Appendix 5: Video 16.1 Transcript
[Ngoc is demonstrating their radiation therapy plan to their peers and the facilitator.]
Ngoc: So yeah, I think, I think it’s sort of, it’s not too bad, but what I’m not happy about here is that I’ve got a lot of high dose splaying out of the PTV, especially around here. Even though I’ve got good coverage, I think that definitely can be improved on, because, yeah, it’s just, it’s not very conformal. The 95 per cent is really, just, especially on this side. I think this side’s all right. Yeah, the left side’s just, yeah, a little bit too, too much down here as well. It’s getting a bit too hot there and warm around there. So that’s something that I could improve on.
And then the next dose level, so 59.5. So, I’m looking at the PTV 60. So, I’m looking at the pink region here, which is PTV 63, as you can see here. Also, the coverage is not too bad; it is a little bit patchy and sort of a little bit missing in parts. But, um, what’s sort of like really obvious about this plan that is not good is that once again, though, the dose is splaying right out of there. I’ve tried really hard to play with the normal tissue objectives (NTOs) and things like that to try to tighten all of that to the point where now it’s sort of, like, it’s not improving, even though I keep pushing it, and it’s sort of then impacting on other parts of the plan. So, yeah, so that’s something that I could definitely get some help on, trying to contain that dose there. And I’ll just show you my next.
So, the high-dose region, I think, is probably the worst out of all of them, and I don’t know why, because I have tried to push this really hard also. I’ll just put that back on. So 70, which is that one there. Yes. So, it’s sort of, the coverage is not bad. I’m still missing quite a little bit here. But as you can see, higher dose is, you know, the 95 is just gone right out from there and there. Um, you know, but coverage, I mean, yeah, coverage is, you know, I think it’s probably not the worst problem. I think the bigger problem is containing the high-dose regions.
To optimise my plan was, I had in the beginning, I had quite a lot of 95s that were running along here, and so I went and put a dose constraint structure. I just, you know, made the 95 per cent isodose line, turned it into a structure, and then I put that in the optimiser and just sort of said, you know, I don’t want any dose to be above 95 per cent in this region and brought it down. And that’s really helped, because, as you can see, where the pink is there used to be all 95s, and so now it’s sort of disappeared to next to nothing. So, I think that’s probably one thing that I’m pretty proud that I was able to do for this plan.
But, um, yeah, I definitely need quite a bit more, I think, um, you know, help with this one to get it clinically, you know, to a point where you could actually use it to treat a patient.
