Radiation dermatitis occurs in a majority of patients with breast cancer who receive radiation therapy (RT), causes significant pain, and may necessitate treatment delay. Light emitting diode (LED) photomodulation has been reported to minimize radiation dermatitis. This study sought to further evaluate the efficacy of LED photomodulation in lessening radiation dermatitis. After surgery, patients with breast cancer received LED photomodulation or sham treatments in conjunction with three-dimensional conformal RT. Reactions were evaluated using standardized photographs graded according to National Cancer Institute criteria. In the LED treatment group (n=18), no patients had grade 0 reactions, six (33.3%) had grade 1 reactions, 12 (66.7%) had grade 2 reactions, and none had a grade 3 reaction. In the sham treatment group (n=15), one (6.6%) patient had a grade 0 reaction, four (26.7%) had grade 1 reactions, 9 (60.0%) had grade 2 reactions, and one (6.7%) had a grade 3 reaction. Two (11.1%) patients in the LED treatment group and one (6.7%) in the control group had to interrupt treatment. Differences between groups were not statistically significant. LED photomodulation did not reduce the incidence of radiation-induced skin reactions or interruptions in therapy. .

Defining functional changes in the brain caused by targeted stereotaxic radiosurgery

Positron production in ${}^{238}\mathrm{U}{+}^{232}\mathrm{Th}$ and ${}^{238}\mathrm{U}{+}^{181}\mathrm{Ta}$ collisions near the Coulomb barrier has been studied. Earlier experiments reported narrow lines in the spectra of positrons, accumulated without the requirement of electrons detected in coincidence. No evidence of such structure is observed in the present data. The positron energy spectra are compared with estimates from dynamic atomic processes, and from internal pair conversion of electromagnetic transitions from the excited nuclei.

The first results are presented from a new experiment, APEX, designed to study the previously reported sharp lines in sum-energy spectra of positrons and electrons produced in collisions of very heavy ions. Data were collected for ${}^{238}$U $+$ ${}^{181}$Ta at 5.95, 6.10, and 6.30 MeV/u and ${}^{238}$U $+$ ${}^{232}$Th at 5.95 MeV/u. In none of our analyses is any evidence found for sharp sum-energy lines. For the specific case of the isolated decay of a neutral particle of mass 1.4–2.1 MeV/ $c^2$, the upper limits on cross sections obtained from the present data are significantly less than the previously reported cross sections.