACT: Lymph nodes, bones, and liver are the most typical metastatic sites for prostate cancer. However, isolated liver metastasis from prostate cancer is extremely rare. Here, we report a 75-year-old man with newly diagnosed prostate adenocarcinoma, with isolated liver metastasis detected by 68 Ga-PSMA ( 68 Ga-prostate-specific membrane antigen) PET/CT. There was no sign of regional or distant metastases elsewhere. This case highlights the value of 68 Ga-PSMA PET/CT in detecting a very uncommon solitary liver metastasis from prostate cancer.

Association of Fluorodeoxyglucose Positron Emission Tomography Radiomics Features with Clinicopathological Factors and Prognosis in Lung Squamous Cell Cancer.

Aim: To evaluate the role of fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) radiomics features (RFs) for predicting clinicopathological factors (CPFs) and prognosis in patients with resected lung squamous cell cancer (LSCC). Material and Methods: Patients with early-stage (stage I-III) LSCC who underwent 18F-FDG PET/CT before surgical resection between August 2012 and February 2020 were analyzed. Patients who received neoadjuvant chemotherapy or radiotherapy were excluded from the study. The maximum standard uptake value (SUVmax) and RFs were extracted from PET images for primary tumors. The diagnostic performances of PET parameters in groups of tumor differentiation, stage, and mediastinal lymph node metastasis (MLNM) status were evaluated. The study endpoints were overall survival (OS) and progression-free survival (PFS). Univariate and multivariate analyses were performed with RFs, SUVmax, and CPFs to find independent predictors of PFS and OS. Results: A total of 77 patients (5 female, 72 male) were included in the study. SUVmax and GLCM entropy were independently associated with tumor differentiation. The only parameter with significant diagnostic performance for MLNM was GLZLM-SLZGE. Tumor diameter and NGLDM busyness were independently associated with the stage. MLNM and tumor differentiation were found to be independent predictors of PFS. NGLDM contrast and MLNM were independently associated with OS. Conclusion: Using radiomic features in addition to CPFs to predict disease recurrence and shorter overall survival can guide precision medicine in patients with LSCC.

Diagnostic compatibility of V/Q SPECT and CTPA, which are non-invasive diagnostic methods, for the detection of CTEPH, which is a treatable cause of pulmonary hypertension.

OBJECTIVE: To evaluate the compatibility between ventilation/perfusion (V/Q) single photon emission computed tomography (SPECT) scintigraphy and computed tomography pulmonary angiography (CTPA) in diagnosing chronic thromboembolic pulmonary hypertension (CTEPH). SUBJECT AND METHODS: Twenty cases of CTEPH, out of 98 patients with pre-diagnosis of pulmonary hypertension (PH), who was diagnosed with CTEPH with a multidisciplinary approach and a council decision, were included in the study retrospectively. The diagnostic performances of V/Q SPECT and CTPA, which are used as noninvasive methods in diagnosing CTEPH, and the compatibility between them were calculated statistically. RESULTS: Of 20 patients diagnosed with CTEPH, 12 were female, and 8 were male; the mean age was 59.1 (range: 36-79). The sensitivity of V/Q SPECT scintigraphy of imaging methods used to diagnose CTEPH was 90%, CTPA was 80%, specificities were 88% and 92%, respectively, and accuracy was 88% in both cases methods. According to the reference standard, the kappa value for V/Q scintigraphy was calculated as 0.765 and 0.678 for CTPA. These values were statistically significant (P<0.01), and there was a substantial concordance between them. CONCLUSION: There is significant compatibility between V/Q SPECT scintigraphy and CTPA in diagnosing CTEPH, whose differential diagnosis is essential because of its high cure potential due to PH causes.

Characterization of bone metastases detected on 68Ga-PSMA PET/CT in newly diagnosed prostate cancer.

OBJECTIVE: This study sought to investigate the characteristics of bone metastasis (BM) and the association of BM with clinicopathological factors in prostate cancer (PCa) patients presenting with BM on the initial staging gallium-68-prostate-specific membrane antigen (68Ga-PSMA) positron emission tomography/computed tomography (PET/CT). MATERIALS AND METHODS: Patients with at least one BM in the initial staging 68Ga-PSMA PET/CT between January 2018 and December 2021 were reviewed retrospectively. Types of BM were classified according to 68Ga-PSMA PET/CT findings as osteoblastic (OB), osteolytic (OL), intramedullary (IM) and coexistence of these types. Patients were divided into two groups according to the number of BM: Oligo-BM for those with five or fewer BMs and poly-BM for those with more than five BM. Receiver-operating characteristic (ROC) curves were generated for serum bone-specific alkaline phosphatase (ALP) and prostate-specific antigen (PSA) levels to discriminate between oligo-BM and poly-BM groups. Univariate and multivariate logistic regression tests were performed to find independent predictors of poly-BM. RESULTS: A total of 53 patients with a median age of 70 (range: 49-88) were included in the study. The median Gleason score of the patients was 8 (range: 6-10). Among the patients, 23 had solely OB-type; 10 had solely IM type; 12 had OB and IM type; four had IM and OL type, two had OB and OL type; one had solely OL type, and one had IM and OB and OL type BM. Oligo-BM was detected in 25 patients (47.2%) and poly-BM was detected in 28 patients (52.8%). In multivariate analyses, serum ALP levels ≥122U/L and PSA levels ≥85.4ng/mL were found to be independent predictors of poly-BM. CONCLUSION: In characterizing BM of PCa, we found that OB-type metastases were the most common type, followed by IM-type and OL-type metastases, respectively. High ALP and PSA levels were found to be independent predictors of poly-BM.

A rare involvement of diffuse large B-cell lymphoma: Peritoneal lymphomatosis with a peritoneal super-scan appearance on 18F-FDG PET/CT.

Peritoneal lymphomatosis (PL) is a rare extranodal involvement of non-Hodgkin's lymphoma (NHL) and is associated with a poor prognosis. It is confused with the more common peritoneal carcinomatosis and may be misdiagnosed. Early diagnosis is the most important step of effective treatment. In patients with NHL, fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is a valuable imaging modality in guiding biopsy, determining extent of the disease, and evaluating metabolic response to therapy. It also provides important information in the differential diagnosis. We report a case of a 40-year-old male patient who presented with abdominal distention and pain, with diffuse thickening of the peritoneum suggestive of peritoneal carcinomatosis on a computed tomography scan. Biopsy from the thickened peritoneum confirmed the diagnosis of diffuse large B cell lymphoma (DLBCL). Fluorine-18-FDG PET/CT performed for staging showed thickening and increased 18F-FDG uptake in almost the entire peritoneum as well as lymph node involvement in supra- and infra-diaphragmatic areas, and a mass in the spleen. Post-treatment 18F-FDG PET/CT revealed a complete metabolic response.

The Role of Histogram-Based Textural Analysis of 18F-FDG PET/CT in Evaluating Tumor Heterogeneity and Predicting the Prognosis of Invasive Lung Adenocarcinoma.

OBJECTIVES: This study aimed to investigate the contributory role of histogram-based textural features (HBTFs) extracted from 18fluorinefluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in tumoral heterogeneity (TH) evaluation and invasive lung adenocarcinoma (ILA) prognosis prediction. METHODS: This retrospective study analyzed the data of 72 patients with ILA who underwent 18F-FDG PET/CT followed by surgical resection. The maximum standardized uptake value (SUVmax), metabolic tumor volume, and total lesion glycolysis values were calculated for each tumor. Additionally, HBTFs were extracted from 18F-FDG PET/CT images using the software program. ILA was classified into the following five histopathological subtypes according to the predominant pattern: Lepidic adenocarcinoma (LA), acinar adenocarcinoma, papillary adenocarcinoma, solid adenocarcinoma (SA), and micropapillary adenocarcinoma (MA). Differences between 18F-FDG PET/CT parameters and histopathological subtypes were evaluated using non-parametric tests. The study endpoints include overall survival (OS) and progression-free survival (PFS). The prognostic values of clinicopathological factors and 18F-FDG PET/CT parameters were evaluated using the Cox regression analyses. RESULTS: The median SUVmax and entropy values were significantly higher in SA-MA, whereas lower in LA. The median energy-uniformity value of the LA was significantly higher than the others. Among all parameters, only skewness and kurtosis were significantly associated with lymph node involvement status. The median values for follow-up time, PFS, and OS were 31.26, 16.07, and 20.87 months, respectively. The univariate Cox regression analysis showed that lymph node involvement was the only significant predictor for PFS. The multivariate Cox regression analysis revealed that higher SUVmax (≥11.69) and advanced stage (IIB-IIIA) were significantly associated with poorer OS [hazard ratio (HR): 3.580, p=0.024 and HR: 7.608, p=0.007, respectively]. CONCLUSION: HBTFs were tightly associated with clinicopathological factors causing TH. Among the 18F-FDG PET/CT parameters, only skewness and kurtosis were associated with lymph node involvement, whereas SUVmax was the only independent predictor of OS. TH measurement with HBTFs may contribute to conventional metabolic parameters in guiding precision medicine for ILA.

Association of 18F-FDG PET/CT textural features with immunohistochemical characteristics in invasive ductal breast cancer / Asociación de características texturales de PET/TC 18F-FDG con características inmunohistoquímicas en el cáncer de mama ductal invasivo

Objetivo: Este estudio investiga si las características de textura (TF) extraídas de la tomografía por emisión de positrones/tomografía computarizada (PET/TC) con fluoruro-18 fluorodesoxiglucosa (F-18 FDG) están asociadas con las características inmunohistoquímicas (IHC) del carcinoma ductal de mama invasivo (IDBC).Materiales y métodos: Se evaluó la relación de TF con IHC [receptor de estrógeno (ER), receptor de progesterona (PR), receptor 2 del factor de crecimiento epidérmico humano (HER-2), índice de proliferación Ki-67 y grados histológicos] de tumores primarios extirpados únicamente para una evaluación más precisa. Por lo tanto, los pacientes con IDBC en estadio temprano que se sometieron a una exploración por PET/TC con F-18 FDG pre-operatoria para la estadificación se incluyeron en este estudio retrospectivo. La estadificación clínica se realizó de acuerdo con la 8a edición del American Joint Committee on Cancer. El valor máximo de captación estandarizada (SUVmáx) y 37 TF del tumor primario se extrajeron de F-18 FDG PET/TC. Se utilizó la prueba de correlación de rango de Spearman para evaluar la correlación entre TF y SUVmáx. Se generaron curvas de características operativas del receptor para definir el rendimiento diagnóstico de cada parámetro. Entre estos parámetros, aquellos con mayor rendimiento diagnóstico se incluyeron en el modelo de regresión logística multivariante para identificar los predictores independientes de las características histopatológicas.Resultados: Se incluyeron un total de 124 pacientes. La uniformidad del histograma, la energía GLCM y la homogeneidad GLCM mostraron una fuerte correlación negativa con SUVmax, mientras que GLRLM-SRHGE, GLZLM-HGZE, GLRLM-HGRE, GLCM-entropía, GLCM-contraste, histograma-entropía y GLCM-disimilitud mostraron una fuerte correlación positiva. Algunos de los TF se asociaron de forma independiente con ER-negatividad, PR-negatividad, HER-2-positividad y aumento del índice

Objectıves: This study investigates whether textural features (TFs) extracted from 18F-FDG positron emission tomography/computed tomography (PET/CT) are associated with immunohistochemical characteristics (IHCs) of invasive ductal breast carcinoma (IDBC).Materials and methods: The relationship of TFs with IHCs [estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER-2), Ki-67 proliferation index, and histological grades] from solely excised primary tumors were evaluated for a more accurate assessment. Therefore patients with early-stage IDBC who underwent pre-operative 18F-FDG PET/CT scan for staging were included in this retrospective study. The clinical staging was performed according to the 8th edition of the American Joint Committee on Cancer. Maximum standardized uptake value (SUVmax) and 37TFs of the primary tumor were extracted from 18F-FDG PET/CT. Spearman’s rank correlation test was used to evaluate the correlation between TFs and SUVmax. Receiver operating characteristic curves were generated to define the diagnostic performance of each parameter. Among these parameters, those with the highest diagnostic performance were included in the multivariate logistic regression model to identify the independent predictors of histopathological characteristics.Results: A total of 124 patients were included. Histogram-uniformity, grey-level co-occurrence matrix (GLCM), GLCM-energy, and GLCM-homogeneity showed a strong negative correlation with SUVmax, while grey-level run-length matrix (GLRLM), GLRLM-SRHGE, grey-level zone length matrix (GLZLM), GLZLM-HGZE, GLRLM-HGRE, GLCM-entropy, GLCM-contrast, histogram-entropy, and GLCM-dissimilarity showed a strong positive correlation. Some of the TFs were independently associated with ER-negativity, PR-negativity, HER-2-positivity, and increased Ki-67 proliferation index (GLCM-contrast, GLZLM-GLNU, histogram-uniformity, and shape-sphericity respectively)

Association of 18F-FDG PET/CT textural features with immunohistochemical characteristics in invasive ductal breast cancer.

OBJECTiVES: This study investigates whether textural features (TFs) extracted from 18F-FDG positron emission tomography/computed tomography (PET/CT) are associated with immunohistochemical characteristics (IHCs) of invasive ductal breast carcinoma (IDBC). MATERIALS AND METHODS: The relationship of TFs with IHCs [estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER-2), Ki-67 proliferation index, and histological grades] from solely excised primary tumors were evaluated for a more accurate assessment. Therefore patients with early-stage IDBC who underwent pre-operative 18F-FDG PET/CT scan for staging were included in this retrospective study. The clinical staging was performed according to the 8th edition of the American Joint Committee on Cancer. Maximum standardized uptake value (SUVmax) and 37TFs of the primary tumor were extracted from 18F-FDG PET/CT. Spearman's rank correlation test was used to evaluate the correlation between TFs and SUVmax. Receiver operating characteristic curves were generated to define the diagnostic performance of each parameter. Among these parameters, those with the highest diagnostic performance were included in the multivariate logistic regression model to identify the independent predictors of histopathological characteristics. RESULTS: A total of 124 patients were included. Histogram-uniformity, grey-level co-occurrence matrix (GLCM), GLCM-energy, and GLCM-homogeneity showed a strong negative correlation with SUVmax, while grey-level run-length matrix (GLRLM), GLRLM-SRHGE, grey-level zone length matrix (GLZLM), GLZLM-HGZE, GLRLM-HGRE, GLCM-entropy, GLCM-contrast, histogram-entropy, and GLCM-dissimilarity showed a strong positive correlation. Some of the TFs were independently associated with ER-negativity, PR-negativity, HER-2-positivity, and increased Ki-67 proliferation index (GLCM-contrast, GLZLM-GLNU, histogram-uniformity, and shape-sphericity respectively). While SUVmax had an independent association with high-grade and triple-negativity, GLZLM-SZLGE, a high-order TF that shows the distribution of the short homogeneous zones with low grey-levels, had an independent association with axillary lymph node metastasis. CONCLUSIONS: ER-negative, PR-negative, HER-2-positive, triple-negative, high-grade, highly proliferative, and high-stage tumors were found to be more glycolytic and metabolically heterogeneous. These findings suggest that the use of TFs in addition to SUVmax may improve the prognostic value of 18F-FDG PET/CT in IDBC, as certain TFs were independently associated with many IHCs and predicted axillary lymph node involvement.

Evaluation of the Histopathological Features of Early-stage Invasive Ductal Breast Carcinoma by 18Fluoride-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Objectives: This study investigates the relationship between 18fluoride-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) parameters and histopathological features in patients with early-stage invasive ductal breast carcinoma (IDBC). Methods: Patients with early-stage IDBC who underwent 18F-FDG PET/CT scan for staging were included in this retrospective study. The status of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2, Ki-67 proliferative index, and grades of tumors were recorded. The conventional metabolic parameters [maximum standard uptake value (SUVmax) and average standard uptake value] and volume-based parameters [metabolic tumor volume (MTV) and total lesion glycolysis] of the primary tumor were obtained from the 18F-FDG PET/CT images. The associations and correlations between the 18F-FDG PET/CT parameters and histopathological features were assessed. Results: One hundred forty-three patients were included. 18F-FDG PET/CT parameters, other than MTV, were significantly associated with the ER and PR status and Ki-67 index, while T-staging was significantly associated with all 18F-FDG PET/CT parameters. In the axillary lymph node (ALN) involvement, no significant difference was found in the 18F-FDG PET/CT parameters. In terms of the pathological stage, a significant difference was found in all 18F-FDG PET/CT parameters. 18F-FDG PET/CT parameters, other than MTV, were significantly higher in non-luminal breast tumors than luminal tumors and in high-grade tumors than low-grade ones. Triple-negative tumors had the highest 18F-FDG PET/CT parameter, but the difference was insignificant for MTV. The SUVmax had the strongest correlation with Ki-67 proliferative index. Conclusion: Tumors with aggressive histopathological features had higher 18F-FDG PET/CT parameter values. This study suggests that 18F-FDG PET/CT may provide prognostic information in patients with early-stage IDBC.

Could the skewness and kurtosis texture parameters of lesions obtained from pretreatment Ga-68 DOTA-TATE PET/CT images predict receptor radionuclide therapy response in patients with gastroenteropancreatic neuroendocrine tumors?

PURPOSE: In our study, tumor heterogeneity was evaluated using the parameters skewness and kurtosis on pretreatment Ga-68 DOTA-TATE PET/CT to assess therapy responses of lesions in patients with gastroenteropancreatic neuroendocrine tumors (GEP NETs) treated with peptide receptor radionuclide therapy (PRRT). METHOD: We retrospectively studied the texture analysis with relatively simple first-order parameters skewness and kurtosis on pretreatment Ga-68 DOTA-TATE PET/CT from 22 patients (eight females, 14 males; with a mean age: 54 ± 11 years) with GEP NETs who were treated with 2-6 therapy cycles of Lu-177 DOTA-TATE. A total of 326 lesions of 22 patients were evaluated in terms of treatment response by Ga-68 DOTA-TATE PET/CT examination performed before and after treatment. Receiver-operating characteristic (ROC) curves were generated to assess skewness and kurtosis to discriminate between responder and nonresponder lesions. RESULT: A total of 326 lesions of 22 patients were evaluated and 137 lesions responded partially or completely to the treatment, 189 lesions did not respond to treatment, remained stable or progressed. The skewness and kurtosis values of the lesions which did not respond to the PRRT were significantly higher than those with response to PRRT treatment (P < 0.001 and P = 0.004, respectively). However, ROC curves provided a moderate area under the curve value for skewness and a relatively low value for kurtosis (0.619 and 0.518, respectively). CONCLUSION: Texture analysis using skewness and kurtosis of the lesions on pretreatment Ga-68 DOTA-TATE PET/CT was able to predict their responsiveness to PRRT.

Which of the fluorine-18 fluorodeoxyglucose positron emission tomography/computerized tomography parameters are better associated with prognostic factors in breast cancer?

The aim of the present study is to evaluate the relationship between the immunohistochemical and histopathological prognostic factors and the metabolic fluorine-18 fluorodeoxyglucose positron emission tomography/computerized tomography (PET/CT) parameters in breast cancer.A total of 94 female patients diagnosed with primary breast cancer (median age: 54.5 years, 94 lesions with size >15 mm) who underwent PET/CT imaging before any treatment were enrolled to this retrospective study. Maximum and average standardized uptake values (SUVmax and SUVavg), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and tumor/liver uptake ratio (TLR) of the primary tumors were calculated and compared between various histopathological and immunohistochemical prognostic factor groups.All metabolic parameters were associated with clinical T stage, metabolic M stage, and nuclear grade. The MTV, TLG, and TLR were significantly higher in patients with suspected lymph node metastasis. There were significant differences according to estrogen receptor and human epidermal growth factor-2 status in the metabolic values other than MTV. In case of progesterone receptor, there were significant differences in the metabolic characteristics except for the MTV and TLG values. The Ki-67 labeling index was moderately correlated with SUVmax, SUVavg, and TLR. All metabolic characteristics except MTV were significantly higher in triple negative breast cancer compared with the other molecular subtypes.The results of the present study suggest that the TLG and TLR values have stronger associations with several prognostic factors in breast cancer (BC) compared with other metabolic parameters.

Treatment of Unstable Thoracolumbar Fractures: Does Fracture-Level Fixation Accelerate the Bone Healing?

OBJECTIVE: To investigate the effect of fusion on short segment including fractured level (SSIFL) and long segment (LS) transpedicular fixation after acute thoracolumbar junction burst fractures. The 2-year clinical and radiologic follow-up results of the 2 groups also were compared. METHODS: Seventy-four patients were randomized into one of 2 groups: SSIFL (n = 39) or LS (n = 35). The SSIFL group included one level above and one level below, including the fracture level, whereas the LS group included 2 levels above and 2 levels below, excluding the fracture level, for the transpedicular fixation. Fusion was assessed by technetium 99m-methylendiphosphonate, bone scintigraphy, and single-photon emission computed tomography. The 2-year follow-up results were compared clinically (Oswestry Disability Index and visual analog scale) and radiologically (kyphosis angle, sagittal index, anterior vertebral body height loss) at regular intervals. The clinical scores and radiologic parameters of patients with and without fusion also were compared. RESULTS: The number of patients with fusion was significantly greater in the SSIFL group compared with the LS group. There was a significant reduction of the clinical scores of patients who had fusion compared with the fusion-free group; however, there was no radiologically significant difference. Furthermore, there was no significant difference between the SSIFL and LS groups in terms of the 2-year radiologic and clinical follow-up results. CONCLUSIONS: Fusion occurred sooner and patients experienced earlier clinical recovery in the SSIFL group compared with the LS group.

Is there any complimentary role of F-18 NaF PET/CT in detecting of osseous involvement of multiple myeloma? A comparative study for F-18 FDG PET/CT and F-18 FDG NaF PET/CT.

Multiple myeloma (MM) is a disease characterized by a monoclonal plasma cell population in the bone marrow whereby osseous involvement is a predominant feature. The aim of this prospective study was to investigate the combined use of F-18 FDG and F-18 NaF PET/CT in the skeletal assessment of patients with MM and to compare the efficacy of these two PET tracers regarding detection of myeloma-indicative osseous lesions. A total of 26 patients (14 females and 12 males, mean age 61.8 ± 1.8 years (range 40-81 years)) with MM diagnosed according to standard criteria. All patients underwent both F-18 FDG PET/CT and F-18 NaF PET/CT scans within 1 week after the completion of the usual staging workup for MM. In total, approximately 128 focal F-18 FDG avid skeletal lesions were detected; the stage I (n = 5) patients had 10 bone lesions, the stage II (n = 11) patients had 43 lesions, and the stage III (n = 10) patients demonstrated 75 focal bone lesions. F-18 NaF PET/CTs demonstrated fewer myeloma indicative lesions than F-18 FDG PET/CTs. Totally, 57 focal bone lesions were detected with whole body F-18 NaF PET/CT (mean 2.19 ± 0.34, between 1 and 9 lesions); the five stage I patients had 6 bone lesions, the 11 stage II pts had 18 lesions, and the ten stage III patients demonstrated 33 focal bone lesions. On the other hand, F-18 NaF PET/CT demonstrated additional 135 bone lesions defined as rib fractures and other findings due to degenerative changes. In conclusion, our study implies that F-18 NaF PET/CT scan did not actually aid for assessing the myelomatous bone lesions in patients with MM. Therefore, a complementary F-18 NaF PET/CT may be an accurate modality for detecting of bone fracture in patients with MM.