HORTIS I - Soft Tissue Radionecrosis
The skin sits squarely within the pathway of all external beam radiation therapy regardless of the target organ or tissue. Earlier radiation delivery systems inadvertently exposed the skin to levels of radiation so damaging that wounds would occasionally occur spontaneously over the ensuing months. They would often require complex and repeated surgical procedures to resolve.
The time course for these wounds to occur (period that the tissue remains "at risk") extends into the decades. Consequently, patients with an historic radiation exposure history will continue to present with such complications for years to come.
Today's cancer patient is treated with a much more sophisticated therapeutic regimen. High energy linear accelerators target tumors with a great degree of "skin sparing" accuracy. This serves to reduce, but not entirely eliminate, the risk of subsequent skin breakdown. Because patients are anticipated to have improved survival, they may live long enough to eventually experience complications, despite "skin sparing" radiotherapy.
Complicating this issue is the occasional need to operate within or through a previously invaded skin/tissue bed. The inadvertent effects of radiotherapy are such that small blood vessels within "non-target" tissues are frequently damaged to the point where they lose their ability to adequately perfuse. Surgical procedures increase a tissue’s demand for oxygen. This demand may, therefore, exceed supply. Post-operative healing complications result.
Hyperbaric oxygen therapy has been used for several decades in this setting. Its goal is to heal less involved lesions or better prepare injured tissue for definitive surgical repair. Results are reported as encouraging, yet the level of supportive evidence is presently poor.
HORTIS I has been designed to better assess the efficacy of hyperbaric oxygenation in soft tissue radionecrosis.