Radiation-induced anatomic changes during fractionated head &amp; neck radiotherapy: a pilot study using an integrated CT-LINAC system

Barker, Jerry L.; Garden, Adam S.; Dong, Lei; O’Daniel, J; Wang, H; Court, Laurence E.; Morrison, William H.; Rosenthal, D.I.; Chao, C.; Mohan, Radhe; Ang, K. Kian

doi:10.1016/s0360-3016(03)01170-2

Cited by 5 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Anatomical changes during the course of treatment can cause radiation overdose to the organ at risk or lack of dose to the target. In some studies (1)(2)(3), influence of anatomical changes that occurred during the course of image guided RT (IGRT) on dose distribution have been investigated using kilovoltage CT (KVCT) and megavoltage CT (MVCT). The study (4) that evaluated changes of gross tumor volume (GTV) occurring during RT for non-small-cell lung cancer concluded that additional radiation treatment planning is necessary when the gross tumor volume (GTV) had decreased by more than 30%.…”

Section: Introductionmentioning

confidence: 99%

Changes of tumor and normal structures of the neck during radiation therapy for head and neck cancer requires adaptive strategy

et al. 2013

View full text Add to dashboard Cite

Radiation therapy (RT) in general requires a treatment period of 5 to 7 weeks. Tumor shrinkage in response to RT and weight loss due to radiationinduced mucositis may impact on the dose distribution in both target and organ at risk in patients Abstract : The treatment period over which radiation therapy is administered extends over several weeks. Since tumor shrinkage in response to radiation therapy and weight loss due to radiation-induced mucositis may impact on the dose distribution in both target and organ at risk in patients with head and neck cancer, the anatomical changes of tumor and neck volumes during this period should be taken into consideration. We investigated the anatomical changes that occurred in the target and normal structure of the neck during radiation therapy for pharyngeal cancer, and evaluated the necessity of an adaptive strategy. Ten patients with pharyngeal cancer who underwent radical chemoradiation therapy using 3-dimensional conformal radiation therapy RT ( ORIGINAL Changes

show abstract

Section: Introductionmentioning

confidence: 99%

Changes of tumor and normal structures of the neck during radiation therapy for head and neck cancer requires adaptive strategy

et al. 2013

View full text Add to dashboard Cite

show abstract

“…As more pretreatment imaging ͑i.e., PET, 1-4 MRS, [5][6][7][8] 4D CT, [9][10][11][12] and MR [13][14][15][16][17] ͒ becomes integrated into the treatment planning process and full three-dimensional ͑3D͒ imageguidance ͑i.e., kV and MV cone-beam, 18-23 tomotherapy, [24][25][26] and conventional CT͒, [27][28][29] becomes part of the treatment delivery the need for a deformable image registration technique becomes more apparent. In addition to being accurate and efficient, the image registration technique must include deformable alignment, allow various regions of interest to behave differently, and maintain the geometric integrity of regions of interest that are presented differently on different imaging modalities.…”

Section: Introductionmentioning

confidence: 99%

Accuracy of finite element model‐based multi‐organ deformable image registration

et al. 2005

View full text Add to dashboard Cite

As more pretreatment imaging becomes integrated into the treatment planning process and full three-dimensional image-guidance becomes part of the treatment delivery the need for a deformable image registration technique becomes more apparent. A novel finite element model-based multiorgan deformable image registration method, MORFEUS, has been developed. The basis of this method is twofold: first, individual organ deformation can be accurately modeled by deforming the surface of the organ at one instance into the surface of the organ at another instance and assigning the material properties that allow the internal structures to be accurately deformed into the secondary position and second, multi-organ deformable alignment can be achieved by explicitly defining the deformation of a subset of organs and assigning surface interfaces between organs. The feasibility and accuracy of the method was tested on MR thoracic and abdominal images of healthy volunteers at inhale and exhale. For the thoracic cases, the lungs and external surface were explicitly deformed and the breasts were implicitly deformed based on its relation to the lung and external surface. For the abdominal cases, the liver, spleen, and external surface were explicitly deformed and the stomach and kidneys were implicitly deformed. The average accuracy (average absolute error) of the lung and liver deformation, determined by tracking visible bifurcations, was 0.19 (s.d.: 0.09), 0.28 (s.d.: 0.12) and 0.17 (s.d.: 0.07) cm, in the LR, AP, and IS directions, respectively. The average accuracy of implicitly deformed organs was 0.11 (s.d.: 0.11), 0.13 (s.d.: 0.12), and 0.08 (s.d.: 0.09) cm, in the LR, AP, and IS directions, respectively. The average vector magnitude of the accuracy was 0.44 (s.d.: 0.20) cm for the lung and liver deformation and 0.24 (s.d.: 0.18) cm for the implicitly deformed organs. The two main processes, explicit deformation of the selected organs and finite element analysis calculations, require less than 120 and 495 s, respectively. This platform can facilitate the integration of deformable image registration into online image guidance procedures, dose calculations, and tissue response monitoring as well as performing multi-modality image registration for purposes of treatment planning.

show abstract

“…Changes in tumor and normal tissue shape and volume have been observed over the multi-fraction course of treatment for cancers in the head and neck. 27 The gross tumor volume had a median relative loss of 69.5% over the course of treatment and a median center of mass displacement of 3.3 mm. The parotid glands, a radiosensitive normal tissue, saw a median decrease in volume of 0.19 cc/day and a median medial shift of 3.1 mm.…”

Section: Head and Neckmentioning

confidence: 96%

Deformable Image Registration for Radiation Therapy Planning: Algorithms and Applications

Kaus

Brock²

2007

Biomechanical Systems Technology

View full text Add to dashboard Cite

Approximately 60% of cancer patients are treated with external beam radiotherapy at some point during disease management. Despite the extended time frame of fractionated therapy (4-6 weeks), radiation therapy planning is carried out based on information that is currently limited to a single 3D anatomical computed tomography scan at the onset of treatment. This concept may result in severe treatment uncertainties, including the irradiation of risk organs and reduced tumor coverage. Repeat 3D single or multi-modality imaging acquired at various time intervals during and after a radiation course provides the opportunity to increase treatment accuracy and precision by optimizing treatment in response to anatomical changes; to improve target delineation through modality-specific complementary tumor representations, and to assess treatment response. Integration of multiple imaging sources into a single patient model requires compensation of geometric differences while maintaining modality-specific differences in information content. Deformable image registration aims to reduce such uncertainties by estimating the spatial relationship between the volume elements of corresponding structures across image data. This paper reviews the algorithmic components of deformation algorithms, and their application to treatment sites with evident geometric changes, including mono-and multi-modal image registration for cancer of the head and neck, lung, liver, and prostate.

show abstract

Radiation-induced anatomic changes during fractionated head & neck radiotherapy: a pilot study using an integrated CT-LINAC system

Cited by 5 publications

References 0 publications

Changes of tumor and normal structures of the neck during radiation therapy for head and neck cancer requires adaptive strategy

Changes of tumor and normal structures of the neck during radiation therapy for head and neck cancer requires adaptive strategy

Accuracy of finite element model‐based multi‐organ deformable image registration

Deformable Image Registration for Radiation Therapy Planning: Algorithms and Applications

Contact Info

Product

Resources

About