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Photodynamic therapy (PDT) produces local tumor necrosis, on activation of a previously administered sensitizer with non-thermal light of an appropriate wavelength. It is attractive for treating tumors of the mouth as tissue healing is particularly good, We describe the use of the photosensitizing agent meta tetrahydroxyphenyl chlorin (mTHPC, Foscan(R)) for PDT of oral cancer, including patients with field cancerization. Nineteen patients with histologically confirmed oral cancer (8 with field change disease) and one with severe dysplasia, were sensitised with mTHPC intravenously. Activation was carried out 72-96 hr later with laser light at 652 nm using a range of light doses, The results were assessed clinically and histologically. Multiple biopsies were taken during the ulcerative stages to look at the effects of PDT and after healing to assess the overall treatment result, All single lesions up to stage T3 cleared after one PDT treatment (total of 6 patients), Three out of 6 T4 tumours were also cleared. Lesions in patients with field change disease did less well, only 9 of 14 T1 and T2s clearing, including 4 that required extra treatments with a higher light dose, Most healed very well, but tongue tethering was seen in patient and another had necrosis in normal areas due to light scattering within the mouth. PDT using mTHPC is a promising new treatment for patients with oral cancer, (C) 1997 Wiley-Liss, Inc. more...

BACKGROUND. Premalignant changes in the mouth, which are often widespread, are frequently excised or vaporized, whereas cancers are treated by excision or radiotherapy, both of which have cumulative morbidity. Photodynamic therapy (PDT) is another option that produces local tissue necrosis with light after prior administration of a photosensitizing agent. This heals with remarkably little scarring and no cumulative toxicity. This article describes the use of PDT with the photosensitizing agent 5-aminolevulinic acid (ALA) for premalignant and malignant lesions of the mouth. METHODS. Eighteen patients with histologically proven premalignant and malignant lesions of the mouth were sensitized with 60 mg/kg ALA by mouth and treated with laser light at 628 nanometers (100 or 200 Joules/cm 2 ). The results were assessed macroscopically and microscopically. Biopsies were taken immediately prior to PDT for fluorescence studies, a few days after PDT to assess the depth of necrosis, when healing was complete, and up to 88 weeks later. RESULTS. The depth of necrosis varied from 0.1 to 1.3 mm, but complete epithelial necrosis was present in all cases. All 12 patients with dysplasia showed improvement (repeat biopsy was normal or less dysplastic) and the treated areas healed without scarring. Some benefit was observed in five of six patients with squamous cell carcinoma, but only two became tumor free (one with persistent mild dysplasia). No patient had cutaneous photosensitivity for longer than 2 days. CONCLUSIONS. PDT using ALA for dysplasia of the mouth produces consistent epithelial necrosis with excellent healing and is a simple and effective way to manage these patients. Results in invasive cancers are less satisfactory, mainly because the PDT effect is too superficial with current treatment regimens using ALA as the photosensitizing agent. more...

Outcomes of surgical treatment for patients with mouth cancer can be limited by the risk of perioperative complications. This study identifies factors that predict for complications in such patients. Between 1992 and 2000, 182 patients had surgery for mouth cancer. The patient, their medical and surgical characteristics as well as perioperative complications were identified. Univariate analysis was carried out to determine which characteristics were associated with complications. Complications occurred in 85 patients (47%). Fifty-three percent of the complications were of intermediate severity and 15.6% were major. The operative death rate was 3.2%. Factors predicting complications included pre-existing cardiovascular (p0.01) and respiratory disease (p=0.02), alcohol consumption (p0.01), stage of disease, nature and scale of surgery, duration of surgery (p0.01). Tracheostomies (p0.01, OR 3.05), poor differentiation of tumour (p0.05) and presence of extracapsular spread were predictive of complications. Patients with more complications are at increase risk of operative death or dying with head and neck cancer (p=0.04). Complications were also analysed into those that may be related to surgical technique and medical management. 113 (37%) complications were in this category. Factors influencing complications are multifactorial. Identification of risk factors allows individualised approach should improve outcome of treatment. more...

True malignant mixed tumours of the salivary gland (carcinosarcoma) are rare tumours composed of both carcinomatous and sarcomatous components. They predominantly occur in the parotid gland. This report presents the clinical, histological and imaging findings of a carcinosarcoma arising in the deep lobe of the parotid. We present magnetic resonance imaging (MRI) findings of this tumour. MRI demonstrated heterogenous intermediate T2-W signal with a thick irregular enhancing rim was suggestive of a malignant lesion. more...

Photodynamic therapy has been proposed as an intra-operative adjunct to surgical resection of tumors invading bone. To assess this, we studied the effects of PDT in normal bone. Forty- four rabbits were sensitized with Photofrin 3 mg/kg, 5-aminolaevulinic acid (ALA) 400 mg/kg, or meso-tetrahydroxyphenylchlorin (mTHPC) 0.3 mg/kg. A mandibular incisor was removed and the socket irradiated with a cylindrical diffusion fiber (630 nm Photofrin and ALA, 650 nm mTHPC, 100 J per treatment). Irradiation was given 1 or 48 hours after Photofrin, 72 hours after mTHPC, whilst 2 doses were given 2.5 and 4 hours after the first fractionated dose of ALA. The socket of the ipsilateral maxillary incisor was used as a nonirradiated control to assess healing without PDT. Other controls assessed healing after irradiation of unsensitized animals. Rabbits were killed 3, 10, and 21 days after treatment. Tooth socket healing appeared to be the same in all groups of animals with evidence of woven bone formation by 10 days. We conclude that PDT is unlikely to have any effect on healing in normal bone, which makes it suitable for treating tumors invading bone.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. more...

Photodynamic therapy (PDT) of tumors, as a primary treatment or as an adjunctive intra- operative therapy, may expose major vascular structures to injury. PDT has also been proposed to prevent neointimal hyperplasia following angioplasty of stenotic arteries. This study aimed to determine the effect of PDT on the normal rabbit carotid artery, and to determine whether this injury resulted in weakening of the vessel wall. PDT of the carotid arteries of NZW rabbits, using either disulphonated aluminum phthalocyanine or 5- aminolaevulinic acid induced protoporphyrin IX as photosensitizers, was performed using a light dose of 100 J/cm2. Histological examination of the carotids treated with both drugs demonstrated full thickness loss of cellularity 3 days following photodynamic therapy. Treated vessels all remained patent and no inflammatory infiltrate was observed. Elastin van Gieson staining showed preservation of inner and medial elastic laminae and medial and adventitial collagen. Further rabbits were similarly treated with PDT to 1 cm segments of both common carotids and sacrificed at 3, 7, and 21 days. The carotids were exposed and control and treated segments subjected to intraluminal hydrostatic distension until the vessels ruptured. No reduction in the pressure required to rupture the vessels was evident in treated vessels compared with controls. It is concluded that in spite of full thickness cell death, PDT treated arteries are not at risk of thrombotic occlusion or hemorrhage.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. more...

Seventeen patients with oral cancer and precancer were treated with photodynamic therapy using systemic 5-aminolaevulinic acid. A brisk PDT response was noted in all patients but damage was confined to the epithelium on histological evaluation. more...