Body Composition Adjusted Dosing of Gemcitabine-Nab-Paclitaxel in Pancreatic Cancer Does Not Predict Toxicity Compared to Body Surface Area Dosing.

Combination gemcitabine and nab-paclitaxel (Gem-Nab-P) is a common regimen used to treat metastatic pancreatic ductal adenocarcinoma (PDAC). Toxicity from this regimen is associated with significant morbidity. Currently, Gem-Nab-P is dosed using estimated body surface area, derived from height and weight. This study investigates whether skeletal muscle assessment could be a useful tool in the dosing of Gem-Nab-P in metastatic PDAC. This study included 52 patients who had received first-line treatment with Gem-Nab-P for PDAC. Demographic and chemotherapy treatment information was gathered from medical records and body composition analysis was performed using single slice computed tomography methods, at spinal level L3. Patients who experienced first-cycle chemotherapy-associated toxicity did not have a different median skeletal muscle area (SkMA) to those who did not (128.6 cm2 vs. 111.4 cm2, P = 0.2). There was also no difference in the gemcitabine dose to SkMA ratio (14.1 mg/cm2 vs. 14.4 mg/cm2, P = 0.8), nab-paclitaxel to SkMA ratio (1.8 mg/cm2 vs. 1.8 mg/cm2, P = 0.6) or combined dose equivalent to SkMA ratio (2.8 mg/cm2 vs. 2.9 mg/cm2, P = 0.9) between the patients that experienced first cycle toxicity versus those that did not. This study suggests that a PDAC patient's SkMA is unlikely to be a useful addition to conventional body surface area in the dosing of first-line Gem-Nab-P, to reduce first-cycle toxicity.

Body composition analysis using abdominal scans from routine clinical care in patients with Crohn's Disease.

OBJECTIVE: Crohn's Disease is associated with body composition changes, which have important treatment and prognostic implications. Measurement of body composition usually requires dedicated scanning or measurement, with retrospective analysis of existing datasets impossible. We sought to determine whether single slice analysis of abdominal scans, obtained during routine clinical care, in patients with Crohn's Disease accurately predicts body composition compartments. MATERIALS AND METHODS: Abdominal CT images of patients with Crohn's disease were analyzed and comparison was made with total body fat-free mass, total body fat mass, femoral neck t-score, and other parameters reported from DXA, the reference method. RESULTS: Thirty-seven subjects were identified, 15 male and 22 female, with a mean age of 43.8 years. There was significant correlation (Pearson r = 0.923, p < 0.001) between skeletal muscle area from CT and total fat-free mass measured by DXA. Similarly, total body fat mass correlated strongly (r = 0.928, p < 0.0001) with subcutaneous fat area. In this cohort of ambulatory Crohn's Disease patients, low muscle mass/sarcopenia was prevalent and predictive of lower bone mineral density. CONCLUSIONS: Fat mass, fat-free mass, and appendicular skeletal muscle index can be predicted by analysis of a single CT slice in patients with Crohn's Disease. Similar to published data from healthy subjects, the L3 vertebral body level provided the most robust correlation with most parameters. This study represents the first published use of routinely obtained abdominal imaging to demonstrate this relationship - and to predict body composition components - in patients with inflammatory bowel disease.