Photodynamic Therapy Using m-Tetra(Hydroxyphenyl) Chlorin: An Animal Model

Photodynamic therapy of early squamous cell carcinoma with tetra(m-hydroxyphenyl)chlorin: optimal drug-light interval

“…At drug-light intervals longer than 4 days after injection, mTHPC disappears almost completely from the vasculature and consequently vascular damage progressively decreases. The results of this study are in agreement with those reported for other types of tumours (Ris et al, 1993a;Lofgren et al, 1994;Peng et al, 1995).…”

Comparative biodistribution of meta-Tetra (Hydroxyphenyl) chlorin in multiple species: Clinical implications for photodynamic therapy

“…Again, the three species of animals vary, and humans are much higher. We have measured the clearance and found that the half-life in rabbits is 24.7 hours [3], compared to 44.5 hours for humans [9,13], consistent with this data. *0.3 mg/kg mTHPC was injected and plasma concentrations determined 6 days later.…”

“…At present, our modelling capabilities are insufficient to provide accurate predictions of the plasma levels at the time of treatment. But we have shown previously that clinical response to two different photosensitizers in our animal tumor model correlated with plasma level at time of treatment [3,8,10]. We therefore propose that individual tailoring of light dose, based on patient's plasma level of photosensitizer at time of therapy, can compensate for this unpredictability.…”

Photodynamic therapy with mTHPC and polyethylene glycol-derived mTHPC: a comparative study on human tumour xenografts

“…This resulted in tumour necrosis up to 10 mm deep (Ris et al, 1991), and suggested that mTHPC is an efficient second-generation sensitizer for clinical application. Similar findings emerged from experimental settings of other investigators (Lofgren et al, 1994;Ma et al, 1994;van Geel et al, 1995) However, as serious PDT-related side-effects were observed in our patients, we orientated our research towards optimization of mTHPCÐPDT by changing drug-light conditions in an experimental setting with nude mice bearing human malignant mesothelioma xenografts. The tumour and tumour-free tissue that served as control were treated under the same conditions and the extent of PDT-related tumour necrosis and normal tissue injury were compared in order to assess the therapeutic ratio for each drug-light parameter.…”