Mapping radiotherapy dose/fractions when split by body region

Vocabulary Users
1

Hi all,

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

  1. One solution would be to add all the dose and use Total radiation dose delivered, i.e. totaldose= chestdose+axilladose+…

  2. 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.

Regarding fractions, a similar approach would be to add all fractions as Phase I Number of Fractions

Same question for radiotherapy boost

Boost boost chest dose boost chest fraction boost axilla dose boost axilla fraction
Yes 15 6 8 3
Proposed mapping
Domain Procedure Measurement Observation Measurement Observation
Name Boost radiation therapy Total boost radiation dose delivered Phase II Number of Fractions Total boost radiation dose delivered Phase II Number of Fractions
Concept id 40482853 40484226 35918771 40484226 35918771

Add all dosage together and use Total boost radiation dose delivered, and add all fractions together as Phase II Number of Fractions

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

2

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.

3

@Achilleas_Chytas:

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?