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 histo-pathologically 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 7[th] and 14[th] 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

In Vitro Biliary Lithotripsy By Q-switched Versus Continuous Wave Nd/YAG Laser

In this work, the role of the Q-switched and continuous wave [CW] Nd:YAG laser biliary lithotripsy was studied. A total of 120 biliary stones was randomly divided into two groups [A and B], which were conducted to CW and Q-switched Nd:YAG laser, respectively. A radiological and spectroscopic examination was done. Gall bladder wall exposure to both laser techniques was done, then was subjected to gross and microscopic examination. During Q-switched technique at the same volume of cholesterol stones, the fragmenting pulse number was inversely proportionate to the spectroscopic calcium [Ca%] content of the stones. Moreover, the thermal effect of both techniques on the gall bladder wall was evaluated. It can be concluded that CW has a hazardous thermal effect on the soft tissue surroundings which limits its use in biliary lithotripsy. The Q-switched Nd:YAG laser is an effective and safe method for biliary lithotripsy. The fragmenting pulse number depends on the pigment content of the stones. In cholesterol stones, the fragmentation pulse number is inversely proportionate to the Ca content of the stone