Which image is used for online treatment verification?

The use of electronic portal imaging for online treatment verification is essential in modern radiation therapy. This type of imaging captures real-time images of the patient’s treatment area during radiation delivery, allowing clinicians to confirm proper patient positioning and alignment with the planned treatment parameters.

Electronic portal images provide immediate feedback, helping to ensure that the radiation beams are accurately delivered to the intended target volume while minimizing exposure to surrounding healthy tissues. This confirmation is critical, especially considering the potential for changes in patient anatomy or tumor position between treatment sessions. The ability to verify treatment online greatly enhances the precision and safety of radiation therapy, contributing positively to patient outcomes.

In contrast, the other imaging modalities listed have different primary functions. Computed tomography is typically used for treatment planning rather than real-time verification. Magnetic resonance imaging is excellent for soft tissue assessment, but it's not commonly utilized for treatment verification during sessions. X-ray images can be useful in various clinical settings but are generally not specifically tailored for the intricacies of online treatment verification in radiation therapy. Thus, electronic portal imaging stands out as the optimal choice for this purpose.