NEOVASCULAR AGE-RELATED MACULAR DEGENERATION WITH ADVANCED VISUAL LOSS TREATED WITH ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY: Clinical Outcome and Prognostic Indicators.

PURPOSE: To describe visual outcome and prognostic indicators in neovascular age-related macular degeneration with advanced visual loss at the initiation of anti-vascular endothelial growth factor therapy. METHODS: A retrospective chart review was performed on a consecutive series of 1,410 patients with neovascular age-related macular degeneration treated with anti-vascular endothelial growth factor therapy at the Medical College of Wisconsin. Subjects were included if at the initiation of therapy they had 20/200 or worse visual acuity (VA) with no other visually limiting eye disease and a minimum follow-up of 6 months. The change in VA at 6 months and 12 months was assessed compared with baseline. Visual improvement/worsening was defined as at least ± 0.3 logMAR (equivalent to 15 ETDRS [Early Treatment Diabetic Retinopathy Study] letters) change. Other factors for analysis included number of injections received, drug type, and various clinical and imaging findings. RESULTS: One hundred thirty-one cases met the study criteria, and 97 were followed for 12 months. Baseline VA was 1.38 logMAR (20/480 Snellen equivalent). Mean VA change (logMAR) consisted of an improvement of 0.23 (P < 0.0001) at 6 months and 0.17 (P = 0.003) at 12 months. At 12 months, VA improved in 45% and worsened in 20%. Among subjects with baseline VA worse than 20/400, VA improved in 57% and worsened in 20%. On univariate analysis at either the 6 months or 12 months follow-up, visual improvement was associated with retinal hemorrhage (P = 0.03) and subretinal fluid (P = 0.02), whereas visual worsening was associated with retinal pigment epithelial detachment (P = 0.04) and intraretinal fluid (P = 0.01). With multivariate analysis, visual improvement was predicted by both a larger number of injections received (P = 0.001) and a poorer baseline VA (P = 0.001). Injection medication type did not influence outcome. CONCLUSION: Statistically significant visual improvement was observed in association with anti-vascular endothelial growth factor therapy in patients with severe neovascular age-related macular degeneration, even in patients whose initial VA was worse than that studied in large anti-vascular endothelial growth factor clinical trials. Numerous clinically discernable or potentially modifiable factors may influence outcome in such patients.

Fasting hypoglycaemia secondary to carnitine deficiency: a late consequence of gastric bypass.

Twelve years following gastric bypass surgery, a cachectic 69-year-old woman presented with both fasting and postprandial hypoglycaemia. Postprandial symptoms were relieved by dietary modification and acarbose, as is common in such cases. During a supervised fast, symptomatic hypoglycaemia occurred. Concurrent laboratory testing showed suppression of plasma insulin, c-peptide, proinsulin and insulin-like growth factor II. However, beta-hydroxybutyrate was also low, surprising given insulin deficiency. Elevated plasma free fatty acid (FFA) concentrations suggested that lipolysis was not impaired, making cachexia/malnutrition a less likely cause of hypoglycaemia. The apparent diagnosis was failure to counter-regulate-subsequent plasma carnitine measurements showed carnitine deficiency which presumably prevented FFA transport across mitochondrial membranes for ketogenesis. Repletion with high-dose oral carnitine supplements effected resolution of fasting hypoglycaemia.

Inappropriate requesting of parathyroid scintigraphy at an academic medical center.

BACKGROUND: Primary hyperparathyroidism is a biochemical, not radiologic diagnosis. Parathyroid scintigraphy should only be requested for surgical planning, not to confirm diagnosis. Here we determined reasons for inappropriately ordered parathyroid scintigraphy. METHODS: We generated a database of patients undergoing parathyroid scintigraphy over 5 years, who did not undergo parathyroidectomy. RESULTS: Over 5 years 129 parathyroid scintigraphies (of 308 total scans) were performed in patients who did not undergo parathyroidectomy. We determined that only 58 (45%) had true primary hyperparathyroidism. The most common reason for the scan was to "confirm the diagnosis." Only 20% were ordered for adenoma localization, although surgery was not performed. Physicians requesting parathyroid scintigraphies specialized in a variety of disciplines. CONCLUSION: Forty-two percent of parathyroid scintigraphies were requested inappropriately to "confirm" a diagnosis of primary hyperparathyroidism. We propose to change the ordering system to clarify that parathyroid scintigraphy is a functional tool to optimize surgery when the diagnosis is secure.

Comparison of various online strategies to account for interfractional variations for pancreatic cancer.

PURPOSE: To identify practical techniques to address the large interfractional variations for pancreas irradiation by comparing various used/proposed online strategies. METHODS AND MATERIALS: The daily computed tomography (CT) images acquired using a respiration-gated in-room CT (CTVision; Siemens) for 10 pancreatic cancer patients treated with image guided radiation therapy (IGRT) were analyzed. The contours of the pancreas and organs at risk on each daily CT set were generated by populating from the planning CT using a deformable registration tool (ABAS; Elekta) with manual editing. Nine online strategies were considered: (1) standard IGRT (ie, IGRT with 0-mm additional margin [AM]); (2) IGRT with 2-mm AM; (3) IGRT with 5-mm AM; (4) IGRT with plan renormalized to maintain 95% planning target volume (PTV) coverage; (5) full-scale reoptimization; (6) reoptimization starting from the original plan; (7) segment aperture morphing (SAM) from the original plan, based on PTV shape change; (8) SAM plus segment weight optimization; and (9) reoptimization starting from the SAM plan. One-way analysis of variance was applied to plan qualities for the 9 strategies to assess statistical significance in difference. RESULTS: The 3 IGRT strategies (1-3) lead to either inadequate PTV coverage or higher doses to critical structures, indicating that the additional margins alone are not adequate to account for the changes. The full-scale reoptimization results in the best plan but requires the delineation of several structures, which is time consuming. The SAM strategy (7) was the fastest one, because it requires delineating only 1 structure (target), and its plan quality was comparable to that for the full-scale reoptimization. CONCLUSION: Online replanning strategies can lead to either reduced organs-at-risk dose and/or improved target coverage as compared with the current practice of IGRT. The SAM-based online replanning is comparable to full-scale reoptimization and is efficient for practical use.