The physics, biophysics and technology of photodynamic therapy

Wilson, Brian C.; Patterson, Michael S.

doi:10.1088/0031-9155/53/9/r01

Cited by 896 publications

(707 citation statements)

References 180 publications

Supporting

Mentioning

657

Contrasting

Unclassified

Order By: Relevance

“…Owing to the localization of verteporfin to the retinal and choroidal vasculature, the effects of the PDT are theoretically localized to these vessels as well as the immediate surrounding tissue. 106 …”

Section: Photochemical Damagementioning

confidence: 99%

Retinal light toxicity

Youssef

Sheibani

Albert

2010

Eye

274

204

View full text Add to dashboard Cite

The ability of light to enact damage on the neurosensory retina and underlying structures has been well understood for hundreds of years. While the eye has adapted several mechanisms to protect itself from such damage, certain exposures to light can still result in temporal or permanent damage. Both clinical observations and laboratory studies have enabled us to understand the various ways by which the eye can protect itself from such damage. Light or electromagnetic radiation can result in damage through photothermal, photomechanical, and photochemical mechanisms. The following review seeks to describe these various processes of injury and many of the variables, which can mitigate these modes of injury.

show abstract

Section: Photochemical Damagementioning

confidence: 99%

Retinal light toxicity

Youssef

Sheibani

Albert

2010

Eye

274

204

View full text Add to dashboard Cite

show abstract

“…PDT PSs often lack selectivity towards neoplastic tissues, which may lead to the generation of reactive oxygen species and cellular damage (burns, swelling, pain) in surrounding healthy tissues upon excitation [14,17,28,29]. The highly localized nature of PDT makes it mostly unsuitable for the treatment of metastases [5].…”

Section: Please Provide Corresponding Author(s) Photographmentioning

confidence: 99%

“…Type III PSs are usually Antioxidant Carrier Sensitizers (ACS), also called Modified Type I (MTO) PSs, which combine properties leading to the efficient generation of singlet oxygen and decreasing the concentration of native free radicals in malignant cells. ACS are usually synthesized from the molecular backbone of originally active PSs used in clinical PDT, such as substituted porphyrin derivatives [5,10,15,17,19,24,26,28,29,[40][41][42][43][44]. Currently novel types of pro-drugs such as combretastatins, discussed fully in section 4.4, are emerging which can be directly photo- activated by multiphoton excitation without the need for the presence of oxygen within the target tissue (see the section on Alternative Strategy for Two-photon Phototherapy (2P-PDT) without ROS below).…”

Section: Photochemistry Of Photosensitizersmentioning

confidence: 99%

“…Unfortunately the longer the wavelength of the excitation light the lower is its energy (photon energy), which restricts its potential to excite a one-photon process due to molecular systems lacking optical absorption on going from the red to nearinfrared wavelengths. A way around this is the use of twophoton (or multiphoton) excitation (2PE), achieved by using a femtosecond pulsed Titanium:sapphire laser with high peak powers (Figure 4) [4,5,16,28,43,50,51] (see sections 5.2 and 5.3 for more details).…”

Section: Action Of Pdt At the Tissue And Cellular Levelmentioning

confidence: 99%

“…Erythrosine is another potentially useful PS for PDT that accumulates in mitochondria as was shown on premalignant and malignant oral cell lines [84]. PDT is currently most successfully used in the palliative treatment of age-related macular degeneration (AMD) using the PS Visudyne® (verteporfin, 690 nm), a derivative of benzoporphyrin, for which it was approved by the FDA in 2000 [4,5,10,20,24,28,59,85]. The combination of conventional PDT PSs with different synergistic drugs has been found to be beneficial to treatment outcomes.…”

Section: Progress In Photosensitizer (Ps) Developmentmentioning

confidence: 99%

See 2 more Smart Citations

New Approaches to Photodynamic Therapy from Types I, II and III to Type IV Using One or More Photons

Scherer

Bisby²,

Botchway³

et al. 2017

ACAMC

View full text Add to dashboard Cite

Photodynamic therapy (PDT) is an alternative cancer treatment to conventional surgery, radiotherapy and chemotherapy. It is based on activating a drug with light that triggers the generation of cytotoxic species that promote tumour cell killing. At present, PDT is mainly used in the treatment of wet age-related macular degeneration, for precancerous conditions of the skin (e.g. actinic keratosis) and in the palliative care of advanced cancers, for instance of the bladder or the oesophagus. Due to a lack of phase III clinical trials and limitations of light penetration to deeper lying tumours (in excess of 1 cm), PDT is still not used as a first line cancer treatment, which is surprising given the first clinical trials by Dougherty's group dating back to the 1970's. However research continues to demonstrate the potential benefits of PDT and the need to stimulate funding and uptake of clinical studies using next generation photosensitizers offering advanced targeted delivery, improved photodynamic dose combined with modern light delivery technologies. This review surveys the available PDT treatments and emerging novel developments in the field with a particular focus on two-photon techniques that are anticipated to improve the effectiveness of PDT in tissues at depth and on next generation drugs that work without the need of the presence of oxygen for photosensitization making them effective where hypoxia has taken hold.

show abstract

Adjuvant Intraoperative Photodynamic Therapy in Head and Neck Cancer

Rigual

Shafirstein

Frustino

et al. 2013

JAMA Otolaryngol Head Neck Surg

View full text Add to dashboard Cite

IMPORTANCE There is an immediate need to develop local intraoperative adjuvant treatment strategies to improve outcomes in patients with cancer who undergo head and neck surgery. OBJECTIVES To determine the safety of photodynamic therapy with 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH) in combination with surgery in patients with head and neck squamous cell carcinoma. DESIGN, SETTING, AND PARTICIPANTS Nonrandomized, single-arm, single-site, phase 1 study at a comprehensive cancer center among 16 adult patients (median age, 65 years) with biopsy-proved primary or recurrent resectable head and neck squamous cell carcinoma. INTERVENTIONS Intravenous injection of HPPH (4.0 mg/m2), followed by activation with 665-nm laser light in the surgical bed immediately after tumor resection. MAIN OUTCOMES AND MEASURES Adverse events and highest laser light dose. RESULTS Fifteen patients received the full course of treatment, and 1 patient received HPPH without intraoperative laser light because of an unrelated myocardial infarction. Disease sites included larynx (7 patients), oral cavity (6 patients), skin (1 patient), ear canal (1 patient), and oropharynx (1 patient, who received HPPH only). The most frequent adverse events related to photodynamic therapy were mild to moderate edema (9 patients) and pain (3 patients). One patient developed a grade 3 fistula after salvage laryngectomy, and another patient developed a grade 3 wound infection and mandibular fracture. Phototoxicity reactions included 1 moderate photophobia and 2 mild to moderate skin burns (2 due to operating room spotlights and 1 due to the pulse oximeter). The highest laser light dose was 75 J/cm2. CONCLUSIONS AND RELEVANCE The adjuvant use of HPPH-photodynamic therapy and surgery for head and neck squamous cell carcinoma seems safe and deserves further study.

show abstract

The physics, biophysics and technology of photodynamic therapy

Cited by 896 publications

References 180 publications

Retinal light toxicity

Retinal light toxicity

New Approaches to Photodynamic Therapy from Types I, II and III to Type IV Using One or More Photons

Adjuvant Intraoperative Photodynamic Therapy in Head and Neck Cancer

Contact Info

Product

Resources

About