Aim To compare the effect of high-dose therapy (HDT consisting of high-dose chemotherapy followed by autologous stem cell transplantation) and conventional-dose chemotherapy (non-HDT) on the uptake of 18 F-sodium fluoride (NaF) in the whole bone, pelvis and femoral neck of multiple myeloma (MM) patients.Method The data of 19 MM patients who received HDT (61.5, SD (5.6) years) and 11 MM patients who received conventional-dose chemotherapy (70.9, SD (7.2) years) were collected in a prospective study. NaF PET/CT imaging was performed at baseline and eight weeks and two weeks after treatment for the HDT group and the non-HDT group, respectively. A CT-based algorithm was applied to segment the bones, and the global mean SUV (GSUVmean) of the whole bone and pelvis was calculated (OsiriX MD v.9.0, Pixmeo SARL; Bernex, Switzerland). In addition, regions of interest for the whole, medial, and lateral femoral neck were delineated bilaterally. Whole bone and pelvis measurements were replicated by two observers.Results The average GSUVmean in the whole bone and pelvis of the patients who underwent HDT significantly decreased from before to after treatment (-16.27%, p= 0.02 and -16.54%, p= 0.01, respectively). A significant decrease in the whole and lateral femoral neck was also observed bilaterally in the HDT group. No significant decrease in average GSUVmean was observed in the non-HDT group. A high level of inter-observer reliability was found in intra-class correlation (ICC for pre-treatment whole bone: 0.983, posttreatment whole bone: 0.989, pre-treatment whole pelvis: 0.998, post-treatment whole pelvis: 0.996).Conclusion NaF uptake significantly decreased after treatment in patients who received high dose therapy. A high level of agreement was observed between two operators for whole bone and pelvis measurements.
We present a novel computed tomography CT-based tissue segmentation methodology for determining volume and global uptake of FDG of the thigh muscles and correlate these parameters with age. Materials and Methods A total of 71 subjects from a prospective clinical trial [NCT01724749] were included. PET/CT scans were acquired 180 min after intravenous injection of FDG. A 3D growing region algorithm with neighborhood Hounsfield unit (HU) threshold between 1 and 150 was used to highlight the muscle. FDG uptake was expressed as the average mean standardized uptake value (SUVmean) normalized for lean body mass (average SULmean). Femur volume was used to normalize thigh muscle volume to calculate normalized volume and correlate with age. Results We found a significant negative correlation between normalized volume and age (left side r=-0.262, p=0.02; right side r=-0.286, p=0.01). No statistically significant difference was found between SUL and age (left side r=0.10, p=0.41; right side r=0.14, p=0.24) or between SUL and BMI (left side r=0.03, p=0.78; right side r=0.02, p=0.90). There was no statistically significant difference in muscle volume on the two sides (left 3606.5±1195.6 cm 3 , right 3633.5±1215.7 cm 3 , p=0.28). Statistically significant difference was noted in the global metabolic activity (SUL) between the two sides (left 0.39±0.06, right 0.42±0.08, p<0.001), with 56/71 (78.8%) subjects having higher uptake on the right side. Conclusion FDG-PET/CT using CT-based segmentation is a novel imaging modality assessing the volume and global metabolic activity of the thigh muscles. It could be possible to utilize this methodology for the research and understanding of lower limb muscle pathophysiology.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.