TITLE: "Radiation Surface Dose Using the Dignicap^TM Hypothermic Cap in Conjunction with Whole-Brain Radiation Treatment"

SPEAKER: Chanté Singleton

TIME: Thursday Apr. 15, 2004 at 11 AM

PLACE: George P. Williams, Jr. Lecture Hall, (Olin 101)

A recent study ¹ suggests the use of a hypothermic scalp cap, in conjunction with whole-brain radiation treatment (WBRT), with the expectation that vasoconstriction will reduce the radiation effect, in order to reduce the amount of alopecia, when treating brain metastases in cancer patients. Radiation surface dose effects from the hypothermic cap must be determined, since alopecia has a known dependence on radiation dose. This study determines and verifies the surface dose on the scalp (that is, hair follicle dose) using an anthropomorphic head phantom and three radiation dose measurement techniques: 1) LiF TLD-100 powder in capsules, 2) Gafchromic (Radiochromic-type) film and 3) a gas-filled ionization Markus chamber. A typical WBRT irradiation geometry was used: 300cGy to midplane, two parallel-opposed beams, and a 22cmx20cm field size. Beam energies of 6MV, 10MV and 18MV were studied. As expected, the TLD and film results show an increase in surface dose build-up by the hypothermic cap of -1%-87%. Markus chamber results show an increase in surface dose build-up greater than 100%.

¹ N Shah, N Groom, S Jackson, A Sibtain, and P Hoskin. "A pilot study to assess the feasibility of prior scalp cooling with palliative whole brain radiotherapy", The British Journal of Radiology, vol. 73, pp. 514-516, 2000.