Hi, two questions! First, does this similar triangle method change at all when treating fields that are side by side rather than end to end (I assume yes, but you would use the width of the fields rather than the length)? Also, what about the overlapping of the beams on the organs and tissues on the anterior side of the patient? Is is not significant (hot enough) to be a major concern due to the distance within the patient at that point? Another words, is the dose in that area calculated to be safe for those organs' tolerances?
Hi Mohammad, we calculate a gap in craniospinal irradiation to avoid hot and cold spots at the junction. If you matched the fields (abutting), you would have scatter in some areas, creating hot spots. Gaps on the surface are especially important because the spinal cord is a critical organ in irradiation, and cannot be overdosed.
Hi, two questions! First, does this similar triangle method change at all when treating fields that are side by side rather than end to end (I assume yes, but you would use the width of the fields rather than the length)?
Also, what about the overlapping of the beams on the organs and tissues on the anterior side of the patient? Is is not significant (hot enough) to be a major concern due to the distance within the patient at that point? Another words, is the dose in that area calculated to be safe for those organs' tolerances?
why do you need calculate a gap? what about field matching
Hi Mohammad, we calculate a gap in craniospinal irradiation to avoid hot and cold spots at the junction. If you matched the fields (abutting), you would have scatter in some areas, creating hot spots. Gaps on the surface are especially important because the spinal cord is a critical organ in irradiation, and cannot be overdosed.