The optically-stimulated/thermoluminescent dosimeter (OSLD/TLD) Group has the responsibility for the daily operations of the remote-output monitoring program. For the year 2010, the group monitored almost 1800 institutions and approximately 14,000 megavoltage beams Ė not including dosimeters processed for repeat irradiations, new machines, and an ever-expanding collection of anthropomorphic phantoms.
The group consists of six full time employees who are constantly updating the IROC Houston QA Center database through questionnaires, phone calls and e-mails. Note: updating an institutionís permanent e-mail address is now imperative because of the electronic transmission of final OSLD/TLD reports. The IROC Houston e-mail address, firstname.lastname@example.org, should be copied to the address book or spam filters in order to prevent delays or denial during transmission.
Other responsibilities of the OSLD/TLD Group include the shipping, receiving and processing of OSLD/TLD dosimeters. The processing of dosimeters consists of gathering institutional OSLD or TLD, by proximity of irradiation date(s), into a session and then reading the session with the appropriate equipment while following highly standardized procedures. Dosimeters are read manually, one at a time. Session results are then entered into the IROC Houston database, along with information from the corresponding irradiations forms. The recorded session information is then checked by another member of the group before the session is assigned to an IROC Houston physicist to be reviewed. Once a session is reviewed by an IROC Houston physicist and signed by the IROC Houston director, it is returned to the OSLD/TLD for electronic transmission. If an OSLD/TLD result is found to be outside of the IROC Houstonís criteria, efforts are made by the IROC Houston to resolve the discrepancy. Repeat OSLD/TLD are always sent to the institution to confirm the discrepancy or resolution of the problem.
The TLD Group is also responsible for bi-weekly irradiations of standard and control dosimeters on M.D. Andersonís cobalt machines. Standards and controls are read along with institutional OSLD/TLD as part of the multi-level QA (quality assurance) process.
The OSLD/TLD monitoring of both photon and electron beam machine outputs help provide an ongoing evaluation of therapy beams at institutions that are participating in cooperative clinical trial studies.
Please note: On June 1, 2010, the IROC Houston began replacing TLD capsules with OSLD dots for annual beam checks. TLD capsules are now used exclusively for checks of proton beams and as the dosimeter of choice for anthropomorphic phantoms, TomoTherapy cylindrical phantoms and Gamma Knife inserts.