Interstitial Photodynamic Therapy of Brain Tumors

Johansson, Ann; Kreth, Friedrich W.; Stummer, Walter; Stepp, Herbert

doi:10.1109/jstqe.2009.2033606

Cited by 23 publications

(29 citation statements)

References 99 publications

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“…Oral administration of ALA and subsequent irradiation at 635 nm has been shown to result in median survival of 15 months . The clinical procedures employed by our group and other groups have so far involved only standardised light and ALA doses. The observation of some intriguing long‐term survivors leads to the speculation that some individuals might present conditions that are particularly beneficial for PDT.…”

Section: Discussionmentioning

confidence: 99%

Protoporphyrin IX Fluorescence and Photobleaching During Interstitial Photodynamic Therapy of Malignant Gliomas for Early Treatment Prognosis

et al. 2013

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Intra-tumoural PpIX concentrations exhibited pronounced inter- and intra-tumoural variations in glioblastoma, which are directly linked to variable degrees of fluorescence intensity. High intra-tumoural PpIX concentrations with strong fluorescence intensity and complete photobleaching after iPDT seem to be associated with favourable outcome. Real-time monitoring of PpIX fluorescence intensity and photobleaching turned out to be feasible and safe and might be employed for early treatment prognosis of iPDT.

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Section: Discussionmentioning

confidence: 99%

Protoporphyrin IX Fluorescence and Photobleaching During Interstitial Photodynamic Therapy of Malignant Gliomas for Early Treatment Prognosis

et al. 2013

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“…Hence, the selective uptake/retention of the photosensitizers provides the primary source for PDT treatment selectivity for GBM microinvasion within normal tissue. 36,[63][64][65] At a¯xed depth, d, beyond the bulk tumor resection, or distance from an interstitial light source with T t , T n , ½PS t , and ½PS n denoting the threshold values and photosensitizer concentrations for tumor and normal tissue respectively, selectivity requires the ratio of T t =½PS t to be smaller than the respective ratio of normal neuronal tissues.…”

Section: Pdt Dose De¯nition and Its Peculiarities In Gliomamentioning

confidence: 99%

“…For gliomas, some groups worked on physical approaches to treat a speci¯c CTV, such as interstitial PDT with image guided¯ber placement to deliver the minimum required photon density. 30,65 In small case studies, these groups have found some success in a limited number of patients. However, various reports showed that some tumors do not synthesize PpIX from exogenous ALA, 30 leading to insu±cient PpIX in the CTV.…”

Section: Modulating Pdt Response: Focusing On the Ps Accumulation Andmentioning

confidence: 99%

Photodynamic therapy in the treatment of intracranial gliomas: A review of current practice and considerations for future clinical directions

Fisher

Lilge

2015

J. Innov. Opt. Health Sci.

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Invasive grade III and IV malignant gliomas remain di±cult to treat with a typical survival time post-diagnosis hovering around 16 months with only minor extension thereof seen in the past decade, whereas some improvements have been obtained towards¯ve-year survival rates for which completeness of resection is a prerequisite. Optical techniques such as°uorescence guided resection (FGR) and photodynamic therapy (PDT) are promising adjuvant techniques to increase the tumor volume reduction fraction. PDT has been used in combination with surgical resection or alternatively as standalone treatment strategy with some success in extending the median survival time of patients compared to surgery alone and the current standard of care. This document reviews the outcome of past clinical trials and highlights the general shift in PDT therapeutic approaches. It also looks at the current approaches for interstitial PDT and research options into increasing PDT's glioma treatment e±cacy through exploiting both physical and biological-based approaches to maximize PDT selectivity and therapeutic index, particularly in brain adjacent to tumor (BAT). Potential reasons for failing to demonstrate a signi¯cant survival advantage in prior PDT clinical trials will become evident in light of the improved understanding of glioma biology and PDT dosimetry.

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“…Even then, Photofrin has been used in addition, obviously since the surgeons have not been trusting in a sufficient phototoxic potential of the accumulated PpIX from 5-ALA alone. Published clinical experience with PDT relying solely on 5-ALA is thus restricted to reports from our group [10][11][12][13][14] . In these trials and individual treatment attempts, PDT was applied by interstitial placement of radial diffusers and relying on the same or only slightly increased dosage of 5-ALA as usually used for FGR (see Materials and Methods).…”

Section: Introductionmentioning

confidence: 99%

“…Compared to attempting complete photobleaching, a precise light dosimetry would not be easily achievable with implanted diffusers, given the irregular and diffuse tumor borders. We have called the approach of simply attempting complete photobleaching "advanced photobleaching" 11 . The only requirement is to supply a minimum fluence (light dose) to the tumor cells receiving the lowest fluence rate, which is usually the case in between diffusers or in the infiltration zone.…”

Section: Introductionmentioning

confidence: 99%

5-ALA based photodynamic management of glioblastoma

et al. 2014

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Objective: Improvement of the clinical outcome of glioblastoma (GBM) patients by employment of fluorescence and photosensitization on the basis of 5-aminolevulinic acid (5-ALA) induced protoporphyrin IX (PpIX). Methods:In this report the focus is laid on the use of tumor selective PpIX fluorescence for stereotactic biopsy sampling and intra-operative treatment monitoring. In addition, our current concept for treatment planning is presented. For stereotactic interstitial photodynamic therapy (iPDT), radial diffusers were implanted into the contrast enhancing tumor volume. Spectroscopic measurements of laser light transmission and fluorescence between adjacent fibers were performed prior, during and post PDT. Results:PpIX concentrations in primary glioblastoma tissue show high intra-and inter-patient variability, but are usually sufficient for an effective PDT. During individual treatment attempts with 5-ALA based GBM-iPDT, transmission and fluorescence measurements between radial diffusers gave the following results: 1. In some cases, transmission after PDT is considerably reduced compared to the value before PDT, which may be attributable to a depletion of oxygenated hemoglobin and/or diffuse bleeding. 2. PpIX fluorescence is efficiently photobleached during PDT in all cases.Conclusion: iPDT with assessment of PpIX fluorescence and photobleaching is a promising treatment option. Individualization of treatment parameters appears to bear a potential to further improve clinical outcomes.

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Interstitial Photodynamic Therapy of Brain Tumors

Cited by 23 publications

References 99 publications

Protoporphyrin IX Fluorescence and Photobleaching During Interstitial Photodynamic Therapy of Malignant Gliomas for Early Treatment Prognosis

Protoporphyrin IX Fluorescence and Photobleaching During Interstitial Photodynamic Therapy of Malignant Gliomas for Early Treatment Prognosis

Photodynamic therapy in the treatment of intracranial gliomas: A review of current practice and considerations for future clinical directions

5-ALA based photodynamic management of glioblastoma

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