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.