Optimal timing of SPECT/CT to demonstrate parathyroid adenomas in 99mTc-sestamibi scintigraphy.

BACKGROUND: Accurate preoperative localisation of the parathyroid adenoma is essential to achieve a minimally invasive parathyroidectomy. The purpose of this study was to validate and improve our single-isotope dual-phase parathyroid imaging protocol utilising 99mTechnetium-Sestamibi ([99mTc]MIBI). There has been no accepted gold standard evidence-based protocol regarding timing of single-photon emission computed tomography/computed tomography (SPECT/CT) acquisition in parathyroid imaging with resultant variation between centres. We sought to determine the optimum timing of SPECT/CT post administration of [99mTc]MIBI in the identification of parathyroid adenomas. We aimed to evaluate the efficacy of early and late SPECT/CT and to establish whether SPECT/CT demonstrates increased sensitivity over planar imaging. MATERIAL AND METHODS: A sample of 36 patients with primary hyperparathyroidism underwent planar and SPECT/CT acquisition 15 minutes (early) and two hours (late) post [99mTc]MIBI administration. Two radionuclide radiologists reviewed the images and Fisher's exact Chi-squared statistic was used to evaluate the diagnostic performances of early versus late SPECT/CT acquisition and SPECT/CT versus planar imaging. RESULTS: Twenty-one likely parathyroid adenomas were identified with a statistically superior diagnosis rate in the late SPECT/CT acquisition compared with both early SPECT/CT and planar imaging (p < 0.05). All adenomas diagnosed on early SPECT/CT acquisition were also identified on late SPECT/CT images. CONCLUSIONS: Single late phase SPECT/CT is significantly superior to early SPECT/CT in the identification of parathyroid adenomas. Late SPECT/CT improves diagnostic accuracy over planar acquisition. Imaging protocols should be revised to include late SPECT/CT acquisition. Early SPECT/CT acquisition can be eliminated from scan protocols with associated implications regarding reduced scan time and increased patient throughput.

Response to aflibercept in patients with persistent exudation despite prior treatment with bevacizumab or ranibizumab for age-related macular degeneration.

BACKGROUND AND OBJECTIVE: This study examines the clinical response of patients transitioned to aflibercept, the newest anti-VEGF medication, due to persistent evidence of exudation on optical coherence tomography (OCT) despite regular treatment with bevacizumab and/or ranibizumab. PATIENTS AND METHODS: Aflibercept was administered to 111 patients considered for study inclusion. Eyes were included if they were transitioned to aflibercept for treatment of persistent exudation on OCT despite regular treatment with at least three injections of ranibizumab or bevacizumab. Retrospective data were collected from medical records. RESULTS: Complete resolution of exudation was seen in 34% of eyes at final follow-up. Clear improvement in exudation amount or severity without complete resolution was seen in 25%. No improvement was seen in 34%, and 6% demonstrated worsening of exudation. Snellen visual acuity at the time of transition versus final follow-up after aflibercept injection did not appreciably change (logMAR 0.494 to 0.505, Snellen equivalent 20/62 to 20/64; P = .84). The mean center point neurosensory retina thickness decreased from 228.6 to 176.9 µm (P = .001). CONCLUSION: Aflibercept may decrease the amount of exudation in a significant number of patients. However, this reduction did not result in an improvement in Snellen visual acuity.

Trends in medical filtration.

Advances in materials, mould tooling and control systems are offering the industry greater design choices in filtration as well as the potential to reduce manufacturing costs. This article describes what is possible.