Canine bladder response to red and green light whole bladder photodynamic therapy

Nseyo, Unyime O.; Whalen, Raymond K.; Lundahl, Scott L.

doi:10.1016/0090-4295(93)90607-c

Cited by 21 publications

(8 citation statements)

References 7 publications

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“…This suggests that the observed PpIX fluorescence was not sufficient to cause untoward damage to healthy urinary bladder tissue during ALA‐based PDT. The lack of pathologic lesions in the urinary bladders of healthy dogs 21 days after ALA‐based PDT suggests that it is unlikely to cause lasting changes in urinary bladder capacity or function, as reported with other photosensitizers (Nseyo et al ., 1993b). Furthermore, the lack of pathologic findings also suggests that no thermal damage occurs to the urinary bladder at the power density used for these PDT sessions.…”

Section: Discussionmentioning

confidence: 65%

“…The resultant photochemical reaction generates oxidative damage sufficient to directly kill tumour cells, causes vascular collapse and ischaemic tumour death, and incites an inflammatory reaction that results in non‐specific tumour cell killing (Henderson & Dougherty, 1992; Oleinick & Evans, 1998). Variability in photosensitizer localization within tissues has been demonstrated (Peavy et al ., 1995), and bladder fibrosis and decreased bladder capacity have been observed in healthy dogs after whole‐bladder PDT (Nseyo et al ., 1993b), presumably owing to the accumulation of photosensitizer within the muscularis and uneven light distribution within the urinary bladder. Another potential complication of PDT in the urinary bladder is full‐thickness necrosis of the bladder wall.…”

Section: Introductionmentioning

confidence: 96%

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Preclinical evaluation of 5‐aminolevulinic acid‐based photodynamic therapy for canine transitional cell carcinoma

Lucroy

Ridgway

Peavy

et al. 2003

Vet Comparative Oncology

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As a prelude to photodynamic therapy, 5-aminolevulinic acid (ALA) was given orally to healthy dogs. ALA-induced protoporphyrin IX (PpIX) fluorescence significantly increased in the mucosa of the urinary bladder in an ALA dose-dependent fashion. Vomiting occurred after ALA administration in 70% of the dogs but did not affect PpIX fluorescence. ALA-based photodynamic therapy (PDT) of the urinary bladder in healthy dogs caused only submucosal oedema within the bladder wall. No haematologic or serum biochemistry abnormalities were observed after ALA administration. Microscopic haematuria was observed in all the dogs after PDT but was mild and self limiting. ALA-based PDT was administered to six dogs with transitional cell carcinoma (TCC) of the lower urinary tract. ALA-based PDT resulted in tumour progression-free intervals from 4 to 34 weeks in five dogs; one dog with pre-existing hydronephrosis died shortly after PDT. Dogs with TCC represent an outbred, spontaneous, tumour model for developing PDT protocols for humans with bladder cancer.

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Section: Discussionmentioning

confidence: 65%

Section: Introductionmentioning

confidence: 96%

Preclinical evaluation of 5‐aminolevulinic acid‐based photodynamic therapy for canine transitional cell carcinoma

Lucroy

Ridgway

Peavy

et al. 2003

Vet Comparative Oncology

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“…The concept of targeted drug delivery was first elaborated by Paul Ehrlich in the early 20 th century [Himmelweit, 1957]. Recent efforts to effect targeted delivery include local photosensitizer administration [Amano et al, 1988], intra-arterial drug administration [Deckelbaum et al, 1990], choice of route of administration [Bachor et al, 1992], photosensitizer activation with green visible light to avoid substantial normal tissue penetration [Nseyo et al, 1993;Veenhuizen et al, 1997], and two-photon excitation in the near-infrared [Fisher et al, 1997]. It has been suggested that the inherently lower pH of many tumors [Wike-Hooley et al, 1984;Thistlethewaite et al, 1985] may be exploited to identify photosensitizers with preferential tumor uptake [Pottier and Kennedy, 1990].…”

Section: Current Developmentsmentioning

confidence: 99%

Immunophotodynamic therapy: Current developments and future prospects

Miller

Lown

1997

Drug Dev. Res.

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Photodynamic therapy (PDT) may offer an enhanced therapeutic index via one or more of the following modalities: a) preferential photosensitizer uptake by the target tissue, b) specific illumination of target tissue to excite the photosensitizer, c) strategic timing of light application to minimize toxicity to normal tissues, d) topical application of the photosensitizer restricted to the target tissue, infusion of the photosensitizer to the vasculature immediately upstream of the target, and intra‐target administration. While each photosensitizer has inherent properties of biodistribution, it is generally accepted that few provide a significant therapeutic index and that the desired effect is far from universal with respect to tumor types. Moreover, the optical properties of tumor and normal tissues vary dramatically and precision dosimetry remains an elusive goal in most clinical situations. Certain tumors, particularly those of the reticuloendothelial system, will usually be surrounded by normal stroma with greater concentrations of photosensitizer than are present in the tumor at a given post‐administration interval, presenting a major obstacle to practical therapy. Deep‐seated or large solid malignancies are not amenable to topical application of the photosensitizer and single tumor masses are frequently served by multiple arterial sources, rendering major dosimetric obstacles for photosensitizers administered via the upstream vasculature. One approach to specific photosensitizer delivery is via covalently bound immunoconjugates of photosensitizer and antibodies or antibody fragments to unique tumor markers. This approach is the subject of several clinical trials and provides encouragement for successful application in a wide variety of neoplastic diseases. In addition to therapeutic endpoints, this approach is capable of facilitating detection of subclinical lesions through the fluorescent properties of photosensitizers. Drug Dev. Res. 42:182–197, 1997. © 1997 Wiley‐Liss, Inc.

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“…Only a few preclinical (Bellnier et al, 1985;van Gemert et al, 1985;Nseyo et al, 1993;Foster et al, 1996;Nauta et al, 1996) and clinical (Bandieramonte et al, 1984;Delaney et al, 1993) PDT studies have been reported with the 514.nm laser light after photosensitization with Photofrin II or HPD. These studies have demonstrated that the destruction of a thin layer of superficial neoplastic tissue is possible, and that tumour necrosis of up to 2-3 mm could be obtained.…”

mentioning

confidence: 99%

Clinical photodynamic therapy for superficial cancer in the oesophagus and the bronchi: 514 nm compared with 630 nm light irradiation after sensitization with Photofrin II

Grosjean

Wagnières²,

Fontolliet³

et al. 1998

Br J Cancer

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Summary Photodynamic therapy (PDT) for cancer in the oesophagus and bronchi with red (630 nm) light may occasionally lead to wall perforation and fistula. Therefore, we investigated the clinical use of a less penetrating wavelength (514 nm) for the curative treatment of nine superficial carcinomas in the oesophagus and bronchi after photosensitization with Photofrin II. Tumours without infiltration beyond the submucosa in the oesophagus and beyond the lamina propria in the bronchi were considered as superficial cancers. The outcome and complications were compared with those of 13 superficial cancers treated with PDT and 630 nm light. In addition, we evaluated histologically the extent of the long-term tissue damage and scarring following treatment of six oesophageal cancers with either green or red light. At first endoscopic control, 7-10 days after PDT, tissue necrosis simply matched the illuminated area, without evidence of selective tumour damage. Six of nine tumours treated with 514 nm light had a complete response compared with nine of 13 after 630 nm irradiation. No perforation or fistula occurred in either treatment group. However, severe chest pain and fever with or without pleural effusion, consistent with occult perforation, were observed in three patients after 630 nm illumination in the oesophagus. Histologically, fibrous scarring in the three distinct sites treated with green light was limited to the superficial layers of the oesophagus. After red light treatment, transmural fibrosis with marked thinning of the oesophageal wall was evident in two of the three specimens available for inspection. These results indicate that PDT with 514 nm light has the potential to cure superficial cancer in the oesophagus and bronchi with essentially the same probability of success as red light. In the oesophagus, green light prevents deep tissue damage, thus reducing the risk of perforation.

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Canine bladder response to red and green light whole bladder photodynamic therapy

Cited by 21 publications

References 7 publications

Preclinical evaluation of 5‐aminolevulinic acid‐based photodynamic therapy for canine transitional cell carcinoma

Preclinical evaluation of 5‐aminolevulinic acid‐based photodynamic therapy for canine transitional cell carcinoma

Immunophotodynamic therapy: Current developments and future prospects

Clinical photodynamic therapy for superficial cancer in the oesophagus and the bronchi: 514 nm compared with 630 nm light irradiation after sensitization with Photofrin II

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