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

Wood, Stephen C.; Bradley, J. K.; Griffiths, John R.; Adams, G. E.; Brown, Sylvia T.

doi:10.1038/sj.bjc.6690738

Cited by 17 publications

(15 citation statements)

References 20 publications

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“…Since PDT (and more so PDT in combination with HT) is a modality in which a number of treatment parameters related to the photosensitiser and light (drug dose, drug-light interval, light dose, etc) used need to be selected, studies have also been carried out in which magnetic resonance spectroscopy (MRS) techniques have been used to try to predict PDT outcome at the time of treatment. In one such study (Bremner et al, 1999), a clear relationship was seen between MRS measurements of energy metabolism immediately following PDT and the ultimate effect on the tumour in terms of regrowth delay. The data obtained in the present study would also support the concept that monitoring of ATP or lactate levels may provide information on the effectiveness of PDT-based treatments.…”

Section: Discussionmentioning

confidence: 99%

Combined hyperthermia and chlorophyll-based photodynamic therapy: tumour growth and metabolic microenvironment

et al. 2003

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The effects of combined and simultaneously applied localised 431C hyperthermia (HT) and an antivascular bacteriochlorophyllserine-based photodynamic therapy (Bchl-ser-PDT) on tumour growth and several microenvironmental parameters were examined. Rats bearing DS-sarcomas were allocated to treatment groups:The light source used was an infrared-A irradiator, which, by use of appropriate filters, delivered the different ranges of wavelengths required. Following treatment, tumour volume was monitored. The greatest tumour growth inhibition was seen with Bchl-ser-PDT þ HT, and subsequent experiments identified the pathophysiological basis for this effect. Red blood cell flux in tumour microvessels declined rapidly upon Bchl-ser-PDT þ HT, reaching approximately 10% of initial values by the end of treatment. Similarly, tumour oxygenation worsened, reaching almost anoxic levels by the end of the treatment period. Assessment of metabolic parameters showed a pronounced increase in lactate levels and a decrease in ATP concentrations after combined treatment. The results presented suggest that vascular collapse and flow stasis resulting in a deterioration of tumour oxygenation and a switch from oxidative to glycolytic glucose turnover are key elements in the tumour eradication seen with this novel approach in which an antivascular PDT and HT are combined and simultaneously applied.

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Section: Discussionmentioning

confidence: 99%

Combined hyperthermia and chlorophyll-based photodynamic therapy: tumour growth and metabolic microenvironment

et al. 2003

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“…NMR data analysis revealed significant differences in the time course of changes in high energy phosphate levels in response to combined hyperthermia and photodynamic therapies [29]. It was also demonstrated that there is a relationship between NMR measurements immediately following PDT and the ultimate effect on the tumor [26]. Third, diffusion-weighted MRI showed a biphasic change in the apparent diffusion coefficient (ADC) within the first 24 hours post-PDT, indicating the early response of PC-14 tumors to PDT [11].…”

Section: Introductionmentioning

confidence: 93%

“…Gadolinium diethylenetriamene pentaacetate (DTPA) contrast-enhanced MRI was used to assess the boundary of PDT-induced tissue necrosis in a canine model [23] and in human patients [24]. Second, in vivo 31 P nuclear magnetic resonance (NMR) spectroscopy has been used to monitor tumor metabolic status before and after the treatment of RIF-1 tumors [25,26] and mammary carcinoma [27][28][29][30]. NMR data analysis revealed significant differences in the time course of changes in high energy phosphate levels in response to combined hyperthermia and photodynamic therapies [29].…”

Section: Introductionmentioning

confidence: 99%

High‐field magnetic resonance imaging of the response of human prostate cancer to Pc 4‐based photodynamic therapy in an animal model

et al. 2007

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Introduction-High-field magnetic resonance imaging (MRI) is an emerging technique that provides a powerful, non-invasive tool for in vivo studies of cancer therapy in animal models. Photodynamic therapy (PDT) is a relatively new treatment modality for prostate cancer, the second leading cause of cancer mortality in American males. The goal of this study was to evaluate the response of human prostate tumor cells growing as xenografts in athymic nude mice to Pc 4-sensitized PDT.

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“…The development of noninvasive means of implicit or explicit treatment dosimetry in PDT has expanded in recent years with reports on singlet oxygen monitoring (55), NADH fluorescence monitoring (56), 31 P magnetic resonance spectroscopy (57,58), and BOLD-contrast magnetic resonance imaging (59) providing evidence of potential utilization of each technique in PDT. Broadband reflectance spectroscopy is based on the diffusion model and photon migration inside scattering media, similar to near-infrared photon-migration spectroscopy reported by Pham et al (21).…”

Section: Oxygen Measurement and Photodynamic Therapy Outcomementioning

confidence: 99%

Treatment-Induced Changes in Tumor Oxygenation Predict Photodynamic Therapy Outcome

Putt²,

et al. 2004

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Photodynamic therapy (PDT) requires oxygen to cause tumor damage, yet therapy itself can deplete or enhance tumor oxygenation. In the present work we measured the PDT-induced change in tumor oxygenation and explored its utility for predicting long-term response to treatment. The tissue hemoglobin oxygen saturation (SO 2 ) of murine tumors was noninvasively measured by broadband diffuse reflectance spectroscopy. In initial validation studies, the oxyhemoglobin dissociation curve for mouse blood was accurately recreated based on measurements during deoxygenation of a tissue phantom of mouse erythrocytes. In vivo studies exhibited excellent correlation between carbogen-induced changes in SO 2 and pO 2 of radiation-induced fibrosarcoma tumors measured by reflectance spectroscopy and the Eppendorf pO 2 histograph, respectively. In PDT studies radiation-induced fibrosarcoma tumor SO 2 was measured immediately before and after Photofrin-PDT (135 J/cm 2 , 38 mW/cm 2 ). Animals were subsequently followed for tumor growth to a volume of 400 mm 3 (time-to-400 mm 3 ) or the presence of tumor cure (no tumor growth at 90 days after treatment). In animals that recurred, the PDT-induced change in tumor SO 2 , i.e., relative-SO 2 (SO 2 after PDT/SO 2 before PDT) was positively correlated with treatment durability (time-to-400 mm 3 ). The predictive value of relative-SO 2 was confirmed in a second group of animals with enhanced pre-PDT oxygenation due to carbogen breathing. Furthermore, when all of the animals were considered (those that recurred and those that were cured) a highly significant association was found between increasing relative-SO 2 and increasing probability of survival, i.e., absence of recurrence. As independent variables, the SO 2 after PDT, the pre-PDT tumor volume, and light penetration depth all failed to predict response. As an independent variable, the SO 2 before PDT demonstrated a weak negative association with treatment durability; this association was driven by a correlation between decreasing pre-PDT SO 2 and increasing relative-SO 2 . These data suggest that monitoring of PDTinduced changes in tumor oxygenation may be a valuable prognostic indicator.

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

Cited by 17 publications

References 20 publications

Combined hyperthermia and chlorophyll-based photodynamic therapy: tumour growth and metabolic microenvironment

Combined hyperthermia and chlorophyll-based photodynamic therapy: tumour growth and metabolic microenvironment

High‐field magnetic resonance imaging of the response of human prostate cancer to Pc 4‐based photodynamic therapy in an animal model

Treatment-Induced Changes in Tumor Oxygenation Predict Photodynamic Therapy Outcome

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