Laser Hyperthermia for Treatment of Implanted Malignant Tumour in Mice

Different modalities could be used for treatment of recurrent and non-resectable malignant tumours. Laser hyperthermia (HPT) is a loco-regional ablative technique that could be applied by surface or interstitial approach. The present study evaluates both approaches of laser HPT using Neodymium: Yttrium Aluminum Garnet (Nd:YAG) laser (1064nm) for treatment of subcutaneously implanted malignant tumour in mice. Seventy-five Swiss albino female mice were included in the present study. Each animal was injected subcutaneously at its dorsum with Ehrlich ascites carcinoma cells. Tumours developed 6-8 days after injection. All mice were randomly divided into three equal groups. Tumours at group (A), had received no treatment and served as a control group. Tumours at group (B), were treated by surface approach of laser HPT, whereas, tumours at group (C), were treated by interstitial approach of laser HPT. The results were grossly and histopathologically evaluated. Both approaches of laser HPT, at the same temperature, had proven favorable responses as denoted by the statistical significant changes at tumours volumes in both groups (B and C) in relation to the control group (A) at the 7t h and 14th days after treatment. Grossly, false deep ulcers after interstitial approach of laser HPT, while large ulcers after surface approach of laser HPT were elicited. The enlightenment of active tumour re-growth was supported by the histopathological findings. Within the limitation of the present study, laser HPT has proven to be an effective, palliative, minimally invasive, loco-regional modality for treatment of subcutaneous malignant tumours. The favorable results at the present study encourage for refinement of laser HPT technique preliminary to its proposed application in humans, especially for those patients with skin metastases when multiplicity of the lesions and/or the debilitating general condition of the patients may interfere with tumours excisions.