Patient doses in gamma-intracoronary radiotherapy: the Radiation Burden Assessment Study.
OBJECTIVE
To determine accurately the radiation burden of both patients and staff from intracoronary radiotherapy (IRT) with (192)Ir and to investigate the importance of IRT in the patient dose compared with interventional X-rays.


METHODS
The Radiation Burden Assessment Study (RABAS) population consisted of 9 patients undergoing gamma-IRT after percutaneous transluminal coronary angioplasty and 14 patients undergoing percutaneous transluminal coronary angioplasty only as the control group. For each patient, the dose to the organs and tissues from the internal and external exposure was determined in detail by Monte Carlo N-particle simulations. Patient skin dose measurements with thermoluminescence dosimeters served as verification. Staff dosimetry was performed with electronic dosimeters, thermoluminescence dosimeters, and double film badge dosimetry.


RESULTS
With respect to the patient dose from IRT, the critical organs are the thymus (58 mGy), lungs (31 mGy), and esophagus (27 mGy). The mean effective dose from IRT was 8 mSv. The effective dose values from interventional X-rays showed a broad range (2-28 mSv), with mean values of 8 mSv for the IRT patients and 13 mSv for the control group. The mean dose received by the radiotherapist from IRT was 4 microSv/treatment. The doses to the other staff members were completely negligible.


CONCLUSIONS
Our results have shown that the patient and personnel doses in gamma-IRT remain at an acceptable level. The patient dose from IRT was within the variations in dose from the accompanying interventional X-rays.
Thierens
Hubert
H
Department of Medical Physics and Radiation Protection, Ghent University, Ghent, Belgium. hubert.thierens@Ughent.be
Reynaert
Nick
N
Bacher
Klaus
K
Van Eijkeren
Marc
M
Taeymans
Yves
Y
D000328:Adult; D015906:Angioplasty, Balloon, Coronary; D002309:Cardiology; D023903:Coronary Restenosis / Q000000981:diagnostic imaging / Q000517:prevention & control* / Q000532:radiotherapy; D005373:Film Dosimetry; D006801:Humans; D007496:Iridium Radioisotopes; D008297:Male; D008875:Middle Aged; D009010:Monte Carlo Method; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D011859:Radiography; D011871:Radiology
D007496:Iridium Radioisotopes