A comparison between four immobilization systems for pelvic radiation therapy using CBCT and paired kilovoltage portals based image-guided radiotherapy

AbstractThe sharp dose gradients in intensity-modulated radiation therapy increase the treatment sensitivity to various inter- and intra-fractional uncertainties, in which a slight anatomical change may greatly alter the actual dose delivered. Image-guided radiotherapy refers to the use of advanced imaging techniques to precisely track and correct these patient-specific variations in routine treatment. It can also monitor organ changes during a radiotherapy course. Currently, image-guided radiotherapy using computed tomography has gained much popularity in radiotherapy verification as it provides volumetric images with soft-tissue contrast for on-line tracking of tumour. This article reviews four types of computed tomography-based image guidance systems and their working principles. The system characteristics and clinical applications of the helical, megavoltage, computed tomography, and kilovoltage, cone-beam, computed tomography systems are discussed, given that they are currently the most commonly used systems for radiotherapy verification. This article also focuses on the recent techniques of soft-tissue contrast enhancement, digital tomosynthesis, four-dimensional fluoroscopic image guidance, and kilovoltage/megavoltage, in-line cone-beam imaging. These evolving systems are expected to take over the conventional two-dimensional verification system in the near future and provide the basis for implementing adaptive radiotherapy.

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Preoperative Image Guided Versus Conventional Pelvic Radiation Therapy for Locally Advanced Rectal Carcinoma: Comparison of Clinical Outcomes and Toxicity

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/j.ijrobp.2014.05.1234 ◽

2014 ◽

Vol 90 (1) ◽

pp. S384

Author(s):

C. Huang ◽

H. Chih-Jen ◽

H. Ming-Yii ◽

W. Jaw-Yuan

Keyword(s):

Radiation Therapy ◽

Clinical Outcomes ◽

Rectal Carcinoma ◽

Locally Advanced ◽

Pelvic Radiation ◽

Image Guided ◽

Preoperative Image

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Optimising Radiation Therapy in Head and Neck Cancers Using Functional Image-Guided Radiotherapy and Novel Biomarkers

Case Medical Research ◽

10.31525/ct1-nct04242459 ◽

2020 ◽

Author(s):

Keyword(s):

Radiation Therapy ◽

Head And Neck ◽

Head And Neck Cancers ◽

Image Guided Radiotherapy ◽

Image Guided ◽

Functional Image ◽

Novel Biomarkers

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Functional Image-guided Radiotherapy Planning in Respiratory-gated Intensity Modulated Radiation Therapy (IMRT) for Lung Cancer Patients with Pulmonary Emphysema

International Journal of Radiation Oncology*Biology*Physics ◽

10.1016/j.ijrobp.2010.07.1677 ◽

2010 ◽

Vol 78 (3) ◽

pp. S723 ◽

Cited By ~ 1

Author(s):

T. Kimura ◽

I. Nishibuchi ◽

Y. Murakami ◽

M. Kenjo ◽

Y. Kaneyasu ◽

...

Keyword(s):

Lung Cancer ◽

Radiation Therapy ◽

Cancer Patients ◽

Intensity Modulated Radiation Therapy ◽

Radiotherapy Planning ◽

Image Guided Radiotherapy ◽

Lung Cancer Patients ◽

Image Guided ◽

Intensity Modulated ◽

Functional Image

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Image-guided radiation therapy for carcinoma of gallbladder: implication on margin for set-up errors

Journal of Radiotherapy in Practice ◽

10.1017/s1460396912000313 ◽

2013 ◽

Vol 12 (3) ◽

pp. 263-271 ◽

Cited By ~ 1

Author(s):

Gagan Saini ◽

Vineeta Goel ◽

Anil K Anand ◽

Kamlesh Kumar Gupta

Keyword(s):

Radiation Therapy ◽

Gall Bladder ◽

Target Volume ◽

Image Guided Radiotherapy ◽

Image Guided Radiation Therapy ◽

Image Guided ◽

Thermoplastic Mask ◽

The Mean ◽

Set Up ◽

Upper Abdominal

AbstractPurposeA retrospective study was undertaken to analyse set-up variations in patients being treated with post-operative radiation therapy for carcinoma of gall bladder by image-guided radiotherapy (IGRT) using cone-beam computed tomography (CBCT) scans and paired kilovoltage beam portals (kVps).Materials and methodsThree consecutive patients receiving post-operative radiation therapy for carcinoma of gall bladder were studied. A total of 32 imaging studies were performed. The immobilisation system was an all-in-one system along with a thermoplastic mask, with knees either resting on the knee rest or in a vacuum cushion. The CBCT scans and kVps were reviewed in an off-line mode. The surrogate markers used for matching during co-registration were 12th rib, coeliac trunk, vertebral bodies and canal. Individual readings were used to calculate mean shifts (m); the mean of these means (M) was calculated to arrive at the systematic error in each direction and its standard deviation (Σ) was calculated. The margins for set-up error (SM) were then calculated.ResultsThere were a total of 32 readings of which 21 were CBCTs and 11 were kVps. The mean shifts in each direction for each patient were 0·06, 0·25 and 0·15 cm in vertical, longitudinal and lateral directions, respectively. The resultant planning target volume margins calculated were 0·24, 0·9 and 0·47 cm in vertical, longitudinal and lateral directions.ConclusionsIGRT for upper abdominal malignancies using CBCT and kVps is a useful method to keep the margins for set-up error low. The use of surrogates for matching should be relevant to the target volume. Good immobilisation system helps in keeping the margins low.

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