Midplane dose determination during total body irradiation using in vivo dosimetry

Ribas, M.; Jornet, N.; Eudaldo, T.; Carabante, Dolores; Duch, M.A.; Ginjaume, M.; Segura, G. Gómez de; Sánchez‐Doblado, F.

doi:10.1016/s0167-8140(98)00094-2

Cited by 23 publications

(32 citation statements)

References 9 publications

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“…As their influence is only small (< 0.5%), other parameters (like dependence on temperature and direction) can be ignored [14]. Quantification of the total dose of relevant points in the patient's mid plane was initially determined by a simplification (D mid plane (noncorrected) = D entrance + D exit ) [17]. Systematic measurements have shown that the dose reading of the diodes depends on the patient's diameter.…”

Section: Dosimetry Systemmentioning

confidence: 99%

In Vivo Dosimetry with Semiconducting Diodes for Dose Verification in Total-Body Irradiation

et al. 2008

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Section: Dosimetry Systemmentioning

confidence: 99%

In Vivo Dosimetry with Semiconducting Diodes for Dose Verification in Total-Body Irradiation

et al. 2008

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“…In order to deliver a homogeneous dose across the body and to limit doses to organs at risk, the beams are modulated using bolus, compensators or shielding. In vivo dosimetry with thermoluminescent dosimeters (TLDs) or semiconductor diodes allows entry and exit doses to be recorded during treatment and used to calculate delivered midline doses 1 , 2 , 3 , 4 , 5 , 6 . These verify the delivery of the prescribed dose and indirectly check the patient position.…”

Section: Introductionmentioning

confidence: 99%

In vivo dosimetry for total body irradiation: five‐year results and technique comparison

Patel

Warry

Eaton

et al. 2014

J Applied Clin Med Phys

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The aim of this work is to establish if the new CT‐based total body irradiation (TBI) planning techniques used at University College London Hospital (UCLH) and Royal Free Hospital (RFH) are comparable to the previous technique at the Middlesex Hospital (MXH) by analyzing predicted and measured diode results. TBI aims to deliver a homogeneous dose to the entire body, typically using extended SSD fields with beam modulation to limit doses to organs at risk. In vivo dosimetry is used to verify the accuracy of delivered doses. In 2005, when the Middlesex Hospital was decommissioned and merged with UCLH, both UCLH and the RFH introduced updated CT‐planned TBI techniques, based on the old MXH technique. More CT slices and in vivo measurement points were used by both; UCLH introduced a beam modulation technique using MLC segments, while RFH updated to a combination of lead compensators and bolus. Semiconductor diodes were used to measure entrance and exit doses in several anatomical locations along the entire body. Diode results from both centers for over five years of treatments were analyzed and compared to the previous MXH technique for accuracy and precision of delivered doses. The most stable location was the field center with standard deviations of 4.1% (MXH), 3.7% (UCLH), and 1.7% (RFH). The least stable position was the ankles. Mean variation with fraction number was within 1.5% for all three techniques. In vivo dosimetry can be used to verify complex modulated CT‐planned TBI, and demonstrate improvements and limitations in techniques. The results show that the new UCLH technique is no worse than the previous MXH one and comparable to the current RFH technique.PACS numbers: 87.55.Qr, 87.56.N‐

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“…Ribas ve ark. [8] da Duch ve ark. ile aynı klinikte aynı tekniği kullanarak TVI'da orta hat dozunu belirlemek için in-vivo dozimetri kullanımına dayanan bir algoritma geliştirmişlerdir.…”

Section: Discussionunclassified

“…Ribas ve ark. [8] her hasta için teorik giriş ve çıkış dozlarını hesaplamışlardır. TLD ölçümlerinin %4, genelde %10'dan büyük olan sapmaların kalınlığı 25 cm üzerinde olan obez hastalarda olduğunu vurgulamışlardır.…”

Section: Tablounclassified

Midplane dose determination and verification of calculated doses in total body irradiation

OZDEMIR¹

2013

TJ Oncol

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OBJECTIVESTo compare calculated and measured doses for different regions of anthropomorphic phantom and patients using ion chamber and thermoluminescence dosimetry (TLD) for total body irradiation. METHODSMeasurements were done for lateral fields with 6 MV, gantry 82º, 40x40 cm 2 field and 400 cm source-axis distance (SAD). Entrance-exit and midline doses were measured on anthropomorphic phantom by TLD and entrance-exit doses were measured by TLD and ion chamber on patients. RESULTSFor anthropomorphic phantom measurements differences between calculated and measured entrance-exit doses of head, neck, shoulder, lung and thick pelvis were 0.8%, 2.7%, 26.4%, 4.4% and 4.9% and for midline doses were 1.6%, 1.6%, 6.3%, -1.4% and 7.4% respectively. For patients; TLD differences were within -4.13% ile 6.7%, -3.3% ile 3.9%, 5.1% ile 16.6%, -7.8% ile 2.4%, and 3.6% ile 7.1% respectively. For thick pelvis measurements with ion chamber differences were within %0.1-1.9. CONCLUSIONTotal body irradiation is being applied in limit values in our clinic.Key words: Total body irradiation, in-vivo dosimetry, thermoluminescence dosimetry. AMAÇTüm vücut ışınlamada (TVI) iyon odası ve termolüminesans dozimetri (TLD) kullanarak antropomorfik fantomda ve hastalarda farklı bölgelerde hesaplanan ve ölçülen dozları karşı-laştırmaktır. GEREÇ VE YÖNTEMÖlçümler lateral sahalarda 6 MV foton, 82º gantri, 40x40 cm 2 alan ve kaynak-eksen mesafesi (SAD) 400 cm'de gerçekleşti-rildi. Antropomorfik fantomda TLD ile giriş-çıkış ve orta hat dozları, hastalarda ise TLD ve iyon odası ile giriş-çıkış dozları ölçüldü. BULGULARFantom sonuçlarında giriş-çıkışta ölçülen ve hesaplanan doz değerleri arasında baş, boyun, omuz, akciğer ve kalın pelviste %0.8, %2.7, %26.4, %4.4 ve %4.9, orta hatta baş, boyun, omuz, akciğer ve kalın pelviste %1.6, %1.6, %6.3, -%1.4 ve %7.4 farklılık saptandı. Hastalarda TLD sonuçlarına göre baş, boyun, omuz, akciğer ve kalın pelviste % -4.13 ile %6.7, % -3.3 ile %3.9, %5.1 ile %16.6, % -7.8 ile %2.4, ve %1.04 ile %7.1, referans noktası için iyon odası sonuçlarında %0.1 ile %1.9 arasında farklılıklar gözlendi. SONUÇTüm vücut ışınlama tedavisi kliniğimizde limit değerler içeri-sinde uygulanmaktadır.Anahtar sözcükler: Tüm vücut ışınlama, in-vivo dozimetri, termolüminesans dozimetri.

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Midplane dose determination during total body irradiation using in vivo dosimetry

Cited by 23 publications

References 9 publications

In Vivo Dosimetry with Semiconducting Diodes for Dose Verification in Total-Body Irradiation

In Vivo Dosimetry with Semiconducting Diodes for Dose Verification in Total-Body Irradiation

In vivo dosimetry for total body irradiation: five‐year results and technique comparison

Midplane dose determination and verification of calculated doses in total body irradiation

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