A study of aminolevulinic acid-induced protoporphyrin IX fluorescence kinetics in the canine oral cavity

Vaidyanathan, Vijay; Rastegar, Sohi; Fossum, Theresa W.; Flores, Patricia; Breggen, Egbertus W. Van Der; Egger, Norman G.; Jacques, Steven L.

doi:10.1002/(sici)1096-9101(2000)26:4<405::aid-lsm9>3.0.co;2-e

Cited by 10 publications

(7 citation statements)

References 21 publications

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“…Temporal fitting can be used with compartmental models to estimate the pharmacokinetics of injected dyes [101,123,124], drug production or bleaching rates [125,126] in vivo [118]. Temporal analysis was used to illustrate how fluorescence signals can identify different organs in vivo by Hillman et al [102].…”

Section: Prior Information: Biophysical Models (A) Biophysical Modelsmentioning

confidence: 99%

Implicit and explicit prior information in near-infrared spectral imaging: accuracy, quantification and diagnostic value

Pogue

Davis

Leblond

et al. 2011

Phil. Trans. R. Soc. A.

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Near-infrared spectroscopy (NIRS) of tissue provides quantification of absorbers, scattering and luminescent agents in bulk tissue through the use of measurement data and assumptions. Prior knowledge can be critical about things such as (i) the tissue shape and/or structure, (ii) spectral constituents, (iii) limits on parameters, (iv) demographic or biomarker data, and (v) biophysical models of the temporal signal shapes. A general framework of NIRS imaging with prior information is presented, showing that prior information datasets could be incorporated at any step in the NIRS process, with the general workflow being: (i) data acquisition, (ii) pre-processing, (iii) forward model, (iv) inversion/reconstruction, (v) post-processing, and (vi) interpretation/diagnosis. Most of the development in NIRS has used ad hoc or empirical implementations of prior information such as pre-measured absorber or fluorophore spectra, or tissue shapes as estimated by additional imaging tools. A comprehensive analysis would examine what prior information maximizes the accuracy in recovery and value for medical diagnosis, when implemented at separate stages of the NIRS sequence. Individual applications of prior information can show increases in accuracy or improved ability to estimate biochemical features of tissue, while other approaches may not. Most beneficial inclusion of prior information has been in the inversion/reconstruction process, because it solves the mathematical intractability. However, it is not clear that this is always the most beneficial stage.

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Section: Prior Information: Biophysical Models (A) Biophysical Modelsmentioning

confidence: 99%

Implicit and explicit prior information in near-infrared spectral imaging: accuracy, quantification and diagnostic value

Pogue

Davis

Leblond

et al. 2011

Phil. Trans. R. Soc. A.

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“…First-order mathematical kinetic models are generally used to extract time constants which describe the rate of conversion of ALA to PpIX and the consecutive conversion of PpIX to heme (4)(5)(6)(7)(8). Especially when higher drug doses are used, the fit to the experimental data is not satisfactory.…”

Section: Introductionmentioning

confidence: 99%

A Mathematical Evaluation of Dose-dependent PpIX Fluorescence Kinetics In Vivo¶

Aalders¹,

Vange²,

Star³

et al. 2001

Photochem Photobiol

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The in vivo pharmacokinetics of protoporphyrin IX (PpIX) after administration of 5-aminolevulinic acid (ALA) cannot be described accurately by mathematical models using first-order rate processes. We have replaced first-order reaction rates by dose-dependent (Michaelis-Menten [MM]) reaction rates in a mathematical compartment model. Different combinations of first-order and dose-dependent reaction rates were evaluated to see which one would improve the goodness-of-fit to experimentally determined in vivo PpIX fluorescence kinetics as a function of concentration. The mathematical models that were evaluated are all based on a three-compartment model for drug distribution, conversion to PpIX and subsequent conversion to heme. Implementation of dose-dependent reaction rates improved the goodness-of-fit and enabled interpolation to other drug doses. For most data sets the time constant for delivery to the target cells turned out to be dose dependent. For all data sets the use of MM rates for the conversion of ALA to PpIX yielded better fits. The clearance of PpIX turned out to be a first-order process for all doses and types of administration. Fluorescence curves measured on a specific tissue type but obtained in different studies with different measurement techniques could be described with a single set of parameters.

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“…This has been reported in both dogs and people given ALA orally and intravenously (Webber et al ., 1997; Ackroyd et al ., 1999; Dalton et al ., 1999; Vaidyanathan et al ., 2000). Intravenous injection of >20 mg kg −1 of ALA to healthy dogs has been reported to cause vomiting (Dalton et al ., 1999; Vaidyanathan et al ., 2000). The mechanism of ALA‐induced emesis in dogs is unclear but may be owing to a sudden increase in circulating porphyrins.…”

Section: Discussionmentioning

confidence: 99%

“…ALA also has the advantage of being administered topically, intravenously or parenterally (Marcus et al ., 1996). Preliminary investigations of ALA as a photosensitizer in veterinary medicine have been performed (Dalton et al ., 1999; Lucroy et al ., 1999; Vaidyanathan et al ., 2000; Stell et al ., 2001). Recently, ALA‐based PDT has been shown to be effective against canine TCC cells in vitro (Ridgway & Lucroy, 2003).…”

Section: Introductionmentioning

confidence: 99%

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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A study of aminolevulinic acid-induced protoporphyrin IX fluorescence kinetics in the canine oral cavity

Cited by 10 publications

References 21 publications

Implicit and explicit prior information in near-infrared spectral imaging: accuracy, quantification and diagnostic value

Implicit and explicit prior information in near-infrared spectral imaging: accuracy, quantification and diagnostic value

A Mathematical Evaluation of Dose-dependent PpIX Fluorescence Kinetics In Vivo¶

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

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