Detailed Description | |
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Modalities | CT, PT, MR, NM | Number of Patients | 260 | Number of Studies | 681 | Number of Series | 3359* | Number of Images | 460,983* | Images Size (GB) | * |
- Estimated, official numbers provided once data is available.
Participant Eligibility and Enrollment: People with newly diagnosed head and neck squamous cell carcinoma being considered for surgical resection, with at least one side of the neck planned for dissection clinically N0, and at risk for occult metastasis (when risk based on clinical data is felt to be greater than 30%). Date Offsets: All dates, like the visit date, are protected by presenting just the year; however, dates are also listed as offset days from the base date. The offset dates are used as a means of protecting patient information provided by the local sites in the original data, while allowing users to determine intervals between events. The standard DICOM date tags (i.e. birth dates, imaging study dates, etc.) have been de-identified so that all patients have a baseline study date of January 1, 1960. This falsified date represents the day patients were entered into trial database. The number of days between a subject’s longitudinal imaging studies are accurately preserved. A patient with a study performed on January 4, 1960 means the images were collected 3 days after the base date. For convenience, this calculation has been performed for all scans with the results inserted in DICOM tag (0012,0050) Clinical Trial Time Point ID. This means an imaging study that took place on January 4, 1960 would contain a value of "3" in tag (0012,0050). Overview of Clinical Data: Case numbers from the clinical data files correlate directly with the case numbers from the image archive for each ACRIN clinical trial. The basic data flow for legacy ACRIN multi-center clinical trials was that all clinical information provided by the local imaging sites were contained in a series of forms. The form data submitted by local investigators to ACRIN during and after the trial, were manually encoded into the ACRIN CTMS (Clinical Trial Management System), and were cross-checked for accuracy by ECOG-ACRIN personnel. These forms, filled out by the local sites, deliver information on imaging, clinical management of the patient and pathology/outcome variables, like dates of progression and survival, along with other critical information. The image data was initially anonymized while uploading from the local sites through TRIAD software and archived in a DICOM database at ACRIN. After the trial accrual had ended, the clinical data was sent to the Brown statistical center, that is funded by NCI to provide support for ECOG-ACRIN clinical trials, specifically for analysis of the primary and sometimes secondary aims of the trial. The statisticians at Brown strip all the actual dates, names and other PHI from the CTMS data and create a .csv file for each form that has selected information useful for analysis of the trial data. A Form Description file detailing all the forms used in the study accompanies the .csv data files. Additionally, the accompanying Data Dictionary file lists each element for each form that has been selected for data retention along with a description of each form element. Extracting clinical (non-imaging) data example: Beginning with the Form Description file, select the form with the desired information needed, such as form BA.csv the patient baseline medical history. Next, using the Data Dictionary file, select the tab corresponding to the form of interest (eg., BA). The Excel file lists the form number, variable name, its description or label, the type of data, and, when applicable, the option codes and corresponding text values (option code:description pairs like 1=’No’, 2=’Yes’; or 1=’Baseline’, 2=’Post treatment’) for each data element available from the form. In the example in Figure 2, the BA form element 7 reports the number of live births for the patient. In the corresponding BA.csf file column G lists the number of live births for each patient, identified by case number (cn) in column A. (insert image) Figure 2: In this example of extracting clinical data, the first step is to 1) find the form from the form list, 2Find the desired element and description in the Data Dictionary and finally 3) extract the values from the .csv data file. ACRIN 685 has about 40 forms, each appears as a separate tab in the Excel Data Dictionary file. For trials, other than ACRIN 6685, the form element descriptions of the Data Dictionary are in one spreadsheet. The procedure above is basically how the statisticians organized the selected data for export, but the structure of the data dictionaries and individual forms are different for each clinical trial. ACRIN 6688 has about 40 forms, with several thousand form elements. |