Dosimetric study of four image mode-guided radiotherapy with Siemens Artiste Linac / 中华放射肿瘤学杂志

ABSTRACT

Objective To measure the irradiation doses from the image beam line (IBL) of Artiste linac under the 2Dplanar,MV CBCT,6 MV 2Dplanar and Somatom CT modes to select an appropriate image-guided mode combined with the irradiation sites. Methods The head, chest and pelvic phantom doses from the IBL under the 2Dplanar,MV CBCT and 6 MV 2Dplanar modes were measured by using IBA Dose 1 electrometer and FC65 ionization chamber.The irradiation doses of Somatom CT scans of the head, chest and pelvis were measured using IBA Dosimax plus A system and the measurement results were analyzed. Results In the head and neck, the average irradiation dose was 16. 60 mGy under IBL 2Dplanar mode, 58. 73 mGy under IBL MV CBCT mode, 19. 83 mGy under 6 MV 2Dplanar mode and 7-9 mGy under Somatom CT. In the chest, the average irradiation dose was 14. 08 mGy under IBL 2Dplanar mode, 49. 17 mGy under MV CBCT mode, 18. 97 mGy under 6 MV 2Dplanar mode and 9-11 mGy under Somatom CT mode.In the pelvis, the average irradiation dose was 13. 36 mGy under IBL 2Dplanar mode, 45. 65 mGy under MV CBCT mode, 17. 52 mGy under 6 MV 2Dplanar mode and 12-15 mGy under Somatom CT mode. Conclusions In the head and neck, the image quality under IBL 2Dplanar mode is recommended, which is qualified for image registration standards. Somatom CT mode is suitable for the chest. In the pelvic region, IBL 2DPlanar mode can be applied when the intestinal cavity and bladder are well filled, and MV CBCT mode can be chosen if they are poorly filled.