Which beam energy is preferable for pelvic treatment when using parallel opposed fields?

In the context of pelvic treatment using parallel opposed fields, the preference for a beam energy of 10MV is influenced by several factors. The primary goal of pelvic radiation therapy is to effectively target the tumor while minimizing dose to surrounding healthy tissues, such as the bladder, rectum, and femoral heads.

A 10MV beam energy strikes a balance between effective tissue penetration and manageable skin sparing. In pelvic treatments, there’s also a need to reach deeper targets, particularly when treating larger volumes or lesions that may be located deep within the pelvis. The 10MV photon beam provides sufficient penetration to reach the target depth, while also ensuring an acceptable dose distribution within the treatment area.

Using this energy allows for adequate dose coverage of the tumor while minimizing the radiation exposure to surface tissues as well as critical organs at risk. Higher energy beams, like 15MV, may deliver more penetrating power, but they can also increase dose to surrounding areas unnecessarily. Conversely, lower energies, such as 60Co or even 8MV, may not provide enough penetration for optimal coverage of the mid-to-deep pelvic structures.

Overall, the choice of 10MV aligns well with the treatment objectives of achieving effective tumor control in the pelvis while safeguarding surrounding healthy tissues