Analysis of intraoperative radiation use in vascular surgery: Catalyst for quality improvement in patient and personnel safety.

OBJECTIVES: There is paucity in the literature reporting radiation usage analysis in vascular surgery. In the era of endovascular surgeries, analyzing the surgeons' use of radiation in vascular procedures can help establish quality improvement initiatives. METHODS: A retrospective review was undertaken of intraoperative fluoroscopic-guided vascular surgery procedures at a single institution from 2010 to 2017. Mobile C-arms were utilized to gather the six radiation usage metrics and cases were categorized into 6 anatomic surgical fields and 10 surgical procedure types. RESULTS: Three hundred and eighteen vascular surgery cases were analyzed and notable trends in all radiation usage metrics were identified both across the surgical field location and type of surgical procedure. The highest cumulative dose was identified in embolization cases with a mean of 932.5 mGy. The highest fluoroscopic time was seen in atherectomies with a mean of 2629.6 s. In terms of surgical field, the highest cumulative does and fluoroscopic time was identified in abdomen/pelvis procedures with a mean of 352.1 mGy and 1186.8 s, respectively. Analysis of dose reduction techniques also demonstrated notable trends. CONCLUSIONS: There were notable trends in the analyzed radiation usage variables both across the surgical field location and type of surgical procedure. Specifically, cases that involve the abdomen/pelvis, embolization and atherectomy have the highest radiation use. These types of cases can be targeted for future improved dose reduction techniques or staged procedures. This data can serve as baseline information for future quality improvement initiatives for patient and personnel radiation exposure safety.

Comparing radiation exposure between ablative therapies for small renal masses.

PURPOSE: The purpose of this study was to evaluate the amount of radiation exposure patients with small renal masses undergoing percutaneous cyroablation (PCA) or percutaneous radiofrequency ablation (PRFA) received during treatment and follow up. MATERIALS AND METHODS: A retrospective review was conducted on all patients with small renal masses <4 cm treated with PCA or PRFA over a 7-year period in a single academic center. Preoperative, operative, and post-operative variables were collected and compared. Radiation exposure received during treatment and 1 year of follow up were also determined for each modality. Statistical analysis was conducted using SPSS V.17 (SPSS, Chicago, IL). The groups were compared using the Mann-Whitney U and Pearson Chi-Square tests. Statistical significance was considered at p<0.05. RESULTS: There was no significant difference in pretreatment parameters or oncologic outcomes. The average PCA treatment radiation exposure was 39.7 mSv (15.5-133.4 mSv) compared with 22.2 mSv (8.1-67.7 mSv) for PRFA (p=0.001). During the initial year after treatment, the estimated mean treatment and follow-up radiation exposure for PCA was 134.5 mSv, compared with 117 mSv for RFA when routine computerized tomography imaging was employed. CONCLUSION: To our knowledge, this is the first published study that quantifies radiation exposure in PCA and PRFA treatment for small renal masses. These relatively high radiation exposures should be included in the informed consent for these procedures. In addition, caution should be employed when applying these technologies in young patients who are most susceptible to long-term radiation damage.

Fluoroscopic organ and tissue-specific radiation exposure by sex and body mass index during ureteroscopy.

INTRODUCTION: Although radiation exposure from CT and plain film imaging has been characterized, the radiation received by patients during modern-era fluoroscopy has not been well described. The purposes of this study were to measure absolute organ and tissue-specific radiation doses during ureteroscopy and to determine the influence of body mass index (BMI) and sex on these doses. MATERIALS AND METHODS: Eight cadavers underwent a simulated left ureteroscopy. Using a modern C-arm with automatic exposure control settings, thermoluminescent dosimeters were exposed for a fluoroscopy time of 145 seconds (mean time of clinical ureteroscopies from 2006 to 2008). Total tissue exposures were compared by BMI and between sexes using the Wilcoxon signed ranks test and the Mann-Whitney test with p < 0.05 considered significant. RESULTS: Among all cadavers, radiation doses were significantly lower in all contralateral organs excluding the gonad (p < 0.012). Doses were similar bilaterally in the gonad in cadavers with BMI <30, and in all organs in cadavers with BMI >30 (p > 0.05). There were significantly higher mean bilateral gonadal doses in female cadavers (3.4 mGy left and 1.9 mGy right) compared with male cadavers (0.36 mGy left and 0.39 mGy right). The highest cancer risk increase was seen at the posterior skin equivalent to 104 additional cancers per 100,000 patients. CONCLUSION: Contralateral doses were lower for all organs except the gonad when the BMI was <30. In contrast, when the BMI was >30, there was no difference in radiation dose delivered to the ipsilateral and contralateral organs. Gonadal doses were significantly higher in female cadavers. Modern-era fluoroscopy remains a significant source of radiation exposure and steps should be taken to minimize exposure during ureteroscopy.

Security of radioactive material at academic institutions.

In recent years, regulatory emphasis on the prevention of loss, theft and intentional misuse of radioactive materials at academic institutions has forced radiation safety personnel to devote increasing amounts of time and effort to address security issues. NRC regulations require that radioactive materials used or stored in controlled or unrestricted areas be secure from unauthorized removal or be under constant surveillance when in use. This leaves open to interpretation what types of security are required for radioactive materials in restricted areas. Adhering to the goal of keeping exposures As Low As Reasonable Achievable (ALARA), a risk-based system for radioactive materials security in a university setting is proposed based on Annual Limits of Intake (ALI). This system establishes levels of security based on physical form, activity and concentration. Using this system, radiation safety personnel can more effectively establish reasonable security measures for radioactive material consistent with minimizing the realistic potential of serious harm or injury.