Lumbar discectomy and fusion: Organs? dose and effective dose estimation using Monte Carlo simulation

In this study, the effect of patient- and procedure-related parameters on organs' dose (OD), peak skin dose (PSD) and effective dose (ED) during lumbar discectomy and fusion (LDF) was assessed. Intra-operative parameters obtained from 102 LDFs were inserted into VirtualDose-IR software implementing sex-specific and BMIadjustable anthropomorphic phantoms for dosimetric calculations. Fluoroscopy time (FT), kerma-area product (KAP), cumulative and incident air-kerma (Kair) were also recorded from the dosimetric report of the mobile Carm. An increase in KAP, Kair, PSD and ED was found for male or higher BMI patients, multi-level or fusion or L5/ S1 procedures. However, a significant difference was found only for PSD and incident Kair between normal and obese patients and for FT between discectomy and discectomy and fusion procedures. The spleen, kidneys and colon received the highest doses. The BMI have a significant impact only for kidneys, pancreas, and spleen doses when comparing obese to overweight and for urinary bladder when comparing overweight to normal patients. Multi-level and fusion procedures resulted in significantly higher doses for lungs, heart, stomach, adrenals, gallbladder and kidneys, while pancreas and spleen doses significantly increased only for multi-level procedures. Additionally, a significant increase was found only for urinary bladder, adrenals, kidneys, and spleen ODs when comparing L5/S1 and L3/L4 levels. The mean ODs were lower compared to the literature. These data may aid neurosurgeons in optimising exposure techniques during LDF to keep patients' dose as low as is practicably possible.