Irradiation Instructions

Monitoring output of a megavoltage photon beam

1. Assemble platform as follows:
   1. Unfold the legs and place them on the treatment table with the arrow pointing upward. 
   2. Place the platform top on the legs with the inscribed square visible on the top of the platform. 
   3. Before irradiating the TLD, make sure the legs are NOT directly underneath the inscribed square (see image below).
2. Set a 10 cm x 10 cm field size with the SSD set to the top of the platform (not the top of the block). The light field should align with the inscribed square for a 10 cm x 10 cm field size.
3. Determine the “reference point” for your machine output. The reference point is the point at which you routinely specify the exposure or dose rate in your clinical dosimetry system. Also specify whether your machine output is in miniphantom (without backscatter) or in phantom (with backscatter).
   1. For example, if you routinely specify dose to dmax for a 6 MV linac, 100 cm SSD, your reference point is at 101.5 cm and you would check the box indicating “in phantom” at 1.5 cm depth and check the “dmax” box. We will correct our TLD reading based on your reference point information.
4. Place the TLD block label side up in the center of the field and set the time to deliver 300 cGy to your reference point.
5. Complete the TLD data sheet on the reverse side of these instructions. Be sure to fill in all requested information (highlighted sections), as incomplete forms will delay the processing of your TLD. Please send back the TLD via regular U.S. mail using the address label provided. TLD cannot be read until seven days after irradiation. If you wish to return TLD by an express or direct carrier, use the following address: Radiation Dosimetry Services, 8060 El Rio Street, Houston, TX 77054. If you have any questions, please call Radiation Dosimetry Services (RDS) at 713-745-8999 or you may e-mail us at RDS@mdanderson.org.

Monitoring output of electron beam therapy machine 

1. Set the standard calibration field size or cone. You may use a radiation field area larger than the phantom.
2. Stack the three lucite blocks with central hole on the treatment table centered in the irradiation field. If the three lucite blocks (electron phantom) are not enclosed with the TLD, you should have already received the phantom in a previous TLD shipment. If you cannot find the electron phantom, do not irradiate the electron TLD; contact our office at 713-745-8999 so we can send another phantom.
3. Set the Target-Surface Distance (TSD) to the top of the lucite blocks.
4. Insert the appropriate plug for the irradiation energy in the central hole with the label side up. The top of the plug should align with the top of the lucite blocks. The correct plug to use for each energy is indicated in the second column of the datasheet table (front side).
5. Irradiate the lucite blocks with plug to 300 cGy. Remove plug. Repeat steps 4 and 5 for each energy.
6. Fill out all requested information (highlighted sections) on the datasheet. Use one datasheet per machine. Enclose copies of your depth dose curves for each machine, energy and field size used if we do not have your current curves on file. We will be unable to process your TLD without the depth dose curves. Return all plugs, datasheets and depth dose curves in an envelope or box using the return address label provided via regular U.S. mail. TLD cannot be read until seven days after irradiation. If you wish to return TLD by an express or direct carrier, use the following address: Radiation Dosimetry Services, 8060 El Rio Street, Houston, TX 77054. If you have any questions about irradiation of the TLD, please call our office at 713-745-8999 or you may e-mail us at RDS@mdanderson.org.

1. Assemble platform as follows:
   1. Unfold the legs and place them on the treatment table with the arrow pointing upward. 
   2. Place the platform top on the legs with the inscribed square visible on the top of the platform. 
   3. Before irradiating the TLD, make sure the legs are NOT directly underneath the inscribed square (see diagram below).
2. Set a 10 cm x 10 cm field size with the SSD set to the TOP OF THE PLATFORM (not the top of the block). The light field should align with the inscribed square. If a 10 cm x 10 cm field size is not possible, use the closest field size available. Do not irradiate with field sizes smaller than the TLD packet.
3. Determine the "reference point" for your machine output. The reference point is the point at which you routinely specify the exposure or dose rate in your clinical dosimetry system. Also specify whether your machine output is in air (without backscattter) or in phantom (with backscatter). For example, if you routinely specify the dose to dmax, 50 cm SSD, your reference point is at 50 cm and you would check the boxes indicating “in phantom” and “dmax”. We will correct our TLD reading based on your reference point information.
4. Place the TLD label side up in the center of the field and set the time to deliver 300 cGy or 300R to your reference point.
5. Complete the TLD data sheet on the reverse side of these instructions. Be sure to fill in all requested information (highlighted sections), as incomplete forms will delay the processing of your TLD. Please send back the TLD via regular U.S. mail using the address label provided. TLD cannot be read until seven days after irradiation. If you wish to return TLD by an express or direct carrier, use the following address: Radiation Dosimetry Services, 8060 El Rio Street, Houston, TX 77054. If you have any questions, please call Radiation Dosimetry Services (RDS) at 713-745-8999 or you may e-mail us at RDS@mdanderson.org.

Special instructions for TLD irradiation with a tomotherapy unit 

1. Open the collimator to a 40 cm X 5 cm field.
2. Set the SSD (85 cm) to the top of the platform.
3. Set the time to deliver 300 cGy to the reference point without machine rotation (stationary beam).