Patient Radiation Dosage During Lower Extremity Endovascular Intervention.

OBJECTIVES: The aims of this study were to determine the incidence of actionably high radiation dosages and to identify predictors of increased patient dosage. BACKGROUND: Peripheral endovascular intervention using fluoroscopic imaging has become a mainstay of treatment for lower extremity peripheral artery disease but exposes patients to ionizing radiation. METHODS: Patient radiation dosage, quantified as dose-area product (DAP), was obtained from the National Cardiovascular Data Registry Peripheral Vascular Intervention Registry. The percentage of procedures exceeding a DAP of 500 Gy · cm2, the threshold above which follow-up for radiation-related adverse effects is indicated by the National Council on Radiation Protection and Measurements, was determined. A multivariate regression model was generated to identify patient and procedural factors associated with increasing DAP. RESULTS: Among 17,174 procedures performed at 73 sites, patient DAP exceeded 500 Gy · cm2 in 7%. Independent predictors of increased patient DAP in order from greatest magnitude of effect included more proximal lesion location, bifurcation lesion, male sex, diabetes, hypertension, prior percutaneous coronary intervention, increasing lesion length, and increasing body mass index; antegrade vascular access, critical limb ischemia, and increasing age predicted decreased DAP. CONCLUSIONS: Radiation dosage with the potential for tissue injury occurs in 1 of every 14 patients undergoing lower extremity endovascular interventions, and all such patients are exposed to the potential for subsequent malignancy. Pre-procedural assessment of patients' risk for elevated radiation dosage may allow targeted use of radiation mitigation strategies in patients at increased risk for elevated exposure.

Direct and indirect measurement of patient radiation exposure during endovascular aortic aneurysm repair.

With the increasing complexity of endovascular procedures, concern has grown regarding patient radiation exposure. Abdominal aortic aneurysm (AAA) repair represents the most common complex endovascular procedure currently performed by vascular specialists. Our study evaluates the patient radiation dose received during endovascular AAA repair. Over a 3-month period we prospectively monitored the radiation dose in a series of consecutive patients undergoing endovascular AAA repair. All patients underwent standard endovascular AAA repair with one of two commercially available grafts using the GE OEC 9800 unit. Direct measurement of maximum radiation dose at skin level (peak skin dose, PSD) was recorded using GAFCHROMIC radiographic dosimetry film. Indirect measurements of radiation dose (fluoroscopy time and dose-area-product [DAP]) were recorded with the C-arm dosimeter. A total of 12 consecutive patients undergoing standard endovascular AAA repair were evaluated. Mean PSD was 0.75 Gy (range 0.27-1.25). Mean total fluoroscopy time was 20.6 min (range 12.6-34.2) with an average of 92% spent in standard fluoroscopy and 8% spent in cinefluoroscopy. Regarding total fluoroscopy time, 49% was spent in normal field of view and 51% in magnified view. Mean DAP was 15,166 cGy x cm(2) (range 5,207-24,536). PSD correlated with DAP (r = 0.9, p < 0.05) but not total fluoroscopy time (r = 0.18, p > 0.05). PSD also correlated with body mass index (BMI; r = 0.82, p < 0.05). Obese patients had a mean PSD of 1.1 Gy compared to 0.5 Gy in nonobese patients. PSD of all patients was well below the accepted 2.0 Gy threshold for skin injury. PSD correlated with DAP but not total fluoroscopy time. PSD also correlated with BMI, and the mean PSD was significantly increased in obese compared to nonobese patients. Despite the complexity and duration of endovascular AAA repair, the procedure can be performed safely without excessive radiation exposure.

Combination therapy for non-Hodgkin's lymphoma: an opportunity for pharmaceutical care in a specialty practice.

OBJECTIVE: To describe the application of pharmaceutical care practices in the administration of new therapeutic radiopharmaceuticals used in the treatment of non-Hodgkin's lymphoma (NHL). PRACTICE DESCRIPTION: At the Antibody Labeling Facility at the University of Nebraska Medical Center, the nuclear pharmacist provides support in the formulation, preparation, and quality testing of radiopharmaceuticals. The nuclear pharmacist also provides direct patient care by assisting in the administration of radiopharmaceuticals, monitoring patients during their infusions, and counseling patients on radioimmunotherapy and radiation safety. PRACTICE INNOVATION: Expanding the role of the nuclear pharmacist in treating patients with NHL using radiolabeled monoclonal antibodies (MABs). INTERVENTIONS: The nuclear pharmacist provides specialized pharmaceutical care by being involved in planning patient care, administering diagnostic and therapeutic radiopharmaceuticals, performing individualized patient dose calculations, monitoring patients, and counseling patients. MAIN OUTCOME MEASURES: Number of patients treated with radiolabeled MABs. RESULTS: Since January 1996, 85 patients with NHL have been treated using 131I-tositumomab (Corixa, GlaxoSmithKline), an anti-B1 MAB, under various clinical research protocols requiring specialized pharmaceutical care. The nuclear pharmacist on the team provided direct patient care, assisting with the administration of diagnostic and therapeutic radiopharmaceuticals under a collaborative agreement with a nuclear medicine physician or a radiation oncologist. Other pharmaceutical care activities performed include calculating individual patient doses, obtaining medication histories, counseling patients on their therapy and on radiation safety after early release, and monitoring patients for adverse effects during medication infusion. Patients have responded favorably to nontraditional nuclear pharmacy activities. CONCLUSION: The nuclear pharmacist has become an important member of the health care team that provides a new and unique therapy for patients with NHL. To date, the nuclear pharmacist, in collaboration with the nuclear medicine physician or the radiation oncologist, has successfully administered the tositumomab and 131I-tositumomab combination therapy without significant incident.