Roman Smucler

Combination of Er:YAG laser and photodynamic therapy in the treatment of nodular basal cell carcinoma

Photodynamic therapy (PDT), via topical aminolevulinic acid (ALA) is an effective treatment for basal cell carcinomas not exceeding a depth of 2 mm. This limits the treatment of basal cell carcinoma (non‐melanoma skin cancer) to superficial forms and nodular therapy (only in aesthetically desired locations). This paper addresses the effectiveness of reducing tumor mass via initial Er:YAG laser ablation to depths that are therapeutically responsive to PDT with ALA.

Fractional Carbon Dioxide Laser Improves Nodular Basal Cell Carcinoma Treatment with Photodynamic Therapy with Methyl 5‐Aminolevulinate

Background The major limitation of photodynamic therapy with 5‐aminolevulinic acid (ALA‐PDT) is proper photosensitizer penetration. The nodular form of BCC (nBCC) is perceived as a contraindication to ALA‐PDT because the tumor layer is thicker than 2 mm. We have improved on the results of previous studies that used an ablative laser to limit tumor thickness. A fractional laser produces skin microtubules that can improve the penetration of ALA into tumors. Objective To evaluate the use of a fractional laser as pretreatment before ALA‐PDT for nBCC treatment in an 18‐month single‐blind clinical trial. Methods Fifty‐six verified nBCCs were ablated using a diode laser under ultrasound control. Half of the tumors were treated 3 weeks later using a fractional carbon dioxide laser, and the other half were treated using curettage (control). We then immediately treated with ALA‐PDT. Fluorescence and photography were evaluated and compared each month, and a final histopathologic examination was performed. Results Fifty‐two of 56 nBCCs in the fractional laser treatment group responded to ALA‐PDT, compared with only 45 of 56 in the control group. Fluorescence was higher in 53 cases in the treatment group; 3 cases demonstrated the same fluorescence level in both groups. Healing took longer in the treatment group, and there were more side effects. Conclusion Fractional laser pretreatment increases the fluorescence and clinical effectiveness of ALA‐PDT for the treatment of nBCC.

Ultrasound guided ablative-laser assisted photodynamic therapy of basal cell carcinoma (US-aL-PDT).

OBJECTIVE With proper noninvasive ultrasound measurement of tumor depth, case selection for laser pre-ablation followed by PDT is possible. This combination of methods provides a less invasive approach to the treatment of BCC. BACKGROUND DATA Basal cell carcinoma (BCC) primarily affects the face, and, therefore, radical excision is problematic because of the possibility of poor aesthetic outcomes. Photodynamic therapy (PDT) offers an advantage in aesthetic outcomes, but topical PDT is only effective for tumors with a depth up to 2 mm. MATERIALS AND METHODS Seventy-five histologically verified BCCs from 67 patients were selected and divided into three therapeutic groups based on the tumor depth, which was determined by 20 MHz skin ultrasound. The three groups were: A/<2 mm (PDT), B/ 2-3 mm (Er:YAG laser ablation+PDT), and C/>3 mm (diode laser ablation+PDT). The treatment consisted of laser ablation (or no ablation) followed by the application of methyl-aminolevulinate (MAL) and a 3-h treatment period using an occlusive bandage. Subsequently, illumination with 630 nm (MAL-PDT) was performed. MAL-PDT was repeated 1-3 weeks after the first treatment. A clinical evaluation was performed after 6 months. RESULTS A 100% clearance rate (CR) in the group with the deepest tumors was observed. In addition, a 94.7% CR occurred in the group with tumors 2-3 mm in depth, and an 81.2% CR was observed in the group with superficial tumors. CONCLUSIONS With proper ultrasound case selection and laser ablation before MAL-PDT, the depth of a BCC lesion is not a limiting factor for PDT, and aesthetic outcomes are very good. Therefore, ultrasound-guided ablative laser-assisted PDT of BCC can be the method of choice, particularly in aesthetically challenging cases.

Effect of the combination of laser excision and interstitial hyperthermia in palliative therapy of head and neck tumours in the advanced stage of the disease

Background and Objectives We evaluated the potential of combining laser excision with laser interstitial hyperthermia in order to improve the quality of life of patients with 3rd or 4th stage malignant head and neck tumours. Study Design/Materials and Methods To evaluate the quality of life, we used the 4th version of the University of Washington Quality of Life assessment score modified for head and neck tumours. The study group of 20 patients assessed their condition in a questionnaire, examining 12 aspects of their quality of life before the laser treatment, the second day after, and 6 weeks after the treatment. Results We observed a gain of 16.41 points, which subjectively represents a 70.32% improvement in the quality of life. Conclusions Following this therapy the quality of life significantly improved in patients with primarily low quality of life, whereas the group of patients with less affected quality of life reported a temporary decline in the quality of life after the treatment. To obtain a proper objective indication, we suggest a mathematical modelling of possible gains for the individual patient using the University of Washington Quality of Life classification. Lasers Surg. Med. 34:12–17, 2004.

Hydrogel tissue expanders for stomatology. Part I. Methacrylate-based polymers

In order to create a soft tissue surplus, implantable volume expanders are often utilized in dental surgery. Implanted tissue expanders should gradually increase their volume, exerting a constant pressure on the surrounding tissue for weeks. Current tissue expanders are based predominantly on externally inflatable balloons or on osmotically active tissue expanders that use soft hydrogels wrapped in perforated plastic coatings, which limit fluid entry and swelling. We have designed and examined tissue expanders based on the controlled rate expansive hydrogels synthesized from copolymers of selected methacrylates and N-vinylpyrrolidone, cross-linked with a combination of non-degradable (glycol dimethacrylates) and hydrolytically degradable (N,O-dimethacryloylhydroxylamine) cross-linkers. These copolymers have close-to-linear volume expansion rates (up to 6-9 times their original volume) and exert an increasing swelling pressure in vitro. The anesthetic benzocaine has been incorporated into the hydrogels, and kinetic release experiments have shown that most of the drug (90%) was released within 48 h. Our proposed hydrogel expanders are homogeneous and have suitable mechanical properties, thus simplifying the surgical manipulations required. Further studies will be needed to completely evaluate their biocompatibility and tissue response to the implants.

The efficacy of diode laser removal of leukoplakias on the tongue and in lower buccal cavity compared to other buccal cavity locations. A two-year study

Introduction. Leukoplakias of the buccal cavity are premalignant lesions with a significant 0–20% potential for malignant transformation. In addition to active follow-up screening procedures, a number of surgical interventions are recommended for their removal. One of the preferred procedures is laser ablation with consecutive histopathology using one of the many types of lasers. The efficacy of such procedure with respect to the lesion location is, however, unclear. Many studies are contradictory. Some shows laser ablations as prevention of malignisation other see it as increased risk. Aim of this is to test treatment in different locations for two years. Material and method. An outpatient ablation by a 980mm diode laser of lesions on the tongue and in the lower buccal cavity (Group A) and lesions in other parts of the buccal cavity (Group B) were performed under local anaesthesia. In total, 76 lesions were treated in 66 patients. Recurrence after 1, 3, 6, 9, 12, and 24 months were followed up. Initially, all lesions were histopathologically tested. Concurrently, the subjective tolerance of the procedure was monitored, using a 1 (ideal) to 5 (worst) scale. Results. Clearing rate of lesions was of 84.6% for Group A and of 94.7% for Group B. In two patients (3% of Group A) malignant transformation occurred which was not observed in Group B. Patient toleration in various time intervals was always higher in Group B, but generally was very high in both groups. Conclusion. Malignant transformation of leukoplakias does occur even after laser ablation, and for this reason it is necessary to subject the patients to systematic follow-ups. It is significantly higher risk of recurrences and malign transformation in tongue and oral base. Laser ablation is a simple and well-tolerated procedure with high clearing rate.

Photodynamic therapy (PDT) for disinfection of oral wounds. In vitro study

ObjectiveThe aim of this in vitro study was to compare the antimicrobial effects of photodynamic antimicrobial chemotherapy (PACT), an ordinary antiseptic (chlorhexidini digluconas), and an antibiotic therapy (bacitracinum zincicum and neomycini sulfas) in vitro.BackgroundPhotodynamic therapy (PDT) is an area of great interest for its potential use as an antimicrobial therapy. It is currently a popular topic in modern medical literature. PDT is, according to recent publications, advantageous over other types of therapies because it acts nonspecifically and it is impossible to develop resistance to the therapy.Materials and MethodsWe investigated the antibacterial effect of these three forms of antiseptics on the selection of G+, G-, aerobic, and anaerobic bacteria that exist in the oral cavity and are involved in the formation of periodontal diseases.Results & ConclusionWe found that the PACT device did not have a sufficient antimicrobial effect in vitro. In contrast, the disinfection agents containing chlorhexidini digluconas were effective and may be a safe, non-specific alternative to antibiotic treatments. Promising results from some clinical studies can have different mechanism of action as disinfection.

Laser and high-frequency cauthery gingivectomy in nonperiodontal indications: assessment and comparison of techniques

The authors have verified the efficiency and safety of laser and high-frequency gingivectomy in non-periodontal indications. Within a prospective, non-selective study, they treated and monitored 357 dental areas in 139 teeth.Out of the total number, 248 areas were treated wtih a diode laser, 980nm; 109 areas with high-frequency electrocautery. The following parameters were monitored: a) regeneration of the marginal gingiva; b) generation of iatrogenic recessions or periodontal pockets; c) bleeding from gingival sulcus during probing; d) changes in tooth vitality; e) patients subjective evaluation. The authors identified a high degree of safety in both laser and high-frequency gingivectomy, with no significant difference between these two methods. Laser gingivectomy appears to have a wider indication range, while high-frequency gingivectomy requires lower financial expenses.

Invasive leg vein treatment with 1064/1319 Nd:YAG laser: combination with dye laser treatment

More than 2 500 leg veins patients were treated with dye laser / ScleroPlus, Candela, USA / successfully in our clinic and we use this therapy as the basic cosmetics treatment. But especially diameter of leg vein is limiting factor. Very often we have to treat some cases that are not ideal for classical surgical or for dye laser method. We decided to make invasive perivenous laser coagulation. We adapted original Czech 1064/1319 nm Nd:YAG laser / US patent pending /, which is new combine tool, for invasive application. Principe: After we have penetrated the cutis with laser fiber we coagulate leg veins during slowly perivenous motion. Perfect preoperative examination is a condition of success. After 15 months we have very interesting results. Some patients / 15%/ were perfect treated only with this possibility but excellent results are acquired from combination with dye laser.

1064-/1319-nm Nd:YAG laser in maxillofacial surgery

Patients feel face destruction as the main problem of oncological treatment in maxillofacial area. Finding a compromise between radicality and esthetic point of view is always problematic. Original Czech 1064/1319 nm Nd:YAG laser--U.S. patient pending--is new precise tool which can give new possibilities. Two wavelengths--with different water absorption--give unique chance to control collateral tissue damage. We can combine vaporization, coagulation and hyperthermic therapy special for every part of face and for every tissue. Thanks to that we use this machine in primary treatment and in palliative therapy independently or in combination with classical knife excision. Thanks to the use of fiber we are able to bit not only superficial lesions but we have opportunity of deep hyperthermic therapy with different collateral penetration. After 20 months we can show interesting results.