Background In the context of increasing obesity prevalence, the relationship between large visceral adipose tissue (VAT) volumes and type 2 diabetes mellitus (T2DM) is unclear. In a clinical sample of severely obese women (mean body mass index [BMI], 46 kg/m2) with fasting normoglycemia (n=40) or dysglycemia (impaired fasting glucose+diabetes; n=20), we sought to determine the usefulness of anthropometric correlates of VAT and associations with dysglycemia. Methods VAT volume was estimated using multi-slice computer tomography; anthropometric surrogates included sagittal abdominal diameter (SAD), waist circumference (WC) and BMI. Insulin sensitivity (Si), and beta-cell dysfunction, measured by insulin secretion (AIRg) and the disposition index (DI), were determined by frequently sampled intravenous glucose tolerance test. Results Compared to fasting normoglycemic women, individuals with dysglycemia had greater VAT (P<0.001) and SAD (P=0.04), but BMI, total adiposity and Si were similar. VAT was inversely associated with AIRg and DI after controlling for ancestry, Si, and total adiposity (standardized beta, −0.32 and −0.34, both P<0.05). In addition, SAD (beta=0.41, P=0.02) was found to be a better estimate of VAT volume than WC (beta=0.32, P=0.08) after controlling for covariates. Receiver operating characteristic analysis showed that VAT volume, followed by SAD, outperformed WC and BMI in identifying dysglycemic participants. Conclusions Increasing VAT is associated with beta-cell dysfunction and dysglycemia in very obese women. In the presence of severe obesity, SAD is a simple surrogate of VAT, and an indicator of glucose dysregulation.

Purpose Extracranial radiosurgery (ECRS) is a novel treatment for inoperable recurrent or metastatic abdominopelvic cancers. However, local control, metabolic response, and acute toxicity remain undefined. We therefore analyzed these endpoints in patients treated with single-fraction image-guided ECRS at Emory University. Methods 20 patients with recurrent or metastatic inoperable abdominal or pelvic cancers (23 sites) were treated with single-fraction ECRS using a Varian linear accelerator between 08/2006 and 02/2008. Patients with pancreas, biliary and liver cancer were part of an IRB-approved ongoing dose-escalation trial. 14 patients had received prior abdominal or pelvic external beam radiation. In 13 patients pre-treatment PET/CT was used to delineate the target volume. Image-guidance was provided by implanted fiducial markers and on-board imaging in 13 patients, and with cone-beam CT in 1 patient. 8 Patients were treated with respiratory gating. The median single-fraction dose delivered was 18 Gy. Each patient was assessed at 1 week, 1 month, and 3 months after radiosurgery for toxicity, and at approximately 1 month and 3 months with PET/CT for metabolic tumor response. Partial response was defined as a reduction in size of > 10% on CT and a decrease in maximum SUV of > 15% on PET. Complete response was defined as complete resolution on CT, and a reduction of SUV to background levels on PET. Results The median follow-up was 6.3 months (range 1.5-12.2 months). The overall response rate (the sum of complete responses and partial responses) by treated site was noted in 36% (1 month), 47% (3 months) and 48% (final). A complete response was achieved in 13% (3 sites). At last follow-up, local control (sum of response rate and stable disease) was 74%. The metabolic response rate by pet only(sum of partial and complete responders) was 85% on final analysis. 23% of pet avid sites achieved a complete response. Two pet avid treated sites (13%) did show evidence of progression at 3 months, but subsequent CT/FDG-PET scans showed a decrease in maximum SUV; no patients suffered progressive disease based on metabolic imaging at last follow-up. Grade 1-2 upper GI acute toxicity (nausea, vomiting, gastritis, and pain) was noted in 47% and 55% of patients at 1 week and 1 month, respectively. Correspondingly, acute lower GI toxicity (diarrhea, pain) was lower at 12% and 6%. Overall grade 1-2 GI toxicity was seen in 59% of patients at 1 week (pain and nausea being the most common) and 61% of patients at 1 month post stereotactic body radiotherapy (SBRT) (nausea being the most common). Conclusions Single-fraction image-guided ECRS for recurrent or metastatic abdominopelvic cancers is safe and effective in the short term. 3-month local control was very good , and was predicted by an early metabolic response as seen on PET/CT. Acute side effects were mild, with no patient experiencing grade 3 or greater toxicity. Dose escalation and long-term studies are warranted for this treatment approach.