PBT Proton Beam Therapy was started in 1990. To date 11,842 patients have used this type of radiation. PDT is in the early stages and has not been used on patients as of yet.(according to their website) It will be used in clinical trials in one or two years. It is a SUCCESS!!! We need more information on this drug. I will try to find out more the next time I visit Princess Margaret Hospital. Carol Ann.

PBT has been around for a while but because of the astronomical expense there are only 6 treatment centers in the US today. MD Anderson spent about 200 million to add it to their lineup of firstline treatment. Comparatively speaking lasers and LINACS are fairly cheap. A LINAC will pay for itself in about 2 years. The tradeoff is that a PBT installation can have multiple treatment rooms (or gantries). I don't believe that the treatment is fractionalized like ionizing radiation either so the treatment protocol is much faster. The throughput of patients is greater. I personally think that PBT is the future of the RT modality for cancer treatment. The concept of an extremely accurate, charged particle only reaching it's full therapeutic dose rate when actually on target, at the tumor site (thereby sparing all healthy tissue in its path), is pretty amazing.

A typical LINAC by comparison weighs in at under 9 tons (probably even less since most don't have the retractable beamstoppers any more, where just the gantry alone for a PBT machine weighs in at 35 tons.

The idea of using a laser is very interesting also. I will be watching the progress of this device very carefully.

Many of the RT treatments in use today for H&N started as prostate cancer treatment, IMRT and PBT among them.

In regards ro PDT: It is premature to say that any treatment modality is a "success" until it has been validated through all 3 phases of FDA sanctioned clinical trials and carefully planned and monitored studies. "Off label" use does not meet the scientific criteria of a clinical trial although early reports look encouraging. This would probably not be allowed in the US. They would have to file an Investigational Device Exemption (IDE) with the FDA as a precursor for a Pre Market Approval (PMA) for a Class III device, especially because of the new "indications for use".

Incidentally, it is technically not a drug but a "combination" treatment, utilizing a sensitization drug in conjunction with a therapeutic (high energy level) laser device.

This drug is called PDT Photodynamic Therapy. It is a new cancer drug triggered by laser light. Princess Margaret Hospital is saying it is a success that kills cancer cells alone. PBT is a form of radiation treatment originally started in 1990. These are two different things we are talking about, is it not. Carol Ann.

In FDA lingo, when a drug is used with a device then it is a "combination" device.

Here are a few bits of general information about PDT:

What types of cancer are currently treated with PDT?

To date, the U.S. Food and Drug Administration (FDA) has approved the photosensitizing agent called porfimer sodium, or Photofrin

Gary,
Thank you so much for your usual informative update on this. It has helped one member who was about to have her esophagus removed and her stomach pulled up to replace it. Would you believe she was having this surgery done at a hospital that already has this equipment and no one mentioned it until she asked. They are now going to try that first and do the esophageal surgery if it doesn't work. Let's pray it works.
She is still going to have to have a laryngectomy but that is liveable as I can attest.

Thanks also to Carol. What a propitious post.

Take care,
Eileen

This morning i happened to catch a slot on ITV's This Morning Programme.It was about PDT and featured a young woman who had been diagnosed with a vascular tumour inher arm when she was five years old.Now in her late teens she has had a recurrence for which they said she must have her arm amputated.Her father unable to accept that this was the only course of treatment available researched alternatives and discovered PDT.The young lady in question told a very graphic story of her admission to hospital to have intra venous chlorphyll injected into the tumour over 4 hours,followed by light laser treatment.The tumour and the pain are gone!!!! and all she had to show for it were two little holes in her arm.She had no side effects is completely pain free and her scans are clear the only thing she had to do was stay in the dark for three days and then monitor her gradual rexposure to light using a light meter.I dont know how to do a link to the web site for the tv company so you can see the video,but the web site is ITV THIS MORNING.I have copied and pasted an article by the This Morning Doctor which i hope you will find interesting.She also pointed out that to treat a cancer patient For example prostate cancer from diagnosis to end of rad costs the NHS

PDT was cleared for use in the US by the FDA, in 2000, under a PMA (Pre-Market Approval) See: http://www.fda.gov/cdrh/pdf/P990021a.pdf

The photosensitizing agent was approved in 2003

See: http://www.fda.gov/bbs/topics/ANSWERS/2003/ANS01246.html

"Wizard X-Cell" PDT PMA: http://www.fda.gov/cdrh/pdf2/P020021b.pdf

There has also been one reported death:
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/Detail.CFM?MDRFOI__ID=129541

Please notice the indications for use in the above PMA summaries. They are very specific.

The EU has different protocols for allowing devices for "investigational use" so this treatment may not be available in the US for H&N cancers, per se, unless they are "off-label" or clinical trials are in place to prove efficacy for expanding it's indications for use. Vascular use sounds like a great application for this because of it's limited penetration depth and the fact that vascular is typically just below the surface of the skin. In the instance of an H&N tumor, it simply doesn't have enough penetration to insure safe margins, especially if the tumor is larger than 1/3" (about 3mm). Most US doctors want a 1 cm margin around a tumor, minimum.

Remember that most scanning modalities can't detect a tumor smaller than 2mm.

It is cleared for esophogeal application so those tumors must be well within the maximum penetration depth.

They may be able to develop more powerful or application specific lasers and more efficacious drugs to enhance the performance and depth penetration as time goes on.

As noted above, it can have some serious adverse effects, although, IMO, less than ionizing radiation.

This powerpoint was done in 2003 and obviously there is much more information needed:
http://www.fda.gov/ohrms/dockets/ac/03/slides/3966S2_02_FDA-Kaminskas_files/frame.htm#slide0001.htm

Here is a Mayo Clinic link to the original studies - PDT has been around for 25 years. It looks particulary interesting for early stage SCC in the lungs.

http://www.mayoclinicproceedings.com/inside.asp?a=1&ref=7207e

I am all for everyone being their own patient advocate and my intent is to educate about the current limitations for the device, particularly in the US. It sure sounds promising and I would love to see an additional weapon in the war against H&N cancer.