Using light rays during extracorporeal therapy is referred to as what?

The use of light rays during extracorporeal therapy is aptly termed phototherapy. Phototherapy involves administering light to treat various conditions, particularly skin disorders, by utilizing specific wavelengths that promote healing and reduce inflammation. For example, broad-spectrum light or blue light is utilized to treat neonatal jaundice or certain types of acne, demonstrating the application of selective light emission in therapeutic contexts.

In this context, while radiotherapy also employs radiation, it typically refers to the use of high-energy radiation to target and kill cancer cells, which does not align with the description given in the question. Cryotherapy involves the application of extreme cold for medical purposes, often for lesions or varicose veins, and is unrelated to light rays. Laser therapy specifically employs focused light in the form of lasers but is a subset of phototherapy and not the broad application that phototherapy represents. Thus, phototherapy is the most encompassing and accurate choice for therapies utilizing light rays.