Late 68Ga PSMA-positive Pancreatic Metastasis From Renal Cell Carcinoma in a Patient with Metastatic Prostate Cancer: A Mission Impossible.

We present the case of a patient with newly diagnosed high-risk prostate cancer. The patient underwent nephrectomy for renal cell carcinoma (RCC) in 2009. The prostate-specific membrane antigen (PSMA) scan revealed a primary tumor with seminal vessel involvement, PSMA-positive regional lymph nodes, several nodular lung lesions with mild PSMA uptake, PSMA-positive mediastinal lymph nodes, and a PSMA-positive mass in the pancreatic head. Ultrasound-guided biopsy was performed for the pancreatic lesions revealing metastasis from a RCC. Simultaneous treatment for prostate cancer and metastatic RCC was initiated. To separate metastatic sites for both primaries, we attempted to use fluorodeoxyglucose positron emission tomography/computed tomography, which was moderately positive for the pancreatic mass but not for the other locations. RCC is a 68Ga PSMA-positive tumor; the synchronous combination of RCC with prostate cancer can be confusing and requires more complex clinical interpretation.

Synchronous papillary thyroid cancer and non-Hodgkin lymphoma: Case report.

RATIONALE: Differentiated thyroid cancer is the most common endocrine malignancy with concomitant hematological malignancy in 7%. PATIENT CONCERNS: We present a case of a synchronous papillary thyroid cancer and a follicular variant of non-Hodgkin lymphoma and discuss the possible diagnostic and treatment dilemmas. DIAGNOSIS: A 48-year-old female was reffered to our hospital with diagnosis "thyroid cancer". Due to a history compatable of synchronous lymphoproliferative disease we performed a computed tomography, which revealed multiple enlarged lymph nodes in the neck, mediastinum, axilla and abdomen. INTERVENTIONS: A total thyroidectomy with dissection of the central compartment was performed. The microscopic examination of thyroid gland revealed multifocal papilary thyroid cancer and metastaes from the same cancer plus aggressive follicular B-cell non-Hodgkin lymphoma in the lymph nodes. Despite the classic approach "solid cancer first", due to the advanced stage of lymphoma we first started the chemotherapy of NHL. She received 8 cycles of CHOP and I therapy with 129 mCi. Because of incomplete response 4 cycles Mabthera plus Bendamustin were added. The follow-up PET scan revealed complete remission of lymphoma and bilaterally enlarged single cervical lymph nodes, previously known to be iodine positive on I-SPECT/CT. She was sheduled for bilateral radical neck LND. OUTCOMES: Complete remission of NHL and residual single metastatic cervical lymph nodes requiring bilateral radical neck LND. LESSONS: The synchronous DTC and NHL is rare. To date, there is no standardized approach due to lack of experience. We suggest lymphoma first approach with synchronized and tailored multidisciplinary efforts. The molecular mechanisms of this link are poorly understood and yet remain to be elucidated.

18F-FDG PET/CT in the diagnosis of an extranodal relapse of diffuse large B-cell lymphoma (DLBCL): a clinical case with a literature review.

Extranodal lymphoma, secondary to or accompanying nodal disease is uncommon, but not unusual finding. 18-Fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) imaging has an essential role in the staging of lymphoma, in treatment response monitoring, and in detection of recurrence. We present a case of a 52-year-old man with generalized diffuse large B-cell lymphoma (DLBCL) with multiple extranodal sites involvement detected by 18F-FDG PET/CT. With this clinical case we demonstrate that 18F-FDG PET-CT is a more effective technique than CE-CT for the evaluation of viable extranodal involvement of the diffuse large B-cell lymphoma (DLBCL) and should be combined in the monitoring of DLBCL.

Dual-time point 18FDG-PET/CT imaging may be useful in assessing local recurrent disease in high grade bone and soft tissue sarcoma.

BACKGROUND: Sarcomas comprise 1% of malignant tumors in adults but represent a significant diagnostic and therapeutic challenge. Molecular imaging with ¹8FDG PET/CT is a powerful modality in oncology. Its use for initial assessment, evaluation of response to therapy and recurrent disease in most tumors is essential for therapeutic decisions. Its indication in sarcomas is still controversial. One of the indications for PET/CT in sarcomas is detection of recurrences. Nowadays magnetic resonance tomography (MRT) has a crucial role in identification of local recurrences in soft tissue and bone sarcoma. ¹8FDG-PET/CT may serve as a complementary method. Dual time point imaging (DTPI) has been studied for most tumors as a method for differentiating benign from malignant lesions. There is limited data on DTPI in sarcomas. Therefore we studied prospectively patients with suspected local recurrences in the treated area and used DTPI as a method for differentiating benign from malignant tissue. THE AIM: of this study was to evaluate the ability of dual-time point PET/CT to enhance sensitivity, specificity, PPV, NPV and accuracy of ¹8FDG PET/CT in high grade and low grade sarcomas. MATERIAL AND METHODS: We conducted a dual-time PET/CT in 15 patients with suspected locally recurrent disease. The delayed scan was conducted on the 120th min in the suspected region. The interpretation of PET/CT was made both upon CT scan and metabolic scans. The percentage change over time per lesion was calculated (%DSUV). The increase in SUVmax with %DSUV > 10% in the late scanning was considered as indicative for malignancy. We assessed the sensitivity, specificity, accuracy, positive and negative predicting value of the interpretation of PET/CT at 60 min and 120 min. All of the patients were followed up for a period of 1-3 years after our examination, either with histologic results, or with an MRT scans. RESULTS: The received sensitivity, specificity and accuracy of ¹8FDG PET/CT interpretation at 120 min in high grade sarcomas were respectively 100%, 80% and 89%. By comparison, in low grade tumors at 120 min scan, these parameters were 50%, 75% and 66%. CONCLUSION: These preliminary data suggests that dual-time imaging in sarcomas improves sensitivity and accuracy in identification of local recurrent disease in high grade sarcomas and have limited role in low grade sarcomas. Further research is necessary to confirm these results.

Cervix carcinoma and incidental finding of medullary thyroid carcinoma by 18F-FDG PET/CT--clinical case.

Thyroid nodules are encountered in clinical practice during the diagnostic procedures or patients' follow-up due to other diseases quite far from the thyroid gland with prevalence 4-50% in general population, depending on age, diagnostic method and race. The prevalence of thyroid nodules increases with age and their clarification should be done for their adequate treatment. An 18F-FDG PET/CT was done with a PET/CT scanner (Philips Gemini TF), consisting of dedicated lutetium orthosilicate full ring PET scanner and 16 slice CT. The PET/CT scan of the whole-body revealed on the CT portion a hypodense nodular lesion in the left lobe of the thyroid gland with increased uptake of 18F-FDG on the PET with SUVmax 10.3 and demonstrated a complete response to the induction therapy of the main oncological disease of the patient--squamous cell carcinoma. This clinical case demonstrates that whole-body 18F-FDG-PET/CT has an increasingly important role in the early evaluation of thyroid cancer as a second independent malignant localization. Focal thyroid lesion with high risk of thyroid malignancy was incidentally found on 18F-FDG PET/CT.

Brain metastases detectability of routine whole body (18)F-FDG PET and low dose CT scanning in 2502 asymptomatic patients with solid extracranial tumors.

As fluorine-18-fluorodesoxyglucose positron emission tomography/computed tomography ( (18)F-FDG PET/CT) is gaining wider availability, more and more patients with malignancies undergo whole body PET/CT, mostly to assess tumor spread in the rest of the body, but not in the brain. Brain is a common site of metastatic spread in patients with solid extracranial tumors. Gold standard in the diagnosis of brain metastases remains magnetic resonance imaging (MRI). However MRI is not routinely indicated and is not available for all cancer patients. Fluorine-18-FDG PET is considered as having poor sensitivity in detecting brain metastases, but this may not be true for PET/CT. The aim of our study was to assess the value of (18)F-FDG PET/CT in the detection of brain metastases found by whole body scan including the brain, in patients with solid extracranial neoplasms. A total of 2502 patients with solid extracranial neoplasms were studied. All patients underwent a routine whole body (18)F-FDG PET/CT scan with the whole brain included in the scanned field. Patients with known or suspected brain metastases were preliminary excluded from the study. Hypermetabolic and ring-like brain lesions on the PET scan were considered as metastases. Lesions with CT characteristics of brain metastases were regarded as such irrespective of their metabolic pattern. Lesions in doubt were verified by MRI during first testing or on follow-up or by operation. Our results showed that brain lesions, indicative of and verified to be metastases were detected in 25 out of the 2502 patients (1%), with lung cancer being the most common primary. Twenty three out of these 25 patients had no neurological symptoms by the time of the scan. The detection rate of brain metastases was relatively low, but information was obtained with a minimum increase of radiation burden. In conclusion, whole body (18)F-FDG PET/CT detected brain metastases in 1% of the patients if brain was included in the scanned field. Brain scanning as a part of whole body scan cannot replace routine imaging techniques, but in case of positive findings provides early and crucial information for further patient management, especially in asymptomatic patients.