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Clinical Commissioning Guidelines
Published in Jinzhong Yang, Gregory C. Sharp, Mark J. Gooding, Auto-Segmentation for Radiation Oncology, 2021
Rapid advances in image-guided radiation therapy have brought forth a range of treatments including high dose radiation therapy, whereby high dose radiation is delivered over a few fractions with high conformity to the target tumors. Clinical studies have shown excellent local control in multiple cancers and with it, the potential to improve progression-free and overall survival [1–4] of some patients.
Developing Technologies for Small Animal Radiotherapy
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
Frank Verhaegen, James Stewart, David Jaffray
CT imaging is the preferred imaging modality for the localization and treatment planning of localized malignancies for treatment with external beam radiation therapy. Though CT imaging has inherently poor soft tissue contrast, it is still a suitable tool for visualizing anatomical spatial orientation and is well suited to provide electron density data for treatment planning dose optimization. MRI imaging may be better at tumor segmentation, but the information contained in the voxels cannot be used for dose calculation. About a decade ago, kV cone-beam CT was introduced in radiotherapy (Jaffray et al. 2002); it features an imaging panel and x-ray tube mounted in-line on the gantry of a linear accelerator, perpendicular to the photon beam direction. This provides a tool for image-guided radiation therapy. Similarly, it would be desirable for a small animal irradiator to contain both the imaging x-ray beam and treatment beam in the same space and coordinate system. From the previous section, we saw that the treatment beam energy for small animals should be between 100 and 300 kV; these energies are also suitable for imaging, so both the imaging and irradiation can be done by a single x-ray tube.
Advances in imaging simulation for lung cancer IGRT
Published in Jing Cai, Joe Y. Chang, Fang-Fang Yin, Principles and Practice of Image-Guided Radiation Therapy of Lung Cancer, 2017
Jing Cai, Daniel Low, Tinsu Pan, Yilin Liu, Zheng Chang, Wei Lu
Radiation therapy of lung cancer is among the most common and important areas of image-guided radiation therapy. Imaging simulations including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography with 2-fluorine-18 fluoro-2-deoxy-D-glucose (FDG-PET) and FDG-PET combined with CT (FDG-PET/CT) are currently being used for clinical assessment of lung cancer. Recent technological advances in these imaging systems hold great promises to produce marked improvements toward more precise treatment of lung cancer. In this chapter, we will focus on recent advances in CT, MRI, PET, and other imaging methods in lung cancer applications, and discuss their potentials and limitations for use in clinical practice.
Novel VMAT planning technique improves dosimetry for head and neck cancer patients undergoing definitive chemoradiotherapy
Published in Acta Oncologica, 2023
David DiBartolo, Todd Carpenter, Joseph P. Santoro, Jonathan W. Lischalk, David Ebling, Jonathan A. Haas, Matthew Witten, Marissa Rybstein, Alec Vaezi, Michael C. Repka
A significant limitation to this study is the lack of available data in regard to treatment planning time. IMRT planning for head and neck cancer is notoriously complex and time-consuming [9,16]. Subjectively, dosimetrists report easier achievement of planning goals in a shorter time and with fewer iterations than with the institutional approach, but this observation was not studied in an objective manner. Future study is needed to quantify the organizational and efficiency benefits to this planning approach. Furthermore, the institutional approach requires additional time during treatment to employ an additional arc. Increased treatment time can result in increased patient discomfort, diminished clinical throughput, and potentially increase risk for intrafractional movement [17]. Although the relatively rigid set-up of the head and neck region in conjunction with thermoplastics and other immobilizing devices generally allows for reliable set-up, intrafractional movement can occur and may increase over time [18]. Furthermore, three-arc plans require significantly more monitor units to deliver. However, when considered in the context of patient immobilization and acquisition of images for image-guided radiotherapy (IGRT), the incremental time increase necessitated by the need for an additional treatment arc is minimal, particularly when weighed against the dosimetric benefits observed in this study.
Simulated dosimetric impact of online replanning for stereotactic body radiation therapy of lymph node oligometastases on the 1.5T MR-linac
Published in Acta Oncologica, 2018
Dennis Winkel, Petra S. Kroon, Anita M. Werensteijn-Honingh, Gijsbert H. Bol, Bas W. Raaymakers, Ina M. Jürgenliemk-Schulz
Image-guided radiation therapy (IGRT) has become increasingly important in modern radiotherapy to reduce the effect of treatment variations, such as setup errors and geometric variations of the target volume and organs at risk (OAR). Currently, most modern radiotherapy treatment systems are equipped with cone-beam computed tomography (CBCT) to visualize the tumour [1]. CBCT has greatly contributed to precision radiotherapy for sites in which the tumour is clearly visible on CBCT, however it yields relatively poor soft tissue contrast. The lack of soft tissue contrast can make it difficult to accurately identify the target and surrounding OARs for soft tissue targets; therefore bony anatomy or artificial markers are frequently used as a surrogate for position verification [2–4]. These procedures still result in quite large planning target volume (PTV) margins [5] or are invasive with additional burden for the patient.
Radiotherapy and hyperthermia with curative intent in recurrent high risk soft tissue sarcomas
Published in International Journal of Hyperthermia, 2018
Franziska Eckert, Lore Helene Braun, Frank Traub, Hans-Georg Kopp, Bence Sipos, Ulf Lamprecht, Arndt-Christian Müller, Frank Paulsen, Daniel Zips
Pre- or postoperative radiotherapy has been established in multimodal treatment of high risk soft tissue sarcomas of the extremities [10]. Postoperative radiation with >60.0 Gy improves local control in high risk soft tissue sarcoma [11,12]. Preoperative irradiation with 45.0 –50.0 Gy leads to more acute wound healing complications after surgery, yet seems to have a benefit for late complications like fibrosis and joint stiffness in comparison to adjuvant treatment [13–15]. Advanced radiation techniques such as intensity-modulated radiotherapy (IMRT) and image guided treatment (IGRT) seem to further reduce the risk of late complications [16–18]. The role of radiotherapy is less clear for retroperitoneal sarcomas as there are no large randomised studies reported up to now. Single centre and database analyses seem to indicate a benefit for preoperative radiotherapy [19–21].