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.

Can shear wave elastography determine remnant thyroid tissue in the early postoperative period in patients with differentiated thyroid carcinoma?

PURPOSE: This study aims to investigate the usability of ultrasonography (US) and shear wave elastography (SWE) in detecting remnant thyroid tissue (RTT) within the first three postoperative months in patients who underwent total thyroidectomy (TT) for differentiated thyroid cancer (DTC) and who were scheduled for radioiodine (RAI) ablation therapy. METHODS: Sixty-nine patients who underwent a TT operation due to DTC were included in the study. The participant's thyroid surgical bed was first evaluated by thyroid scintigraphy and then by greyscale US and SWE to investigate RTT. The participants were divided into two groups, those with and those without RTT. SWE quantitative data were compared between the two groups. Receiver operating characteristic (ROC) curve analysis was performed to determine the best cut-off values for stiffness and velocity in distinguishing RTT. RESULTS: A total of 149 regions were analysed in 69 participants (43 females, 26 males). The average time elapsed after the operation was 65.2 ± 24.1 days. RTT was determined by scintigraphy and US-SWE in 38 (55%) patients. The stiffness and velocity values were significantly higher in the group with RTT than in the group without RTT. To distinguish RTT from the thyroid bed, the best cut-off values for stiffness and velocity were 15.7 kPa and 2.12 m/s, respectively. CONCLUSIONS: US with SWE can detect RTT in the early postoperative period in patients who have undergone TT due to DTC and who are scheduled for RAI treatment. The use of US and SWE will be particularly beneficial in patients with RTT but who have false-negative Tg levels and RTT that is not I-131 avid.

Using 2-dimensional color superb microvascular imaging vascularization index technique in the assessment of thyroid surgical bed.

AIM: The purpose of this study was to investigate the effectiveness of the vascularization index (VI) obtained using color superb microvascular imaging (cSMI) technique in the assessment of thyroid surgical bed for remnant thyroid tissue (RTT). MATERIAL AND METHODS: We evaluated the thyroid surgical bed of 65 patients who had underwent total thyroidectomy (TT) due to papillary carcinoma (PC) using thyroid scintigraphy and cSMI. Color SMI was also performed for the examination of the thyroid parenchyma of 39 healthy asymptomatic participants. VI measurements were performed by manually drawing the contours of the RTT in those with remnant thyroid, the thyroid surgical bed in the patients' group without remnant thyroid, and normal thyroid parenchyma in the control group, using the free region of interest (ROI) with 2-dimensional color SMI VI (2DcSMIVI) mode. The volume of ROI was measured and echogenicity was evaluated. The quantitative 2DcSMIVI values of the surgical bed with RTT (Group A), the surgical bed without RTT (Group B) and normal thyroid of healthy asymptomatic participants (Group C) were compared. RESULTS: The mean 2DcSMIVI values of Group A was significantly higher than Group B and C (p=0.001). The presence of RTT can be diagnosed with 89.1% sensitivity and 87.5% specificity when 1.75 2DcSMIVI is designated as the cut-off value. CONCLUSION: The 2DcSMIVI is an effective imaging technique that can be used for the diagnosis of RTT.

Hyoid osteoradionecrosis accompanied by candida infection.

Osteoradionecrosis of the hyoid bone is a rare complication of therapeutic irradiation performed for head and neck cancer. In this article, we present a 52-year-old male patient who admitted with severe odynophagia following chemo-radiotherapy administration for tonsil carcinoma. Fluorine-18-fluorodeoxy-glucose positron emission tomography-computed tomography revealed a metabolic activity in hyoid bone. The pathological findings were consistent with fungal infection and hyoid bone necrosis. Hyoid osteoradionecrosis should be kept in mind in patients with intractable dysphagia following irradiation for head and neck tumors.

Fluorodeoxyglucose positron emission tomography/computed tomography imaging of a patient with squamous cell carcinoma of prostate.

Primary squamous cell carcinoma is an uncommon tumor of the prostate gland. We report a 77-year-old male patient with urinary frequency and constipation. Fine needle biopsy from prostate was suspicious of squamous cell carcinoma of the prostate. Whole body positron emission tomography/computed tomography scan revealed high fluorodeoxyglucose uptake in prostate gland. Transurethral resection confirmed the diagnosis. In contrast to prostatic adenocarcinoma, high fluorodeoxyglucose accumulation was observed in the primary tumor of the prostate gland.

Rare Thyroid Cartilage and Diaphragm Metastases from Lung Cancer Visualized on F-18 FDG-PET/CT Imaging.

UNLABELLED: Positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) has evolved as a useful imaging modality in the assessment of a variety of cancers, especially for tumor staging and post treatment monitoring. It provides metabolic information. Although, when used alone, relative lack of anatomic landmarks, is a major limitation of PET imaging, this limitation of PET imaging is overcome by the availability of integrated PET/CT imaging. PET and CT images are acquired in one procedure, yielding fused anatomical and functional data sets. Studies with integrated PET/CT imaging have shown promising results. In this case, we present an interesting integrated PET/CT imaging in a lung cancer patient with rare, diaphragm and thyroid cartilage metastases. CONFLICT OF INTEREST: None declared.

Detection of bone metastases in initial staging of orbital embryonal rhabdomyosarcoma by fluorodeoxyglucose positron emission tomography/computed tomography.

UNLABELLED: Rhabdomyosarcoma is the most common form of soft tissue sarcoma in young children. In soft tissue sarcomas, isolated metastases are seen in the lung, soft tissue, and bone. The optimal management of these tumors depends on the site, size, and grade of the local growth, and accurate staging of the disease when first seen. Although detection of the primary site of disease is usually accomplished well with conventional techniques, the performance of fluorodexyglucose (FDG) positron emission tomography/computed tomography (PET/CT) may be useful to determine metastases that are not clinically evident. We describe a case of early detection of distant metastases by FDG PET/CT in a young patient diagnosed with orbital embryonal rhabdomyosarcoma. CONFLICT OF INTEREST: None declared.

Findings on fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in a patient with malignant pheochromocytoma.

UNLABELLED: Pheochromocytomas are rare tumors arising from chromaffin cells of the sympathoadrenal system and 85% of them are located in the adrenal medulla. Malignant pheochromocytomas account for 10% of all pheochromocytomas. Since clinical, biochemical and histopathological features can not reliably distinguish malignant from benign tumors, malignancy is established in the presence of distant metastases. Although in some cases, metastases may develop during follow-up, most of these tumors have metastatic disease at initial presentation. In this case report, detection of distant metastases and recurrence developed during follow-up with 18-flouro-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in a patient with malignant pheochromocytoma was presented. CONFLICT OF INTEREST: None declared.

The role of fluorodeoxyglucose-positron emission tomography/computed tomography in differentiating between benign and malignant adrenal lesions.

OBJECTIVES: This retrospective study was designed to investigate the clinical role of whole-body positron emission tomography/computed tomography (PET/CT) by using 2-[18F]fluoro-2-deoxy-D-glucose (FDG), for the evaluation of adrenal lesions and to find the best index to distinguish benign from malignant lesions in various cancer patients. MATERIALS AND METHODS: A total of 81 patients (55 male and 26 female, age range: 31-81 years, mean: 61.5) who had confirmed primary malignancies (lung cancer in 47 patients, gastrointestinal malignancies in 13 patients, malignant melanoma in one patient, renal cell cancer in three patients, mesothelioma in two patients, breast carcinoma in nine patients, cervical cancer in one patient, ovarian cancer in two patients, pheochromocytoma in one patient, unknown primary in two patients) underwent PET/CT examinations for cancer screening, staging, restaging, and detection of suspected recurrence. Of the 81 patients, 104 adrenal lesions (34 benign and 70 malignant adrenal lesions) were shown by CT. On visual analysis of PET/CT imaging, adrenal uptake was based on a three-scale grading system. For final assessment standards of references for adrenal malignant lesions was based on biopsy (n=2), interval growth, or reduction after chemotherapy. An adrenal lesion, which remained unchanged on clinical and imaging follow-up of at least 7 months (mean follow-up time 19.31 months±6.46, range 7-30 months), was decided as a benign lesion. RESULTS: In adrenal malignant lesions maximum standardized uptake value (SUVmax) (8.82±4.47) was higher than that of adrenal benign lesions (3.02±1.15, P<0.0001). In the differentiation of adrenal benign and malignant lesions, a CT threshold of 10 Hounsfield units corresponded to a sensitivity of 64.7%, specificity of 98.6%, and accuracy of 87.5%. An SUVmax cut-off value of 2.5 corresponded to a sensitivity of 100%, specificity of 38.2%, and accuracy of 80%. An SUVmax cut-off value of 4.2 corresponded to a sensitivity of 88.6%, specificity of 88.2%, and accuracy of 88.5%. The ratio of tumor SUVmax to liver SUVmean was 3.61±1.77 for adrenal malignant lesions whereas it was 1.20±0.38 for adrenal benign lesions (P<0.0001). T/L SUV ratio cut-off value of 1.8 corresponded to a sensitivity of 87%, specificity of 91%, and accuracy of 88.5%. T/L SUV ratio cut-off value of 1.68 corresponded to a sensitivity of 90%, specificity of 91.1%, and accuracy of 90.4%. CONCLUSION: 2-[18F]fluoro-2-deoxy-D-glucose-PET/CT improves the diagnostic accuracy in the differentiation of benign from malignant adrenal lesions in various cancer patients. Combined information obtained from PET/CT (SUVmax, T/L SUV ratio, visual analysis) and unenhanced CT (size, Hounsfield units measurement) is recommended for better differentiation.

Askin's Tumor in an Adult: Case Report and Findings on 18F-FDG PET/CT.

Primitive neuroectodermal tumor (PNET) of the chest wall or Askin's tumor is a rare neoplasm of chest wall. It most often affects children and adolescents and is a very rare tumor in adults. In this case report, we present an Askin's tumor occurred in a 73-year-old male. The patient was admitted with a history of 3-month lower back pain and cough. In computed tomography, there was a lesion with dimensions of 70 x 40 x 65 mm in the superior segment of the lower lobe of the left lung. Positron emission tomography/computed tomography with 18F-flourodeoxyglucose revealed a pleural-based tumor in the left lung with a maximum standardized uptake value of 4.36. No distant or lymph node metastases were present. The patient had gone through surgery, and wedge resection of the superior segment of left lobe and partial resection of the ipsilateral ribs were performed. Pathology report with immunocytochemistry was consistent with PNET and the patient received chemotherapy after that.