In Vivo Laser Light Distribution in Human Prostatic Carcinoma

Whitehurst, Colin; Pantelides, M L; Moore, James; Brooman, P. J. C.; Blacklock, N. J.

doi:10.1016/s0022-5347(17)35270-9

Cited by 42 publications

(29 citation statements)

References 17 publications

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“…Accurate optical dosimetry is an important factor to achieve an accurate lesion volume in the prostate and solid tumors (11,18,37,38). Uniformity of light distribution, deep light penetration, and minimal fluctuation of the light distribution during treatment are desirable.…”

Section: Discussionmentioning

confidence: 99%

Effects of Pd-bacteriopheophorbide (TOOKAD)-Mediated Photodynamic Therapy on Canine Prostate Pretreated with Ionizing Radiation

et al. 2004

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The aim of this study was to evaluate the effects of photodynamic therapy (PDT) using a novel palladium bacteriopherophorbide photosensitizer TOOKAD (WST09) on canine prostate that had been pretreated with ionizing radiation. To produce a physiological and anatomical environment in canine prostate similar to that in patients for whom radiotherapy has failed, canine prostates (n = 4) were exposed to ionizing radiation (54 Gy) 5 to 6 months prior to interstitial TOOKAD-mediated PDT. Light irradiation (763 nm, 50-200 J/cm at 150 mW/cm from a 1-cm cylindrical diffusing fiber) was delivered during intravenous infusion of TOOKAD at 2 mg/kg over 10 min. Interstitial measurements of tissue oxygen profile (pO 2 ) and of local light fluence rate were also measured. The prostates were harvested for histological examination 1 week after PDT. The baseline pO 2 of preirradiated prostate was in the range 10-44 mmHg. The changes in relative light fluence rate during PDT ranged from 12 to 43%. The acute lesions were characterized by hemorrhagic necrosis, clearly distinguishable from the radiotherapy-induced pre-existing fibrosis. The lesion size was correlated with light fluence and comparable to that in unirradiated prostate treated with a similar TOOKAD-PDT protocol. There was no noticeable damage to the urethra, bladder or adjacent colon. The preliminary results obtained from a small number of animals indicate that TOOKAD-PDT can effectively ablate prostate pretreated with ionizing radiation, and so it may provide an alternative modality for those prostate cancer patients for whom radiotherapy has failed.

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Section: Discussionmentioning

confidence: 99%

Effects of Pd-bacteriopheophorbide (TOOKAD)-Mediated Photodynamic Therapy on Canine Prostate Pretreated with Ionizing Radiation

et al. 2004

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“…22,23 For the case of prostate tissue, several papers have addressed the issue of optical properties, e.g., the effective attenuation coefficient eff and in some cases also absorption and reduced scattering coefficients a and s Ј, respectively. 4,18,[24][25][26][27][28][29][30][31] Most of them rely on interstitial fiber optic steady state fluence rate measurements at multiple sourcedetector separations. By measuring relative fluence rate in a range of source-detector separations larger than a few millimeters ͑i.e., the diffuse regime͒, the diffusion approximation of light transport can be employed to determine eff .…”

Section: Introductionmentioning

confidence: 99%

“…25 In vivo effective attenuation in prostates diagnosed with benign prostatic hyperplasia ͑BPH͒ or prostatic carcinoma ͑PC͒ has been estimated at 630, 633, and 665 nm, by employing steady state fluence rate measurements. 26,28,29 Other studies rely on absolute fluence rate measurements to determine both absorption and scattering coefficients. By measuring fluence rates along a linear channel ͑5 mm away from the source fiber͒, one such study presents optical properties at 732 nm, before and after motexafin-lutetium-mediated PDT of locally recurrent prostate cancer.…”

Section: Introductionmentioning

confidence: 99%

In vivo optical characterization of human prostate tissue using near-infrared time-resolved spectroscopy

et al. 2007

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In vivo optical characterization of human prostate tissue using near-infrared timeresolved spectroscopy.Svensson, Tomas; Andersson-Engels, Stefan; Einarsdóttír, Margrét; Svanberg, Katarina General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.In vivo optical characterization of human prostate tissue using near-infrared time-resolved spectroscopy Tomas Svensson Stefan Andersson-EngelsLund University Department of Physics SE-221 00 Lund Sweden Margrét Einarsdóttír Katarina SvanbergLund University Hospital Department of Oncology SE-221 00 Lund Sweden Abstract. The development of photodynamic therapy into a modality for treatment of prostate cancer calls for reliable optical dosimetry. We employ, for the first time, interstitial time-resolved spectroscopy to determine in vivo optical properties of human prostate tissue. Nine patients are included in the study, and measurements are conducted prior to primary brachytherapy treatment of prostate cancer. Intrasubject variability is examined by measuring across three tissue volumes within each prostate. The time-resolved instrumentation proves its usefulness by producing good signal levels in all measurements. We are able to present consistent values on reduced scattering coefficients ͑ s Ј͒, absorption coefficients ͑ a ͒, and effective attenuation ͑ eff ͒ at the wavelengths 660, 786, and 916 nm. At 660 nm, s Ј is found to be 9±2 cm −1 , and a is 0.5± 0.

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“…Several investigators have attempted to characterize the optical properties of prostate tissue in animals (10)(11)(12) and in humans (13)(14)(15) to predict light dosimetry more reliably. Using diffusion theory for a point source, the absorption (μ a ) and transport scattering ( ) coefficients of a particular tissue can be determined yielding the effective attenuation coefficient (μ eff ), which provides a measure of light penetration in that tissue (11).…”

Section: Introductionmentioning

confidence: 99%

Optical Properties of Human Prostate at 732 nm Measured In Vivo during Motexafin Lutetium-Mediated Photodynamic Therapy

Zhu¹,

Dimofte²,

Finlay³

et al. 2004

Photochem Photobiol

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Characterization of the tissue light penetration in prostate photodynamic therapy (PDT) is important to plan the arrangement and weighting of light sources so that sufficient light fluence is delivered to the treatment volume. The optical properties (absorption [μ a ], transport scattering [ ] and effective attenuation [μ eff ] coefficients) of 13 patients with locally recurrent prostate cancer were measured in situ using interstitial isotropic detectors. Measurements were made at 732 nm before and after motexafin lutetium (MLu)-mediated PDT in four quadrants. Optical properties were derived by applying the diffusion theory to the fluence rates measured at several distances (0.5-5 cm) from a point source. μ a and varied between 0.07 and 1.62 cm −1 (mean 0.37 ± 0.24 cm −1 ) and 1.1 and 44 cm −1 (mean 14 ± 11 cm −1 ), respectively. μ a was proportional to the concentration of MLu measured by an ex vivo fluorescence assay. We have observed, on average, a reduction of the MLu concentration after PDT, presumably due to the PDT consumption of MLu. μ eff varied between 0.91 and 6.7 cm −1 (mean 2.9 ± 0.7 cm −1 ), corresponding to an optical penetration depth (δ = 1/μ eff ) of 0.1-1.1 cm (mean 0.4 ± 0.1 cm). The mean penetration depth at 732 nm in human prostate is at least two times smaller than that found in normal canine prostates, which can be explained by a four times increase of the mean value of in human prostates. The mean light fluence rate per unit source strength at 0.5 cm from a point source was 1.5 ± 1.1 cm −2 , excluding situations when bleeding occurs. The total number of measurements was N = 121 for all mean quantities listed above. This study showed significant inter-and intraprostatic differences in the optical properties, suggesting that a real-time dosimetry measurement and feedback system for monitoring light fluences during treatment should be considered for future PDT studies. ¶ Posted on the website on 9 November 2004.

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In Vivo Laser Light Distribution in Human Prostatic Carcinoma

Cited by 42 publications

References 17 publications

Effects of Pd-bacteriopheophorbide (TOOKAD)-Mediated Photodynamic Therapy on Canine Prostate Pretreated with Ionizing Radiation

Effects of Pd-bacteriopheophorbide (TOOKAD)-Mediated Photodynamic Therapy on Canine Prostate Pretreated with Ionizing Radiation

In vivo optical characterization of human prostate tissue using near-infrared time-resolved spectroscopy

Optical Properties of Human Prostate at 732 nm Measured In Vivo during Motexafin Lutetium-Mediated Photodynamic Therapy

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