PDT is very promising in cancer and tumors treatment, the chemotherapy and radiotherapy using isotopes have shown a lot of problems for their side effects. I believe that PDT is still borning and providing a good material as a PS with high singlet oxygen quantum yield is still challenging. The issue is also to approve some tested nanoparticles and materials that have shown good applicability to PDT in order to use with patients. The process of make it legal and commercial by FDA sometimes can be very slow or some big companies which sells other drugs would not encourage the development of these materials because it will blocks a lot of their selling unuseful drugs in markets. I expect that PDT will compete within 5 - 10 years. Regarding the development of the technique itself, it was reported using endoscope and some fiber optics to focus light in malignant cells which has the photosensitizer and then will kill the tumor. The limitation would be for some specific types of cancer where the applicability of the endoscope or the fiber optics is not possible.

For any therapy to be considered effective, it has to be shown in randomized clinical trials to be at least equal to currently available therapies. Can any of you quote a SINGLE clinical trial of this benefit with photodynamic therapy in tumors? Clinical Medicine is NOT controlled by pharmaceutical companies. They frequently fund research but in the end the research has to be done. FDA and other regulatory authorities perform an indispensable function, otherwise people would be using whatever the THINK is effective on live human beings.

To Irfan Maghfoor: Here you have a review and some examples that could help you (sorry for the long links):

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1317568/

http://www.cancerresearchuk.org/cancer-help/trials/a-trial-looking-at-the-timing-of-photodynamic-therapy-for-brain-tumours?SearchQuery=and%28crtreattype%3astring%28%22Photo-dynamic%20therapy%22%29%29and%28crdtype%3astring%28%22ClinicalTrial%22%29%29and%28crtrialstatus%3astring%28%22Results%22%29%29&AdvancedSearchFormType=clinical_trials_adv_search_form&OffsetValue=8

http://www.cancerresearchuk.org/cancer-help/trials/a-trial-looking-at-photodynamic-therapy-and-surgery-for-basal-cell-skin-cancer?SearchQuery=and%28crtreattype%3astring%28%22Photo-dynamic%20therapy%22%29%29and%28crdtype%3astring%28%22ClinicalTrial%22%29%29and%28crtrialstatus%3astring%28%22Results%22%29%29&AdvancedSearchFormType=clinical_trials_adv_search_form&OffsetValue=7

http://www.cancerresearchuk.org/cancer-help/trials/a-study-to-see-how-the-body-gets-rid-of-photodynamic-therapy-drugs?SearchQuery=and%28crtreattype%3astring%28%22Photo-dynamic%20therapy%22%29%29and%28crdtype%3astring%28%22ClinicalTrial%22%29%29and%28crtrialstatus%3astring%28%22Results%22%29%29&AdvancedSearchFormType=clinical_trials_adv_search_form&OffsetValue=4

http://www.cancerresearchuk.org/cancer-help/trials/photodynamic-therapy-for-biliary-tree-cancer?SearchQuery=and%28crtreattype%3astring%28%22Photo-dynamic%20therapy%22%29%29and%28crdtype%3astring%28%22ClinicalTrial%22%29%29and%28crtrialstatus%3astring%28%22Results%22%29%29&AdvancedSearchFormType=clinical_trials_adv_search_form&OffsetValue=2

http://www.cancerresearchuk.org/cancer-help/trials/a-trial-looking-at-photodynamic-therapy-for-more-severe-cell-changes-in-people-with-barretts-oesophagus?SearchQuery=and%28crtreattype%3astring%28%22Photo-dynamic%20therapy%22%29%29and%28crdtype%3astring%28%22ClinicalTrial%22%29%29and%28crtrialstatus%3astring%28%22Results%22%29%29&AdvancedSearchFormType=clinical_trials_adv_search_form&OffsetValue=6

http://www.cancerresearchuk.org/cancer-help/trials/a-trial-to-see-if-ala-works-better-than-photofrin-in-photodynamic-therapy-for-barretts-oesophagus?SearchQuery=and%28crtreattype%3astring%28%22Photo-dynamic%20therapy%22%29%29and%28crdtype%3astring%28%22ClinicalTrial%22%29%29and%28crtrialstatus%3astring%28%22Results%22%29%29&AdvancedSearchFormType=clinical_trials_adv_search_form&OffsetValue=9

http://www.clinicaltrials.gov/ct2/results?term=photodynamic+therapy&recr=Completed&rslt=With&type=&cond=&intr=&titles=&outc=&spons=&lead=&id=&state1=&cntry1=&state2=&cntry2=&state3=&cntry3=&locn=&gndr=&rcv_s=&rcv_e=&lup_s=&lup_e=

I also think PDT has a good future for cancer therapy (even beyond solid tumours) but, as Khaled Habiba pointed, still a lot work need to be done.

Article Soft versus Hard Nanoparticles in the Delivery of Aromatic M...

Alejando Diaz-Moscoso- Thanks however, what I had written was "is there a well done randomized trial" proving its efficacy and superiority. Lab data, in vivo pre-clinical data, phase I and phase II studies don't constitute evidence. The only clinical use these days for such therapy is photopharesis for skin confined cutaneous T-cell lymphoma with circulating sezary cells. Even this constitutes palliative treatment. I will keep my mind open though. Any ideas for future clinical trials in any lymphomas will be welcome. We are willing to collaborate as well.

Majority of trials listed above are not about invasive cancers.

PpIX is under extensive study as a photosensitizer for tumor detection and photo-dynamic therapy. However, because the generation of PpIX depends on a sufficient intracellular concentration of the precursor 5-ALA, exogenous addition of this acidic substance is necessary which carries a risk for the patients. Therefore, there is a need to reduce the 5-ALA concentration and to improve the specificity of the treatment. Previously, we have shown that PpIX can be induced by down-regulation of the activity of the FECH enzyme. Meanwhile, we were able to demonstrate that PpIX-fluorescence within the tumor tissue can be induced by folate-coupled liposomes or dendritic polyglycerolamine nanoparticles carrying FECH-siRNA in conjunction with a low amount of 5-ALA. On the one hand, the specificity of the treatment is increased, because FECH is silenced only within the tumor due to selective penetration of the carrier. On the other hand, addition of 5-ALA could be reduced significantly to 5 mg 5-ALA / kg body weight, which is about 20-40 times less than that used in older studies. In the future, application of nanocarriers containing FECH siRNA could be used for sensitive detection of small tumor clusters e.g. in lymph nodes, or during endoscopy and on the same time for photodynamic depletion of the tumor cells.

Please check here.

http://www.ncbi.nlm.nih.gov/pubmed/22349098

While PDT is an intellectually stimulating subject; from the perspective of someone who treats patients with Head and Neck cancer, usually with curative intent on a weekly basis in the UK, it has not lived up to initial promise as a practical therapuetic agent. It's role in diagnostics is quite different.

At least part of the problem has been that the necessary prospective randomised clinical trials have not been funded and carried out. The UK subjects all active clinical treatments to intense scrutiny at a national level (one of the purported advantages of our state and ostensibly centrally run system). That organisation, sometimes referred to as NICE has not supported it's introduction as a standard therapy along with surgery and radiotherapy for Head and Neck cancers (I'm excluding skin cancer as while there is an overlap it is regarded differently). At least some of the difficulties centered around the commercial aspects of the main agent temoporfin.

There remains a group of enthusuasts who are challenging this and it may be that some decent trials subsequently develop but at the moment for everyday clinical management, these patients are treated within a multidisciplinary environment primarily by surgery and or radiotherapy (the adjunctive chemotherapy regimens are controversial and I include them in the term "radiotherapy").

I should add that for many years I ran my regions Head and Neck PDT service - it had limited application but was useful on occasions - so I could be seen as a "sort of" enthusiast. Recently that same group of patients (other treatments not suitable for whatever reason) were due to be offered the new version of electroporation but I have not seen any great impact from that modality either.

From the point of view of treating day to day patients suffering from Head and Neck cancer the most useful advances are being made slowly but steadily in refining existing proven treatment techniques and characterising the varying biology of individual cancers which may soon influence the types and intensities of treatment offered. From a preventative perspective education on tobacco use and vaccination against HPV 16 & 18 are clearly going to have the most profound impact on the future of the suffering this disease causes.

PDT is a promising treatment for cancer and it is not so applicable because of limitation in giving light to deep seated tissues  and the disadvantages of photosensitizes. when fibre optic probes used successfully designed it will be a better alternate for conventional cancer treatments like Radiation,Chemotherapy. Nowadays Nanomaterials were in place of Sensitizers with efficient modality.