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ABSTRACT: Multiple primary tumours are a common problem in the head and neck cancer patients. Curative surgery or radiotherapy of these tumours can be very mutilating or even impossible. This study aims at evaluating meta-tetrahydroxy-phenyl chlorin-mediated photodynamic therapy for second or multiple primary tumours in the head and neck.
Retrospective study of all patients with second or multiple primary tumours treated by photodynamic therapy over a 10-year period.
All patients were treated in the Netherlands Cancer Institute, a tertiary referral centre for the head and neck cancer patients.
A total of 27 patients with 42 the second or the multiple primary head and neck tumours were treated by photodynamic therapy (0.15 mg/kg meta-tetrahydroxy-phenyl chlorin).
Cure rates.
Twenty-eight of 42 tumours were cured (67%). Cure rates for stage I or in situ disease were 85%versus 38% for stage II/III.
Cure rates for photodynamic therapy of the multiple primary head and neck tumours were lower than previously described for first primaries, but were still very encouraging for this difficult patient population. The high cure rate obtained in stage I multiple primaries emphasises the importance of a meticulous follow-up of patients treated for the head and neck cancer to detect new tumours at a curable stage.
Clinical otolaryngology: official journal of ENT-UK; official journal of Netherlands Society for Oto-Rhino-Laryngology & Cervico-Facial Surgery 07/2007; 32(3):185-9. · 2.39 Impact Factor
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ABSTRACT: Photodynamic therapy (PDT) is being evaluated for treatment of localized head and neck cancer. "Light dose" is usually prescribed as incident fluence, which takes no account of reflected and scattered light. This study investigates variations in total tissue fluence for a given incident fluence in the oral cavity.
Light dosimetry was performed in 19 patients treated with PDT for cancers in the oral cavity and in 5 volunteers. Illumination was with 652 nm laser light delivered via a microlens. In situ dosimetry was performed with isotropic probes held against the tissue in the illuminated area.
Tissue fluences of 254% to 305% of the incident fluence were measured in the illuminated area in healthy volunteers. In the patient population tissue fluences were 133% to 545% of the incident fluence.
The relationship between incident and total tissue fluence depended on the location and pigmentation of the target area and was not predictable. In situ dosimetry during cavity illumination allows for more controlled tissue illumination and should be employed as the basis for light dose prescription in PDT for head and neck cancer.
Head & Neck 09/1999; 21(5):434-41. · 2.40 Impact Factor
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ABSTRACT: The aim of this study was to compare red (652 nm) and green (514 nm) light for photodynamic therapy (PDT) of the peritoneal cavity with emphasis on light distribution and toxicity. Red-light PDT was limited by intestinal toxicity and it was hypothesized that less penetrating green light would allow higher light doses to be used in the peritoneal cavity. Female non-tumor-bearing rats were photosensitized with mTHPC (meta-tetrahydroxyphenylchlorin, Foscan) intravenously or intraperitoneally and the peritoneum was illuminated using a minimally invasive technique. For both red and green light, the time of illumination was varied to give the required dose. Light fluence rate was measured in situ at multiple sites within the abdominal cavity. The toxicity experiments were carried out with a total of 160 J incident red or 640 J incident green light and a drug dose of 0.15 mg/kg Foscan. For red light a mean fluence rate of 55.2 +/- 38.5 mW cm-2 was measured, with a peak fluence rate of 128 mW cm-2 on the intestines. For green light the mean and peak fluence rates were 8.2 +/- 9.0 (i.e. including zero fluence rate measurements) and 28 mW cm-2, respectively. Intestines were most vulnerable to red light illumination. The intravenous injection route resulted in increased toxicity for red light, but for green light there were no major differences between intravenous and intraperitoneal routes. The 4 h interval between drug and illumination resulted in very little toxicity for both wavelengths. We conclude that for intraperitoneal PDT green light allows higher light doses than red light, but the light distribution over the peritoneum is much less favorable and may not be suitable for whole peritoneal illumination using a minimal-access technique.
Photochemistry and Photobiology 10/1997; 66(3):389-95. · 2.41 Impact Factor
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ABSTRACT: Distribution of the photosensitizer Foscan (meta-tetrahydroxyphenylchlorin, mTHPC), after i.v. or i.p. injection, was investigated in Wag/Rij rats bearing i.p. tumours. These results were compared with the efficacy of mTHPC-mediated photodynamic therapy for illumination intervals of 4 hr to 3 days. For the distribution experiments a single tumour (CC53I colon carcinoma) was implanted intra-abdominally in a fat pad, or a cell suspension (1 x 10(6) CC531 cells) was injected into the peritoneal cavity, which results in a dissemination of tumour nodules on the peritoneum. 14C-mTHPC was not selectively taken up in the single-tumour model after i.v. or i.p. injection, but higher concentrations were achieved for i.p. administration. For this tumour model the concentration ratios between tumour and normal tissue never exceeded a value of 3. In the disseminated-tumour model, an uptake of up to 40% of the injected dose was found per gram tumour at 4 hr after an i.p. injection and this resulted in very high (> 14) concentration ratios of tumour to normal tissues. Low uptake was found after the i.v. injection route (1% of the injected dose per gram tumour) with lower tumour/normal tissue ratios (<8). The efficacy of i.p. photodynamic therapy (IPPDT) was evaluated using the single-tumour model only. The lower abdomen was illuminated at 4 hr to 3 days after mTHPC, and tumour size was repeatedly measured via a small laparoscopy. Significant delay in tumour regrowth was achieved for 6 J x cm-2 at 1 day after i.v., or at 4 hr after i.p. mTHPC (p values 0.019 and 0.045 respectively). Response to PDT, of tumours implanted in the fat pad, was not greater for i.p. administration of the photosensitizer and there was a poor correlation between times of maximum drug uptake in tumours and optimal illumination times for PDT efficacy.
International Journal of Cancer 10/1997; 73(2):230-5. · 5.44 Impact Factor
