Revista Espanola De Medicina Nuclear最新文献

Sentinel node biopsy has become the standard practice in lymph node staging in breast cancer in early stages. However, uncertainty remains regarding the best method of radiotracer/dye injection. Currently, the subareolar injection is being widely used because of its technical simplicity and higher rates of SN location versus the so-called deep techniques (peritumoral, intratumoral) that require greater specialization and greater use of resources in the non-palpable lesions.

We present a case of a discrepancy between the two techniques that could have caused a false negative.

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.

Objective

To assess the value of intraoperatory radioguided probe detection to guide surgical resection of malignant lesions previously detected by ¹⁸F-FDG PET-CT.

Material

Twelve consecutive patients with suspected tumor recurrence detected by ¹⁸F-FDG PET-CT considered resectable were enrolled in the study. Ultrasound guided fine needle aspiration (FNA) before surgery was performed in 6 patients and CT guided biopsy was performed in 1 patient. In 5 patients with accessible lesions, a radioguided occult lesion localization (ROLL) technique was performed after injection of ^99mTc-colloid (1.7-2.4 mCi) inside the lesion under ultrasound or CT guidance, pre-operatively. Radioguided surgical detection was then carried out 19-24 hours afterwards using the gamma probe. In 7 patients with non-accessible needle lesions or multiple lesions, 9.5-10.5 mCi of ¹⁸F-FDG were injected 3-5 hours before radioguided surgery using a PET-dedicated probe (Gamma locator DXI-GF&E).

Results

ROLL technique: All lesions injected with nanocolloid were resected (6 lesions in 5 patients, 1 patient with 2 lesions), and recurrence was histologically confirmed. PET probe: Fourteen out of 16 hypermetabolic lesions detected on the PET-CT were resected. One cervical and one mediastinal lymph node in different patients could not be excised. Histological recurrence was confirmed in 12 out of 14 lesions. In one patient, the 2 lymph nodes excised were inflammatory.

Conclusions

¹⁸F-FDG PET-CT can be key in deciding surgical approach and appropriate radioguided protocol. When lesions are solitary and easily accessible, ROLL technique seems the method of choice. PET probe is more adequate for less accessible lesions.

Premature atherosclerosis and its consequent heart disease play a crucial role in patients with systemic lupus erythematosus, even in premenopausal women. It is one of the leading causes of death in long evolution lupus.

We present the case of a 42-year-old premenopausal woman, smoker, with a history of hypertension, cholecystectomy and lupus for 23 years, treated with NSAID, steroids and antimalarial drugs. The patient consulted due to chest pain on moderate efforts. Due to the suspicion of ischemic heart disease, a cardiology study was initiated, performing a myocardial perfusion SPECT. This revealed an intense and extensive anterolateral perfusion defect, with very light reperfusion in rest images, consistent with the diagnosis of acute infarction in the apical region and ischemia in the territory of the left anterior descending artery, which was confirmed later by cardiac catheterization.

¹⁸F-FDG PET-CT has become an essential tool in oncology patient management. The normal distribution of the FDG and the possible artifacts (pitfalls), including those from CT-based attenuation correction, have already been described in several reviews.

However, only a few cases of FDG focal lung uptake have been reported recently.

We present two cases of oncology patients during a routine follow-up with this type of pitfall, without morphological correlation in the CT scan. We repeated the study in one of them, which made it possible to verify normalization of the hyperuptake, orienting us towards a possible pitfall.