1
|
Aumiller M, Arazar A, Sroka R, Dietrich O, Rühm A. Investigations on correlations between changes of optical tissue properties and NMR relaxation times. Photodiagnosis Photodyn Ther 2024; 45:103968. [PMID: 38215958 DOI: 10.1016/j.pdpdt.2024.103968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 01/03/2024] [Accepted: 01/09/2024] [Indexed: 01/14/2024]
Abstract
BACKGROUND Accurate light dosimetry is a complex remaining challenge in interstitial photodynamic therapy (iPDT) for malignant gliomas. The light dosimetry should ideally be based on the tissue morphology and the individual optical tissue properties of each tissue type in the target region. First investigations are reported on using NMR information to estimate changes of individual optical tissue properties. METHODS Porcine brain tissue and optical tissue phantoms were investigated. To the porcine brain, supplements were added to simulate an edema or high blood content. The tissue phantoms were based on agar, Lipoveneous, ink, blood and gadobutrol (Gd-based MRI contrast agent). The concentrations of phantom ingredients and tissue additives are varied to compare concentration-dependent effects on optical and NMR properties. A 3-tesla whole-body MRI system was used to determine T1 and T2 relaxation times. Optical tissue properties, i.e., the spectrally resolved absorption and reduced scattering coefficient, were obtained using a single integrating sphere setup. The observed changes of NMR and optical properties were compared to each other. RESULTS By adjusting the NMR relaxation times and optical tissue properties of the tissue phantoms to literature values, recipes for human brain tumor, white matter and grey matter tissue phantoms were obtained that mimic these brain tissues simultaneously in both properties. For porcine brain tissue, it was observed that with increasing water concentration in the tissue, both NMR-relaxation times increased, while µa decreased and µs' increased at 635 nm. The addition of blood to porcine brain samples showed a constant T1, while T2 shortened and the absorption coefficient at 635 nm increased. CONCLUSIONS In this investigation, by changing sample contents, notable changes of both NMR relaxation times and optical tissue properties have been observed and their relations examined. The developed dual NMR/optical tissue phantoms can be used in iPDT research, clinical training and demonstrations.
Collapse
Affiliation(s)
- Maximilian Aumiller
- Laser-Forschungslabor, LIFE Center, LMU University Hospital, LMU Munich, Planegg 82152, Germany; Department of Urology, LMU University Hospital, LMU Munich, Munich 81377, Germany.
| | - Asmerom Arazar
- Laser-Forschungslabor, LIFE Center, LMU University Hospital, LMU Munich, Planegg 82152, Germany
| | - Ronald Sroka
- Laser-Forschungslabor, LIFE Center, LMU University Hospital, LMU Munich, Planegg 82152, Germany; Department of Urology, LMU University Hospital, LMU Munich, Munich 81377, Germany
| | - Olaf Dietrich
- Department of Radiology, LMU University Hospital, LMU Munich, Munich 81377, Germany
| | - Adrian Rühm
- Laser-Forschungslabor, LIFE Center, LMU University Hospital, LMU Munich, Planegg 82152, Germany; Department of Urology, LMU University Hospital, LMU Munich, Munich 81377, Germany
| |
Collapse
|
2
|
Kaniyala Melanthota S, Kistenev YV, Borisova E, Ivanov D, Zakharova O, Boyko A, Vrazhnov D, Gopal D, Chakrabarti S, K SP, Mazumder N. Types of spectroscopy and microscopy techniques for cancer diagnosis: a review. Lasers Med Sci 2022; 37:3067-3084. [PMID: 35834141 PMCID: PMC9525344 DOI: 10.1007/s10103-022-03610-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 07/05/2022] [Indexed: 11/25/2022]
Abstract
Cancer is a life-threatening disease that has claimed the lives of many people worldwide. With the current diagnostic methods, it is hard to determine cancer at an early stage, due to its versatile nature and lack of genomic biomarkers. The rapid development of biophotonics has emerged as a potential tool in cancer detection and diagnosis. Using the fluorescence, scattering, and absorption characteristics of cells and tissues, it is possible to detect cancer at an early stage. The diagnostic techniques addressed in this review are highly sensitive to the chemical and morphological changes in the cell and tissue during disease progression. These changes alter the fluorescence signal of the cell/tissue and are detected using spectroscopy and microscopy techniques including confocal and two-photon fluorescence (TPF). Further, second harmonic generation (SHG) microscopy reveals the morphological changes that occurred in non-centrosymmetric structures in the tissue, such as collagen. Again, Raman spectroscopy is a non-destructive method that provides a fingerprinting technique to differentiate benign and malignant tissue based on Raman signal. Photoacoustic microscopy and spectroscopy of tissue allow molecule-specific detection with high spatial resolution and penetration depth. In addition, terahertz spectroscopic studies reveal the variation of tissue water content during disease progression. In this review, we address the applications of spectroscopic and microscopic techniques for cancer detection based on the optical properties of the tissue. The discussed state-of-the-art techniques successfully determines malignancy to its rapid diagnosis.
Collapse
Affiliation(s)
- Sindhoora Kaniyala Melanthota
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Karnataka, 576104, Manipal, India
| | - Yury V Kistenev
- Laboratory of Biophotonics, Tomsk State University, Tomsk, 634050, Russia
- Central Research Laboratory, Siberian State Medical University, Tomsk, 634050, Russia
| | - Ekaterina Borisova
- Laboratory of Biophotonics, Institute of Electronics, Bulgarian Academy of Sciences, Tsarigradsko Chaussee Blvd, 72, 1784, Sofia, Bulgaria.
- Biology Faculty, Saratov State University, 83, Astrakhanskaya Str, 410012, Saratov, Russia.
| | - Deyan Ivanov
- Laboratory of Biophotonics, Institute of Electronics, Bulgarian Academy of Sciences, Tsarigradsko Chaussee Blvd, 72, 1784, Sofia, Bulgaria
| | - Olga Zakharova
- Laboratory of Biophotonics, Tomsk State University, Tomsk, 634050, Russia
| | - Andrey Boyko
- Laboratory of Biophotonics, Tomsk State University, Tomsk, 634050, Russia
| | - Denis Vrazhnov
- Laboratory of Biophotonics, Tomsk State University, Tomsk, 634050, Russia
| | - Dharshini Gopal
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Karnataka, 576104, Manipal, India
| | - Shweta Chakrabarti
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Karnataka, 576104, Manipal, India
| | - Shama Prasada K
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Karnataka, 576104, Manipal, India
| | - Nirmal Mazumder
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Karnataka, 576104, Manipal, India.
| |
Collapse
|
3
|
VİTHANAGE V, C.D. J, M.D.P. DE. C, RAJENDRAM S. Photodynamic Therapy : An Overview and Insights into a Prospective Mainstream Anticancer Therapy. JOURNAL OF THE TURKISH CHEMICAL SOCIETY, SECTION A: CHEMISTRY 2022. [DOI: 10.18596/jotcsa.1000980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Photodynamic therapy (PDT) procedure has minimum invasiveness in contrast to conventional anticancer surgical procedures. Although clinically approved a few decades ago, it is not commonly used due to its poor efficacy, mainly due to poor light penetration into deeper tissues. PDT uses a photosensitizer (PS), which is photoactivated on illumination by light of appropriate wavelength and oxygen in the tissue, leading to a series of photochemical reactions producing reactive oxygen species (ROS) triggering various mechanisms resulting in lethal effects on tumor cells. This review looks into the fundamental aspects of PDT, such as photochemistry, photobiological effects, and the current clinical applications in the light of improving PDT to become a mainstream therapeutic procedure against a broad spectrum of cancers and malignant lesions. The side effects of PDT, both early and late-onset, are elaborated on in detail to highlight the available options to minimize side effects without compromising therapeutic efficacy. This paper summarizes the benefits, drawbacks, and limitations of photodynamic therapy along with the recent attempts to achieve improved therapeutic efficacy via monitoring various cellular and molecular processes through fluorescent imagery aided by suitable biomarkers, prospective nanotechnology-based targeted delivery methods, the use of scintillating nanoparticles to deliver light to remote locations and also combining PDT with conventional anticancer therapies have opened up new dimensions for PDT in treating cancers. This review inquires and critically analyses prospective avenues in which a breakthrough would finally enable PDT to be integrated into mainstream anticancer therapy.
Collapse
|
4
|
Interrelation between Spectral Online Monitoring and Postoperative T1-Weighted MRI in Interstitial Photodynamic Therapy of Malignant Gliomas. Cancers (Basel) 2021; 14:cancers14010120. [PMID: 35008284 PMCID: PMC8749816 DOI: 10.3390/cancers14010120] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 12/24/2022] Open
Abstract
Simple Summary Treatment monitoring is highly important for the delivery and control of brain tumor therapy. For interstitial photodynamic therapy (iPDT), an intraoperative spectral online monitoring (SOM) setup was established in former studies to monitor photosensitizer fluorescence and treatment light transmission during therapy. In this work, data from patients treated with iPDT as the initial treatment for newly diagnosed glioblastoma (n = 11) were retrospectively analyzed. Observed changes in treatment light transmission were assessed, and changes in optical tissue absorption were calculated out of these. In addition, magnetic resonance imaging (MRI) data were recorded within 48 h after therapy and showed intrinsic T1 hyperintensity in the treated area in non-contrast-enhanced T1-weighted sequences. A 3D co-registration of intrinsic T1 hyperintensity lesions and the light transmission zones between cylindrical diffuser fiber pairs showed that reduction in treatment light transmission corresponding to increased light absorption had a spatial correlation with post-therapeutic intrinsic T1 hyperintensity (p ≤ 0.003). Abstract In a former study, interstitial photodynamic therapy (iPDT) was performed on patients suffering from newly diagnosed glioblastoma (n = 11; 8/3 male/female; median age: 68, range: 40–76). The procedure includes the application of 5-ALA to selectively metabolize protoporphyrin IX (PpIX) in tumor cells and illumination utilizing interstitially positioned optical cylindrical diffuser fibers (CDF) (2–10 CDFs, 2–3 cm diffusor length, 200 mW/cm, 635 nm, 60 min irradiation). Intraoperative spectral online monitoring (SOM) was employed to monitor treatment light transmission and PpIX fluorescence during iPDT. MRI was used for treatment planning and outcome assessment. Case-dependent observations included intraoperative reduction of treatment light transmission and local intrinsic T1 hyperintensity in non-contrast-enhanced T1-weighted MRI acquired within one day after iPDT. Intrinsic T1 hyperintensity was observed and found to be associated with the treatment volume, which indicates the presence of methemoglobin, possibly induced by iPDT. Based on SOM data, the optical absorption coefficient and its change during iPDT were estimated for the target tissue volumes interjacent between evaluable CDF-pairs at the treatment wavelength of 635 nm. By spatial comparison and statistical analysis, it was found that observed increases of the absorption coefficient during iPDT were larger in or near regions of intrinsic T1 hyperintensity (p = 0.003). In cases where PpIX-fluorescence was undetectable before iPDT, the increase in optical absorption and intrinsic T1 hyperintensity tended to be less. The observations are consistent with in vitro experiments and indicate PDT-induced deoxygenation of hemoglobin and methemoglobin formation. Further investigations are needed to provide more data on the time course of the observed changes, thus paving the way for optimized iPDT irradiation protocols.
Collapse
|
5
|
Komolibus K, Fisher C, Swartling J, Svanberg S, Svanberg K, Andersson-Engels S. Perspectives on interstitial photodynamic therapy for malignant tumors. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210111-PERR. [PMID: 34302323 PMCID: PMC8299827 DOI: 10.1117/1.jbo.26.7.070604] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 07/08/2021] [Indexed: 05/17/2023]
Abstract
SIGNIFICANCE Despite remarkable advances in the core modalities used in combating cancer, malignant diseases remain the second largest cause of death globally. Interstitial photodynamic therapy (IPDT) has emerged as an alternative approach for the treatment of solid tumors. AIM The aim of our study is to outline the advancements in IPDT in recent years and provide our vision for the inclusion of IPDT in standard-of-care (SoC) treatment guidelines of specific malignant diseases. APPROACH First, the SoC treatment for solid tumors is described, and the attractive properties of IPDT are presented. Second, the application of IPDT for selected types of tumors is discussed. Finally, future opportunities are considered. RESULTS Strong research efforts in academic, clinical, and industrial settings have led to significant improvements in the current implementation of IPDT, and these studies have demonstrated the unique advantages of this modality for the treatment of solid tumors. It is envisioned that further randomized prospective clinical trials and treatment optimization will enable a wide acceptance of IPDT in the clinical community and inclusion in SoC guidelines for well-defined clinical indications. CONCLUSIONS The minimally invasive nature of this treatment modality combined with the relatively mild side effects makes IPDT a compelling alternative option for treatment in a number of clinical applications. The adaptability of this technique provides many opportunities to both optimize and personalize the treatment.
Collapse
Affiliation(s)
- Katarzyna Komolibus
- Tyndall National Institute, Biophotonics@Tyndall, IPIC, Cork, Ireland
- Address all correspondence to Katarzyna Komolibus,
| | - Carl Fisher
- Tyndall National Institute, Biophotonics@Tyndall, IPIC, Cork, Ireland
| | | | - Sune Svanberg
- Lund University, Department of Physics, Lund, Sweden
- South China Normal University, South China Academy of Advanced Optoelectronics, Guangzhou, China
| | - Katarina Svanberg
- South China Normal University, South China Academy of Advanced Optoelectronics, Guangzhou, China
- Lund University Hospital, Department of Clinical Sciences, Lund, Sweden
| | - Stefan Andersson-Engels
- Tyndall National Institute, Biophotonics@Tyndall, IPIC, Cork, Ireland
- University College Cork, Department of Physics, Cork, Ireland
| |
Collapse
|
6
|
Garcia MR, Requena MB, Pratavieira S, Moriyama LT, Becker M, Bagnato VS, Kurachi C, Magalhães DV. Development of a system to treat and online monitor photodynamic therapy of skin cancer using PpIX near-infrared fluorescence. Photodiagnosis Photodyn Ther 2020; 30:101680. [DOI: 10.1016/j.pdpdt.2020.101680] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 01/15/2020] [Accepted: 01/27/2020] [Indexed: 11/28/2022]
|
7
|
Buzalewicz I, Hołowacz I, Ulatowska-Jarża A, Podbielska H. Towards dosimetry for photodynamic diagnosis with the low-level dose of photosensitizer. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017. [PMID: 28641204 DOI: 10.1016/j.jphotobiol.2017.06.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Contemporary medicine does not concern the issue of dosimetry in photodynamic diagnosis (PDD) but follows the photosensitizer (PS) producers recommendation. Most preclinical and clinical PDD studies indicate a considerable variation in the possibility of visualization and treatment, as e.g. in case of cervix lesions. Although some of these variations can be caused by the different histological subtypes or various tumor geometries, the issue of varying PS concentration in the tumor tissue volume is definitely an important factor. Therefore, there is a need to establish the objective and systematic PDD dosimetry protocol regarding doses of light and photosensitizers. METHODS Four different irradiation sources investigated in PDD (literature) were used for PS excitation. The PS luminescence was examined by means of the non-imaging (spectroscopic) and imaging (wide- and narrow-field of view) techniques. The methodology for low-level intensity photoluminescence (PL) characterization and dedicated image processing algorithm for PS luminescence images analysis were proposed. Further, HeLa cells' cultures penetration by PS was studied by a confocal microscopy. RESULTS Reducing the PS dose with the choice of proper photoexcitation conditions decreases the PDD procedure costs and the side effects, not affecting the diagnostic efficiency. We determined in vitro the minimum incubation time and photosensitizer concentration of Photolon for diagnostic purposes, for which the Photolon PL can still be observed. It was demonstrated that quantification of PS concentration, choice of proper photoexcitation source, appropriate adjustment of light dose and PS penetration of cancer cells may improve the low-level luminescence photodynamic diagnostics performance. CONCLUSIONS Practical effectiveness of the PDD strongly depends on irradiation source parameters (bandwidth, maximum intensity, half-width) and their optimization is the main conditioning factor for low-level intensity and low-cost PDD.
Collapse
Affiliation(s)
- Igor Buzalewicz
- Bio-Optics Group, Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 27 Wybrzeze Wyspianskiego St., 50-370 Wroclaw, Poland.
| | - Iwona Hołowacz
- Bio-Optics Group, Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 27 Wybrzeze Wyspianskiego St., 50-370 Wroclaw, Poland
| | - Agnieszka Ulatowska-Jarża
- Bio-Optics Group, Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 27 Wybrzeze Wyspianskiego St., 50-370 Wroclaw, Poland
| | - Halina Podbielska
- Bio-Optics Group, Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 27 Wybrzeze Wyspianskiego St., 50-370 Wroclaw, Poland
| |
Collapse
|
8
|
Protti S, Albini A, Viswanathan R, Greer A. Targeting Photochemical Scalpels or Lancets in the Photodynamic Therapy Field—The Photochemist's Role. Photochem Photobiol 2017; 93:1139-1153. [DOI: 10.1111/php.12766] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 02/20/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Stefano Protti
- PhotoGreen Lab Department of Chemistry University of Pavia Pavia Italy
| | - Angelo Albini
- PhotoGreen Lab Department of Chemistry University of Pavia Pavia Italy
| | | | - Alexander Greer
- Department of Chemistry Brooklyn College Brooklyn NY
- Ph.D. Program in Chemistry The Graduate Center of the City University of New York New York City NY
| |
Collapse
|
9
|
Baran TM. Recovery of optical properties using interstitial cylindrical diffusers as source and detector fibers. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:77001. [PMID: 27447954 PMCID: PMC4956772 DOI: 10.1117/1.jbo.21.7.077001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/07/2016] [Indexed: 05/26/2023]
Abstract
We demonstrate recovery of optical properties using arrays of interstitial cylindrical diffusing fibers as sources and detectors. A single 1-cm diffuser delivered laser illumination at 665 nm, while seven 1- and 2-cm diffusers at 1-cm grid spacing acted as detectors. Extraction of optical properties from these measurements was based upon a diffusion model of emission and detection distributions for these diffuser fibers, informed by previous measurements of heterogeneous axial detection. Verification of the technique was performed in 15 liquid tissue-simulating phantoms consisting of deionized water, India ink as absorber, and Intralipid 20% as scatterer. For the range of optical properties tested, mean errors were 4.4% for effective attenuation coefficient, 12.6% for absorption coefficient, and 7.6% for reduced scattering coefficient. Error in recovery tended to increase with decreasing transport albedo. For therapeutic techniques involving the delivery of light to locations deep within the body, such as interstitial photodynamic and photothermal therapies, the methods described here would allow the treatment diffuser fibers also to be used as sources and detectors for recovery of optical properties. This would eliminate the need for separately inserted fibers for spectroscopy, reducing clinical complexity and improving the accuracy of treatment planning.
Collapse
Affiliation(s)
- Timothy M. Baran
- University of Rochester Medical Center, Department of Imaging Sciences, 601 Elmwood Avenue, Box 648, Rochester, New York 14642, United States
| |
Collapse
|
10
|
Wang P, Qin F, Zhang Z, Cao W. Quantitative monitoring of the level of singlet oxygen using luminescence spectra of phosphorescent photosensitizer. OPTICS EXPRESS 2015; 23:22991-3003. [PMID: 26368404 DOI: 10.1364/oe.23.022991] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The lack of accurate and robust photodynamic therapy dosimetry is one of the obstacles for the widespread clinical applications. In this study, we propose a methodology to monitor the production of reactive oxygen species in real-time using the phosphorescent spectra of metalloporphyrin based photosensitizer. The correlation among the phosphorescence intensity, the (1)O(2) quantum yield (Φ(Δ)) and the oxygen concentration [O(2)] was established. A method of determining Φ(Δ) with different [O(2)] was studied based on comparative spectrophotometry, and the quantum yield Φ(Δ) of gadolinium metalated hematoporphyrin mono ether (Gd-HMME) in methanol was determined for different [O(2)]. With our method, both [O(2)] and Φ(Δ) could be monitored simultaneously using the phosphorescence spectra. The photochemical reactions in a liquid phantom composed of Gd-HMME and (1)O(2) capture 1,3-diphenylisobenzofuran (DPBF) were correlated using the kinetics equations of singlet oxygen generation and reaction. Using our method, the (1)O(2) quantum yield becomes observable and the (1)O(2) dose rate could be calculated by the product of photosensitizer absorption and its (1)O(2) quantum yield. Moreover, this (1)O(2) dosimetry could be observed by spectral imaging intuitively without complex analysis, and is especially suitable for precise customized photodynamic treatment.
Collapse
|
11
|
Gallagher-Colombo SM, Quon H, Malloy KM, Ahn PH, Cengel KA, Simone CB, Chalian AA, O'Malley BW, Weinstein GS, Zhu TC, Putt ME, Finlay JC, Busch TM. Measuring the Physiologic Properties of Oral Lesions Receiving Fractionated Photodynamic Therapy. Photochem Photobiol 2015; 91:1210-8. [PMID: 26037487 DOI: 10.1111/php.12475] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 05/26/2015] [Indexed: 11/28/2022]
Abstract
Photodynamic therapy (PDT) can treat superficial, early-stage disease with minimal damage to underlying tissues and without cumulative dose-limiting toxicity. Treatment efficacy is affected by disease physiologic properties, but these properties are not routinely measured. We assessed diffuse reflectance spectroscopy (DRS) for the noninvasive, contact measurement of tissue hemoglobin oxygen saturation (St O2 ) and total hemoglobin concentration ([tHb]) in the premalignant or superficial microinvasive oral lesions of patients treated with 5-aminolevulinic acid (ALA)-PDT. Patients were enrolled on a Phase 1 study of ALA-PDT that evaluated fluences of 50, 100, 150 or 200 J cm(-2) delivered at 100 mW cm(-2) . To test the feasibility of incorporating DRS measurements within the illumination period, studies were performed in patients who received fractionated (two-part) illumination that included a dark interval of 90-180 s. Using DRS, tissue oxygenation at different depths within the lesion could also be assessed. DRS could be performed concurrently with contact measurements of photosensitizer levels by fluorescence spectroscopy, but a separate noncontact fluorescence spectroscopy system provided continuous assessment of photobleaching during illumination to greater tissue depths. Results establish that the integration of DRS into PDT of early-stage oral disease is feasible, and motivates further studies to evaluate its predictive and dosimetric value.
Collapse
Affiliation(s)
| | - Harry Quon
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Kelly M Malloy
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Peter H Ahn
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Keith A Cengel
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Charles B Simone
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ara A Chalian
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Bert W O'Malley
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Gregory S Weinstein
- Department of Otorhinolaryngology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Timothy C Zhu
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Mary E Putt
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Jarod C Finlay
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Theresa M Busch
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
12
|
Baran TM, Foster TH. Comparison of flat cleaved and cylindrical diffusing fibers as treatment sources for interstitial photodynamic therapy. Med Phys 2014; 41:022701. [PMID: 24506647 DOI: 10.1118/1.4862078] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
PURPOSE For interstitial photodynamic therapy (iPDT) of bulky tumors, careful treatment planning is required in order to ensure that a therapeutic dose is delivered to the tumor, while minimizing damage to surrounding normal tissue. In clinical contexts, iPDT has typically been performed with either flat cleaved or cylindrical diffusing optical fibers as light sources. Here, the authors directly compare these two source geometries in terms of the number of fibers and duration of treatment required to deliver a prescribed light dose to a tumor volume. METHODS Treatment planning software for iPDT was developed based on graphics processing unit enhanced Monte Carlo simulations. This software was used to optimize the number of fibers, total energy delivered by each fiber, and the position of individual fibers in order to deliver a target light dose (D90) to 90% of the tumor volume. Treatment plans were developed using both flat cleaved and cylindrical diffusing fibers, based on tissue volumes derived from CT data from a head and neck cancer patient. Plans were created for four cases: fixed energy per fiber, fixed number of fibers, and in cases where both or neither of these factors were fixed. RESULTS When the number of source fibers was fixed at eight, treatment plans based on flat cleaved fibers required each to deliver 7180-8080 J in order to deposit 90 J/cm(2) in 90% of the tumor volume. For diffusers, each fiber was required to deliver 2270-2350 J (333-1178 J/cm) in order to achieve this same result. For the case of fibers delivering a fixed 900 J, 13 diffusers or 19 flat cleaved fibers at a spacing of 1 cm were required to deliver the desired dose. With energy per fiber fixed at 2400 J and the number of fibers fixed at eight, diffuser fibers delivered the desired dose to 93% of the tumor volume, while flat cleaved fibers delivered this dose to 79%. With both energy and number of fibers allowed to vary, six diffusers delivering 3485-3600 J were required, compared to ten flat cleaved fibers delivering 2780-3600 J. CONCLUSIONS For the same number of fibers, cylindrical diffusers allow for a shorter treatment duration compared to flat cleaved fibers. For the same energy delivered per fiber, diffusers allow for the insertion of fewer fibers in order to deliver the same light dose to a target volume.
Collapse
Affiliation(s)
- Timothy M Baran
- Department of Imaging Sciences, University of Rochester, Rochester, New York 14642
| | - Thomas H Foster
- Department of Imaging Sciences, University of Rochester, Rochester, New York 14642
| |
Collapse
|
13
|
Karakullukcu B, van Veen RLP, Aans JB, Hamming-Vrieze O, Navran A, Teertstra HJ, van den Boom F, Niatsetski Y, Sterenborg HJCM, Tan IB. MR and CT based treatment planning for mTHPC mediated interstitial photodynamic therapy of head and neck cancer: description of the method. Lasers Surg Med 2013; 45:517-23. [PMID: 24037957 DOI: 10.1002/lsm.22174] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2013] [Indexed: 12/18/2022]
Abstract
BACKGROUND AND OBJECTIVE Interstitial photodynamic therapy is a potentially important tool in the management of voluminous or deep-seated recurrent head and neck cancers. STUDY DESIGN/METHODS The described treatment algorithm in this manuscript consists of the treatment simulation, implantation of light sources, verification, modification of the treatment plan if necessary, and illumination. The tumor is delineated on imaging sections (CT, MRI, and/or PET/CT) and the treatment is simulated by virtually introducing light sources to the tumor volume on specially modified brachytherapy software. This enables us to determine if the treatment is technically feasible, and information about approximate number and location of light sources necessary. Following implantation of catheters in which the light sources will be introduced, CT or MR scan is performed to verify the actual location of the implanted catheters. The verification-CT is imported to the software and co-registered with pre-treatment images to observe the deviations from the simulation. The simulation is run again with the actual position of the light sources to determine if any additional light sources are necessary and adaptation of the source length in order to cover the tumor volume (modification). Thereafter the tumor is illuminated. RESULTS This method has the potential to help with identifying iPDT feasible patients by simulating before the actual treatment. The suboptimal placement of light sources can be identified and corrected. The simulations were documented and saved for subsequent evaluation of the technique. CONCLUSION The proposed technique can help standardize and document iPDT.
Collapse
Affiliation(s)
- Baris Karakullukcu
- Department of Head and Neck Oncology and Surgery, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Liang X, Wang KKH, Zhu TC. Feasibility of interstitial diffuse optical tomography using cylindrical diffusing fibers for prostate PDT. Phys Med Biol 2013; 58:3461-80. [PMID: 23629149 DOI: 10.1088/0031-9155/58/10/3461] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Interstitial diffuse optical tomography (DOT) has been used to characterize spatial distribution of optical properties for prostate photodynamic therapy (PDT) dosimetry. We have developed an interstitial DOT method using cylindrical diffuse fibers (CDFs) as light sources, so that the same light sources can be used for both DOT measurement and PDT treatment. In this novel interstitial CDF-DOT method, absolute light fluence per source strength (in unit of 1 cm(-2)) is used to separate absorption and scattering coefficients. A mathematical phantom and a solid prostate phantom including anomalies with known optical properties were used, respectively, to test the feasibility of reconstructing optical properties using interstitial CDF-DOT. Three dimension spatial distributions of the optical properties were reconstructed for both scenarios. Our studies show that absorption coefficient can be reliably extrapolated while there are some cross talks between absorption and scattering properties. Even with the suboptimal reduced scattering coefficients, the reconstructed light fluence rate agreed with the measured values to within ±10%, thus the proposed CDF-DOT allows greatly improved light dosimetry calculation for interstitial PDT.
Collapse
Affiliation(s)
- Xing Liang
- Department of Radiation Oncology, School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, PA 19104, USA
| | | | | |
Collapse
|
15
|
Yi WS, Cui DS, Li Z, Wu LL, Shen AG, Hu JM. Gastric cancer differentiation using Fourier transform near-infrared spectroscopy with unsupervised pattern recognition. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 101:127-131. [PMID: 23099170 DOI: 10.1016/j.saa.2012.09.037] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 09/08/2012] [Accepted: 09/16/2012] [Indexed: 06/01/2023]
Abstract
The manuscript has investigated the application of near-infrared (NIR) spectroscopy for differentiation gastric cancer. The 90 spectra from cancerous and normal tissues were collected from a total of 30 surgical specimens using Fourier transform near-infrared spectroscopy (FT-NIR) equipped with a fiber-optic probe. Major spectral differences were observed in the CH-stretching second overtone (9000-7000 cm(-1)), CH-stretching first overtone (6000-5200 cm(-1)), and CH-stretching combination (4500-4000 cm(-1)) regions. By use of unsupervised pattern recognition, such as principal component analysis (PCA) and cluster analysis (CA), all spectra were classified into cancerous and normal tissue groups with accuracy up to 81.1%. The sensitivity and specificity was 100% and 68.2%, respectively. These present results indicate that CH-stretching first, combination band and second overtone regions can serve as diagnostic markers for gastric cancer.
Collapse
Affiliation(s)
- Wei-song Yi
- College of Chemistry and Molecular Sciences, Wuhan University, and Gastric & Intestine Department, Hubei Cancer Hospital, Wuhan 430072, PR China
| | | | | | | | | | | |
Collapse
|
16
|
Wei Y, Song J, Chen Q, Xing D. Enhancement of photodynamic antitumor effect with pro-oxidant ascorbate. Lasers Surg Med 2012; 44:69-75. [DOI: 10.1002/lsm.21157] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2011] [Indexed: 12/11/2022]
|
17
|
Sandell JL, Zhu TC. A review of in-vivo optical properties of human tissues and its impact on PDT. JOURNAL OF BIOPHOTONICS 2011; 4:773-87. [PMID: 22167862 PMCID: PMC3321368 DOI: 10.1002/jbio.201100062] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
A thorough understanding of optical properties of biological tissues is critical to effective treatment planning for therapies such as photodynamic therapy (PDT). In the last two decades, new technologies, such as broadband diffuse spectroscopy, have been developed to obtain in vivo data in humans that was not possible before. We found that the in vivo optical properties generally vary in the ranges μ(a) = 0.03-1.6 cm⁻¹ and μ'(s) = 1.2-40 cm⁻¹, although the actual range is tissue-type dependent. We have also examined the overall trend of the absorption spectra (for μ(a) and μ'(s)) as a function of wavelength within a 95% confidence interval for various tissues in vivo. The impact of optical properties on light fluence rate is also discussed for various light application geometries including superficial, interstitial, and within a cavity.
Collapse
Affiliation(s)
- Julia L. Sandell
- Department of Radiation Oncology. University of Pennsylvania, Philadelphia, PA 19104
| | - Timothy C. Zhu
- Department of Radiation Oncology. University of Pennsylvania, Philadelphia, PA 19104
| |
Collapse
|
18
|
Valentine RM, Brown CTA, Moseley H, Ibbotson S, Wood K. Monte Carlo modeling of in vivo protoporphyrin IX fluorescence and singlet oxygen production during photodynamic therapy for patients presenting with superficial basal cell carcinomas. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:048002. [PMID: 21529097 DOI: 10.1117/1.3562540] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present protoporphyrin IX (PpIX) fluorescence measurements acquired from patients presenting with superficial basal cell carcinoma during photodynamic therapy (PDT) treatment, facilitating in vivo photobleaching to be monitored. Monte Carlo (MC) simulations, taking into account photobleaching, are performed on a three-dimensional cube grid, which represents the treatment geometry. Consequently, it is possible to determine the spatial and temporal changes to the origin of collected fluorescence and generated singlet oxygen. From our clinical results, an in vivo photobleaching dose constant, β of 5-aminolaevulinic acid-induced PpIX fluorescence is found to be 14 ± 1 J/cm(2). Results from our MC simulations suggest that an increase from our typical administered treatment light dose of 75-150 J/cm(2) could increase the effective PDT treatment initially achieved at a depth of 2.7-3.3 mm in the tumor, respectively. Moreover, this increase reduces the surface PpIX fluorescence from 0.00012 to 0.000003 of the maximum value recorded before treatment. The recommendation of administrating a larger light dose, which advocates an increase in the treatment time after surface PpIX fluorescence has diminished, remains valid for different sets of optical properties and therefore should have a beneficial outcome on the total treatment effect.
Collapse
Affiliation(s)
- Ronan M Valentine
- University of St. Andrews, School of Physics and Astronomy, North Haugh, St Andrews, Fife KY16 9SS, United Kingdom
| | | | | | | | | |
Collapse
|
19
|
Wei Y, Song J, Chen Q. In vivo detection of chemiluminescence to monitor photodynamic threshold dose for tumor treatment. Photochem Photobiol Sci 2011; 10:1066-71. [DOI: 10.1039/c0pp00346h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
20
|
Svanberg K, Bendsoe N, Axelsson J, Andersson-Engels S, Svanberg S. Photodynamic therapy: superficial and interstitial illumination. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:041502. [PMID: 20799780 DOI: 10.1117/1.3466579] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Photodynamic therapy (PDT) is reviewed using the treatment of skin tumors as an example of superficial lesions and prostate cancer as an example of deep-lying lesions requiring interstitial intervention. These two applications are among the most commonly studied in oncological PDT, and illustrate well the different challenges facing the two modalities of PDT-superficial and interstitial. They thus serve as good examples to illustrate the entire field of PDT in oncology. PDT is discussed based on the Lund University group's over 20 yr of experience in the field. In particular, the interplay between optical diagnostics and dosimetry and the delivery of the therapeutic light dose are highlighted. An interactive multiple-fiber interstitial procedure to deliver the required therapeutic dose based on the assessment of light fluence rate and sensitizer concentration and oxygen level throughout the tumor is presented.
Collapse
|
21
|
Wang Y, Gu Y, Liao X, Chen R, Ding H. Fluorescence monitoring of a photosensitizer and prediction of the therapeutic effect of photodynamic therapy for port wine stains. Exp Biol Med (Maywood) 2010; 235:175-80. [PMID: 20404032 DOI: 10.1258/ebm.2009.009294] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this study, a fluorescence method was established to obtain the local concentration of a photosensitizer (PS) based on the realtime fluorescence measurement of skin with port wine stain (PWS) during photodynamic therapy (PDT). This algorithm corrected for the distortions of PS fluorescence spectra imposed by the absorption of melanin and hemoglobin in skin and other factors, which yields a semi-quantitative measurement of PS concentration. Based on this information, a therapeutic effect correlation index (TECI) was proposed as the area under the PS concentration-time curve during PDT. The correlation between TECI and PDT treatment outcome was analyzed from 31 PWS patients. The measured PS fluorescence spectra showed that under the same PS dose, there were clear variations in the concentrations of the PS during PDT. Statistical analysis showed that TECI has a positive correlation with PDT outcome. Patients with a higher TECI value had a better treatment outcome. These results suggest that fluorescence spectroscopy can be used in situ to monitor skin PS concentration during PDT and to provide a valuable diagnostic tool to predict PDT outcome.
Collapse
Affiliation(s)
- Ying Wang
- Department of Laser Medicine, Chinese People's Liberation Army General Hospital, Beijing 100853, China.
| | | | | | | | | |
Collapse
|
22
|
Kruijt B, van der Ploeg-van den Heuvel A, de Bruijn HS, Sterenborg HJCM, Amelink A, Robinson DJ. Monitoring interstitial m-THPC-PDT in vivo using fluorescence and reflectance spectroscopy. Lasers Surg Med 2010; 41:653-64. [PMID: 19802884 DOI: 10.1002/lsm.20845] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND AND OBJECTIVE In order to understand the mechanisms of photodynamic therapy (PDT) it is important to monitor parameters during illumination that yield information on deposited PDT dose. The aim of this study is to investigate the possibility of monitoring implicit parameters, such as photobleaching, in addition to monitoring explicit parameters (fluence (rate), oxygenation, photosensitizer concentration) directly or indirectly. These parameters are monitored during PDT without interrupting the therapeutic illumination. MATERIALS AND METHODS Rats were injected with 0.3 mg kg(-1) m-THPC. Sixteen hours after administration the abdominal muscle in rats was irradiated for 1,500 seconds using clinically relevant fluence rates of 50, 100, and 250 mW cm(-1) of diffuser length at 652 nm. In addition to the linear diffuser for delivering treatment light, isotropic fiber-optic probes and fiber-optic probes for differential path-length spectroscopy (DPS) were placed on both sides of the muscle to monitor tissue physiological parameters, fluence rate, and fluorescence. RESULTS The m-THPC treatment groups show a decrease in fluence rate throughout PDT of 16%, 19%, and 27% for the 50, 100, and 250 mW cm(-1) groups, respectively. Both during and post-PDT differences in vascular response between treatment groups and animals within the same treatment group are observed. Furthermore we show fluence rate dependent bleaching of m-THPC up to a measured fluence rate of 100 mW cm(-1). CONCLUSION The data presented in this study show the possibility of simultaneously monitoring fluence (rate), fluorescence, hemoglobin oxygen saturation, and blood volume during PDT without interruptions to the therapeutic illumination. Differences in saturation profiles between animals and treatment groups indicate differences in vascular response during illumination. Furthermore, the relationship between fluence rate and m-THPC fluorescence photobleaching is complex in an interstitial environment.
Collapse
Affiliation(s)
- Bastiaan Kruijt
- Center for Optical Diagnostics and Therapy, Department of Radiation Oncology, Erasmus MC, Rotterdam, The Netherlands
| | | | | | | | | | | |
Collapse
|
23
|
|
24
|
Kruijt B, de Bruijn HS, van der Ploeg-van den Heuvel A, de Bruin RWF, Sterenborg HJCM, Amelink A, Robinson DJ. Monitoring ALA-induced PpIX photodynamic therapy in the rat esophagus using fluorescence and reflectance spectroscopy. Photochem Photobiol 2008; 84:1515-27. [PMID: 18557821 DOI: 10.1111/j.1751-1097.2008.00379.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The presence of phased protoporphyrin IX (PpIX) bleach kinetics has been shown to correlate with esophageal response to 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) in animal models. Here we confirm the existence of phased PpIX photobleaching by increasing the temporal resolution of the fluorescence measurements using the therapeutic illumination and long wavelength fluorescence detection. Furthermore fluorescence differential pathlength spectroscopy (FDPS) was incorporated to provide information on the effects of PpIX and tissue oxygenation distribution on the PpIX bleach kinetics during illumination. ALA at a dose of 200 mg kg(-1) was orally administered to 15 rats, five rats served as control animals. PDT was performed at an in situ measured fluence rate of 75 mW cm(-2) using a total fluence of 54 J cm(-2). Forty-eight hours after PDT the esophagus was excised and histologically examined for PDT-induced damage. Fluence rate and PpIX photobleaching at 705 nm were monitored during therapeutic illumination with the same isotropic probe. A new method, FDPS, was used for superficial measurement on saturation, blood volume, scattering characteristics and PpIX fluorescence. Results showed two-phased PpIX photobleaching that was not related to a (systematic) change in esophageal oxygenation but was associated with an increase in average blood volume. PpIX fluorescence photobleaching measured using FDPS, in which fluorescence signals are only acquired from the superficial layers of the esophagus, showed lower rates of photobleaching and no distinct phases. No clear correlation between two-phased photobleaching and histologic tissue response was found. This study demonstrates the feasibility of measuring fluence rate, PpIX fluorescence and FDPS during PDT in the esophagus. We conclude that the spatial distribution of PpIX significantly influences the kinetics of photobleaching and that there is a complex interrelationship between the distribution of PpIX and the supply of oxygen to the illuminated tissue volume.
Collapse
Affiliation(s)
- Bastiaan Kruijt
- Department of Radiation Oncology, Centre for Optical Diagnostics and Therapy, Erasmus MC, Rotterdam, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
25
|
Kondepati VR, Heise HM, Backhaus J. Recent applications of near-infrared spectroscopy in cancer diagnosis and therapy. Anal Bioanal Chem 2007; 390:125-39. [DOI: 10.1007/s00216-007-1651-y] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Revised: 08/22/2007] [Accepted: 09/21/2007] [Indexed: 11/29/2022]
|
26
|
Johansson A, Axelsson J, Andersson-Engels S, Swartling J. Realtime light dosimetry software tools for interstitial photodynamic therapy of the human prostate. Med Phys 2007; 34:4309-21. [DOI: 10.1118/1.2790585] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
27
|
Woodhams JH, Macrobert AJ, Bown SG. The role of oxygen monitoring during photodynamic therapy and its potential for treatment dosimetry. Photochem Photobiol Sci 2007; 6:1246-56. [PMID: 18046479 DOI: 10.1039/b709644e] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Understanding of the biology of photodynamic therapy (PDT) has expanded tremendously over the past few years. However, in the clinical situation, it is still a challenge to match the extent of PDT effects to the extent of the disease process being treated. PDT requires drug, light and oxygen, any of which can be the limiting factor in determining efficacy at each point in a target organ. This article reviews techniques available for monitoring tissue oxygenation during PDT. Point measurements can be made using oxygen electrodes or luminescence-based optodes for direct measurements of tissue pO2, or using optical spectroscopy for measuring the oxygen saturation of haemoglobin. Imaging is considerably more complex, but may become feasible with techniques like BOLD MRI. Pre-clinical studies have shown dramatic changes in oxygenation during PDT, which vary with the photosensitizer used and the light delivery regimen. Better oxygenation throughout treatment is achieved if the light fluence rate is kept low as this reduces the rate of oxygen consumption. The relationship between tissue oxygenation and PDT effect is complex and remarkably few studies have directly correlated oxygenation changes during PDT with the final biological effect, although those that have confirm the value of maintaining good oxygenation. Real time monitoring to ensure adequate oxygenation at strategic points in target tissues during PDT is likely to be important, particularly in the image guided treatment of tumours of solid organs.
Collapse
Affiliation(s)
- Josephine H Woodhams
- National Medical Laser Centre, Royal Free and University College Medical School, University College London, Charles Bell House, 67-73 Riding House Street, London, UKW1W 7EJ
| | | | | |
Collapse
|
28
|
Svensson T, Andersson-Engels S, Einarsdóttír M, Svanberg K. In vivo optical characterization of human prostate tissue using near-infrared time-resolved spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2007; 12:014022. [PMID: 17343497 DOI: 10.1117/1.2435175] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
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 (mu(s)'), absorption coefficients (mu(a)), and effective attenuation (mu(eff)) at the wavelengths 660, 786, and 916 nm. At 660 nm, mu(s)' is found to be 9+/-2 cm(-1), and mu(a) is 0.5+/-0.1 cm(-1). Derived values of mu(eff) are in the range of 3 to 4 cm(-1) at 660 nm, a result in good agreement with previously published steady state data. Total hemoglobin concentration (THC) and oxygen saturation are spectroscopically determined using derived absorption coefficients. Derived THC values are fairly variable (215+/-65 microM), while derived values of oxygen saturation are gathered around 75% (76+/-4%). Intrasubject variations in derived parameters correlate (qualitatively) with the heterogeneity exhibited in acquired ultrasound images.
Collapse
Affiliation(s)
- Tomas Svensson
- Lund University, Department of Physics, SE-221 00 Lund, Sweden.
| | | | | | | |
Collapse
|
29
|
Influence of treatment-induced changes in tissue absorption on treatment volume during interstitial photodynamic therapy. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.mla.2006.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|