I am trying to convert a Breast Cancer registry to CDM5.4 and I have a few questions regarding the mapping and the granularity of radiotherapy terms.
How to handle dose and fractions radiotherapy data per region?
The registry contains data per region for radiotherapy, chest, axilla, brain etc. which can be mapped as procedure with the corresponding term
Radiotherapy to chest wall, Radiotherapy to axilla, etc. but I am not sure how to handle the dose and the fractions per region.
chestwallbreast
chestdose
chestfractions
axilla_
axilladose
axillafractions
Yes
50
25
Yes
45
15
Proposed mapping
Domain
Procedure
Measurement
Observation
Procedure
Measurement
Observation
Name
Radiotherapy to chest wall
Total radiation dose delivered
Phase I Number of Fractions
Radiotherapy to axilla
Total radiation dose delivered
Phase I Number of Fractions
Concept id
178919
40483776
35918481
4180586
40483776
35918481
For dosage
One solution would be to add all the dose and use Total radiation dose delivered, i.e. totaldose= chestdose+axilladose+…
Alternatively, from what I can tell the Incident radiation dose could be used each individual dose, but if then it would still not be linked to a region.
Is this approach valid? Or is there a more proper way to map such concepts, perhaps using more the NAACCR vocabulary which I am not really familiar with
Hi @Achilleas_Chytas. When I was last involved with the Oncology Workgroup, the representation of radiotherapy in general was still an open question (see here, and outstanding decision points here)
I can’t offer much help except to direct you to the discussion threads on the topic in the second link I shared. @rtmill and @gkenno may have a better idea. Ultimately, I think moving forward with your proposed mapping, note the missing radiotherapy terminology, and then contribute your findings and proposal back to Oncology WG.
As @kzollove, right now the model does not cover all the detail. Generally, we would not collect total, but individual fractions as a procedure every day. However, we don’t have a way to collect that information. But even having fractions, without the dose, would be very valuable for many use cases.
What is your use case? Instead of a complete bottom up job you may want to start with what’s possible to answer your scientific question. Do you have that?
Hi, radiation oncologist here. In general it is a challenge to get summary data from individual radiation plans. For instance, in your example, where the chest wall and axilla were treated, those would have been two different treatment areas during the same treatment course and generally treated on the same days. So the patient might get 25 sessions, where axilla and chest wall were both treated in each session. You would not want to add up the dose that chest wall and axilla got to create a total dose (in your example, 50+45=95 Gy) because no part of the body got 95 Gy and that total would be misleading.
For other situations like a boost where the breast gets 50 Gy and then a 10 Gy boost, it is OK to add up the doses to get the total dose of 60 Gy to the breast.
You can usually figure out the total radiation dose to various areas by looking in the oncology information system like Aria/Mosaiq at a combination of the radiation plans (with first/last treatment dates, site name, etc.) and prescriptions (site name, target name, linked plans), but this requires some specialized expertise.
I don’t have a lot of answers, just wanted to make sure you understood the challenges.