Marcelo Livorsi da Cunha

Lista de recomendações do Exame PET/CT com 18F-FDG em Oncologia. Consenso entre a Sociedade Brasileira de Cancerologia e a Sociedade Brasileira de Biologia, Medicina Nuclear e Imagem Molecular

The authors present a list of recommendations on the utilization of 18F-FDG PET/CT in oncology for the diagnosis, staging and detection of cancer, as well as in the follow-up of the disease progression and possible recurrence. The recommendations were based on the analysis of controlled studies and a systematic review of the literature including both retrospective and prospective studies regarding the clinical usefulness and the impact of 18F-FDG PET/CT on the management of cancer patients. 18F-FDG PET/CT should be utilized as a supplement to other conventional imaging methods such as computed tomography and magnetic resonance imaging. Positive results suggesting changes in the clinical management should be confirmed by histopathological studies. 18F-FDG PET should be utilized in the diagnosis and appropriate clinical management of cancer involving the respiratory system, head and neck, digestive system, breast, genital organs, thyroid, central nervous system, besides melanomas, lymphomas and occult primary tumors.

(18) F-FDG PET imaging of rheumatoid articular and extraarticular synovitis.

During the past few years (18) F-FDG fluor deoxyglucose positron emission tomography (FDG-PET) has become a major advance in the staging of tumors and monitoring of treatment. FDG-PET can also be used to image active synovitis and its usefullness in monitoring treatment is currently being evaluated. Patient DGC is a 62-year-old male attending our clinic with long standing rheumatoid arthritis. He failed to respond to DMARDs and was assigned to biologic therapy. He received 3 infusions of Infliximab in a 6 week period. He had whole body FDG-PET images acquired prior to and 2 months after the first infusion (Figs. 1 and 2). Image analysis shows significant uptake of FDG in several joints indicating severe metabolic activity before treatment followed by marked reduction after anti TNF therapy. DAS28 before and after therapy was 5.6 and 3.4,

F-18 FDG PET/CT imaging in small cell prostate cancer.

Abstract: Positron emission tomography/computed tomography scan with F-18 fluorodeoxyglucose was performed in a 77-year-old patient with prostatic adenocarcinoma treated with hormonal therapy, who presented 2 years later with an abdominal mass and slowly increasing prostate specific antigen and carcinoembryonic antigen. Positron emission tomography-computed tomography scan showed intense uptake of F-18 fluorodeoxyglucose in the prostate tumor, iliac, and periaortic lymph nodes and also in a focal area in the right lobe of the liver. The new biopsy of the tumor and lymph nodes was compatible with small cell prostate cancer.

Valor diagnóstico da tomografia por emissão de pósitrons / tomografia computadorizada (PET-CT) com flúor-18 fluordeoxiglicose (FDG-18F) em pacientes com carcinoma diferenciado da tireóide, níveis séricos de tireoglobulina elevados e pesquisa de corpo inteiro com iodo negativa

PURPOSE To evaluate the role of PET-CT with FDG-18F in the detection of recurrence and/or metastasis of differentiated thyroid carcinoma (DTC) in patients with elevated levels of thyroglobulin (TG) and negative whole body scan (WBS). PATIENTS AND METHOD PET-CT findings of 25 patients were compared to histopathology evaluation and conventional imaging (CI). RESULTS PET-CT scan was positive in 16 patients finding 14 true-positive and 2 false-positive cases (positive predictive value 87.5%). Nine patients had negative PET-CT; two had decrease of TG to undetectable levels. One patient had residual disease detected by post-therapeutic WBS. Six patients had no evidence of tumor during follow-up (mean time 16 months). PET-CT was concordant with CI in 52%, partially concordant in 12% and discordant in 36% (6 false-negatives and 3 false-positive of CI). We observed a tendency of increasing proportion of positive PET-CT with increasing TG. CONCLUSION PET-CT scan with FDG-18F is useful in the detection of recurrence and/or metastases of DTC with high TG levels but negative WBS. It presents elevated positive predictive value and is superior to CI being more effective as higher the serum TG levels.

Solitary testicular metastasis from prostate cancer. A case report diagnosed by PET/CT with PSMA

A 69-year-old man was referred to the Department of Radiotherapy for treatment with prostate bed radiotherapy for biochemical relapse after radical prostatectomy with no lymph node dissection performed 6 years previously. The pathological examination showed Gleason score 7 (3 + 4) adenocarcinoma with negative margins and no involvement of the seminal vesicles (stage pT2b pNXM0). He developed rapid elevation of prostate-specific antigen from 0.039 ng/ mL during June 2015 to 2.6 ng/mL during July 2016. On physical examination, the left testicle showed a hard consistency and smooth surface, there were no inflammatory signs, and no abnormalities were detected on digital rectal examination. A Ga-PSMA PET/CT scan was requested and it showed intense pathological radiotracer uptake only in the left testicle (SUVmax 28,8). Although prostate cancer (PCa) is the third most common cancer according to the National Cancer Institute [1], testicular metastases are very uncommon. Most are incidentally identified after therapeutic surgery or on autopsy in patients with previously diagnosed PCa [2, 3]. Approximately 4% of * Marcelo Livorsi da Cunha cunhaml@yahoo.com

Normalization of lymphocyte count after high ablative dose of I-131 in a patient with chronic lymphoid leukemia and secondary papillary carcinoma of the thyroid. Case report

ABSTRACT The authors report the case of a 70-year-old male patient with chronic lymphoid leukemia who presented subsequently a papillary carcinoma of the thyroid with metastases to regional lymph nodes. The patient was treated with surgical thyroidectomy with regional and cervical lymph node excision and radioiodine therapy (I-131). The protocolar control scintigraphy 4 days after the radioactive dose showed I-131 uptake in both axillae and even in the inguinal regions. PET/CT showed faint FDG-F-18 uptake in one lymph node of the left axilla. An ultrasound guided fine needle biopsy of this lymph node identified by I-131 SPECT/CT and FDG-F-18 PET/CT revealed lymphoma cells and was negative for thyroid tissue and thyroglobulin content. The sequential blood counts done routinely after radiation treatment showed a marked fall until return to normal values of leucocytes and lymphocytes (absolute and relative), which were still normal in the last control 19 months after the radioiodine administration. Chest computed tomography showed a decrease in size of axillary and paraaortic lymph nodes. By immunohistochemistry, cells of the lymphoid B lineage decreased from 52% before radioiodine therapy to 5% after the procedure. The authors speculate about a possible sodium iodide symporter expression by the cells of this lymphoma, similar to some other non-thyroid tumors, such as breast cancer cells.

Estudo comparativo da qualidade de imagem dos modos de aquisição da PET: validação de um protocolo para reduzir a dose de radiação

OBJECTIVE: The present study is aimed at validating a 3D acquisition protocol for positron emission tomography as a replacement for the 2D mode, to reduce the radiation dose delivered to patients, without any loss in the quality of images. MATERIALS AND METHODS: The study comprised 27 simulations in a Discovery ST equipment with four-minute 2D acquisitions, and two-minute and four-minute 3D acquisitions, utilizing a chest phantom according to the National Electrical Manufacturers Association protocol. Six spheres with different diameters were inserted into this phantom as a means for determining the images quality. The images were blindly reviewed by three experienced nuclear physicians who did not know the acquisition modes. Each observer attributed a score 1 when one of the spheres was not identified, or 2 for visible spheres. RESULTS: The qualitative analysis based on generalized kappa coefficient demonstrated that the frequency of visible spheres was higher with four-minute 3D acquisitions (85%), with an also higher interobserver agreement (88.9%), generalized kappa = 0.725 [0.507;0.942]. CONCLUSION: The protocol with four-minute 3D acquisition with lower 18F-FDG activity can be utilized for patients with a biotype similar to the phantom, without any loss in the imaging quality.