Portal imaging for the verification of breast treatments

Increasing demands are being made for more accurate versatile and precise methods of quality control for radiation therapy, in general. To this end, we have used a digital, on-line, megavoltage imaging system for the verification of breast treatments, in particular. Quick, high-quality images are produced from which the depth of lung irradiated during treatment is very easily determined using the system software. We describe how this quantitative clinical information has been used to assess critical aspects of the treatment technique, and also patient orientated criteria, throughout the course of treatment.