Absorbed dose and deterministic effects to patients from interventional neuroradiology.

Abstract

Following the presentation of radiation-induced skin effects by three patients who had undergone glue embolisation of intracranial arteriovenous malformation (AVM), measurements were made of absorbed dose to the skin of patients undergoing other interventional neuroradiological procedures that involve long fluoroscopy times. The maximum absorbed dose to the skin measured by thermoluminescent dosemeters during these procedures was 4 Gy. From these measurements and from records of fluoroscopy time and the number of digital runs acquired, estimates of the maximum absorbed skin dose were made for the AVM patients. The best estimate of maximum absorbed dose to the skin received by any of the AVM patients during a procedure was 5 Gy, which is consistent with the skin effects presented by the AVM patients, that is temporary epilation and main erythema. Maximum absorbed dose to the skull was estimated to be 45 Gy and to the outer table of the skull 55 Gy. Although it is unlikely that the AVM patients will suffer serious effects from these skin doses, there remains some uncertainty over the risk of long-term effects to the skull. Examination of the fluoroscopy unit showed that the image intensifier was not performing optimally in terms of entrance dose rate and resolution. Replacement of the unit with modern X-ray equipment designed for interventional radiology was prioritized. Operators should be aware of the potential risks to patients from complex interventional neuroradiology procedures and should optimize their procedures to minimize such risks. Patients undergoing prolonged and complex procedures should be counselled regarding the symptoms and risks of large doses of radiation.

Cumulative Radiation Dose during Hospitalization for Aneurysmal Subarachnoid Hemorrhage

“…This recognized radiation risk has prompted multiple medical committees to regulate and monitor equipment and recommend techniques to reduce the exposure. [1][2][3] While studies have identified cerebral embolization as a high-radiation exposure procedure, [4][5][6][7][8][9][10][11]19 the cumulative exposure to the patient from repetitive procedures and imaging studies within a single hospitalization has not been documented. We demonstrate that the radiation exposure of the index procedure substantially underestimates the total radiation given through a full hospitalization.…”

“…Long-term outcome studies have not explored the effects of radiation in the patient with subarachnoid hemorrhage, and reports of short-term complications of radiation exposure are limited. 6,[21][22][23] Because the essential question that underlies this and other studies of radiation exposure for this patient group is one of short-and long-term risk, better controlled longitudinal studies are needed to follow patients for the development of skin, lens, thyroid, and cerebral injury or neoplasia.…”

“…[1][2][3] Embolization of cerebral aneurysms and arteriovenous malformations has been identified as a procedure that routinely exposes the patient and operator to high doses of radiation. [4][5][6][7][8][9][10][11][12][13][14][15] Following an aneurysmal subarachnoid hemorrhage, patients are hospitalized for treatment of multiple neurologic and medical sequelae. Interventions that use ionizing radiation are integral to the continued care of these patients and include aneurysm embolization and angioplasty for vasospasm.…”

Local skin and eye lens equivalent doses in interventional neuroradiology

“…Patients at risk should be counselled and advised to check for skin changes 2-4 weeks after the procedure. Several papers present data on measured absorbed dose to patient skin following interventional neuroradiology [23][24][25][26] or energy imparted to the patient [27] in order to correlate with acute and late radiation effects respectively. In this paper, we report on measured local skin doses on the head of patients undergoing diagnostic or therapeutic neuroangiography using thermoluminescence dosimeters, TLD, and compare these with the doses at the IRP as estimated by the x-ray unit in order to provide a method to determine the risk of local overexposure of skin and eye-lenses.…”

MR‐guided intravascular interventions: Techniques and applications

“…The numbers of lengthy complex interventions such as embolizations, percutaneous porto-systemic shunt placements, invasive electrophysiology, and catheter ablations have continuously grown over the last years. With some of these procedures deterministic radiation effects such as erythema or loss of hair have been reported (84,85). These damages are-regardless of patient age, morbidity, or life expectancy-intolerable and must be avoided by all means.…”