photodynamic therapy

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Promising Cancer treatment

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Photodynamic therapy : 

Photodynamic therapy A novel therapy for the treatment of cancer RameshBabu R Nair ramesh.nair@biolitec.com

Main components… : 

Main components… Photosensitizer Laser Light (of appropriate wavelength) Oxygen

Slide 3: 

"The children attending the Open Air School (Brownhill School) continue to receive this treatment. Rochdale Infirmary Annual Report 1928 Ancient India – Extracts of Psoralea carylifolia which contains furocoumarins, were given orally, followed by exposure to sunlight in order to treat vitiligo.

How it works ? : 

How it works ? Administer Foscan (temoporfin) Intravenously Irradiate the site with Diode Laser light having the wavelength of 652nm Photosensitiser at the malignant cells gets activated leading to apoptosis Inducing effective local tumor destruction

Foscan (Temoporfin) : 

Foscan (Temoporfin) Foscan (Temoporfin) is a second-generation photosensitiser, offers a novel treatment option using photodynamic therapy (PDT), and is an important tool in the management of advanced head and neck cancer. The aim of treatment with Foscan®-PDT includes preservation of organ function, local tumour destruction, relief of symptoms and avoidance of disease-related complications

Slide 6: 

Photosensitizing agent called Porfimer sodium or Photofrin®, for use in PDT to treat or relieve the symptoms of esophageal cancer and non-small cell lung cancer. (approved by US FDA in 2003) Other PDT agent in ca. treatment Foscan (m-THPC) has been shown to be approximately 200 times more effective then Photofrin when considering photodynamic dose (i.e. a lower photosensitiser dose and shorter illumination times are required to achieve similar results). m-THPC has a longer half life in the triplet state generating more cytotoxic oxygen species, and is observed to be more selective between tumour and normal tissue. m-THPC is more hydrophobic than Photofrin which thus increases cellular uptake leading to higher efficacy in vitro . However, the skin photosensitivity caused by m-THPC is only slightly less than that of Photofrin.

Foscan Mediated PDT Procedure : 

Foscan Mediated PDT Procedure Foscan® administration Iv administration at a dosage of 0.15mg / kg For treatment of premalignancies, superficial lesions very low dosage is required - 1mg of foscan administered Iv.

Foscan Mediated PDT Procedure (contd….) : 

Irradiation of the target lesion, post 96 hrs to the drug administration. Irradiation can also be done post 8 – 12hrs for premalignancies, superficial lesions with low drug dosage (1mg) The light dose required varies from 20 -100 joules/cm2 depending on the site of irradiation. The duration of irradiation is 200 seconds. It is most important to deliver the appropriate light energy to achieve optimal prognosis. Adjacent healthy tissues must be properly shielded while irradiation to avoid necrosis of healthy tissues. Laser Irradiation Foscan Mediated PDT Procedure (contd….)

Foscan Mediated PDT Procedure (contd….) : 

Foscan Mediated PDT Procedure (contd….) Target lesion illumination PDT is a strongly localized treatment. The necrosis induced by PDT will occur only in tissue that has received adequate dose of light. It is important to illuminate the entire lesion. Careful planning is required to ensure that complete illumination is achieved including the safety margin

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Foscan Mediated PDT Procedure (contd….) PDT Methods :- Surface Illumination – Locally accessible lesion having tumor thickness < 1cm Interstitial Illumination - Tumor Thickness > 1cm - Deep seated lesions (locally not accessible) Microlens Fibre Cylindrical Diffuser Fibre

Interstitial PDT : 

Interstitial PDT Intra-tumoral light delivery via bare / diffuser fibres. No restriction in tumor size (upto 90mm can be covered using the diffuser fibre) Wide application laser tumor fibre

Ceralas PDT 652 laser : 

Ceralas PDT 652 laser Specification: 2 W at 652 ( 3) nm

PDT of Head and Neck CancerHistorical Development : 

PDT of Head and Neck CancerHistorical Development Palliation of massive tumors Curative treatment of early larynx and oral cavity tumors Combined modality treatment PDT and surgery PDT and radiation therapy PDT and chemotherapy PDT and immunotherapy

Limitations of Standard treatment… : 

Limitations of Standard treatment… Surgery Functional & cosmetic impairment Radiotherapy Usually only single treatment possible Effective in early cancers Long term side effects Prolonged treatment >6 weeks Chemotherapy Systemic toxicity Investigational

Why do we need a new treatment modality? : 

Why do we need a new treatment modality? Options after recurrence limited (40-60%) Second Primary (15-25%) Difficult palliation in advanced disease (60%) For diffuse lesions / carcinoma in situ (10%)

Outcome Response of PDT : 

Outcome Response of PDT Pre-treatment Post –treatment

What is the Futureof PDT in Head and Neck Neoplasia? : 

What is the Futureof PDT in Head and Neck Neoplasia?

Slide 21: 

Treatment of choice for early carcinomas CIS-T2 Adjuvant intraoperative treatment of head and neck cancer resection sites Percutaneous treatment of metastatic disease Neoadjuvant PDT with radiation, chemotherapy and immunotherapy

PDT is Effective Treatment for: : 

PDT is Effective Treatment for: Leukoplakia, Tis, 1, 2 Ca larynx CIS, T1 Ca oral cavity Superficial T2, T3, Ca oral cavity Nasal and nasopharyngeal Ca Intraoperative adjuvant PDT for recurrent head and neck Ca

Adjuvant intraoperative Photodynamic Therapy Treatment of Recurrent Head and Neck Cancers : 

Adjuvant intraoperative Photodynamic Therapy Treatment of Recurrent Head and Neck Cancers Head and neck squamous cell carcinomas with soft tissue invasion have high rates of local and regional recurrence – 43-71% 90% of recurrences occur within 12 months of surgical resection

Indications for Intraoperative PDT: : 

Indications for Intraoperative PDT: PDT for curative intent following gross tumor debulking Achieve complete tumor eradication with preservation of normal vital functional structures, e.g. larynx PDT of surgical resection bed following resection of T3, T4 tumors Increase tumor free resection margins Destroy microscopic disease and preserve normal structures

Authors of Published PDT Head and Neck Cancer Therapy(to name a few) : 

Authors of Published PDT Head and Neck Cancer Therapy(to name a few) Keller Freyh Wenig Grossweiner Freche Schweitzer Gluckman Grant Biel Zhao Monnier Dilkes Fan Hooper Cai Carruth Schuller McCaughan Taketa Wile Buchanan Savary Putnam Tan D’Cruz

Conclusion : 

Conclusion The Foscan Mediated PDT for treating h & n cancers have been extensively reviewed. It is found to be effective with less toxicity / morbidity compared to the other modalities of treatment. Less Invasive procedure; having low morbidity and can be repeated with out having any functional impairment / cosmetic disfigurement. Interstitial PDT to be used in treatment of large, buried tumors and is particularly suitable for those in which surgery would involve extensive resection.

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Effective for small primary-tumours of the oral cavity as well as for advanced Head & Neck Ca. palliative treatment Tumour responses appear durable PDT treatment does not hinders the subsequent use of standard treatment modalities Conclusion (contd...)

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Thank you…