Clinical, genetic, and pathology data resides reside in the TCGA data portal while the radiological data is stored on The Cancer Imaging Archive (TCIA). The data utilizes the same TCGA patient identifiers in both repositories, allowing researchers to explore the correlations between tissue genotype and radiological phenotype. This Collection within TCIA is related to the GBM disease type within TCGA.
TCIA and TCGA Subject Identifiers and Dates
Subject Identifiers: a subject with radiology images stored in The Cancer Imaging Archive (TCIA) is identified with a Patient ID that is identical to the Patient ID of the same subject with demographic, clinical, pathological, and/or genomic data stored in the Cancer Genome Atlas (TCGA). For each TCGA case, the baseline TCGA imaging studies found on TCIA are pre-surgical.
Dates: TCIA and TCGA handle dates differently, and there are no immediate plans to reconcile:
- TCIA Dates: dates (be they birthdates, imaging study dates, etc.) in the DICOM headers of TCIA radiology images have been discounted by a random number of days. The discount is a number of days between 3 and 10 years that is consistent for each TCIA image-submitting site and collection but that varies among sites and among collections from the same site. Thus, it is possible to figure the number of days between a subject’s imaging studies when more than one study has been archived within a site-collection. These random numbers are not known to TCIA image consumers.
- TCGA Dates: the patient demographic and clinical event dates are all the number of days from the index date, which is the actual date of pathologic Dx. So all the dates in the data are relative negative or positive integers, except for the “days_to_pathologic_diagnosis” value, which is 0 – the index date. The years of birth and Dx are maintained in the distributed clinical data file. The NCI retains a copy of the data with complete dates, but those data are not made available.With regard to other TCGA dates, if a date comes from a HIPAA “covered entity’s” medical record, it is turned into the relative day count from the index date. Dates like the date TCGA received the specimen or when the TCGA case report form was filled out are not such covered dates, and they will appear as real dates (month, day, year).
We would like to acknowledge the individuals and institutions that have provided data for this collection: