Experiments were performed on six batches (Batches I ∼ VI) of inbred Wistar rats with Walker-236 carcinosarcoma. The groups received, respectively, photodynamic therapy on its own (PDT, Batch I); perfusion of tumour infiltrating lymphocytes on its own (TIL, Batch II); or both of the above in conjunction therapy (PDT+TIL-A, Batch III; PDT+TIL-B, Batch IV: and PDT+TIL-AB, Batch V); and one control batch (Batch VI, which was injected with Hank’s buffered salt solution) which consisted of animals with untreated Walker-256 tumours. The results were as follows: the individual treatment (PDT, TIL) gave survival rates between 28.6% ∼ 49.8%, the cure rates ranging from 19.0% ∼ 28.2% The “combined” therapy in multiple doses increased significantlythe survival of tumour-bearing rats (84.7%) as well as the highest incidence of complete regression (65.3%). Cell-mediated immunity test values in Batches III-V exposed to multiple PDT+TIL doses showed higher values as compared to the values noticed in Batches I-II and the control Batch VI at 14, 28 and 42 days post-treatment. Summing up, this work demonstrates that “combined” photodynamic therapy with TIL immunotherapy stimulates cell-mediated antitumoural activity, produces modifications in tumour histological structure, increases survival rate and reduces tumoural incidence in Walker-256 carcinosarcoma in the rat model.
In the last decade the applications of the laser in surgery and medicine have increased dramatically. With the increase of indications has come a concomitant increase in possible classification of laser reactions, including the erroneous ‘low power laser ’, ‘high power laser’ and others. The author presents a classification which is based on the laser/tissue reaction rather than on the hardware used to produce the laser beam. Laser/tissue reactions fall into two broad groups. When the tissue reaction to absorption of the incident laser energy results in photodestruction of, or an irreversible photomodulated change to the tissue architecture, then the level of reaction is higher than the survival threshold of the target cells. The author refers to this as high reactive-level laser treatment (HLLT), or more generally as laser surgery. On the other hand, the level of tissue reactivity to very low incident power and energy densities is well below the cells’ survival threshold so that instead of being damaged the cells are directly activated by the low incident photon density. In this case the changes in the irradiated tissue are photoactive and reversible: the author refers to this group of reactions as low reactive-level laser therapy (LLLT), or more generally as laser therapy. In general when laser energy is incident on tissue, whether it is intended for laser surgery or laser therapy, it propagates into the target tissue in a wavelength-specific manner, but the resultant pattern, for example a HeNe laser viewed in a block of methylacrylate or an infrared laser viewed in vivo with a CCD camera, resembles very closely the shape of an apple. The author has used this basic apple shape and has modified it so that the ‘Laser Apple’ is capable of giving a range of information about the laser and its tissue effect, including the laser type, wavelength, output power, irradiated area, irradiation time and penetration depth: from these parameters the incident power and energy densities can be calculated. The apple itself can represent the scattering pattern and is capable of graphically demonstrating the range of tissue reactions which in turn give their name to the range of ‘Laser Apples’, such as the C-Apple (carbonization), V-Apple (vaporization) and A-Apple (activation).
Sympathetic reflex dystrophy (SRD) is a frequent occurrence in geriatric hemiplegic patients, but the pathogenic factors (involvement of the peripheral and/or central nervous systems) of the disease are not yet clearly defined and are still a matter of debate. Many different diseases may produce SRD; this may frequently occur in hemiplegic patients so that elderly people cannot undergo rehabilitative kinetic therapy after a stroke, due to osteoarticular pain and dystrophic diseases. The aim of the present work is to analyze the effect of laser therapy at different wavelengths and doses (i.e. HeNe and CO2 laser at low and high energy densities), in order to identify the technical conditions yielding the maximum treatment effectiveness in the protocol of rehabilitation of hemiplegic patients suffering from SRD. The method adopted by our Institute to establish the clinical diagnosis of each patient is based on the creation of a card in which the personal data; clinical diagnosis; medical history; the physical therapist’s evaluation; the radiologist's report; and the clinician’s assessment are recorded. The treatment was carried out by sweeping the laser beam over the area of articulation of the shoulder (area size ≅ 10 x 15 cm) and on the hand (area size ≅ 10 x 10 cm). Since the physical parameters of laser therapy for the treatment of this disease in hemiplegic patients have not yet been established, our trial was performed either with defocused CO2 laser or with the HeNe laser at a range of increasing doses (energy density) in order to identify the laser parameters yielding the maximum effectiveness for the treatment. Therapy was performed daily (5 treatments/week), either with the CO2 laser (energy densities ranging from 137 to 290 J/cm2) or with the HeNe laser (energy densities ranging from 0.229 to 0.311 J/cm2). At the time of writing there are 140 patients who have completed the therapy regimen with completed record cards. The results are still preliminary, due to the as yet unbalanced numbers of patients admitted to the different treatments, but a statistically significant difference was observed in the effect of HeNe and CO2 laser (p < 0.026). In addition, a significant difference was found between the effects of low and high doses of CO2 laser (p < 0.024) and between the results of treatments based on low dose CO2 laser and high dose HeNe laser (p < 0.006).
One of the major claims laid against low reactive-level laser therapy (LLLT) is its purported lack of penetration in biologic tissues, particularly inhomogeneous turbid soft tissue and bone. In order to assess the actual penetration depth of 830 nm laser energy in the head and neck region, a commercially-available radiographic ‘phantom’ model was used (Rand Phantom, Rand Laboratories, U.S.A.). This model consists of dried human skeletal bones (skull and cervical vertebrae) cast inside a proprietary urethane compound having the same effective atomic number and optical density as soft tissue, thus simulating a mix of soft tissue types with randomly distributed fat at radiographic wavelengths and exposure doses. The phantom is sliced horizontally at 2.5 cm intervals allowing the insertion of X-ray sensitive film for training of radiographers or assessment of penetration of X-rays in the head and neck. In this study the authors used wavelength specific imaging film for 830 nm radiation (Konika Medical Laser Imaging Film, LP820H). The phantom is designed to replicate absorption of tissue at X-ray wavelengths. X-ray photons have a very high frequency (≅ 3 x 1018 Hz), approximately three orders of magnitude higher than near infrared (IR) photons at 830 nm (frequency ≅ 3 x 1013 Hz). It was therefore theorized that the penetration of near IR laser energy would be minimized by the high optical density of the phantom’s ‘soft tissue’ thereby providing an accurate penetration model. In a preliminary experiment, penetration of 830 nm diode laser energy (OhLase-3D1, Proli Japan, GaAlAs, continuous wave, 60 mW, 1∼20 sec) was assessed in a skin model (MIX-DP, Saisei Medical, Japan) at thicknesses from 2 mm to 15 mm. The optical density of the ‘skin’ slices was assessed using densinometry (X-RITE Co., Inc., USA), and then the laser penetration was assessed for each skin model thickness with the medical imaging film placed under the ‘skin’, developed, and the esposure areas plotted graphically. It was found that thepenetration of 830 nm laser energy decreased with the increase in optical density, although in a nonlinear fashion, but that extending the exposure time increased the penetration. In the subsequent experiment the laser was irradiated at various points of the phantom head and neck, maintaining the angle of the probe to the head at about 15°, with 830 nm sensitive imaging film inserted between the slices. Contrary to the results of the previous experiment, at exposure times of 180 sec and 300 sec, penetration of laser energy at 830 nm into the head and neck model as assessed by exposure patterns seen in the 830 nm-sensitive film, was in the range of several centimeters rather than millimetres. It is thought that the presence of bone possibly has an echo effect on incident laser energy at 830 nm thereby giving greater penetration than in the skin alone model. It is also possible that the bone structure may also help to focus the laser energy. The implications for applications of LLLT are discussed.
The effectiveness of low level laser therapy in accelerating would healing has been clinically well documented. We report our experience treating 42 patients with resistant venous ulcers (ulcus cruris) due to chronic venous insufficiency syndrome, using low level laser therapy (LLLT). Full granulation and closure of the ulcers was achieved in 36 patients, two of whom had a recurrence after two years. Complete wound closure in 85.7% of our patients is attributed to the biostimulating effect of laser therapy.
One hundred and thirty-nine patients who presented in a 22 month period were treated with low reactive-level laser therapy LLLT using combined HeNe and infrared diode lasers (632.8 nm, 20 mW and 830 nm 100 mW, respectively) for a variety of chronic complex diseases of the inner ear with such symptoms of tinnitus and vertigo. They received 15 treatments for the purpose of this study. In addition to the laser therapy they were prescribed a daily dose of a plant-based drug (ginkgoflavonglycoside). In response to a post-therapy questionnaire, 77.4% of the patients reported significant overall improvement including their general sense of well-being; 67.7% reported significant improvement in their tinnitus; and 82.5% reported significant improvement of their vertigo. Audiometric tests showed a significant improvement in hearing of around 20 dB over all frequencies in 83% of the patients. Treatment was continued after the trial for those patients with persistent irritating symptoms associated with their inner ear condition, and by the end of two years, all patients were cured. There has been no recurrence in a two-year follow-up. Although some patients reported some exacerbation of their condition (2.2%, general well being, 2.2% in tinnitus but 0% in vertigo), they did not associate this with the laser therapy but rather with individual stress-related problems. Laser therapy is therefore reported in this pilot study as being effective for improvement of well-being, treatment of tinnitus and alleviation of vertigo in a large percentage of chronic inner ear conditions. In addition LLLT was easy to apply, pain-free, noninvasive and had no significant adverse side effects.