Utilizing 808 nm laser for sensitizing of melanoma tumors to megavoltage radiation therapy

• Published in: Lasers in medical science Vol. 35; no. 1; pp. 87 - 93
• Main Authors: Kefayat, Amirhosein, Ghahremani, Fatemeh, Taheri, Navid, Amouheidari, Alireza, Okhravi, Seyed Mehdi
• Format: Journal Article
• Language: English
• Published: London Springer London 01-02-2020; Springer Nature B.V
• Subjects: Animals; Bearing; Cell Line, Tumor; Dentistry; Electricity; Female; Laser radiation; Laser Therapy; Lasers; Medicine; Medicine & Public Health; Melanin; Melanoma; Melanoma, Experimental - pathology; Melanoma, Experimental - radiotherapy; Mice; Mice, Inbred C57BL; Necrosis; Optical Devices; Optics; Original Article; Photonics; Quantum Optics; Radiation; Radiation therapy; Radiation-Sensitizing Agents - pharmacology; Radioresistance; Sensitizing; Survival; Survival Analysis; Temperature effects; Tumor Burden - radiation effects; Tumors; B16-F10; Radiation therapy; 808 nm laser; Melanoma
• ISSN: 0268-8921; 1435-604X
• DOI: 10.1007/s10103-019-02796-3

Melanotic melanoma has high content of melanin and laser can destroy melanin-containing cells through thermal effect. In this study, the therapeutic effect of 808 nm laser therapy was investigated on B16-F10 melanoma tumor growth and tumor-bearing mice survival time. In addition, as laser can destroy melanin as the main cause of melanoma radioresistance, the effect of laser administration to enhance radiation therapy efficacy at B16-F10 cancer cells was evaluated in vitro and in vivo. Laser therapy (1 W/cm
2
 × 4 min) could cause significant (
P
 < 0.05) inhibition of melanoma tumors’ growth (~ 61%) and about three times increase of the tumor-bearing mice survival time in comparison with no-treatment group. In addition, the mice which were treated with 1 W/cm
2
 × 4 min laser administration plus 6 Gy megavoltage radiation therapy exhibited ~ 68% lesser tumors’ volume and 27 days increase of survival time in comparison with 6 Gy irradiated tumor-bearing mice. Also, significantly higher (
P
 < 0.05) tumor necrosis percentage was observed at the histopathological slides of 1 W/cm
2
 × 4 min laser + RT treated mice tumors (57 ± 12%) in comparison with radiation therapy group (31 ± 10%). Therefore, not only laser therapy can inhibit melanoma tumors’ growth per se but also its combination with radiation therapy can cause a significant enhancement of radiation therapy efficacy. The laser administration can be used as a radiosensitizing method for melanotic melanoma radiation therapy.