Verification of Planning Target Volume Settings in Volumetric Modulated Arc Therapy for Stereotactic Body Radiation Therapy by Using In-Treatment 4-Dimensional Cone Beam Computed Tomography

2013 ◽  
Vol 86 (3) ◽  
pp. 426-431 ◽  
Author(s):  
Wataru Takahashi ◽  
Hideomi Yamashita ◽  
Satoshi Kida ◽  
Yoshitaka Masutani ◽  
Akira Sakumi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Therapy ◽  
Cone Beam Computed Tomography ◽  
Planning Target Volume ◽  
Stereotactic Body Radiation Therapy ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Cone Beam ◽  
Arc Therapy ◽  
Dimensional Cone

scholarly journals Impact of four-dimensional cone-beam computed tomography on target localization for gastric mucosa-associated lymphoid tissue lymphoma radiotherapy: reducing planning target volume

2020 ◽  
Author(s):  
Yoshinobu Shimohigashi ◽  
Ryo Toya ◽  
Tetsuo Saito ◽  
Yumiko Kono ◽  
Yasuhiro Doi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Soft Tissue ◽  
Gastric Mucosa ◽  
Cone Beam Computed Tomography ◽  
Planning Target Volume ◽  
Lymphoid Tissue ◽  
Target Volume ◽  
Target Localization ◽  
Cone Beam ◽  
Dimensional Cone

Abstract Background: Radiotherapy of gastric mucosa-associated lymphoid tissue (MALT) lymphoma should be delivered to the entire stomach with planning target volume (PTV) that accounts for variations in stomach volume, respiratory movement, and patient set-up error. In this study, we evaluated whether the use of four-dimensional cone-beam computed tomography (4D-CBCT) reduces the PTV. Methods: Eight patients underwent radiotherapy with 15 fractions of gastric MALT lymphoma using 4D-CBCT. PTV structures of 5–30 mm margins (5 mm intervals) from the clinical target volume (CTV) delineated based on the 4D-CT images (CTV-4D) were generated. For the target localization, we performed matching based on skin marking (skin matching), bone anatomy (bone matching), and stomach anatomy (4D soft-tissue matching) based on registration between planning CT and 4D-CBCT images from 10 phases. For each patient, we calculated the covering ratio (CR) of the stomach with variable PTV structures, based on the 4D-CBCT images, with a total of 150 phases [CR (%) = (number of covering phases / 150 phases) × 100], for three target localization methods. We compared the CR values of the different target localization methods and defined the PTV with an average CR of ≥ 95 % for all patients. Results: The average CR for all patients increased from 17.9 % to 100 %, 19.6 % to 99.8 %, and 33.8 % to 100 %, in the skin, bone, and 4D soft-tissue matchings, respectively, as the PTV structures increased from 5 to 30 mm. The CR obtained by 4D soft-tissue matching was superior to that obtained by skin (P = 0.013) and bone matching (P = 0.008) for a PTV structure of 15 mm margin. The PTV required an additional margin of 20 mm (average CR: 95.2 %), 25 mm (average CR: 99.1 %), and 15 mm (average CR: 98.0 %) to CTV-4D for the skin, bone, and 4D soft-tissue matchings, respectively. Conclusions: This study demonstrates that the use of 4D-CBCT reduces the PTV when applying 4D soft-tissue matching, compared to skin and bone matchings. Additionally, bone matching does not reduce the PTV as compared with traditional skin matching.

scholarly journals Access of Patients With Lung Cancer to High Technology Radiation Therapy in Brazil

2021 ◽  
pp. 726-733
Author(s):  
Lilian Dantonino Faroni ◽  
Arthur Accioly Rosa ◽  
Veronica Aran ◽  
Renan Serrano Ramos ◽  
Carlos Gil Ferreira
Keyword(s):  
Public Health ◽  
Computed Tomography ◽  
Lung Cancer ◽  
Radiation Therapy ◽  
Cone Beam Computed Tomography ◽  
Volumetric Modulated Arc Therapy ◽  
High Technology ◽  
Cone Beam ◽  
Intensity Modulated ◽  
Arc Therapy

PURPOSE Lung cancer is a global health problem, with more than 220,000 new cases and 150,000 deaths per year in the United States. Likewise, in Brazil, lung cancer is the most lethal cancer with 30,200 new cases expected in 2020. Regarding treatment types, radiation therapy (RT) represents an important approach, since 60%-70% of the patients will receive this modality of treatment during the course of their disease. However, access to RT remains challenging because of the socioeconomic inequalities in the Brazilian population, where approximately 100,000 patients/year die without access to RT. This work provides an overview on the availability of high technology RT in Brazil. METHODS A retrospective study was performed using the Brazilian Radiotherapy Census, local public and private databases, and the current literature published in 2019. RESULTS The Brazilian radiotherapy network relies on approximately 363 linear accelerators and 20 cobalt machines that remain operational. Most of these machines are installed at public health facilities. Regarding high technology, intensity-modulated RT is available in 53.7% (n = 130) and volumetric modulated arc therapy in 28.5% (n = 69) of the institutions, although only 19.8% (n = 48) of those facilities are capable of performing image-guided RT using cone beam computed tomography. Considering only the public health care system, the scenario is more restricted, with 40.1% (n = 65) of the institutions offering intensity-modulated RT, 21% (n = 34) volumetric modulated arc therapy, and 14.8% (n = 24) using cone beam computed tomography. Because of these scare resources, only 16% of Radiation Departments offer stereotactic body RT. CONCLUSION Brazil still needs to improve and provide high and safer RT technologies to patients with lung cancer across all Brazilian regions to attend the population needs and obtain better patient outcomes.

scholarly journals Impact of four-dimensional cone-beam computed tomography on target localization for gastric mucosa-associated lymphoid tissue lymphoma radiotherapy: reducing planning target volume

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yoshinobu Shimohigashi ◽  
Ryo Toya ◽  
Tetsuo Saito ◽  
Yumiko Kono ◽  
Yasuhiro Doi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Soft Tissue ◽  
Gastric Mucosa ◽  
Cone Beam Computed Tomography ◽  
Planning Target Volume ◽  
Lymphoid Tissue ◽  
Target Volume ◽  
Target Localization ◽  
Cone Beam ◽  
Dimensional Cone

Abstract Background Radiotherapy of gastric mucosa-associated lymphoid tissue (MALT) lymphoma should be delivered to the entire stomach with planning target volume (PTV) that accounts for variations in stomach volume, respiratory movement, and patient set-up error. In this study, we evaluated whether the use of four-dimensional cone-beam computed tomography (4D-CBCT) reduces the PTV. Methods Eight patients underwent radiotherapy with 15 fractions of gastric MALT lymphoma using 4D-CBCT. PTV structures of 5–30 mm margins (5 mm intervals) from the clinical target volume (CTV) delineated based on the 4D-CT images (CTV-4D) were generated. For the target localization, we performed matching based on skin marking (skin matching), bone anatomy (bone matching), and stomach anatomy (4D soft-tissue matching) based on registration between planning CT and 4D-CBCT images from 10 phases. For each patient, we calculated the covering ratio (CR) of the stomach with variable PTV structures, based on the 4D-CBCT images, with a total of 150 phases [CR (%) = (number of covering phases/150 phases) × 100], for three target localization methods. We compared the CR values of the different target localization methods and defined the PTV with an average CR of ≥ 95% for all patients. Results The average CR for all patients increased from 17.9 to 100%, 19.6 to 99.8%, and 33.8 to 100%, in the skin, bone, and 4D soft-tissue matchings, respectively, as the PTV structures increased from 5 to 30 mm. The CR obtained by 4D soft-tissue matching was superior to that obtained by skin (P = 0.013) and bone matching (P = 0.008) for a PTV structure of 15 mm margin. The PTV required an additional margin of 20 mm (average CR: 95.2%), 25 mm (average CR: 99.1%), and 15 mm (average CR: 98.0%) to CTV-4D for the skin, bone, and 4D soft-tissue matchings, respectively. Conclusions This study demonstrates that the use of 4D-CBCT reduces the PTV when applying 4D soft-tissue matching, compared to skin and bone matchings. Additionally, bone matching does not reduce the PTV as compared with traditional skin matching.

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