Extended Bragg Peak Research Articles

Preliminary clinical observations after extended Bragg peak helium ion irradiation.

Laboratory studies of single cell survival after irradiation with extended Bragg peak helium ions suggest a relative biological effectiveness (RBE) of 1.4 for oxygenated cells. A clinical radiobiological investigation has been initiated using patients with mycosis fungoides. One patient received standard total body electron beam irradiation according to the Memorial Hospital technique, which consists of six weekly doses of 400 rads. Small selected areas were shielded and received single, graduated doses of electron and helium ion extended Bragg peak therapy. Two additional comparable regions received six weekly doses of the two therapeutic beams. Changes in the severity of lesions according to a semi-quantative severity score (SS) were observed following treatment. Values for maximum reduction in the SS observed for the two therapy beams after treatment were consonant with a RBE of 1.4. Recurrence patterns after therapy with the two beams also differed. Lesions treated with the heavy particles remained under control longer than those treated with doses of electrons yielding comparable initial effects. These data suggest that, in addition to processes involved in the increased RBE for helium ions, other factors may be operating to produce a more sustained benefit from extended helium ion Bragg peak irradiation.

Preliminary clinical observations after extended bragg peak helium ion irradiation

Preliminary clinical observations after extended bragg peak helium ion irradiation