A quick Google search for "rapidarc" provided lots of details.
This is Varian's own website:www.varian.com/us/oncology/treatments/treatment_techniques/rapidarc/
It would appear that it delivers an infinite number of tiny doses from an infinite number of directions as it rotates through 360 degrees, thus the non-target tissue only receives a tiny fraction of the total dose (Effectively 360 doses from 360 directions delivering 1/360th of the total dose.) This must greatly reduce the amount of dose that goes through any single section of bowel so I can see that the side effects might be much less.
It would also seem to offer a better deal by way of patient comfort (particularly for those with other cancers) as it is faster and you don't have to stay quite so still. I always thought it must be really difficult for the people with cancers in the head/brain who are having their heads clamped to the table in those masks. With Rapidarc it would appear that they don't need to be be clamped in position and that the machine can track any movement of the head, and also do the whole thing must faster anyway.
Having watched the CT scanner revolve around me before my SRT I did wonder during my treatments why the RT couldn't be delivered through 360 degrees as well, so I'm glad it can, even if I missed out. I did ask my rad team about
new types of machines: they do have plans, but they mentioned the enormous cost and I think the plan at that unit is to get a proton beam machine. There were however workman installing a new machine down the corridor during my time there so maybe that is going to turn out to be a Rapidarc proton machine
Another major hospital in Amsterdam already has a Rapidarc machine, their have info about
in (in English) at:www.vumc.com/patientcare/1071297/2648155/
The follow-up question is: are there any risks from the extra CT scans needed to guide Rapidarc, or is it just the same as with any image guidance?
Sounds like a great advance.
Born Jun ‘60
Apr 09 PSA 8.6
Biop 2 of 12 pos
29 Jul 09 DaVinci AVL-NKI Amsterdam
6 Aug 09 Cath out
PostOp Gleason 3+4 Bladder neck & Left SVI -T3b
No perin’l No vasc invasion Clear margins
Dry at night
21 Sep 09 No pads daytime
17 Nov 09 PSA 0.1
17 Mar 10 PSA 0.4 sent to RT
13 Apr 10 CT
28 Apr 10 start RT 66Gy
11 Jun 10 end RT
14 Sep 10 PSA <0.1