Which method is commonly used to assess tumor response to treatment?

Imaging studies, such as CT (computed tomography) or MRI (magnetic resonance imaging), are commonly utilized to assess tumor response to treatment because they provide detailed visual images of the internal structures of the body. These modalities allow for the direct visualization of tumors, enabling clinicians to evaluate changes in tumor size, density, and overall morphology over time. This information is critical to determine whether the tumor is responding positively to treatment, remaining stable, or progressing.

Blood tests, while useful for evaluating biomarkers or broader health parameters, do not provide a direct assessment of tumor size or localization, limiting their effectiveness in assessing tumor response. Physical examinations can help identify changes in palpable tumors or assessing overt symptoms, but they do not provide the level of detail offered by imaging studies. Similarly, urine analysis has limited relevance in assessing tumors as it typically does not reflect the size or response of solid tumors. Thus, imaging studies stand out as the most definitive method for this purpose.