Revista Espa?ola de Medicina Nuclear (English Edition)最新文献

Treatment with radioiodine (RDI) has been shown to be an effective option in patients with differentiated thyroid cancer with recurrent or metastatic disease. However, in spite of having elevated levels of thyroglobulin in blood, in some of these patients, the whole body scan does not detect radioiodine uptake due to loss of differentiation of the neoplastic cells, thus leading to loss of efficacy of the treatment. That is why drugs with potential differentiating properties, like rosiglitazone or retinoids, are being studied. The aim of these drugs is to improve RDI uptake by the tumor cells. In this work, we have described the case of a patient in whom uptake of RDI by the pulmonary metastases, with subsequent decrease of their size, was achieved after treatment with rosiglitazone (8 mg/day for 2 months) as redifferentation therapy.

Aim

The aim of this study was to establish the efficacy and safety of sentinel lymph node biopsy for lymph node staging in patients with breast cancer and prior breast surgery, considering its extension, localization and time since the previous surgical procedure.

Materials and methods

A sentinel lymph node biopsy was performed in 38 patients with early breast cancer and previous breast surgery: recent excisional biopsy in 22 patients (Group I), previous lumpectomy or mammoplasty in 16, including one case of cancer treated with breast-conserving surgery (tumor recurrence). Lymphoscintigraphy was performed after periareolar injection, also sometimes adding an injection near to the surgical scar. After removing the sentinel node, axillary lymph node dissection was performed when the lymph node was positive (and not localized).

Results

The efficacy of the scintigraphic localization of the sentinel node was 92.1% of the patients, with 15.8% of extra-axillary drainages. Axillary intraoperative detection was 81.6%. The identification rate after recent excisional biopsy or previous surgery was similar (81.8 vs 81.2%). However, extra-axillary sentinel nodes were more frequent in Group II (9.1 vs 25%). Having a localization of previous surgical procedures in upper outer quadrant caused drainages outside of the axilla more frequently (27.2 vs 11.1%). Axillary detection rate was similar to other quadrants (81.8 vs 81.5%). The rate of breast cancer-related events was 5.2% (2/38), without axillary recurrences (mean follow-up: 3 years).

Conclusion

Sentinel lymph node biopsy in patients with previous but not extensive breast surgery is safe. Extra-axillary drainages are more common when the previous surgical area was wide, especially in the upper-outer quadrant.

Aims

Using ¹²³I-FP-CIT SPECT images makes it possible to identify presynaptic deterioration of the dopaminergic pathway by studying the dopamine transporter (DAT). A correct analysis of the SPECT images contributes to an adequate interpretation and diagnosis of movement disorders. Aims: 1. To compare visual and semiquantitative analysis of ¹²³I-FP-CIT SPECT images in patients with movement disorders. 2. To evaluate interobserver agreement in visual and semiquantitative analysis. 3. To obtain a cut-off in the semiquantitative analysis to discriminate primary Parkinsonism Syndrome (PS) from non-primary PS.

Methods

A ¹²³I-FP-CIT SPECT was performed in 32 patients with movement disorders suggestive of primary PS. Visual and semiquantitative images analyses were performed independently by two nuclear medicine physicians. Visual analysis was based on the visual interpretation. Semiquantitative analysis was calculated as specific uptake (caudate, putamen and striatum) versus non-specific uptake (occipital). Sensitivity, specificity, PPV, and NPV were calculated. Data were compared using ANOVA test followed by Bonferroni post hoc test. Interobserver agreement of the visual and semiquantitative analysis was assessed by intraclass correlation coefficient and Kappa statistics, respectively. ROC curve was generated with semiquantitative data.

Results

Visual analysis showed 86% sensitivity and 100–88% specificity for the differential diagnosis of primary PS from non-primary PS. Semiquantitative analysis showed a gradual hypouptake proportional to the disease severity obtained in the visual analysis. Semiquantitative analysis did not provide any additional information to the visual analysis. Intraclass correlation coefficient and Kappa statistics showed 0.92 and 0.80 values, respectively. The cut-off value to differentiate primary PS from non-primary PS was 1.9 on the putamen index.

¹⁸F-FDOPA is an amino acid analogue used to evaluate presynaptic dopaminergic activity, which has aroused great interest in neuro-oncology. We have evaluated five ¹⁸F-FDOPA PET studies of patients referred for study of parkinsonian syndrome. Two subjects had previously treated high- grade brain tumors, one nonspecific brain injury, and 2 subjects presented unexpected tumoral lesions. For all lesions SUVmax, time to SUVmax and tumor-to-normal grey matter SUVmax rate (T/N) were calculated, and 90 minutes ¹⁸F-FDOPA kinetics were analyzed. Tumor lesions corresponded to three malignant neurocytomas, one meningioma, one pineocytoma and one intrasinusal heman- gioma. Both malignant and benign tumors exhibited high uptake of ¹⁸F-FDOPA well above the normal cortex. However, the analysis of the curve uptake displayed characteristic patterns that facilitate the characterization of tumor lesions. A dual phase maximum uptake was observed, with an early 10 minutes uptake in malignant lesions, and a late 60 to 90 minutes uptake in benign or low grade lesions.

Takotsubo syndrome can mimic an acute myocardial infarction. It is characterized by anginal chest pain with ST elevation in precordial leads, no coronary obstruction on angiography, and typical and reversible deformation of the left ventricular due to antero-apical ballooning with basal hyperkinesis. The pathophysiology of this syndrome is uncertain. It is probably multifactorial, cardiac adrenergic nervous dysfunction standing out in the acute phase. We report two cases performed within the diagnostic context of Takotsubo syndrome. Cardiac SPECT was performed using ¹²³I Metaiodobenzlguanidine (MIBG) and ^99mTc-Tetrofosmin and the results of two cases were adrenergic denervation in the anterior wall without alterations in myocardial perfusion study. Identification of Takotsubo syndrome is of clinical importance because its management and prognosis differ significantly from that of acute myocardial infarction.

Aim

To assess the role of PET/CT with retrograde filling of urinary bladder (RFUB) in the assessment of pelvic malignancy in patients with urothelial or gynecological tumors.

Material and methods

A retrospective longitudinal analysis based on 62 studies belonging to 52 patients was performed. All of them had a history of pelvic malignancy (29 urothelial and 23 gynecological) and 42 had undergone previous treatments. All patients underwent a standard PET/CT protocol. Inclusion criteria were radiological alterations in pelvic organs or increased urinary activity of ¹⁸F-FDG that hindered evaluation of the pelvic structures. Pathological pelvic locations were assessed as the additional value of PET/CT with RFUB. The pathologic lesions were histologically or clinically evaluated with a minimum follow-up of 12 months.

Results

Pelvic malignancy was confirmed in 33 cases, 16 of which were of urothelial origin. A total of 35/62 studies showed a pathologic PET/CT in pelvis, 4 of them were false positive and 2 false negative. In 19 cases, malignancy was detected in the bladder wall, 16 of which were true positive. No false negative was detected. Regarding standard imaging acquisition, RFUB helped to confirm or rule out bladder and/or gynecological disease in 54 cases.

Conclusion

Retrograde bladder filling is a highly recommended technique in the assessment of malignant pelvic disease, especially of bladder origin.

Objective

To know the treatment and follow-up protocols of differentiated thyroid carcinoma patients in Spanish Metabolic Therapy Units, the clinical variability between them and the adaptation to the consensus guidelines.

Materials and methods

Analysis of the results obtained from the questionnaire submitted by E-mail to the Spanish Society of Nuclear Medicine (SEMNIM) members on the treatment and follow-up of differentiated thyroid carcinoma patients. A descriptive study was made of the qualitative variables (frequency, percentage) and quantitative variables (mean, standard deviation).

Results

Twenty Radiometabolic Therapy Units responded to the questionnaire. In spite of the varied origin of the patients, the Units receive sufficient clinical information and have specialized surgeons. There is variability in the surgical protocols and indication for ablation in patients with intermediate and low risk of recurrence. The Units agree on the use of ¹³¹I doses for ablation and therapy, but show great variability regarding the preparation protocols (previous ¹³¹I-whole body scan or other imaging techniques, ¹³¹I-whole body scan dose, diet and radioiodine contrast prohibition, total dose per patient). Nuclear Medicine physicians perceive radioiodine adverse effects and prevention methods are used. The post-ablation follow-up protocol differs between Units.

Conclusions

Treatment and follow-up protocols of differentiated thyroid carcinoma patients in the Spanish Radiometabolic Therapy Units show variability in aspects such as surgery and ablation indications, patient preparation for radioiodine therapy and follow-up. Our clinical practice differs in several aspects from the recent consensus guideline recommendations.

Objective

To assess the effectiveness of radioactive iodine (RAI) therapy and the incidence of hypothyroidism post RAI in patients with subclinical hyperthyroidism or clinical hyperthyroidism with Multinodular Goiter (MNG).

Methods

A retrospective study of 69 consecutive patients treated with ¹³¹I for MNG during the year 2008 observed for six months. All patients received a single fixed dose of 16 mCi (592 MBq) weighted by the gland size. They were categorized into two groups: subclinical hyperthyroidism or clinical hyperthyroidism. We compared the success rate and the incidence of hypothyroidism.

Results

The thyroid dysfunction was corrected in 82.09% of the patients. Success rate was 100% in the clinical hyperthyroidism group and 78.13% in the subclinical hyperthyroidism group (P = 0.105). The overall incidence of hypothyroidism was 16.42%; 25.00% of patients with clinical hyperthyroidism and 14.55% with subclinical hyperthyroidism developed this secondary effect (P = 0.400). No statistically significant differences were found in the success rate in the incidence of hypothyroidism when the results were analyzed according to the thyrotropin decrease in patients with subclinical hyperthyroidism. Seven patients had positive anti-thyroid peroxidase antibodies (anti-TPO) before therapy. The incidence of hypothyroidism was significantly higher in them (57.14% vs 11.67%; P = 0.011). Cardiac arrhythmias were four times more frequent in patients with clinical hyperthyroidism. Previous treatment with thiamazol positively affected the outcome.

Conclusions

A single fixed weighted dose of ¹³¹I is highly effective and safe for the control of clinical and subclinical hyperthyroidism due to MNG. Patients with anti-TPO antibodies may have a high risk of developing post-iodine hypothyroidism.

Parathyroid carcinoma (PTC) is a rare malignant disease that is usually hyperfunctioning, which produces an excess of parathyroid hormone. Hyperparathyroidism causes bone metabolism disorders, as osteopenia and sometimes brown tumors. Brown tumors are benign but locally aggressive bone lesions, whose differential diagnosis with metastases or other primary malignancies may be complicated. 99mTc- Sestamibi scan is the usual procedure for the detection of parathyroid pathology, with a sensitivity of 85–100% and specificity close to 100% in parathyroid adenomas, it having similar percentages in the detection of PTC. We present the case of a patient diagnosed of a malignant hyperparathyroidism associated with bone lesions in which the 99mTc-Sestamibi scan showed a false negative result in the detection of parathyroid condition. However, 18F-FDG-PET/CT detected the PTC and helped in the differential diagnosis of associated bone lesions, which were finally confirmed as brown tumors