Assessment of patient and neurosurgeon radiation exposure using a direct-reading dosimeter during transpedicular fixation for thoracic and lumbar spine injuries

Introduction. Individual dosimetry is routinely performed using thermoluminescent dosimeters (TLDs). Total dose is accumulated in these devices and periodically recorded by an accredited laboratory. This method does not provide real-time information on intraoperative radiation exposure. Objective. To compare X-ray doses received by patients with traumatic thoracic and/or lumbar spine injury during open and minimally invasive interventions. Material and methods. Ninety-two patients underwent surgery for thoracic and/or lumbar spine injury. Intraoperative analysis included dose-area products (DAP, cGy×cm2), individual TLD dosimeter readings of surgeons. Individual radiation dose equivalent was determined using four direct-reading dosimeters positioned on the operating table at distances of 0, 40, 80, and 120 cm from direct beam of radiation source. Results. Fifty-four patients underwent open surgery, 38 – transcutaneous procedure. Mean DAP was 2171 cGy×cm2, mean radiation dose equivalent — 1.6 mSv. Minimally invasive procedures were associated with significantly higher radiation exposure: median DAP 3408.8 cGy×cm2 and dose equivalent 2.3 mSv compared to 327.8 cGy×cm2 and 0.2 mSv for open surgeries. Neurosurgeon radiation exposure did not exceed standards. Conclusion. Patient radiation exposure is significantly higher during minimally invasive procedures compared to open surgeries (mean dose equivalent 3 mSv versus 0.6 mSv). Understanding the patterns of radiation field is necessary for informed and safe use of X-rays.