Talk:Photodynamic therapy

A rewrite

I have rewritten the intro and history sections. I'll continue to work on the other sections at before updating the wiki page Mattbimbo2011before updating the wiki page. Mattbimbo2011 (talk) 04:12, 5 August 2011 (UTC)

Needs to be revised

"When the photosensitizer and an oxygen molecule are in proximity, an energy transfer can take place that allows the photosensitizer to relax to its ground singlet state, and create an excited singlet state oxygen molecule"

This is only true with some PDT drugs. Newer drugs are composed of dinuclear or trinuclear complexes containing a light absorbing unit, a bridging ligand, and a biologically active site that undergoes metal to metal charge transfer. So when targeted with photons of a certain wavelength the light absorbing unit loses an electron (photoelectric effect?) which travels across the ligand and reduces the metal at the biologically active site and causes the cleavage of DNA. This method of action is completely independant of molecular oxygen and does not produce singlet oxygen in the body.

"...involving three key components: a photosensitizer, light, and tissue oxygen"

"and tissue oxygen" should be removed.

Can anyone provide sources for that please ? Rod57 (talk) 15:29, 2 March 2011 (UTC)

New treatments in Darwin, Australia

Inventor Terry Wright is currently working on new light arrays for use in PDT. Please see his website at Cytoluminator.com.

PDT as a method of hair removal

There is nothing in this topic about PDT as a hair removal technology. See [[1]]

PTD with PPIX mimics Erythropoietic Protoporphyria, not Porphyria cutanea tarda!

Source: http://www.ncbi.nlm.nih.gov/pubmed/15570383?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

In EPP the last step of heme biosynthesis is affected (fixing of iron inside the protoporphyrin IX- ring) which causes PPIX accumulation and reactions to visible light similar seen in PDT. In PCT other heme precursers accumalate (Uroporphyrins, Heptacarboxylporphyrin and Isocoporphyrin), but not PPIX. —Preceding unsigned comment added by 195.176.146.92 (talk) 14:30, 31 March 2008 (UTC)

Text removed from article

I removed the following text from that article, because it looks like an article abstract that has been dropped into the article without any context. However, I can't find this text on the web: can someone integrate it into the article, if appropriate? -- The Anome (talk) 11:02, 11 May 2008 (UTC)

Post surgical removal of large tumors PDT can be useful in removing traces of malignant tissue.

Treatment Regimens

New protocols that involve refining the timing of photosensitizer delivery and light delivery to maximize photodynamic effect are being sought. Traditional 'acute regimens' are conducted with high doses of photosensitizer and light and may be fractionated to allow for tissue re-oxygenation. Recent studies have introduced the concept of continuous low dose PDT or metronomic PDT. It is proposed that metronomic PDT will preferentially kill cells via apoptosis rather than necrosis which is typically seen following acute regimens and may be important when treating inside the brain for instance. The technologies necessary for metronomic PDT in patients have yet to be made.

New Sections?

Perhaps some sections could be added describing the current range of photosensitizers and specific conditions for which PDT has been approved. I'll try to incorporate this and other general info the next chance I get. Afireinside13t (talk) 03:22, 30 June 2008 (UTC)

I have added a section on photosensitizers (forgot to sign the update). If it is too much a list, please tell me and I will modify it as needed. Afireinside13t (talk) 18:18, 10 July 2008 (UTC)

How about a section on two-photon excitation of photosensitisers for PDT? Azo bob (talk) 23:06, 26 April 2009 (UTC)

Hollow needles for deeper cancers

These are being used in the UK, maybe elsewhere, to get the laser light into "deeper cancers". It would be good to have some details of current capabilities and limitations. Rod57 (talk) 17:11, 10 September 2008 (UTC)

I've been working on this lately, so I've read a lot of papers on the topic. When I get a chance, I'll try to add in some information on it. Afireinside13t (talk) 16:58, 1 December 2008 (UTC)

Surgical Emphasis?

The huge photo and overall feel of the document give the general feeling that this technique is useful as a surgical one, "during surgery", but the little section on light needles strongly implies that actual surgery might be very nearly completely unnecessary, especially if used in conjunction with ultrasound imaging to visualize the areas inside and around the tumor.

Can the technique also be used with endoscopy instruments carrying an additional fiber optic cable for the purpose of adding the sensitizing wavelength? Seems an obvious enough application that it must have been tried by now, is it ineffective or does the article just lack text about such possibilities?Zaphraud (talk) 18:46, 8 January 2009 (UTC)

Head and neck cancer

Need to mention cancers other than just skin cancer, eg Amphinex is being trialled for advanced head and neck cancer in the UK. Rod57 (talk) 01:36, 6 April 2010 (UTC)