Chronic radiation bone toxicity is associated with decreased perfusion without elevation of circulating or soft tissue TGF beta or TNF alpha.

Abstract

Concern over long term bone growth hampers the full utility of radiation in pediatric oncology. We know of no therapies that have been used routinely as prophylaxis following irradiation to prevent complications of bone, though some have been suggested.23 Radiation is known to have severe and prolonged anti-angiogenic and fibrogenic effects.20,21,29,30 These effects are species and strain dependent in experimental animals.15 Though the mechanism of this anti-angiogenic response is unknown, it is likely that a component of this effect is cytokine mediated.2,15 In previous studies we have found that angiogenic factors can alleviate some acute complications of radiotherapy. We hypothesize that angiogenic therapies featuring cytokines or cytokine modifying agents can also prevent or reduce some late complications. To test this hypothesis we electively treated mice with basic fibroblast growth factor (bFGF) up to 2 months after irradiating a single hind leg and then measured tibia growth, circulating and local tissue anti-angiogenic cytokine production, and tibia bone blood flow