In vivo dosimetry of intraoral stent using TLD during external photon beam radiotherapy of oral cavity

Introduction: Individual oral stent is a mouth-opening device that used in head and neck cancer radiotherapy with the intention of decreasing radiation dose to health tissues. The aim of this study was to check the dose delivered to both the hard palate and tongue when patient uses the stent during radiotherapy of tongue carcinoma. Methods and materials: The intraoral stents were made for 10 patients and TLD-100 dosimeters were placed at superior and inferior parts of stent at the level of hard palate and tongue, respectively. Then patients treated with 3DCRT technique using 6MV photons, the data from the TLDs and treatment planning system calculations were analyzed. Results: The results showed that the mean (±standard deviation) relative difference between measured and calculated doses for tongue and hard palate was -4.41± 6.34, 0.57± 9.6 respectively. Conclusion: This study demonstrated the value of thermoluminescent dosimetry as a treatment verification method and its usefulness departmental quality assurance program.