Reducing the Risk of Glowing in the Dark; a Protocol to Reduce Patient and Personal Exposure to Ionizing Radiation during Biopsy

Abstract

<h3>Purpose</h3> Despite rapid progress in non-invasive techniques such as cMRI, endomyocardial biopsy (EMBx) remains the corner stone of the detection of rejection after cardiac transplantation. Since the first publications in the 1960's, the technique has hardly changed. A typical heart transplanted patient will be exposed to 80-120mSv during the first four years after transplantation, 10-20% of this exposition resulting from EMBx. As the risk of malignancy is higher among transplant patients, efforts to reduce the exposition to ionizing energy are mandatory. <h3>Methods</h3> In order to reduce patient and personel exposition to radiation, a set of non-mandatory guidelines were introduced at our institution. This internal protocol is based on ECG guiding to reach the ventricular septum (SVS and VES), followed by a static fluoroscopy image to confirm adequate position. This is combined with a reduced amount of X-ray delivered to the patient by aggressive collimation and reduction of energy (A and KeV) applied to the vacuum chamber. Two months after the adoption of this technique, we conducted an audit of the practice to observe radiation exposure and complication rates in comparison with the preceding 2 months. <h3>Results</h3> 143 biopsies were observed before, and 154 biopsies after implementation of the guidelines. The median radiation dose decreased from 1.2mGy to 0.1mGy (p<0.001). This difference was due to a reduction of the duration of radiation per biopsy (from 18 to 1.4sec., p<0.001) and a reduction of the dose per second (from 0.06mGy/sec. to 0.04mGy/sec., p<0.001). The two patient cohorts had comparable BMIs (26kg/m2 (+/-4.9), p=0.84). No complications were observed. <h3>Conclusion</h3> A reduction of radiation exposition to radiation is achievable with minimal changes in the procedure, and without posing additional risks. Adoption of such radiation reduction policies could result in a long-term reduction of neoplasia in transplant patients and treating interventionalists.