Quantification of noninvasive fat reduction: A systematic review

Background and Objective: Noninvasive fat reduction appears effective, but there are various methods for quantifying changes. The objective of this review is to assess comparative utility measures of subcutaneous fat. Study Design/Materials and Methods: Articles describing noninvasive fat reduction were searched using MEDLINE, EMBASE, CINAHL and Scopus electronic databases on two dates (January 28, 2014 and February 16, 2016). Titles of studies and abstracts were screened for eligibility. Manual review was performed by two investigators to detect those that: (1) included original data; (2) were randomized controlled trials, or prospective or retrospective cohort studies; (3) quantified fat outcomes; and (4) enrolled at least 10 subjects. Results: Of 1,057 retrieved articles, 36 met criteria. Most reported four or more measurement techniques. Circumference measurements were most commonly cited. Other objective techniques, like caliper thickness, ultrasound, magnetic resonance imaging (MRI), and three-dimensional (3D) photography, were also used. Common subjective methods were evaluation of standardized photographs by blinded raters and patient satisfaction surveys. Conclusions: For quantifying noninvasive fat reduction, all available methods had significant limitations: photographic comparisons were subjective; circumference or caliper measurements were confounded; ultrasound was operator dependent; MRI was expensive; computed models and simulations were in early development. As new technologies are developed, the need for reliable, accurate and practical measures of subcutaneous fat will increase. Lasers Surg. Med. 50:96–110, 2018.