Evaluation of Field-in-Field Technique for Total Body Irradiation

Onal, Cem; Sonmez, Aydan; Arslan, G.; Sonmez, Serhat; Efe, Esma; Oymak, Ezgi

doi:10.1016/j.ijrobp.2011.10.045

Cited by 22 publications

(27 citation statements)

References 20 publications

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“…14 The calculations of the treatment plan were verified by in vivo dosimetric measurements to be within a 6% error range, which is consistent with values in the literature. [14][15][18][19] The dose to the umbilicus mid-plane was taken to be 200 cGy, and the dose to the lungs was 133 cGy. Percent differences were calculated per patient, and the average percent difference was tabulated for each reference point.…”

Section: Discussionmentioning

confidence: 99%

Total Body Irradiation Using a Modified Standing Technique: In Vivo Dosimetry with Semiconductor Diodes

Çeçen¹

2013

UHOD

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The aim of this study was to establish a fast and simple online dosimetric verification method for total body irradiation (TBI) using semiconductor diodes. Twenty one patients were treated with fractionated TBI (12 Gy, 2 Gy BID) using a modified standing technique between February 2010 and March 2012. The prescribed dose was administered to the patient's mid-plane at the level of the umbilicus. The lungs were shielded to allow only the absorption of an 8 Gy dose. To verify the dose administered during TBI, 12 semiconductor diodes were attached to the patient's skin to measure the entrance and exit doses at six anatomical reference points (umbilicus, lungs, neck, forehead, hand, and knee). An adapted version of the arithmetic method which uses a correction factor was used to calculate the mid-plane doses from the entrance and exit dose measurements. The mid-plane doses were then compared with the expected doses. The results of in vivo dosimetry showed that the mid-plane dose calculations conducted using the adapted arithmetic method were consistent with the expectations of the treatment plan. The average percentage dose differences and standard deviations were -0.5 ± 5.3 % for the neck, -2.1 ± 3.7 % for the umbilicus, 2.8 ± 5.2 % for the forehead, and -5.9 ± 11.1 % for the lungs. The extremity doses (hand and knee) were not calculated in the treatment planning program; however they were measured for documentary purposes. In vivo dose verification under TBI conditions was efficiently conducted through the use of semiconductor diodes. The measurement results were consistent with treatment plan dose calculations. The modified standing technique provides a practical method for TBI treatments. The observed heterogeneity is acceptable, the technique does not require additional shields or bolus material, the dosimetric verification is simple and fast, the set-up of the patient is easily reproducible, and the treatment time is within the acceptable limits for a non-dedicated treatment machine. Keywords: Total body irradiation, In vivo dosimetry, Semiconductor diodes ÖZET Modifiye-Ayakta Tedavi Tekni¤i ile Tüm Vücut Ifl›nlamas›: Yar›-iletken Diyotlarla ‹n-vivo DozimetriBu çal›flmada amaç tüm vücut ›fl›nlamas›nda (TVI) h›zl›, kolay ve eflzamanl› bir dozimetrik do¤rulama yöntemi olan yar› iletken diyotlar› klinik uygulamaya geçirmektir. fiubat 2010 ve Mart 2012 tarihleri aras›nda 21 hastaya modifiye-ayakta tedavi tekni¤i ile fraksiyone TVI uygulanm›flt›r (12 Gy, 2 Gy BID). Tan›mlanan doz umbilikus hizas›nda orta-hatta olacak flekilde uyguland›. Akci¤erler toplamda sadece 8 Gy doz so¤urulacak flekilde korundu. TVI s›ras›nda verilen dozu do¤rulamak için 12 yar› iletken diyot cilt yüzeyine, girifl ve ç›k›fl dozlar›n› ölçecek flekilde, alt› farkl› anatomik referans noktas›na (umbilikus, akci¤er, boyun, al›n, el ve diz) yerlefltirildi. Orta-hat dozlar› aritmetik metodun düzeltme faktörü içeren bir uyarlamas› ile girifl ve ç›k›fl doz ölçümleri kullan›larak hesapland›. Daha sonra orta-hat dozlar› beklenen dozlar ile karfl›...

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Section: Discussionmentioning

confidence: 99%

Total Body Irradiation Using a Modified Standing Technique: In Vivo Dosimetry with Semiconductor Diodes

Çeçen¹

2013

UHOD

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“…5 The field-in-field (FIF) technique, also named as forward IMRT planning, is a simple preferred method that can be performed at any center that has a multileaf collimator (MLC). 6,7 Although the FIF technique achieves a more homogenous dose distribution compared with standard tangential field RT, IMRT plans can be more susceptible to set-up errors and breast shape changes because IMRT plans contain nonglancing segments. 8 Both organ motion and patient positioning inaccuracies have been well documented for various breast RT techniques [9][10][11] ; however, the impact of motion on dosimetry for the FIF technique has not yet been well studied.…”

Section: Inroductionmentioning

confidence: 99%

Effects of Setup Errors on Dose Distribution for Tangential Wedge Field and Field-in-Field Techniques During Breast Irradiation

Önal¹

2014

UHOD

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This study is aimed to evaluate the effects of setup errors on dose distribution for target volume and healthy tissue within the irradiated volume and also critical surrounding organs for breast radiotherapy (RT) using both the tangential field and the field-in-field (FIF) technique. Ten patients with breast cancer were enrolled. For each patients two plans were generated; tangential field plan and FIF-plan. The setup errors were simulated for a series of displacements of ±5 mm and ±10 mm in superior-inferior (x-axis), medial-lateral (y-axis), and anteriorposterior (z-axis) directions and dose volume comparisons were made both between and within groups. The most prominent changes were observed in setup errors at z-axis. In wedge plan, 10-mm setup error at the +z axis caused a significant decrease in tumor coverage compared with the plan with no setup error (96.5% vs. 99.2%; p= 0.01). The 5 and 10 mm setup errors at the +z-axis resulted in significantly higher healthy tissue doses in wedge plans compared with FIF plans. The setup errors along z-axis had a significant effect on the dose distribution for target volume and also to the lungs. The setup error in the isocenter should be kept strictly below 5 mm.Keywords: Breast cancer, Radiotherapy, Field-in-field technique, Setup errors ÖZET Meme Radyoterapisi Sırasında Set-up Hatalarının Tanjansiyel Wedge ve Field-in-field Tekniklerindeki Doz Dağılımına EtkileriBu çalışmanın amacı, meme radyoterapisi (RT) sırasında kullanılan tanjansiyel alan ve 'field-in-field' (FIF) tekniklerindeki set-up hatalarının hedef hacim, ışınlanan hacimdeki sağlıklı doku ve çevre organ dozları üzrindeki etkilerini değerlendirmektir. Meme kanseri tanılı 10 hasta çalışmaya dahil edilmiştir. Her hasta için ikişer plan oluşturulmuştur: tanjansiyel alan ve FIF tekniği. Set-up hataları superior-inferior (x-axis), medial-lateral (y-axis), and anterior-posterior (z-axis) istikamatte ±5 mm ve ±10 mm olarak oluşturulmuş olup, doz volüm karşılaştırmaları hem grup içinde hem de gruplar arasında yapılmıştır. En belirgin değişiklik z-axis de gözlenmiştir. Tanjansiyel planda +z-axis de oluşan 10 mm lik setup hatasındaki hedef hacimi kapsama, set up hatası olmayan plana gore anlamlı düşük bulunmuştur (%96.5 vs. %99.2; p= 0.01). +z-axisteki 5 ve 10 mm'lik setup hataları sonucunda oluşan sağlıklı doku dozları tanjansiyel planda FIF planına gore anlamlı olarak yüksek bulunmuştur. z-axisteki hatalar hem hedef volüm hem de akciğer dozlarında belirgin bir etki yaratmaktadır. İzosentrdaki hataların 5 mm nin altında olması güvenlidir.Anahtar Kelimeler: Meme kanseri, Radyoterapi, Field-in-field tekniği, Setup hataları

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“…An added benefit of the latter approach is that at an extended distance, the patient can be treated in two large fields, and with two patient positions per fraction (one field each for prone and supine, or one each of left and right lateral fields). Otherwise, TBI would require more complex radiation planning (eg, multiple unmodulated arcs, field‐in‐field, helical tomotherapy, translation of the patient longitudinally under a stationary radiation source) . Regardless of how the plan is made, care must be taken to create a relatively homogeneous dose distribution both internally, and at the skin surface.…”

Section: Introductionmentioning

confidence: 99%

Implementation of total body photon irradiation as part of an institutional bone marrow transplant program for the treatment of canine lymphoma and leukemias

Gieger

Nolan

Roback

et al. 2019

Vet Radiology Ultrasound

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A total body irradiation (TBI) protocol was developed to support a bone marrow transplant (BMT) program for the treatment of canine hematologic malignancies. The purpose of this prospective study is to describe implementation of the protocol and resultant dosimetry. Nongraphic manual treatment planning using 6 MV photons, isocentric delivery, 40 × 40 cm field size, wall-mounted lasers to verify positioning, a lucite beam spoiler (without use of bolus material), a dose rate of 8.75 cGy/min at patient isocenter, and a source-to-axis distance of 338 cm were used for TBI. A monitor unit calculation formula was derived using ion chamber measurements and a solid water phantom. Five thermoluminescent dosimeters (TLDs) were used at various anatomic locations in each of four cadaver dogs, to verify fidelity of the monitor unit formula prior to clinical implementation. In vivo dosimetric data were then collected with five TLDs at various anatomic locations in six patients treated with TBI. A total dose of 10 Gy divided into two 5 Gy fractions was delivered approximately 16 h apart, immediately followed by autologous stem cell transplant. The mean difference between prescribed and delivered doses ranged from 99% to 109% for various sites in cadavers, and from 83% to 121% in clinical patients. The mean total body dose in cadavers and clinical patients when whole body dose was estimated by averaging doses measured by variably placed TLDs ranged from 98% to 108% and 93% to 102% of the prescribed dose, respectively, which was considered acceptable. This protocol could be used for institutional implementation of TBI. K E Y W O R D Scadaver, lymphosarcoma, myeloablation, thermoluminescent dosimeter 1 586

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Evaluation of Field-in-Field Technique for Total Body Irradiation

Cited by 22 publications

References 20 publications

Total Body Irradiation Using a Modified Standing Technique: In Vivo Dosimetry with Semiconductor Diodes

Total Body Irradiation Using a Modified Standing Technique: In Vivo Dosimetry with Semiconductor Diodes

Effects of Setup Errors on Dose Distribution for Tangential Wedge Field and Field-in-Field Techniques During Breast Irradiation

Implementation of total body photon irradiation as part of an institutional bone marrow transplant program for the treatment of canine lymphoma and leukemias

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