Prognostic value of myocardial perfusion scintigraphy in diabetic patients and without coronary lesion. / Valor pronóstico de la gammagrafía de perfusión miocárdica en pacientes diabéticos sin lesiones coronarias.

OBJECTIVE: To determine the prognostic value of myocardial perfusion scintigraphy-gated SPECT in patients with diabetes mellitus and without obstructive coronary artery disease. MATERIALS AND METHODS: This retrospective study included consecutive patients undergoing adenosine stress-rest myocardial perfusion imaging (MPI) by 99mTc-tetrofosmin between 2009 and 2011. The patients had diabetes mellitus and coronary angiography without significant coronary lesions. In total, 37 diabetic patients (female/male: 20/17; mean age: 65.2 (range: 40-78). 29 non-diabetic patients were included wich are matched with the group of diabetic patients with positive MPI. The group of non-diabetic patients had scintigraphy with myocardial ischemia and without angiographic lesions. A 36-month clinical follow-up was performed, and major cardiac events were recorded. RESULTS: In 78.3% (29/37) of diabetic patients the scintigraphic study showed myocardial ischemia, while it was negative in the 21.7%. The cardiac event rate in both groups was 6%. In diabetics with a myocardial perfusion study with myocardial ischemia, there were 3 major cardiac events. In diabetic patients with negative study had no cardiac event. In the non-diabetic control group the cardiac events rate was 3.4% (1/29). CONCLUSION: In diabetic patients without obstructive coronary disease, myocardial perfusion study can be predictor of cardiac events. A negative study can be an indicator of a better cardiovascular prognosis.

Value of the negative PET-FDG in the middle term follow-up of differentiated thyroid cancer in patients with negative 131 I-Na scan and elevated thyroglobulin serum levels.

OBJECTIVE: This study has aimed to analyze the evolution of patients diagnosed with differentiated thyroid carcinoma (DTC) with a negative (131)I-Na whole body scan (WBS), high levels of serum thyroglobulin (Tg) and negative (18F)fluorodeoxyglucose positron emission tomography (PET-FDG) study. MATERIAL AND METHODS: Twenty-three patients diagnosed and treated for DTC were studied retrospectively. Patients were aged between 23 and 83 and had shown, between January 2001 and December 2002, negative WBS, Tg values in a range of suspected recurrence or metastasis (Tg>2 ng / mL with thyroid hormone withdrawal) and a negative PET-FDG study. The patients were monitored clinically, radiologically and analytically for a minimum period of 4 years. After this, a new evaluation was made of their state of disease with a control WBS, also observing the evolution of Tg. All WBS were performed with a 185 MBq diagnostic dose of (131)I-Na. RESULTS: In 18/23 patients, Tg decreased and in 5 it increased. Four patients (17%) were free of active disease (negative WBS Tg<2 ng / mL). A total of 16 patients (70%) were free of disease according to the WBS but had elevated Tg. Three patients (13%) had disease and high levels of Tg, two of them with positive WBS and the third with (99m)Tc-MIBI scan and CT positive. CONCLUSIONS: Most patients with a negative WBS, high Tg serum levels and negative FDG PET had good evolution, with descending Tg levels, normal levels even being reached in a significant percentage of them.

[Evaluation of efficacy and clinical impact of 18F-FDG-PET in the diagnosis of recurrent medullary thyroid cancer with increased calcitonin and negative imaging test]. / Evaluación de la eficacia y del impacto clínico de la PET-18F-FDG en el diagnóstico de recurrencia del carcinoma medular de tiroides con calcitonina elevada y pruebas de imagen negativas.

AIM: To evaluate the efficacy and clinical impact of the FDG-PET in the diagnosis of suspicion of recurrence of medullary thyroid cancer (MTC) in patients with elevated serum calcitonin and negative imaging test. MATERIAL AND METHODS: We performed a retrospective study of 31 consecutive cases from february 2001 to october 2007 of 17 women and 14 men, mean age 56.2 years (range: 26-88), with anatomical-pathology diagnosis of medullary thyroid cancer and suspicion of recurrence due to abnormal elevation of calcitonin and negative imaging tests. All of the patients underwent whole body FDG-PET scan with a dedicated PET or PET-CT 60 minutes after intravenous injection of 333-434 MBq of (18)F-FDG. Results were confirmed by pathology study in 45.2% of the patients and by clinical follow-up with a mean of 4 years (range: 16 m-8 years) RESULTS: Sensitivity was 88%, specificity 84.6%, positive predictive value 88%, negative predictive value 84.6% and diagnostic accuracy 87%. The results of the FDG PET modified the therapeutic strategy in 14 cases (45.2%). A comparison was made of the mean values of calcitonin using the Student's "t" test between positive PET studies for the disease and negative ones. No significant differences were found (P=.3). CONCLUSIONS: In patients with MTC and suspected recurrence with elevated calcitonin and negative imaging test, the FDG is the best test for the diagnosis of occult recurrence in MTC with elevated calcitonin and negative imaging techniques with elevated clinical impact. It facilitates the therapeutic management of the patients with MTC recurrence, and should be included in the diagnosis algorithm in these patients.

[Evaluation of efficacy and clinical impact of positron emission tomography with 18F fluoro-deoxyglucose in patients with suspicion of recurrent head and neck cancer or distant metastases]. / Evaluación de la eficacia y el impacto clínico de la tomografía de emisión de positrones con 18F-FDG en pacientes con sospecha de recurrencias locales y metástasis de carcinomas de cabeza y cuello.

AIMS: To evaluate the efficacy and clinical impact of Positron Emission Tomography with FDG (FDG-PET) in patients with suspected recurrent head and neck cancer or distant metastases. MATERIALS AND METHODS: Sixty patients (12 women and 48 men) with suspicion of recurrent head and neck cancer and ambiguous conventional imaging modalities. In all patients a whole body scan was performed with FDG-PET in fasting patients following i.v. administration of 370-444 MBq FDG. The results were confirmed by histology and clinical evolution (follow-up period > 12 months) and imaging test. RESULTS: Prevalence of recurrence was 66.6 %. FDG-PET was positive in 40/60 patients, with confirmation in 39 cases, and 18 were true negative (TN). We have found 2 false positive and 1 false negative. Overall sensitivity, specificity, PPV, NPV and accuracy were 97.5 %, 90 %, 95.12 %, 94.7 % and 95 %, respectively. FDG-PET changed the modality of treatment in 34 patients (clinical impact 56.6 %) CONCLUSIONS: FDG-PET has high clinical impact in patients with suspicion of recurrent head and neck cancer, and should be incorporated in the diagnostic protocols before making a therapy decision.

[Evaluation of efficacy and clinical impact of positron emission tomography with 18F fluoro-deoxyglucose (FDG) in patients with suspicion of recurrent laryngeal carcinoma]. / Evaluación de la eficacia y el impacto clínico de la tomografía de emisión de positrones (PET) con 18F fluoro-desoxiglucosa (FDG) en pacientes con sospecha de recurrencia de carcinoma de laringe.

AIMS: To evaluate the efficacy and clinical impact of FDG-PET in patients with suspected recurrent laryngeal carcinoma. MATERIALS AND METHODS: 15 patients, with suspicion of recurrent laryngeal carcinoma and ambiguous conventional imaging modalities. In all patients a whole body scan was performed with FDG-PET in fasting patients following i.v. administration of 370-444 MBq FDG. The results were confirmed by histology and clinical evolution (follow-up period > 12 months). RESULTS: Prevalence of recurrence was 86.6%. FDG-PET was positive in 13 patients, with confirmation in all cases, and 2 were true negative (TN). Overall sensitivity, specificity, PPV, NPV and accuracy were 100%. FDG-PET changed the modality of treatment in 10 patients (clinical impact 63.3%). CONCLUSIONS: FDG-PET has high clinical impact in patients with a suspicion of recurrent laryngeal carcinoma, and should be incorporated to the diagnostic protocols before making a therapy decision.

[F-18-fluordeoxyglucose positron emission tomography on patients with differentiated thyroid cancer who present elevated human serum thyroglobulin levels and negative I-131 whole body scan]. / PET con 18FDG en pacientes con cáncer diferenciado de tiroides que presentan niveles elevados de tiroglobulina sérica y rastreos con 131I negativos.

UNLABELLED: This study aimed to evaluate the role of Fluorine-18-fluorodeoxyglucose positron emission tomography (PET-FDG) in patients with elevated serum thyroglobulin (hTg) levels where thyroid cancer tissue does not concentrate radioiodine, rendering false-negative results on I-131 scanning. MATERIAL AND METHODS: Whole-body PET imaging using FDG was performed in 54 patients (37 female, 17 male) aged 17-88 years: 45 with papillary tumors and 9 with follicular tumors who were suspected of having recurrent thyroid carcinoma due to elevated thyroglobulin levels (hTg > 2 ng/ml) under thyroid-stimulating hormone (TSH > or = 30 microIU/ml) in whom the iodine scan was negative. All whole body scans were obtained with diagnostic doses (185 MBq). Whole body PET imaging was performed in fasting patients following i.v. administration of 370 MBq FDG while the patients were receiving full thyroid hormone replacement. Before PET, 99mTc methoxyisobutylisonitrile scintigraphy (99mTc-MIBI) was done in 14 patients and morphologic imaging in 26 by CT scan. RESULTS: Positive PET results confirmed the presence of hypermetabolic foci in 25/54 patients (46.29 %). Positive findings were found for PET-FDG in patients with hTg levels higher than 10 ng/ml receiving full thyroid hormone replacement. 99mTc-MIBI demonstrated lesions in 7/14 patients (50 %). PET-FDG and 99mTc-MIBI had congruent positive results in 4/7 patients. All the lesions found by CT were detected by PET-FDG, while recurrent disease was found in 12/21 patients with previous negative CT. CONCLUSIONS: These results suggest that PET-FDG seems to be a promising tool in the follow-up of thyroid cancer and should be considered in patients suffering from differentiated thyroid cancer with suspected recurrence and/or metastases by elevated thyroglobulin levels, and negative I-131 whole body scans. PET-FDG might be more useful at hTg levels > 10 ng/ml.

[Evaluation of efficacy and clinical impact of FDG-PET in patients with suspicion of recurrent colorectal cancer]. / Evaluación de la eficacia y del impacto clínico de la PET-FDG en pacientes con sospecha de recurrencia de cáncer colorrectal.

AIMS: To evaluate the utility and clinical impact of Positron Emission Tomography with FDG (FDG-PET) in patients with suspected recurrent colorectal cancer (RCR). MATERIALS AND METHODS: Eighty five (85) patients with suspicion of RCR (Group A: 35 for increased tumor markers and negative imaging tests, Group B: 25 operable malignant lesions and Group C: 25 with non-conclusive morphological tests) were studied retrospectively. In all patients a whole body scan was performed with FDG-PET. In 29 cases the results were confirmed by histology and clinical evolution (follow-up period > 12 months) and imaging test in 56. RESULTS: Prevalence of RCR was 89.4 %. FDG-PET was positive in 30/35 patients in Group A, with confirmation in 29 cases (PPV: 96.6 %) and 4/5 were true negative (TN) (NPV: 80 %). FDG-PET enabled surgery for 6 patients. In Group B, PET was positive in 22/25, and all of them had confirmation (PPV: 100 %) but surgery was performed in only 7 patients. NPV was 66.6 %. Out of the 25 cases of Group C, FDG-PET obtained 21 TP, 1 FP case, 1 TN, 2 FN, and was able to avoid surgery in 8 patients (PPV: 95.4 % and NPV: 33.3 %). Overall sensitivity, specificity, PPV, NPV and accuracy were 94.7 %, 77.7 %, 97.2 %, 63.3 % and 92.9 %, respectively. CONCLUSIONS: FDG-PET has high clinical impact in patients with suspicion of recurrent colorectal cancer, and should be incorporated in the diagnostic protocols before making a surgery decision.