Ultrasonography and MR imaging can help to identify the area and depth of different lesions, like injury, overuse, inflammation, degenerative diseases. The appropriate power density, sufficient dose and direction of the laser treatment can be optimally estimated. If required minimum 5 mW photon density and required optimal energy dose: 2-4 Joule/cm<sup>2</sup> wouldn’t arrive into the depth of the target volume - additional techniques can help: slight compression of soft tissues can decrease the tissue thickness or multiple laser diodes can be used. In case of multiple diode clusters light scattering results deeper penetration. Another method to increase the penetration depth is a second pulsation (in kHz range) of laser light. (So called continuous wave laser itself has inherent THz pulsation by temporal coherence). Third solution of higher light intensity in the target volume is the multi-gate technique: from different angles the same joint can be reached based on imaging findings. Recent developments is ultrasonography: elastosonography and tissue harmonic imaging with contrast material offer optimal therapy planning. While MRI is too expensive modality for laser planning images can be optimally used if a diagnostic MRI already was done. Usual DICOM images offer “postprocessing” measurements in mm range.
Biostimulation, as a non thermic laser irradiation provoked biological effect, results in the enhancement of reparative and regenerative processes. It is a strict dose dependent functional change in the range of 1 - 4 Joule/cm<SUP>2</SUP> incident energy density. Repeated low power irradiations in that particular dose range lead to a cumulative effect, which depends on the frequency of sessions. In the case of daily repetition the cumulation is much quicker than with one or two days interruption. Too high a dose per session or too quick a repetition with maximal doses for more than 20 consecutive irradiations (i.e., daily leads to the opposite effect, which is inhibition.
Radiological procedures to destroy deep neoplastic laesions of internal organs - without surgical exploration is a highly instnimentation dependent technique, reducing the risk for patients and the costs of hospitalisation. Nonturnor therapeutic radiology can be used for chernolysis: syrnpathectomy, discectorny, but there is a danger of complications because of uncontrolable fluid distribu— tion, wich can produce unexpected necrosis. Laser, guided by radiologiacal imaging methods, gives the possibility of precise intervention /nucleus pulposus denaturalisation or brain tumor fiber optic destruction, as introduced by Ascher/. Laser — intersti— tial — hypertherrnia is a new method /developed by Bown/ to increase the tumor destruction, and it promotes the effect of other anti— tumo r therapies, as radiotherapy, cytostatic therapy or photodynainic therapy. Photodynarnic therapy by systemic administration causes a skin photosensitivity for 30 — 40 days, and the hernatoporphyrin concentration in the tumor tissue is only 1 — 2 ,ug/g. Ideal application for deep tumor effective laser desstruction was developed by Gatenby: CT — guided fiberoptic direct injection of HpD prepared PDT. The direct HpD injection into the tumor reults 50 — 100 ,ug/g concentration of the photosensitiser in the tumor tissue, without systemic effects, as skin photosensitivity. That's, why the exposure can be repeated at weekly intervals. Under 2 cm size the results are excellent, but even larger masses, have had not respomided to conventional therapy showed significant improvement in size and in pain aswell. The procedure can be on outpatient basis