The IROC Houston QA Center's contributions to quality assurance of radiotherapy treatment of patients entered onto cooperative clinical trials include three major areas:
On-Site Audit: "On-site dosimetry reviews" are performed to help institutions resolve problems and to verify the validity of important mechanical and radiation parameters used by the institution for each therapy unit. Data collected are used:
∑ In the retrospective evaluation of patientís charts from those sites visited.
∑ In generating standard data used to evaluate patientís charts in general.
∑ In the resolution of dosimetry problems at the institution.
Off-Site Audit: Since not all-participant facilities can be visited on a routine basis several "off-site dosimetry review" auditing techniques have been developed. These include:
∑ A mailable TLD program to verify machine output on a periodic basis.
∑ Comparison of the institutionís dosimetry data with IROC Houston "Standard dosimetry" data to identify potential problems on the data used for patient dose calculations.
∑ Evaluation of reference/or actual patient calculations to verify treatment planning algorithms.
∑ Review of institutionís written QA procedures and records.
∑ Mailed anthropomorphic phantoms to verify tumor dose delivery for special treatment techniques such as IMRT, stereotactic radiosurgery, etc.
Collaboration: Close collaboration with other Quality Assurance Offices, and feedback of instructive findings to the radiotherapy community while maintaining the anonymity of participating institutions.
∑ Credentialing of institutions for participation on specific protocols.
∑ Retrospective review of treatment records for patients entered onto cooperative clinical trials.
The IROC Houston continuously modifies its techniques to reflect new protocols and changes in practice at participating institutions. The IROC Houston also continues to research dosimetry questions that rise from multiple institutions using a wide variety of therapy equipment to deliver clinically comparable treatments.
The IROC Houston serves as a resource in radiation dosimetry and physics to the medical physicistís community and to all nine cooperative groups. We collaborate and exchange data with the four other radiotherapy QA offices that serve the various groups. We also provide advice to cooperative groups on QA questions, and development of the radiotherapy sections of protocols.