Feasibility of Margin Reduction for Level II and III Planning Target Volume in Head-and-Neck Image-Guided Radiotherapy – Dosimetric Assessment via A Deformable Image Registration Framework

2015 ◽  
Vol 10 (4) ◽  
pp. 323-333 ◽  
Author(s):  
X. Qi ◽  
John Neylon ◽  
Sumeyra Can ◽  
Robert Staton ◽  
Jason Pukala ◽  
...  
Keyword(s):  
Image Registration ◽  
Head And Neck ◽  
Planning Target Volume ◽  
Deformable Image Registration ◽  
Target Volume ◽  
Image Guided Radiotherapy ◽  
Image Guided ◽  
Level Ii ◽  
Dosimetric Assessment

scholarly journals Set-up Errors and Determination of Planning Target Volume Margins Protocol for Different Anatomical Sites in a Newly Established Tertiary Radiotherapy Centre in India

2020 ◽  
Vol 6 (02) ◽  
pp. 81-87
Author(s):  
Avik Mandal ◽  
Pritanjali Singh ◽  
Soumen Bera ◽  
Avajeet Kumar ◽  
Dharmendra Singh ◽  
...  
Keyword(s):  
Head And Neck ◽  
Planning Target Volume ◽  
Random Error ◽  
Target Volume ◽  
Curative Intent ◽  
Image Guided Radiotherapy ◽  
Image Guided ◽  
Number Of Patients ◽  
Set Up ◽  
The Brain

Abstract Objective Our study aimed to assess the set-up errors for image-guided radiotherapy at a newly established tertiary radiation center in India and to establish the departmental protocol of clinical target volume–planning target volume (CTV–PTV) margins for different anatomical sites. Materials and Methods This study enrolled the first 200 patients who were treated with curative intent at All India Institute of Medical Sciences, Patna, from February 2019 to September 2019. Number of patients were 53, 26, 53, 11, 6, 47, and 4 for head and neck, brain, breast, thorax, abdomen, pelvis, and craniospinal irradiation (CSI), respectively. The translational vectors for total 1,463 kV cone-beam computed tomography (CBCT) images were collected from the treatment record. Results For the systematic error, the largest value is found for the thoracic subset on the X and Y directions, and for breast patients on Z axis, whereas the smallest values were found for CSI. For random error, the largest value was found for pelvic in the X, Y direction, and for breast subset on Z axis, whereas the smallest values on X and Z axes were found in the brain and for head and neck on the Y axis. Largest value for systemic error is smaller than 5 mm in all directions and for all anatomical subsets. The highest random error value is 5.07 mm in Y axis for pelvic subset. The largest values for CTV–PTV margin are found for thoracic subset and the smallest for CSI followed by the brain. Significant reduction of set-up error observed for the last hundred patients as compared to the first half of the patient population. Conclusion Use of thermoplastic cast along with breast board and respiratory motion management should be recommended to reduce set-up error for breast and thoracic subset. Six degrees of freedom robotic couch system can also further rectify the set-up error in image-guided radiotherapy.

scholarly journals Noncoplanar Radiation using Tomotherapy: A Phantom Study

2020 ◽  
Vol 19 ◽  
pp. 153303382094577
Author(s):  
Masahiro Yuasa ◽  
Hiromasa Kurosaki
Keyword(s):  
Image Registration ◽  
Head And Neck ◽  
Treatment Planning ◽  
Planning Target Volume ◽  
Dose Distribution ◽  
Deformable Image Registration ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Computed Tomography Images

Background: There are very few studies on noncoplanar radiation in tomotherapy because deformable image registration is not implemented in the TomoTherapy Planning Station, a treatment planning device used in tomotherapy. This study examined whether noncoplanar radiation can be performed on the head using a tilt-type head and neck fixture and deformable image registration. Methods: Planning target volume spheres with diameters of 2, 3, and 4 cm were set on a head phantom, and computed tomography images were taken at 0° and 40° using a tilt-type head and neck fixture. Irradiation plans were created in the Tomotherapy Planning Station. Noncoplanar radiation was simulated, and the dose volume was evaluated by adding the 0° dose distribution and 40° dose distribution using the deformable image registration of the RayStation treatment planning system. Results: The ratio of the phantom volume to the irradiation dose for 20% to 30% of the planning target volume in noncoplanar radiation was smaller than that for 40% to 90% of the planning target volume in single-section irradiation at 0° or 40°. Conclusions: Noncoplanar radiation on the head region using tomotherapy was possible by using a tilt-type head and neck fixture, and the dose distribution could be evaluated using deformable image registration. This method helps reduce the dose of the organ-at-risk region located slightly away from the planning target volume.

scholarly journals Evaluation of interfraction patient setup errors for image-guided prostate and head-and-neck radiotherapy using kilovoltage cone beam and megavoltage fan beam computed tomography

2013 ◽  
Vol 12 (4) ◽  
pp. 334-343 ◽  
Author(s):  
X. Sharon Qi ◽  
Sutan Wu ◽  
Francis Newman ◽  
X. Allen Li ◽  
Angie Y. Hu
Keyword(s):  
Computed Tomography ◽  
Head And Neck ◽  
Target Volume ◽  
Cone Beam ◽  
Setup Errors ◽  
Image Guided Radiotherapy ◽  
Image Guided ◽  
Significant Difference ◽  
Late Stages ◽  
Head And Neck Radiotherapy

AbstractPurposeTo analyse interfraction setup using two different image guidance modalities for prostate and head-and-neck (H&N) cancer treatment.Materials and methodsSeventy-two prostate and 60 H&N cancer patients, imaged with kilovoltage cone beam computed tomography (KVCBCT) or megavoltage fan beam computed tomography (MVFBCT), were studied retrospectively. The daily displacements in mediolateral (ML), craniocaudal (CC) and anteroposterior (AP) dimensions were investigated. The setup errors were calculated to determine the clinical target volume to planning target volume (CTV-to-PTV) margins.ResultsBased on 1,606 KVCBCT and 2,054 MVFBCT scans, average interfraction shifts in ML, CC and AP direction for H&N cases were 0·5 ± 1·5, −0·3 ± 2·0, 0·3 ± 1·7 mm using KVCBCT, 0·2 ± 1·9, −0·2 ± 2·4 and 0·0 ± 1·7 mm using MVFBCT. For prostate cases, average interfraction displacements were −0·3 ± 3·9, 0·2 ± 2·4, 0·4 ± 3·8 mm for MVFBCT and −0·2 ± 2·7, −0·6 ± 2·9, −0·5 ± 3·4 mm for KVCBCT. The calculated CTV-to-PTV margins, if determined by image-guided radiotherapy (IGRT) data, were 5·6 mm (H&N) and 7·8 mm (prostate) for MVFBCT, compared with 4·8 mm and 7·2 mm for KVCBCT. We observed no statistically significant difference in daily repositioning using KVCBCT and MVFBCT in early, middle and late stages of the treatment course.ConclusionIn the absence of IGRT, the CTV-to-PTV margin determined using IGRT data, may be varied for different imaging modalities for prostate and H&N irradiation.

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