Patient Organ Doses From Imaging in IGRT: KV Radiograph Vs. KV-CBCT Vs. MV Portal Image Vs. MV-CBCT
G Ding1*, P Alaei2, (1) Vanderbilt University , NASHVILLE, TN, (2) Univ Minnesota, Minneapolis, MNTH-B-211-1 Thursday 9:00:00 AM - 9:55:00 AM Room: 211
Image-guided radiation therapy (IGRT) plays an increasingly essential role in the accurate delivery of highly conformal dose to the target as it makes it possible to see the target and organs at risk before treatment while the patient is in the treatment position. X-ray imaging devices, especially kilovoltage x-ray imaging devices integrated in a radiation treatment delivery unit, are increasingly available in the clinics. The conventional electronic portal imaging devices (EPID) using megavoltage photon beams are still available and being used as well. X-ray imaging procedures deliver additional radiation dose to patients and this dose may entail risk to patients. Knowledge of radiation dose resulting from x-ray imaging and the techniques to reduce the imaging dose are important for clinicians in making informed decisions for treatment management regarding the benefit and risk to patients.
This lecture will provide an overview of radiation doses to patients resulting from different imaging procedures and an update on the progress of AAPM TG-180 report.
1. Understand the different available image guidance modalities and devices used in IGRT;
2. Understand the magnitude of the organ dose resulting from difference devices and acquisition procedures;
3. Understand the variation of patient imaging dose distributions among different imaging procedures;
4. Understand how patient dose distributions from an image procedure are calculated
5. Understand the increased magnitude of the dose to bone as compared to soft tissue for kilovoltage x-rays;
6. Learn the techniques to reduce the imaging dose to patients and sensitive organs;
7. Update on the progress of AAPM TG-180 report: “Modeling and Accounting for the Imaging Guidance Radiation Doses to Radiotherapy Patients in Treatment Planning”