Comparison of 2D Radiographic Images and 3D Cone Beam Computed Tomography for Positioning Head-and-Neck Radiotherapy Patients

Li, Heng; Zhu, Xiangxin; Zhang, Lifei; Dong, Lei; Tung, S.; Ahamad, A.; Chao, K.S. Clifford; Morrison, William H.; Rosenthal, David I.; Schwartz, David L.; Mohan, Radhe; Garden, Adam S.

doi:10.1016/j.ijrobp.2008.01.008

Cited by 117 publications

(89 citation statements)

References 26 publications

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“…Previous studies 21 , 37 , 44 have addressed setup uncertainties for brain and H&N treatment sites and described a number of common factors that can contribute to setup errors for these sites. The factors consist of curved external anatomy, a loosening of the fixation mask due to a reduced body contour following weight loss, and tightening of the mask by the swelling of some part of the lesion.…”

Section: Discussionmentioning

confidence: 99%

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Assessment of setup uncertainties for various tumor sites when using daily CBCT for more than 2200 VMAT treatments

Baek

Kim

et al. 2014

J Applied Clin Med Phys

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The aim of this study was assess the patient setup errors for various tumor sites based on clinical data from a sufficient number of treatments with volumetric‐modulated arc therapy (VMAT) using daily pretreatment CBCT imaging guidance. In addition, we calculated and compared the planning target volume (PTV) margins for all disease sites based on an analysis of specific systematic and random errors in our institution. All patients underwent pretreatment kV‐CBCT imaging. The various tumor sites were divided into four categories; 21 brain (438 fractions), 35 head‐and‐neck tumors (H&N, 933 fractions), 19 thorax and abdomen tumors (T&A, 313 fractions), and 17 prostate cancer tumors (546 fractions). Overall distributions of setup corrections in all directions, frequencies of 3D vector lengths, institution‐specific setup error, and PTV margins were analyzed. The longitudinal distribution for the T&A site represented an asymmetric offset in the negative direction. Rotational distributions were comparable for all treatment sites, and the prostate site had the narrowest distribution of ≤±2∘. The cumulative frequencies of 3D vector length of ≥ 7 mm were rare for brain lesions and H&N, but more common for T&A and prostate lesions at 25.6% and 12.1%, respectively. The overall mean error for all treatment sites were within ±1 mm and ±0.1∘, with the exception of the T&A site, which had overall mean error of 2 mm in the negative longitudinal direction. The largest magnitude of systematic error and random error for the brain lesions and H&N was 1.4 mm in the translational directions, and 3.3 mm for T&A and prostate lesions. The PTV margins required in this analysis are ≤ 4 mm for the brain lesions and H&N in all translational directions, but ranged from 4 to 10 mm for T&A and prostate lesions. Analysis of each institution's specific setup errors using daily CBCT is essential for determining PTV margins and reducing setup uncertainties, because setup errors vary according to each immobilization system and patient.PACS number: 87.55.km

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Section: Discussionmentioning

confidence: 99%

“…Based on the previous observation (44) that a patient‐specific vacuum bag headrest can reduce setup errors in the vertical direction, all patients with a tumor in the brain or H&N region used a patient‐specific headrest made from rigid urethane compound.…”

Section: Discussionmentioning

confidence: 99%

Assessment of setup uncertainties for various tumor sites when using daily CBCT for more than 2200 VMAT treatments

Baek

Kim

et al. 2014

J Applied Clin Med Phys

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“…[12][13][14][15] In the literature different techniques have been used for setup procedures for head and neck cancer patients. As a result the defined limits are sparse.…”

Section: Discussionmentioning

confidence: 99%

Determination of the Planning Target Volume Margin by the Use of kv Portal Imaging and kvCone Beam Computerized Tomography.

Yazıcı¹

2013

UHOD

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With portal imaging devices we can easily determine the position of bones in the patient, but we cannot visualize soft tissues. Kilo voltage cone beam computed tomography (CBCT) imaging integrated to treatment machine is relatively a new technique and provides higher resolution of soft tissues for imaging. In this study, our aim was to measure the differences between 2D-2D and 3D-3D registration based set-ups. We investigated whether using kV cone beam CT reduced setup errors compared to kV portal imaging. Four patients with the diagnosis of head and neck cancer (2 patients with cancer in the base of tongue, 2 with hypopharyngeal cancer) and 6 patients with prostate cancer were included in our study. The treatments were delivered with IMRT. kvCBCT-kv film comparisions were evaluated in 44 sets of data for head and neck cancer patients, and in 130 sets of data for prostate cancer patients. We analyzed the necessary planning target volume (PTV) margins for each group when only kv portal imaging is performed every day and found that a margin of 2.1 and 1.5 mm in all directions would be sufficient in case of pelvic tumors and head and neck cancers respectively if the kv portal images are performed every day. Compared to the literature the shifts were minimal when kvCBCT was performed after kv portal imaging. The immobilization procedures, followed strictly, may be reason for this observation.Keywords: Planning target volume margin, Set-up margin, kv portal imaging, Cone beam computed tomography ÖZET kv Portal Görüntüleme ve kvCone Beam Bilgisayarl› Tomografi ile Planlanan Hedef Hacim S›n›rlar›n›n BelirlenmesiPortal görüntüleme yöntemleri ile hastan›n kemik yap›lar›n› kolayca görüntüleyebiliriz, ancak yumuflak dokular bu yöntemle izlenemez. Kilo voltaj cone beam bilgisayarl› tomografi (CBCT) görüntüleme yöntemlerinin tedavi cihazlar›na entegre edilmesi nispeten yeni bir yöntemdir ve yumuflak dokular›n daha yüksek çözünürlükte görüntülemesini sa¤lar. Bu çal›flmada amac›m›z iki buyutlu görüntüleme ifllemleri ile yap›lan set-up ile üç boyutlu görüntüleme yöntemleri ile yap›lan set-up aras›ndaki fark› araflt›rmak ve set-up hatalar› aç›-s›ndan kvCBCT nin portal görüntülemeye göre set-up hatalar›n› ne kadar düzeltti¤ni incelemektir. Dört bafl ve boyun kanserli (2 hasta dil kökü, 2 hasta hipofarinks) ve dört prostat kanserli hasta çal›flmaya dahil edildi. Tedaviler yo¤unluk ayarl› radyoterapi (YART) yöntemi ile uyguland›. Bafl boyun kanserli hastalardan elde olunan 44 kvCBCT-kv portal film karfl›laflt›rmas› ve prostat kanserli hastalardan elde olunan 130 kvCBCT-kv portal film karfl›laflt›rmas› de¤erlendirildi. Analizler sonucunda her gün sadece kv portal görüntüleme yap›ld›¤›nda gerekli PTV emniyetinin bafl boyun kanserleri için 1.5mm ve prostat kanseri için 2.1 mm oldu¤u bulundu. Literatür ile k›yasland›¤›nda kv portal görüntüleme sonras› kvCBCT uyguland›¤›nda kaymalar›n minimal oldu¤u bulunmufltur. Bunun nedenlerinden biri immobilizasyon yöntemlerinin ve haz›rl›k aflamalar›n›n her hasta için özenle uygulanm›fl olm...

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“…Those studies show that there are variations in terms of the observed setup error. 7,[19][20][21] Although the planar kV images are quicker to acquire and to observe apart from offering a lower dose to the patient, 8,11,12 the advantages of using a 3D verification image are the possibility of observing soft tissues with good contrast, like the tumour or the oesophagus, and providing a more accurate match of the area being treated. 5,10,19 …”

Section: Assessment Of Differences Between Planar Kv and Cbctmentioning

confidence: 99%

Use of planar kV vs. CBCT in evaluation of setup errors in oesophagus carcinoma radiotherapy

Martins

Couto

Barbosa

2016

Reports of Practical Oncology & Radiotherapy

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Comparison of 2D Radiographic Images and 3D Cone Beam Computed Tomography for Positioning Head-and-Neck Radiotherapy Patients

Cited by 117 publications

References 26 publications

Assessment of setup uncertainties for various tumor sites when using daily CBCT for more than 2200 VMAT treatments

Assessment of setup uncertainties for various tumor sites when using daily CBCT for more than 2200 VMAT treatments

Determination of the Planning Target Volume Margin by the Use of kv Portal Imaging and kvCone Beam Computerized Tomography.

Use of planar kV vs. CBCT in evaluation of setup errors in oesophagus carcinoma radiotherapy

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