Parathyroid Adenoma Mimicking a Malignant Lymph Node on 18F-Choline PET-CT.

Prostate carcinoma is the most common cancer in men. After local therapy, disease recurs in many patients. A choline PET/CT is indicated in case of biochemical relapse of prostate carcinoma to determine the site of recurrence (local and/or distant) and to help select the next line of therapy. Choline PET-CT is also known to show an elevated uptake in hyperfunctioning parathyroid adenoma. This case report shows the difficulty to distinguish between both entities if they occur simultaneously in an oncologic patient.

Influence of time delay on the estimated lung shunt fraction on 99mTc-labeled MAA scintigraphy for 90Y microsphere treatment planning.

90Y-microspheres therapy is used to treat selected patients with primary or metastatic liver tumors in a safe and effective way. As a preparation for 90Y-microspheres treatment, a 99mTc-macroaggregated albumin (99mTc-MAA) simulation procedure is essential to evaluate particle shunting to the lung or gastrointestinal tract. We investigated the effect of interval between injection of 99mTc-MAA and time of scanning on the lung shunt fraction (LSF). In 4 patients with secondary hepatic malignancies who underwent repeated whole-body scintigraphy up to 5 hours after injection of 99mTc-MAA, a marked change in LSF was observed. It appears that tracer degradation leads to an important overestimation of LSF at later time points. An overestimation of LSF can lead to dose reduction or canceling of the planned 90Y-microspheres treatment. It is concluded that the interval between injection and scanning should be kept as short as possible.

Deposition of aerosols delivered by nasal route with jet and mesh nebulizers.

PURPOSE: To quantify the amount of aerosol deposited in different parts of the airways with a commercially available nasal sonic jet nebulizer (NJN) using a sound effect, and to compare its performance with a new nasal mesh nebulizer (NMN). METHODS: Seven healthy non-smoking male volunteers aged 21-36 years with a mean weight of 77±10 kg were included in this single-center study. Both nebulizer systems were loaded with (99m)Tc-DTPA and scintigraphies were performed with a gamma camera. Particle size distribution of the aerosols produced by the two nebulizer systems was measured. RESULTS: There was no statistical difference between the two nebulizers in terms of fraction of particles smaller than 5 µm (44±4% vs 45±2%) (p>0.9). Aerosol deposition in the nasal region was 73±10% (% of aerosol deposited in airways) with the NJN, and 99±3% with the NMN (p=0.01). Total nasal deposition was 9.6±1.9% of the nebulizer charge with the NJN and 28.4±8.9% with the NMN (p=0.01). 0.5±0.3% of the nebulizer charge was deposited in the maxillary sinuses with the NJN, compared to 2.2±1.6% with the NMN (p=0.01). CONCLUSION: Although the two nebulizers had the same particle size, NMN significantly improved aerosol deposition in nasal cavity and prevents deposition into the lungs.