An overview on extremity dosimetry in medical applications

Abstract

Some activities of EURADOS Working Group 9 (WG9) are presently funded by the European Commission (CONRAD project). The objective of WG9 is to promote and co-ordinate research activities for the assessment of occupational exposures to staff at workplaces in interventional radiology (IR) and nuclear medicine. For some of these applications, the skin of the fingers is the limiting organ for individual monitoring of external radiation. Therefore, sub-group 1 of WG9 deals with the use of extremity dosemeters in medical radiation fields. The wide variety of radiation field characteristics present in a medical environment together with the difficulties in measuring a local dose that is representative for the maximum skin dose, usually with one single detector, makes it difficult to perform accurate extremity dosimetry. Sub-group 1 worked out a thorough literature review on extremity dosimetry issues in diagnostic and therapeutic nuclear medicine and positron emission tomography, interventional radiology and interventional cardiology and brachytherapy. Some studies showed that the annual dose limits could be exceeded if the required protection measures are not taken, especially in nuclear medicine. The continuous progress in new applications and techniques requires an important effort in radiation protection and training.

Exposure of Treating Physician to Radiation during Prostate Brachytherapy Using Iodine-125 Seeds

“…It is composed of two dose contributions with varying weights, originating from the seeds and the fluoroscopy. Consequently, it is difficult to deduce the dose to the fingertips from ring dosimeter measurements, as proposed by Vanhavere et al [25]. These considerations have motivated the measurements presented in this study.…”

“…Since this procedure relies a great deal on "feeling" [16,22], the treating physician does not wear lead gloves. These would impede sensitivity and lengthen the duration of the application, and in turn increase the exposure to radiation [1,9,25].…”

“…The dose to the fingertips can be considerably higher than the dose measured with a ring dosimeter worn at the usual position [25]. It is composed of two dose contributions with varying weights, originating from the seeds and the fluoroscopy.…”

“…It has to be assumed that the maximum skin dose is several times larger [25]. Nevertheless, there are very few published data about the dose to the hands in manual brachytherapy [9,25].…”

“…During manual seed insertion into the prostate, however, it is obvious that the skin of the fingertip leading the needle gets the maximum dose and therefore limits the number of applications from the viewpoint of radiation protection [5,9,25].…”