In patients we trust. Reliability of self-reported weight and size in patients attending a nuclear medicine department.

Purpose: The aim of the study was to assess the reliability of self-reported weight and size of nuclear medicine patients in view of recommendation for the weight-dependent tracer application for imaging and therapy. Methods: A total of 824 patients (334m, 490f) were asked to report their weight and size prior imaging or therapy and their level of confidence. Subsequently, weight and size of each patient was measured and body mass index (BMI), body surface area (BSA) and lean body mass (LBM) were calculated. Differences between reported and true values were compared for statistically significant differences. Results: The average patient age was (60+/-14) years ((17-91) years). An over-or underestimation of weight of ≥10% was observed in 3% of patients, size was overestimated by 1% by the patients. The BMI-calculation was affected by incorrect self-reported values. Conclusion: Most self-reported weights and sizes of nuclear medicine patients are accurate. However since over- and underestimation of weight and size leads to incorrect BMI, BSA and LBM values patient weights should be measured at least for patients receiving a weight-adapted therapy or if quantification in PET/CT is needed.