{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T23:16:03Z","timestamp":1771024563112,"version":"3.50.1"},"reference-count":22,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2020,3,11]],"date-time":"2020-03-11T00:00:00Z","timestamp":1583884800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Safe quality control of radiotherapy treatments lies in reliable dosimetric sensors. Currently, ionization chambers and solid-state diodes along with electrometers as readout systems are accomplishing this task. In this work, we present a well-known and low-cost semiconductor sensor, the light-dependent resistor (LDR), as an alternative to the existing sensing devices for dosimetry. To demonstrate this, a complete characterization of the response to radiation of commercial LDRs has been conducted in terms of sensitivity, reproducibility and thermal correction under different bias voltages. Irradiation sessions have been applied under the common conditions in radiotherapy treatments using a hospital linear accelerator. Moreover, the same electrometer used for the ionization chamber has also been successfully used for LDRs. In comparison with the sensitivity achieved for the ionization chamber (0.2 nC\/cGy at 400 V bias voltage), higher sensitivities have been measured for the proposed LDRs, ranging from 0.24 to 1.04 nC\/cGy at bias voltages from 30 to 150 V, with a reproducibility uncertainty among samples of around 10%. In addition, LDR temperature dependence has been properly modeled using the simple thermistor model so that an easy thermal drift correction of dose measurements can be applied. Therefore, experimental results show that LDRs can be a reliable alternative to dosimetric sensors with the advantages of low size, affordable cost and the fact that it could be adopted with minimal changes in routine dosimetry quality control since the same readout system is fully compatible.<\/jats:p>","DOI":"10.3390\/s20061568","type":"journal-article","created":{"date-parts":[[2020,3,12]],"date-time":"2020-03-12T04:13:57Z","timestamp":1583986437000},"page":"1568","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Light-Dependent Resistors as Dosimetric Sensors in Radiotherapy"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7932-925X","authenticated-orcid":false,"given":"Juan","family":"Rom\u00e1n-Raya","sequence":"first","affiliation":[{"name":"Instituto de Investigaci\u00f3n Biosanitaria, Ibs.Granada. Hospital Universitario Cl\u00ednico San Cecilio, 18160 Granada, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2522-6108","authenticated-orcid":false,"given":"Isidoro","family":"Ruiz-Garc\u00eda","sequence":"additional","affiliation":[{"name":"ECsens, Department of Electronics and Computer Technology, Sport and Health University Research Institute (iMUDS), University of Granada, 18071 Granada, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1701-8878","authenticated-orcid":false,"given":"Pablo","family":"Escobedo","sequence":"additional","affiliation":[{"name":"Bendable Electronics and Sensing Technologies (BEST) Group, Electronics and Nanoscale Engineering, University of Glasgow, Glasgow G128QQ, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9050-5413","authenticated-orcid":false,"given":"Alberto J.","family":"Palma","sequence":"additional","affiliation":[{"name":"ECsens, Department of Electronics and Computer Technology, Sport and Health University Research Institute (iMUDS), University of Granada, 18071 Granada, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3257-360X","authenticated-orcid":false,"given":"Dami\u00e1n","family":"Guirado","sequence":"additional","affiliation":[{"name":"Instituto de Investigaci\u00f3n Biosanitaria, Ibs.Granada. Hospital Universitario Cl\u00ednico San Cecilio, 18160 Granada, Spain"},{"name":"CIBER de Epidemiolog\u00eda y Salud P\u00fablica (CIBERESP), 18016 Granada, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0234-4758","authenticated-orcid":false,"given":"Miguel A.","family":"Carvajal","sequence":"additional","affiliation":[{"name":"Instituto de Investigaci\u00f3n Biosanitaria, Ibs.Granada. Hospital Universitario Cl\u00ednico San Cecilio, 18160 Granada, Spain"},{"name":"ECsens, Department of Electronics and Computer Technology, Sport and Health University Research Institute (iMUDS), University of Granada, 18071 Granada, Spain"}]}],"member":"1968","published-online":{"date-parts":[[2020,3,11]]},"reference":[{"key":"ref_1","unstructured":"Knoll, G.F. (2000). Radiation Detection and Measurement, John Wiley & Sons, Inc. [3rd ed.]."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"R303","DOI":"10.1088\/0031-9155\/59\/20\/R303","article-title":"Review on the characteristics of radiation detectors for dosimetry and imaging","volume":"59","author":"Seco","year":"2014","journal-title":"Phys. Med. Biol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"987","DOI":"10.1016\/S0360-3016(97)00894-8","article-title":"Calibration of a MOSFET detection system for 6-MV in vivo dosimetry","volume":"40","author":"Scalchi","year":"1998","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2658","DOI":"10.1118\/1.1778809","article-title":"An implantable radiation dosimeter for use in external beam radiation therapy","volume":"31","author":"Scarantino","year":"2004","journal-title":"Med. Phys."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"4031","DOI":"10.1088\/0031-9155\/49\/17\/014","article-title":"Performance characteristics of a microMOSFET as an in vivo dosimeter in radiation therapy","volume":"49","author":"Ramaseshan","year":"2004","journal-title":"Phys. Med. Biol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/j.radmeas.2007.01.005","article-title":"Electronic dosimetry in radiation therapy","volume":"41","author":"Rosenfeld","year":"2006","journal-title":"Radiat. Meas."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Ruiz-Arrebola, S., Fabregas-Borr\u00e1s, R., Rodr\u00edguez, E., Fernandez-Montez, M., P\u00e9rez-Macho, M., Ferri, M., Garc\u00eda, A., Cardenal, J., Pacheco, M.T., and Anchuelo, J. (2020). Characterization of microMOSFET detectors for in vivo dosimetry in high-dose rate brachytherapy with 192Ir. Med. Phys.","DOI":"10.1002\/mp.14080"},{"key":"ref_8","first-page":"235","article-title":"Radfet\u2014A Review of the Use of Metal-Oxide Silicon Devices as Integrating Dosimeters","volume":"28","author":"Adams","year":"1986","journal-title":"Radiat. Phys. Chem."},{"key":"ref_9","unstructured":"Sons, J.W. (1989). Ionizing Radiation Effects in MOS Devices and Circuits, John Wiley & Sons."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1016\/j.sna.2016.06.009","article-title":"Dose verification system based on MOS transistor for real-time measurement","volume":"247","author":"Carvajal","year":"2016","journal-title":"Sens. Actuators A Phys."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/j.sna.2016.11.007","article-title":"Response to ionizing radiation of different biased and stacked pMOS structures","volume":"252","author":"Jaksic","year":"2016","journal-title":"Sens. Actuators A Phys."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1093\/oxfordjournals.rpd.a005956","article-title":"Filtered X ray beam dosimetry from 10(-3) to 10(2) Gy dose range by using phototransistors","volume":"101","author":"Santos","year":"2002","journal-title":"Radiat. Prot. Dosim."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"112","DOI":"10.1016\/j.ejmp.2014.11.001","article-title":"Characterization of a low-cost PIN photodiode for dosimetry in diagnostic radiology","volume":"31","author":"Romei","year":"2015","journal-title":"Phys. Med."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/j.radmeas.2015.03.005","article-title":"Current mode response of phototransistors to gamma radiation","volume":"75","year":"2015","journal-title":"Radiat. Meas."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1504","DOI":"10.1118\/1.1489042","article-title":"An in-phantom dosimetry system using pin silicon photodiode radiation sensors for measuring organ doses in X-ray CT and other diagnostic radiology","volume":"29","author":"Aoyama","year":"2002","journal-title":"Med. Phys."},{"key":"ref_16","first-page":"92","article-title":"Characterization of three photodetector types for computed tomography dosimetry","volume":"80","author":"Paschoal","year":"2011","journal-title":"World Acad. Sci. Eng. Technol."},{"key":"ref_17","unstructured":"Fraden, J. (2010). Handbook of Modern Sensors Physics, Designs, and Applications, Springer. [4th ed.]."},{"key":"ref_18","unstructured":"Sze, S.M. (1981). Physics of Semiconductor Devices, John Wiley & Sons."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"204","DOI":"10.1016\/S0368-3273(15)30029-8","article-title":"The Use of Cadmium Sulphide Photo-Conductors in Radiation Dosimetry","volume":"1","author":"Deev","year":"1960","journal-title":"J. Nucl. Energy. Part B React. Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1007\/BF00179227","article-title":"Radiation effects on non-linear resistances","volume":"4","author":"Soliman","year":"1993","journal-title":"J. Mater. Sci. Mater. Electron."},{"key":"ref_21","unstructured":"American Association of Physicists in Medicine (2005). Report No. 87. Diode in Vivo Dosimetry for Patients Receiving External Beam Radiation Therapy, Medical Physics Publishing. Available online: https:\/\/www.aapm.org\/pubs\/reports\/RPT_87.pdf."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1063\/1.4751626","article-title":"The electrical conductivity and thermoelectric power dependence on the thicknesses for thermally deposited thin CdS films","volume":"1476","author":"Abdullah","year":"2012","journal-title":"AIP Conf. Proc."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/6\/1568\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:06:12Z","timestamp":1760173572000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/6\/1568"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,3,11]]},"references-count":22,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2020,3]]}},"alternative-id":["s20061568"],"URL":"https:\/\/doi.org\/10.3390\/s20061568","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,3,11]]}}}