RDT aims to take advantage of the relatively safer toxicity profiles of both lower dose
radiation therapy and systemic ALA to treat non-superficial lesions in a manner similar to
photodynamic therapy. The doses of radiation administered in this study will be lower than
those typically used to treat cancer. However, with administration of ALA, which has been
shown to be selectively concentrated in neoplastic cells, it is reasonable to expect
responses in the target lesion(s) with relative sparing of nearby normal structures. A
similar therapy is currently being used in a single institution in China. Members of the Fox
Chase Cancer Center have visited the Chinese medical site multiple times and have gained
first-hand experience with this therapy. Based on thus-far unpublished data, this treatment
appears to be both safe and well-tolerated. There have been marked responses seen in some of
these patients, but this therapy has not yet been investigated in a more formalized clinical
trial setting, nor has it been used on Western patients. Thus, while these findings are
encouraging, much work is necessary to determine the efficacy and role of this intervention.