Enhancing PSMA PET/CT imaging of prostate cancer: investigating the impact of multiple time point evaluation, diuretic administration, cribriform pattern, and intraductal carcinoma.

OBJECTIVE: Our objective was to correlate staging PSMA PET imaging parameters to final histopathology. Second objective was to assess the performance of standard versus delayed PSMA PET to detect primary prostate tumor. METHODS: Thirty-one patients (mean age, 61.4 ± 8.2) who underwent radical prostatectomy and preoperative staging PSMA PET scans were included in the study. After defining dominant lesion in pathology, correlations with PET images were performed. Additionally, two physicians blind to clinical and pathological information retrospectively reviewed staging Ga-68 PSMA PET scans with standard and delayed imaging. RESULTS: Dominant lesion SUV's increased with time 8.2(± 4.5), 10(± 7.1), and 10.2(± 7.8) at 1, 2, and 3 h (P = .03 T1-T3). WHO Grade group 3 had highest SUV (group 3 11.9 ± 5.6 vs. group 2 7.9 ± 1.5, p = .02). Addition of cribriform pattern on intraductal component was associated with higher SUV's (11 ± 2.9 vs. 6.5 ± 2.1, p = .01) and higher Gleason four ratios (64 ± 9% vs. 37 ± 17%, p = .01). Intraductal carcinoma was associated with larger tumors (6.3 ± 2.3 cm3 vs. 2.6 ± 1.7 cm3, p < .001). Physician sensitivities ranged from 61 to 81%. Excluding Gleason 3 + 3 lesions and small lesions (< 1 cm3), sensitivities increased to 80-100%. Differences of sensitivity between different time points were not significant. Combined evaluation of all time points did not increase sensitivity. CONCLUSIONS: Cribriform pattern correlates with higher Gleason 4 ratios and SUVs in PSMA PET. Intraductal carcinoma is associated with larger tumors but not higher Gleason 4 ratios and SUVs. Multiple late imaging times did not enhance tumor detection and may pose tolerability issues for some patients.

Optimizing the Personalized Care for the Management of Rectal Cancer: A Consensus Statement.

Colorectal cancer is the third most common cancer in Turkey. The current guidelines do not provide sufficient information to cover all aspects of the management of rectal cancer. Although treatment has been standardized in terms of the basic principles of neoadjuvant, surgical, and adjuvant therapy, uncertainties in the management of rectal cancer may lead to significant differences in clinical practice. In order to clarify these uncertainties, a consensus program was constructed with the participation of the physicians from the Acibadem Mehmet Ali Aydinlar and Koç Universities. This program included the physicians from the departments of general surgery, gastroenterology, pathology, radiology, nuclear medicine, medical oncology, radiation oncology, and medical genetics. The gray zones in the management of rectal cancer were determined by reviewing the evidence-based data and current guidelines before the meeting. Topics to be discussed consisted of diagnosis, staging, surgical treatment for the primary disease, use of neoadjuvant and adjuvant treatment, management of recurrent disease, screening, follow-up, and genetic counseling. All those topics were discussed under supervision of a presenter and a chair with active participation of related physicians. The consensus text was structured by centralizing the decisions based on the existing data.

Findings of Gynecomastia That Developed in Follow-up Secondary to Bicalutamide Treatment on Bone Scan.

Prostate cancer is a common neoplastic disease especially in elder patients. Metastatic prostate disease has low five-year survival rate. Bicalutamide is an androgen receptor antagonist that acts as an inhibitor by competizing androgen receptors in the target tissue and used as a treatment option in prostate cancer. Bone scan was performed on a 79-year-old male with prostate cancer in our department. Blood pool images showed bilateral hyperemia in the breast regions which was not present on the previous scan one year ago. On physical examination, there was bilateral painful gynecomastia. It was learned that the patient was given Bicalutamide therapy after the first bone scan. Blood pool images may detect this side effect and should be evaluated with physical examination in case of clinical doubt.

Physiological fluorodeoxyglucose uptake of spinal cord in adults.

OBJECTIVE: Physiological fluorodeoxyglucose (FDG) uptake of spinal cord needs to be correctly recognized during evaluation of whole-body PET scans, especially for oncological cases. Our aim was to analyze physiological cord FDG uptake and its relation to gender, age, body weight, environmental temperature and time to imaging. MATERIALS AND METHODS: PET scans of 254 patients in a single year, one patient for every working day were retrospectively selected. Temperature data were obtained from meteorology recordings. Maximum standard uptake value (SUVmax) of spinal cord at cervical and lower thoracic levels were noted. Spinal canal at L5 level, cerebellum and liver were used for normalization. Correlations with age, body weight, time to imaging and environmental temperature were analyzed. RESULTS: Cervical SUV was higher than thoracic SUV (2.5-2.3). Cervical and lower thoracic SUV's were strongly correlated, highest when corrected with L5 level vertebral canal and liver (corr coeff 0.84 and 0.75) and lowest with cerebellum (corr coeff 0.4). Cervical spinal cord FDG uptake was higher for females than males (2.6 to 2.4). Temperature and age did not change spinal cord uptake. There were weak positive correlations with body weight (corr coeff 0.16 and 0.28, cervical and thoracic). There was weak negative correlation of cervical uptake with time to imaging (corr coeff -0.17). CONCLUSION: Spinal cord FDG uptake at cervical and lower thoracic levels are strongly correlated. Females have slightly higher cervical SUV. Age and temperature does not change spinal cord FDG uptake in adults. Cord SUV's slightly increased with body weight.

Effectiveness of the addition of the brain region to the FDG-PET/CT imaging area in patients with suspected or diagnosed lung cancer.

PURPOSE: We aimed to evaluate the effectiveness of the brain region imaging in FDG-PET/CT scanning of patients with suspected or diagnosed lung cancer. MATERIALS AND METHODS: We performed the study retrospectively on the medical charts of 427 patients. We divided the FDG-PET/CT field of view (FOV) into four major imaging regions: brain, head-neck, abdomen and pelvis. Metastatic findings on these regions were checked and determined the potential of these findings to affect the chemotherapy or radiotherapy protocol or surgical management. If metastatic findings had a potential to modify these parameters, we named this situation as "clinical contribution". Considering the number of bed positions of these regions, we calculated the clinical contribution of each region and named as "effective clinical contribution". Then, we calculated the metastatic findings, clinical contribution, and effective clinical contribution ratios. RESULTS: We found different brain metastasis ratios for lung cancer, solitary pulmonary mass (SPM), and solitary pulmonary nodule (SPN) groups (8.7, 2.8 and 0.9 %, respectively). In addition, the clinical contribution and effective clinical contribution ratios in the brain region for these three groups were 6.4, 2.8, 0.0 and 6.4, 2.8, 0.0 %, respectively. The highest metastatic findings (30.6 %) and clinical contribution (9.8 %) ratios were found in the abdomen region of the lung cancer group. However, the highest effective clinical contribution ratio (6.8 %) was found in the brain region within the same group. CONCLUSIONS: The addition of the brain region to the limited whole-body FOV in FDG-PET/CT scanning seems to be effective in the lung cancer and SPM groups, but not in the SPN group.

What approach should we take for the incidental finding of increased 18F-FDG uptake foci in the colon on PET/CT?

INTRODUCTION: F-Fluorodeoxyglucose (F-FDG) PET/CT represents an imaging modality that is gaining increasingly more prominence in screening, staging, and therapeutic monitoring of malignant diseases. An incidental focus of uptake in different regions of the body is not an uncommon finding during PET/CT imaging. Patients with incidental gastrointestinal tract findings comprise ∼3% of the overall patient group. The aim of the current study was to provide contributory information in relation to the answer on the most appropriate approach in cases with incidental colonic F-FDG uptake. PATIENTS AND METHODS: A retrospective examination was performed on PET/CT results of 5258 patients. Of these, 152 were recommended to undergo colonoscopy because of the presence of suspicious foci and 31 underwent colonoscopy within 60 days with biopsy from all visible lesions. These dates were also examined. RESULTS: Of the 24 patients undergoing colonoscopy with a suspicion of malignancy, five (20.83%) had no pathological findings. Of the 19 (79.17%) cases with a pathological finding in endoscopy, histopathology showed a benign lesion in five (20.83%), premalignant lesion in seven (29.17%), and a malignant lesion in seven (29.17%). Among seven patients undergoing colonoscopy because of a suspicion of inflammatory bowel disease, five were free of pathological signs and two patients with pathological endoscopy findings had nonspecific inflammation as documented by histopathological examination. CONCLUSION: Colonoscopic and histopathological examination of the increased foci of colonic F-FDG uptake incidentally detected at PET/CT seems to be a plausible approach.

Unexpected Uptake by the Gallbladder in Post-Ablative I-131 Scan.

A 47-year-old woman was diagnosed as papillary thyroid carcinoma. I-131 ablation therapy was applied following total thyroidectomy, and the whole-body scan revealed a focus of increased uptake in the right upper quadrant. Lateral view images of the uptake site showed that the focus was located near the right liver lobe. The patient was referred to radiology department for correlative abdominal Computed Tomography (CT) and Ultrasonography (US) to rule out a possible liver metastasis. CT images detected a gallstone in the corresponding area, which was verified by US. These methods did not reveal any metastatic disease in the liver or in other abdominal organs. This is the first published case report documents a rare false-positive finding of I-131 scan that was associated with an asymptomatic gallstone, and emphasizes the importance of correlative imaging in gallbladder related I-131 uptake.

Evaluation of clinical contributions provided by addition of the brain, calvarium, and scalp to the limited whole body imaging area in FDG-PET/CT tumor imaging.

PURPOSE: The aim of this study was to detect additional findings in whole body FDG-PET/CT scan including the brain, calvarium, and scalp (compared to starting from the base of the skull) in cancer patients and to determine contributions of these results to tumor staging and treatment protocols. MATERIALS AND METHODS: We noted whether the findings related to the brain, calvarium, and scalp in 1359 patients had a potential to modify staging of the disease, chemotherapy protocol, radiotherapy protocol, and surgical management. We identified rates of metastatic findings on the brain, calvarium, and scalp according to the tumor types on FDG-PET/CT scanning. RESULTS: We found FDG-PET/CT findings for malignancy above the base of the skull in 42 patients (3.1%), one of whom was a patient with an unknown primary tumor. Twenty-two of the metastatic findings were in the brain, 16 were in the calvarium, and two were in the scalp. CONCLUSION: This study has demonstrated that addition of the brain to the limited whole body FDG-PET/CT scanning may provide important contributions to the patient's clinical management especially in patients with lung cancer, bladder cancer, malignant melanoma, breast cancer, stomach cancer, and unknown primary tumor.

18F-FDG PET/CT findings of radiotherapy-related myocardial changes in patients with thoracic malignancies.

OBJECTIVE: The purpose of this study was to investigate myocardial findings of F-fluorodeoxyglucose PET/computed tomography (F-FDG PET/CT) after thoracic radiotherapy. METHODS: F-Fluorodeoxyglucose PET/CT examination was performed in 38 patients at least 4 months after radiotherapy. Patients with known cardiac diseases, high cardiovascular risk factors, or diabetes mellitus were excluded. RESULTS: On visual analysis, 28 patients were seen to have regional myocardial F-FDG uptake (74%), five patients were seen to have diffuse myocardial F-FDG uptake (13%), and five patients were seen to have no significant myocardial F-FDG uptake (13%). Regions of interest were drawn on irradiated and nonirradiated segments of the myocardium. The standardized uptake value measurements of the 28 patients with regional myocardial F-FDG uptake revealed significantly higher values in the irradiated segments in comparison with nonirradiated segments (P<0.001). CONCLUSION: Annular or focal increased F-FDG uptake in irradiated myocardial segments may be observed after thoracic radiotherapy. These myocardial uptake regions were not consistent with the vascular territory of coronary arteries, and the patients had no prior myocardial infarction or coronary artery disease. The patients with a history of thoracic radiotherapy, who showed increased F-FDG uptake on PET/CT, especially in the basal myocardium, should be followed up cautiously for the early diagnosis of cardiac events.

The role of positron emission tomography/CT in hypoxic ischaemic encephalopathy in children.

The role of positron emission tomography/CT (PET/CT) in diagnosis and follow-up of newborns with hypoxic ischaemic encephalopathy has been documented before; however, this is the first presentation of elder children with both diagnostic and follow-up PET/CT results as far as we know.

Incidental detection of pericardial effusion on bone scan.

The patient was a 57-year-old man with lung cancer. He was referred to nuclear medicine department for the evaluation of bone metastases. Bone scintigraphy was performed with 99mTc-labeled HDP. An abnormal photopenic area around the heart was seen on blood pool images. Delayed image of the thorax was normal. Chest x-ray study and echocardiography were performed to reveal the abnormality. Asymptomatic pericardial effusion was diagnosed in the corresponding area.

PET/CT images of a patient with haemophagocytic lymphohistiocytosis.

Haemophagocytic lymphohistiocytosis (HLH) is a rare immune disorder that predominantly affects macrophages and T lymphocytes and leads to multiple organ disease and death. The characteristic pathological finding in the bone marrow and the other affected tissues is haemophagocytosis of macrophages (macrophages digesting erythrocyte). Primary (hereditary) and secondary (acquired) forms of the disease are present. A patient with documented HLH disease revealed by positron emission tomography/CT is reported in this paper.

Detection of previous brain infarct on PET/CT study of a Hodgkin lymphoma patient.

Positron emission tomography/CT examination was performed to 62-year-old male patient with diagnosis of Hodgkin lymphoma for treatment response which revealed complete response. During re-evaluation process of this patient in our department, asymmetrical brain metabolism defect of right thalamus and hipometabolism of right parietal lobe was observed. This finding was confirmed with additional CT imaging as a subacute infarct tissue.

Liver schwannoma incidentally discovered in a patient with breast cancer.

BACKGROUND: Benign schwannomas, also referred to as neurilemomas, neurinomas, and perineural fibroblastomas, are encapsulated nerve sheath tumors. Primary schwannomas of the liver are extremely rare. We present a case of liver schwannoma, incidentally found in a patient with breast cancer. CASE: A 66-year-old female consulted her physician for a mass she palpated on her left breast. The abdominal ultrasonography (USG) revealed a 44 x 28 mm mass in the medial segment of the left lobe of her liver suspicious of a metastasis. An USG-guided biopsy was performed and the histo-pathological examination revealed a "peripheral nerve sheath tumor". Positron emission tomography (PET-CT) revealed a pathologic FDG uptake in the lesion that was previously defined in the liver. The tumor resected from the liver was 5 x 4 x 3 cm, yellowish, soft, and capsulated tumor. Microscopic examination revealed that the mass consisted of bundles of spindle cells with hypercellular and hypocellular areas. In immunohistochemistry, there was a strong positive staining for S-100. The tumor was diagnosed as benign liver schwannoma. CONCLUSION: Schwannomas are benign, encapsulated neoplasms. Symptoms and signs vary depending on the anatomical site and the size of the neoplasm; however, most schwannomas present as an asymptomatic or painless mass. Recurrence is unusual, despite of an incomplete removal, and malignant transformation is exceedingly rare (Fig. 4, Ref. 8). Full Text (Free, PDF) www.bmj.sk.