<title>Pecularities of clinical photodynamic therapy of cancer</title>

Abstract

The analysis of the results of photodynamic therapy (PDT) for treating malignant neoplasms of the skin, mammary glands, tongue, oral mucous, lower lip, larynx, lungs, urinary bladder rectum and other locations has been made. During 1992-1995 478 tumoral foci in 125 patients have been treated with PDT. All patients were previously treated with conventional techniques without effect or they were not treated due to contraindications either because of severe accompanying diseases or because of old age. A part of the patients had PDT because of recurrences or intradermal metastases in 1 -2 years after surgical, radial or combined treatment. Two home-made preparations were used as photosensitizers: Photohem (hematoporphyrine derivative) and Photosense (aluminium sulfonated phthalocyanine). Light sources were: the argon pumped dye laser ("Innova-200", "Coherent") and home-made laser devices: copper-vapour laserpumped dye laser ("Yakhroma-2", Frjazino), gas-discharge unit "Ksenon" (wavelength 630 nm), gold-vapour laser (wavelength 627,8 nm) -for Photohem; while for Photosense sessions we used solid-state laser on ittrium aluminate "Poijus-1" (wavelength 670 mn). Up to now we have follow-up control data within 2 months and 3 years. Positive effect of PDT was seen in 92% of patients including complete regression of tumours in 66,4% and partial -in 25,6%. Currently, this new perspective technique of treating malignant neoplasms is successfully being used in Russia; new photosensitizers and light sources for PDT and fluorescent tumour diagnostics are being developed as well.

Current status of phthalocyanines in the photodynamic therapy of cancer

“…Fifty percent underwent complete tumor regression without re-growth while 43% exhibited a partial response. Only 7% gave no response at all [25]. The phthalocyanine mixture exhibited no systemic toxicity.…”

“…In addition, Photofrin 1 is being investigated as a possible therapy for a number of other malignant and non-malignant conditions. Other hematoporphyrin derivatives are also being used, with Photoheme, an enriched hematoporphyrin derivative similar to Photofrin 1 accepted for clinical use in Russia for easily accessible cancers including skin, breast, oropharingeal, lung, larynx and gastrointestinal cancers along with psoriasis and prophylaxis for corneal transplant opacity and recurrent blindness, where newly formed blood vessels result in loss of corneal transparency [23][24][25][26].…”

Photocytotoxic 3d-Metal Scorpionates with a 1,8-Naphthalimide Chromophore Showing Photoinduced DNA and Protein Cleavage Activity

“…Organic dyes like porphyrin and phthalocyanine bases have been extensively studied as PDT agents considering their photosensitizing ability within the PDT spectral window of 600-800 nm. [25][26][27][28][29] Photofrin, the currently used PDT drug, is a hematoporphyrin species that on photoactivation of its lowest energy Q-band at ∼630 nm generates a (π-π*) state with subsequent formation of the triplet state that activates molecular oxygen to cytotoxic singlet oxygen ( 1 O 2 ) by energy transfer. 20 Such organic dyes along with squaraines and boradiazaindacenes generally follow the mechanistic pathway that involves the formation of singlet oxygen ( 1 O 2 ) as an important criterion for their anticancer activity.…”

“…20 Such organic dyes along with squaraines and boradiazaindacenes generally follow the mechanistic pathway that involves the formation of singlet oxygen ( 1 O 2 ) as an important criterion for their anticancer activity. [25][26][27][28][29][30][31][32] In contrast, transition metal complexes with low-energy d-d or charge transfer band(s) could photocleave DNA following alternate mechanistic pathways like type-I or photoredox processes in the presence of redox active metal ions. [33][34][35] Although various types of organic dyes have been studied as potential PDT agents, the chemistry of metal-based PDT agents is relatively unexplored.…”

31P magnetic resonance spectroscopy as a predictor of efficacy in photodynamic therapy using differently charged zinc phthalocyanines

“…Nevertheless, the need for new clinical photosensitizers with improved purity, tumour selectivity, light absorption profile, photophysical properties and tissue clearance has been recognized (Bellnier and Henderson, 1992;Dougherty, 1993). Phthalocyanines have the potential to fulfil many of these criteria (Ben Hur, 1992;Griffiths et al, 1994) but, although many potential candidates have been studied experimentally (Spikes, 1986;Ben Hur et al, 1987), there has been little clinical application and that appears to have been restricted largely to the use of aluminium sulphonated phthalocyanine in Russia (Stranadko et al, 1996).…”