Radioguided surgery of primary hyperparathyroidism using the low-dose 99mTc-sestamibi protocol: multiinstitutional experience from the Italian Study Group on Radioguided Surgery and Immunoscintigraphy (GISCRIS).

UNLABELLED: This study evaluated the accuracy of (99m)Tc-sestamibi scintigraphy and neck ultrasonography in patients with primary hyperparathyroidism (PHPT) and the role of intraoperative hand-held gamma-probes in minimally invasive radioguided surgery (MIRS) of patients with a high likelihood of a solitary parathyroid adenoma (PA). The study was undertaken under the aegis of the Italian Study Group on Radioguided Surgery and Immunoscintigraphy (GISCRIS). METHODS: Clinical records were reviewed for 384 consecutive PHPT patients undergoing radioguided surgery using a low dose of (99m)Tc-sestamibi. Selection of patients for MIRS instead of traditional bilateral neck exploration was based on preoperative imaging indicating a solitary PA. (99m)Tc-Sestamibi (37-110 MBq, or 1-3 mCi) was injected in the operating theater 10-30 min before the start of the intervention. Either 11-mm collimated (309 patients) or 14-mm collimated (75 patients) gamma-probes were used. Intraoperative quick parathyroid hormone (IQPTH) assay was used on 308 patients (80.2%). RESULTS: MIRS was successfully performed on 268 (96.8%) of 277 patients. Conversion to bilateral neck exploration was necessary in 9 patients (3.3%) because of either persistently high IQPTH levels after removal of the preoperatively visualized PA (4 patients), intraoperative frozen-section diagnosis of parathyroid carcinoma (2 patients), or hard-to-remove PA (3 patients). MIRS, which was performed under locoregional anesthesia in 72 patients, required a mean operating time of 37 min and a mean hospital stay of 1.2 d. MIRS was successfully performed also on 32 (78.0%) of 41 patients who had previously undergone thyroid or parathyroid surgery. No major surgical complications were observed in the MIRS group, and there were only 24 cases (11%) of transient postoperative hypocalcemia. The probe was of little help in patients with concomitant (99m)Tc-sestamibi-avid thyroid nodules and not helpful at all in patients with negative scan findings preoperatively. IQPTH measurement helped to disclose some cases of multigland parathyroid disease. CONCLUSION: (99m)Tc-Sestamibi scintigraphy, especially if combined with neck ultrasonography, is highly accurate in selecting PHPT candidates for MIRS. The low-dose (99m)Tc-sestamibi protocol (which entails a low-to-negligible radiation exposure to the surgical team) is safe and effective for MIRS. MIRS plays a limited role in patients with concomitant (99m)Tc-sestamibi-avid thyroid nodules and should be discouraged in patients with negative (99m)Tc-sestamibi finding preoperatively. IQPTH can be recommended during MIRS to facilitate intraoperative identification of previously undiagnosed multigland parathyroid disease.

Reduced value of thallium-201 single-photon emission computed tomography in the management of HIV-related focal brain lesions in the era of highly active antiretroviral therapy.

To evaluate the diagnostic value of thallium-201 single-photon emission computed tomography (201Tl SPECT) in the management of focal brain disorders in the era of highly active antiretroviral therapy (HAART), a validation study of diagnostic procedure was performed in a tertiary clinical care center in Italy. Thirty-eight consecutive HIV-infected patients with neurological impairment and focal brain lesions (FBL) were enrolled in a prospective evaluation and underwent diagnostic procedures according to a standardized protocol based on modified previously released guidelines. Six out of seven PCNSL presented high uptake at 201Tl SPECT [sensitivity 86% (95% CI 42-99); specificity 77% (95% CI 58-90); positive predictive value (PPV) 46% (95% CI 20-74); negative predictive value (NPV) 96% (95% CI 78-100)]. Among toxoplasmic encephalitis (TE) cases 14 showed no uptake and 5 showed an increased uptake [sensitivity 74% (95% CI 49-90); specificity 42% (95% CI 21-66); PPV 56% (95% CI 35-75); NPV 61% (95% CI 32-85)]. Patients taking HAART were more likely to display an increased uptake of 201Tl in the cerebral lesions than patients without HAART (OR 5.07; 95% CI 1.19-21.5). Considering only the patients with diagnosis of TE, 60% of patients who showed high radionuclide uptake were taking HAART, while 79% of patients without relevant uptake were not taking HAART. As a result of the impact of HAART, the diagnostic value of 201Tl SPECT in the management of HIV-associated FBL could be substantially reduced. This observation suggests that in HAART-treated patients, this diagnostic tool be used only when combined with other more specific diagnostic markers.

Implantable cardioverter-defibrillator lead infection detected by 99mTc-sulesomab single-photon emission computed tomography/computed tomography 'fusion' imaging.

We describe a case of implantable cardioverter-defibrillator (ICD) lead infection that was diagnosed by means of sulesomab imaging whereas ultrasound examinations were inconclusive. Nuclear techniques may be helpful in such, not infrequent, settings.