Extremely aggressive course in a poorly differentiated thyroid carcinoma presenting a double mutation of the TERT promoter.

BRAF and TERT oncogenes hotspot mutations are associated with a more aggressive outcome in thyroid carcinomas (TC). TERT promoter (pTERT) mutations (C228T and C250T) are related to cancer growth and reduced overall- and disease-free survivals in TC. We report a patient followed up for 8 years with a poorly differentiated thyroid carcinoma (PDTC) presenting an extremely aggressive course, who developed a large volume of metastases in a short period. Molecular analysis of the primary tumor revealed two pTERT mutations (C228T and C250T), and no BRAF V600E mutation. pTERT mutations C228T and C250T have been described as mutually exclusive, indicating that one mutation is enough for telomerase activation and exerts its action in thyroid tumorigenesis. This report describes both pTERT hotspot mutations in the same PDTC patient presenting a very aggressive course, even for PDTC, suggesting a relationship between the two events. However, more studies are needed to prove this causality.

Value of sentinel lymph node biopsy in papillary thyroid cancer: initial results of a prospective trial.

The objectives of the study were to evaluate the performance of sentinel lymph node biopsy (SLNB) in detecting occult metastases in papillary thyroid carcinoma (PTC) and to correlate their presence to tumor and patient characteristics. Twenty-three clinically node-negative PTC patients (21 females, mean age 48.4 years) were prospectively enrolled. Patients were submitted to sentinel lymph node (SLN) lymphoscintigraphy prior to total thyroidectomy. Ultrasound-guided peritumoral injections of (99m)Tc-phytate (7.4 MBq) were performed. Cervical single-photon emission computed tomography and computed tomography (SPECT/CT) images were acquired 15 min after radiotracer injection and 2 h prior to surgery. Intra-operatively, SLNs were located with a gamma probe and removed along with non-SLNs located in the same neck compartment. Papillary thyroid carcinoma, SLNs and non-SLNs were submitted to histopathology analysis. Sentinel lymph nodes were located in levels: II in 34.7 % of patients; III in 26 %; IV in 30.4 %; V in 4.3 %; VI in 82.6 % and VII in 4.3 %. Metastases in the SLN were noted in seven patients (30.4 %), in non-SLN in three patients (13.1 %), and in the lateral compartments in 20 % of patients. There were significant associations between lymph node (LN) metastases and the presence of angio-lymphatic invasion (p = 0.04), extra-thyroid extension (p = 0.03) and tumor size (p = 0.003). No correlations were noted among LN metastases and patient age, gender, stimulated thyroglobulin levels, positive surgical margins, aggressive histology and multifocal lesions. Sentinel lymph node biopsy can detect occult metastases in PTC. The risk of a metastatic SLN was associated with extra-thyroid extension, larger tumors and angio-lymphatic invasion. This may help guide future neck dissection, patient surveillance and radioiodine therapy doses.

Radioguided Intraoperative Margins Evaluation (RIME): preliminary results of a new technique to aid breast cancer resection.

AIMS: Women undergoing breast-conserving surgery for cancer can present residual disease. We have developed a technique called Radioguided Intraoperative Margins Evaluation (RIME) that uses a radiopharmaceutical to distinguish normal and cancer tissues. The aim of this study was to assess whether RIME is a feasible technique, and if it could help in breast cancer resection with free margins, minimizing residual disease. METHODS: Twenty-three breast cancer patients programmed for mastectomy were selected. Before surgery, the patients were submitted to scintimammography with 99mTc-sestamibi to estimate the optimal time to begin radioguided surgery. Twenty patients were submitted to magnetic resonance imaging (MRI), to evaluate skin, deep fascia and to detect other tumor foci. At the beginning of the surgery, the same dose of 99mTc-sestamibi was intravenously injected into patients. Tumor resection was performed under guidance of a gamma-probe, characterizing the RIME technique. Finally, modified radical mastectomy was performed. Tumor and residual breast were histopathologically examined. RESULTS: The RIME technique was successfully performed in all patients. The principal tumor was removed by this technique and provided 82.6% of histologically free margins (mean margins, 4.8 mm). Additionally, 47.8% of patients were without residual disease. The mean size of residual carcinoma was 3.67 mm and generally located near the tumor bed (<1.5 cm). There was no significant association between presence of residual disease and tumor size or margin status. CONCLUSION: RIME is a feasible technique that could help tumor resection with free margins; however, it seems to be limited for small carcinoma foci.

99mTc-sestamibi thyroid uptake in euthyroid individuals and in patients with autoimmune thyroid disease.

PURPOSE: We investigated the biokinetics of (99m)Tc-sestamibi in the thyroid of euthyroid volunteers (EVs) and in patients with autoimmune thyroid diseases and determined the best time interval between (99m)Tc-sestamibi injection and calculation of uptake. METHODS: Forty EVs, 30 patients with Graves' disease (GD), 15 patients with atrophic Hashimoto's thyroiditis (AHT) and 15 patients with hypertrophic Hashimoto's thyroiditis (HHT) underwent (99m)Tc-sestamibi thyroid scintigraphy. Dynamic images were acquired for 20 min, and static images were obtained 20 min, 60 min and 120 min post injection. Five-, 20-, 60- and 120-min uptake, time to maximal uptake (T(max)) and T(1/2) of tracer clearance were calculated. Thyroid hormones and antibodies were measured. (99m)Tc-pertechnetate uptake was investigated in GD patients. RESULTS: T(max) was approximately 5 min in all four groups. The mean T(1/2) value for EVs was similar to the GD value and lower than the HHT and AHT values. The mean (+/-SD) 5-min uptake was 0.13% (+/-0.05%) for EVs. The 5-min uptake in GD was higher than that in EVs(P<0.001) and correlated with free thyroxine (r=0.54) and with (99m)Tc-pertechnetate uptake (r=0.68). Uptake in HHT was higher than that in AHT (P=0.0003) and EVs (P=0.002). Uptake in AHT was lower than uptake in EVs (P=0.0001). CONCLUSION: Five minutes is the optimal time interval between (99m)Tc-sestamibi injection and calculation of thyroid uptake. Five-minute uptake differentiates euthyroid individuals from GD patients. There is a high correlation between (99m)Tc-sestamibi and (99m)Tc-pertechnetate uptake in GD. The reduced (99m)Tc-sestamibi uptake in AHT patients is probably due to glandular destruction and fibrosis. Inflammatory infiltrate and high mitochondrial density in thyrocytes possibly explain the increased uptake in GD and HHT.

Intraoperative localization of an osteoid-osteoma using a gamma probe.

The purpose of this study was to evaluate whether intraoperative nidus detection with a hand-held gamma probe was efficient enough for use as a routine procedure. Thirty-seven patients with osteoid-osteomas were submitted to surgical treatment. The first group consisted of 19 patients submitted to open nidus resection using a hand-held gamma probe as guide. The control group consisted of 18 patients operated on by conventional technique. The procedures were classified as successful if nidus resection could be confirmed by histology or postoperative imaging studies. Patients in the gamma group were followed for a mean of 13 months; patients in the control group for a mean of 39 months. In the gamma group, 17/19 procedures were successful; in the control group, only 12/18 procedures were successful. The gamma probe helped to locate the osteoid-osteoma nidus, and the same probe could be used in various hospitals.

Qualitative and quantitative comparison between images obtained with filtered back projection and iterative reconstruction in prostate cancer lesions of (18)F-FDG PET.

BACKGROUND: Recently, iterative reconstruction with segmented attenuation corrections (IRSAC) has been introduced for reconstruction of (18)F-FDG PET images. IRSAC produces images that are more pleasing to the eye, but qualitative and quantitative comparisons between IRSAC and filtered back projection (FBP) have not been reported for metastatic cancer. Since quantitative data has been widely used as an adjunct to interpretation of PET scans, comparison between IRSAC and FBP is needed. The purpose of this study was to compare image quality and the maximum standardized uptake value (SUVmax) obtained with FBP and with IRSAC in metastatic lesions from prostate cancer. METHODS: Twenty (18)F-FDG PET scans (10 baseline and 10 follow-up) were performed in 10 patients with prostate cancer (ages 66-85 yrs, mean 73.6 yrs). Acquisition began 45 min after injection of 370 MBq of (18)F-FDG. Images were reconstructed using FBP and IRSAC, and submitted to visual and quantitative analysis. SUVmax was obtained for all metastases, on FBP and IRSAC. A Jaszczak phantom study was also performed. RESULTS: IRSAC images showed better image quality than FBP especially in regions of high activity concentrations. IRSAC detected 106 lesions on both baseline and follow-up scans, while FBP detected 100 and 95 lesions on baseline and follow-up scans, respectively. Therefore, 17 more lesions were seen on IRSAC. The mean SUVmax values on baseline scans for FBP and IRSAC were systematically different, at 4.46+/-1.99 and 5.13+/-2.67, respectively. On follow-up scans values were 3.89+/-1.72 for FBP and 4.29+/-1.93 for IRSAC. Comparison of FBP with IRSAC on baseline and follow-up scans were statistically significant (baseline: paired "t"-test p=0.0017; follow-up: paired "t"-test p=0.0008). Phantom studies reveal that these differences can be explained by the type of reconstruction filters used, and IRSAC was more accurate than FBP. CONCLUSIONS: IRSAC detects smaller volumes in phantoms, patient images are easier to interpret and more metastatic lesions were detected. In addition, IRSAC provides reproducible quantitative data, comparable to data provided by FBP. IRSAC SUV and FBP SUV are in close agreement but there was a statistically significant difference between the two, and therefore threshold values of SUV will probably need to be re-determined with IRSAC, and are likely to be 10 to 19% higher than currently reported.

Valor prognóstico da cintilografia na avaliaçäo da formaçäo do regenerado ósseo no tratamento por alongamento do fêmur curto congênito / Prognostic value of scintigraphy in the evaluation of calus formation in the treatment by congenital short femur lengthening

O fêmur curto congênito é a deficiência longitudinal mais comum do fêmur. O membro acometido é aproximadamente 10 por cento menor do que o normal. O tratamento geralmente é feito por alongamento ósseo e as técnicas mais empregadas utilizam as corticotomias e a colocaçäo de fixador externo com alongamento progressivo. A avaliaçäo da resposta ao tratamento é difícil, baseando-se na análise radiográfica do calo ósseo em formaçäo. O objetivo deste estudo foi avaliar se a cintilografia óssea trifásica seria capaz de prever a formaçäo de calo ósseo adequado ou näo nos pacientes com fêmur curto congênito submetidos ao alongamento com fixador externo. Cinco pacientes, submetidos ao alongamento ósseo com fixador externo, foram investigados com radiografias e cintilografia óssea trifásica. Em três pacientes que apresentaram boa evoluçäo clínica a cintilografia óssea trifásica mostrou captaçäo moderada ou acentuada do radiofármaco no calo ósseo. Nos dois pacientes que apresentaram má evoluçäo clínica, a captaçäo do radiofármaco no calo ósseo foi normal ou apenas discretamente aumentada. Portanto, a captaçäo do radiofármaco na fase tardia da cintilografia óssea correlacionou-se com a evoluçäo clínica. A cintilografia óssea parece ser um método capaz de prever o prognóstico dos pacientes com fêmur curto congênito submetidos a alongamento por fixador externo

Cintilografia óssea trifásica para guiar a retirada de implantes metálicos em fraturas: estudo preliminar / Three-phase bone scintigraphy as a guide to metallic implant removal

O objetivo deste estudo foi avaliar o papel da cintilografia óssea trifásica na indicação da retirada do material de síntese de pacientes com fratura diafisária do fêmur, submetidos à fixação com haste intramedular bloqueada (HIB) ou com placa em ponte (PP), já que, atualmente, a indicação da retirada é feita por critérios não totalmente confiáveis. Foram estudados 13 pacientes, seis com colocação de HIB e sete com PP. Todos os pacientes foram submetidos a cintilografia óssea trifásica com 740MBq de MDP-99mTc em uma câmara de cintilação computadorizada. Em quatro pacientes (dois com HIB e dois com PP) houve retirada do material de síntese, em média, 42,2 meses após a fratura. Os pacientes com HIB apresentaram alterações discretas na fase tardia da cintilografia óssea e formação discreta do calo ósseo, enquanto os com PP mostraram alterações cintilográficas moderadas e formação anormal do calo ósseo. As discretas alterações descritas na cintilografia óssea nos pacientes com HlB indicam que este tipo de fixação leva a menor exigência mecânica do calo ósseo com remodelação mais fisiológica, comprovada pelo estudo tomográfico em dois pacientes, mostrando sua anatomia semelhante à do fêmur contralateral. Isto não ocorreu nos pacientes com PP, talvez devido a uma maior movimentação dos fragmentos ósseos permitida por este material. Esta movimentação sugere que este tipo de fixação talvez não seja o mais fisiológico, não proporcionando à fratura condições adequadas para se consolidar.