Hassanpour N. et al., 2019: Study on Radiation Dose Received by Patients during Extracorporeal Shock Wave Lithotripsy
Hassanpour N, Panahi F, Naserpour F, Karami V, Fatahi Asl J, Gholami M. A
Student Research Committee, Lorestan University of Medical Sciences, Khorramabad, Iran.
Department of Radiology Technology, School of Allied Medical Sciences, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Department of Medical Physics, Lorestan University of Medical Sciences, Khorramabad, Iran.
BACKGROUND: Extracorporeal shock wave lithotripsy (ESWL) is considered as the method of choice for treatment of most stone diseases. The present study aims to evaluate radiation dose received by patients undergoing ESWL. METHODS: In total, 46 patients from both genders were referred to the Shohadaye Ashayer hospital of Khorramabad, Iran and were included in the present study. Patients were positioned in anteroposterior (AP) projection and along 30° anterior oblique (AO) projection upon the X-ray fluoroscopy table and exposures were conducted. Thermoluminescent dosimeters (TLDs) were used for radiation dose measurements. To evaluate the entrance surface dose (ESD), each TLD chip was taped on back of patient at the entrance surfaces of the X-ray beam. RESULTS: The mean number of stones in each patient was 1.4. The stone sizes ranged from 7 to 29 mm, and a mean of 3200 pulses were need for each patient. The mean ESD in the postero-anterior (PA) and oblique X-ray beam entrance were obtained at 12.04 and 68.84 mGy, respectively. There was linear correlation between patient dose with fluoroscopy time, tube current (mA), tube potential (kVp) and patient position (P < 0.001); however, we found no strong correlation between patient dose with patient body mass (P = 0.837), number of shock wave pulses (P = 0.089), stone size (P = 0.773) and locations (P = 0.463) CONCLUSION: The data obtained in the current study are comparable with information available in the literature. They emphasized that ESWL exposes patients to much more radiation compared to those from conventional radiography and is in the range of computed tomography (CT) procedures. Therefore, following safety guidelines is recommended.
Arch Iran Med. 2018 Dec 1;21(12):585-588.
The oblique position may be chosen in case obese patients have to be treated with a short focal depth machine. I remember the review of Karatzas et al. (1): They treated obese patients in a modified lateral position with equivalent results compared to a series treated in the classical supine position. The advantage of the modified oblique position was a shorter treatment time. However, the radiation dose was not measured but must have been high. A table in the present publication (2) shows that the oblique position doubled the radiation dose or even increased it 5-fold.
The present authors (2) and three references (3,5,6) in the present publication used oblique positions.
Sandilos et al. (3) used the HM-4 Lithotripter with two fluoroscopy units (4). The other two references from 1987 (5) and 1989 (6) very probably also used lithotripters not more in use to today. Therefore, the data in the table from the present publication are not comparable and measurements with currently used machines and techniques should be done.
1 Karatzas, A., Gravas, S., Tzortzis, V., Aravantinos, E., Zachos, I., Kalogeras, N., & Melekos, M. (2011). Feasibility and efficacy of extracorporeal shock-wave lithotripsy using a new modified lateral position for the treatment of renal stones in obese patients. Urological Research, 40(4), 355–359. doi:10.1007/s00240-011-0416-4
2 Hassanpour N, Panahi F, Naserpour F, Karami V, Fatahi Asl J, Gholami M. A Study on Radiation Dose Received by Patients during Extracorporeal Shock Wave Lithotripsy.
Arch Iran Med. 2018 Dec 1;21(12):585-588.
3 Sandilos P, Tsalafoutas I, Koutsokalis G, Karaiskos P, Georgiou E, Yakoumakis E, et al. Radiation doses to patients from extracorporeal shock wave lithotripsy. Health Physics. 2006; 90(6):583-7
4 Jocham D, Liedl B, Chaussy Ch, Schmiedt E. Preliminary clinical experience with the
HM-4 bath-free Dornier lithotriptor World J Urol (1987) 5:208-212
5 Bush WH, Jones D, Gibbons RP. Radiation dose to patient and personnel during extracorporeal shock wave lithotripsy. J Urol.
6 Huda W, Bews J, Saydak A. Radiation doses in extracorporeal
shock wave lithotripsy. The Br J Radiol. 1989;62(742):921-6.