Role of 830 nm Low Reactive Level Laser on the Growth of an Implanted Glioma in Mice.

The effect of low reactive level laser therapy (LLLT: 830nm, 60mW, continuous wave) was studied using the model of a glioma implanted in mice. Two different models were used. In the first model, therapies were applied post the first day of glioma implantation; in the second model, post the fourteenth day of glioma implantation. Using the first model, therapies were designed as follows. 1) control group (no therapy), 2) direct LLLT (15 seconds twice per day; on the skin covering the implanted glioma), 3) indirect LLLT (15 seconds twice per day; on abdominal skin area rather than the site of the implanted glioma), 4) indirect LLLT (30 seconds twice per day), 5) anti-cancer drug (ACNU) group, 6) mouse β-interferon (Mu-β-IFN) group, 7) direct LLLT plus Mu-β-IFN group, 8) ACNU plus Mu-β-IFN group, 9) indirect LLLT (15 seconds twice per day) plus ACNU plus Mu-β-IFN group. Using the second model, therapies were designed as follows. 1) control group (no therapy), 2) indirect LLLT (15 seconds twice per day), 3) indirect LLLT (15 seconds twice per day) plus Mu-β-IFN group, 4) Mu-β-IFN plus ACNU group. Our results indicated that, applied on the first day after glioma implatation, both direct and indirect LLLT were effective in inhibiting the tumor growth. In addition, it appeared that the effect of LLLT might be dose-dependent. Finally, the group of direct LLLT plus Mu-β-IFN was most effective in limiting the tumor growth and the incidence of growth as compaired with the other groups. However, when applied to the model fourteen days after glioma implantation, indirect LLLT contributed to tumor growth. LLLT (830nm, 60mW) may therefore be one of the biological responsive modifier's via skin tissue. Also, the active role of the LLLT in vivo model might depend on the biological interaction between the tumor bearing host and the tumor.