The Dose Verification System (DVS) for cancer patients receiving radiation therapy.

The Dose Verification System (DVS) is the first implantable radiation dosimeter designed for in situ measurement of dose delivered to the tissue being irradiated. The success of radiation therapy is predicated on maximizing tumor cell death and minimizing normal tissue toxicity. Tumor control increases with the delivery of appropriate radiation doses to the target area. These doses have been determined from in vitro and animal studies, which generated specific dose-response data. However, there has not been a practical system available to ensure that the appropriate dose was being delivered in situ to monitor the daily patient dose during radiation therapy. Studies have shown that dose variations can occur. Recently completed pivotal clinical studies using the DVS found a greater than 7% (positive or negative) change in cumulative dose in seven out of 36 (19%) breast cancer patients; and six out of 29 (21%) and eight out of 19 (42%) patients during large-field and boost irradiation of the prostate. The device is an important step to enable physicians to expand the concept of individualization of therapy.