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Advances in radiation therapy dosimetry.

Paliwal B, Tewatia D - J Med Phys (2009)

Bottom Line: Advanced techniques are less tolerant to poor implementation than are standard techniques.Mis-administrations are more difficult to detect and can possibly lead to poor outcomes for some patients.Some of the major challenges in the above areas are discussed.

View Article: PubMed Central - PubMed

Affiliation: University of Wisconsin Radiation Oncology Physics 600 Highland Ave., K4/B100 - 0600 Madison, USA.

ABSTRACT
During the last decade, there has been an explosion of new radiation therapy planning and delivery tools. We went through a rapid transition from conventional three-dimensional (3D) conformal radiation therapy to intensity-modulated radiation therapy (IMRT) treatments, and additional new techniques for motion-adaptive radiation therapy are being introduced. These advances push the frontiers in our effort to provide better patient care; and with the addition of IMRT, temporal dimensions are major challenges for the radiotherapy patient dosimetry and delivery verification. Advanced techniques are less tolerant to poor implementation than are standard techniques. Mis-administrations are more difficult to detect and can possibly lead to poor outcomes for some patients. Instead of presenting a manual on quality assurance for radiation therapy, this manuscript provides an overview of dosimetry verification tools and a focused discussion on breath holding, respiratory gating and the applications of four-dimensional computed tomography in motion management. Some of the major challenges in the above areas are discussed.

No MeSH data available.


Related in: MedlinePlus

Comparison of isodose distributions for (left to right - transverse, saggital and coronal planes) a prostate patient with IMRT plan in 28 fractions: (a) plan with shifts; (b) plan with maximum offsets (0.0, 0.3, -0.6)
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Figure 0005: Comparison of isodose distributions for (left to right - transverse, saggital and coronal planes) a prostate patient with IMRT plan in 28 fractions: (a) plan with shifts; (b) plan with maximum offsets (0.0, 0.3, -0.6)

Mentions: Recently MVCT and CBCT systems were also utilized for dose verification and implementing the dose-adaptive radiotherapy. For these systems, the establishment of the system's geometric-positioning accuracy and precision is critical for the image sets obtained from these systems to be of value in the guidance of treatment. A specific calibration procedure had to be developed to correlate the coordinate systems of the imaging and delivery systems, such that image sets from MVCT or CBCT can be used to estimate the target position with respect to isocenter. CBCT-guided shifts for all fractions of 8 prostate patients are shown in Figure 4A. A comparison of isodose distributions for a patient with IMRT plan in 28 fractions is shown in Figure 4B: (a) plan with shifts; (b) plan with maximum offsets (0.0, 0.3, -0.6). Figure 4C shows comparison of dose volume histograms (DVHs) for a prostate patient (plans shown in Figure 4B). Solid curves represent the plan with shifts, and dashed curves represent the plan with no shift with maximum positional offsets.


Advances in radiation therapy dosimetry.

Paliwal B, Tewatia D - J Med Phys (2009)

Comparison of isodose distributions for (left to right - transverse, saggital and coronal planes) a prostate patient with IMRT plan in 28 fractions: (a) plan with shifts; (b) plan with maximum offsets (0.0, 0.3, -0.6)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2807673&req=5

Figure 0005: Comparison of isodose distributions for (left to right - transverse, saggital and coronal planes) a prostate patient with IMRT plan in 28 fractions: (a) plan with shifts; (b) plan with maximum offsets (0.0, 0.3, -0.6)
Mentions: Recently MVCT and CBCT systems were also utilized for dose verification and implementing the dose-adaptive radiotherapy. For these systems, the establishment of the system's geometric-positioning accuracy and precision is critical for the image sets obtained from these systems to be of value in the guidance of treatment. A specific calibration procedure had to be developed to correlate the coordinate systems of the imaging and delivery systems, such that image sets from MVCT or CBCT can be used to estimate the target position with respect to isocenter. CBCT-guided shifts for all fractions of 8 prostate patients are shown in Figure 4A. A comparison of isodose distributions for a patient with IMRT plan in 28 fractions is shown in Figure 4B: (a) plan with shifts; (b) plan with maximum offsets (0.0, 0.3, -0.6). Figure 4C shows comparison of dose volume histograms (DVHs) for a prostate patient (plans shown in Figure 4B). Solid curves represent the plan with shifts, and dashed curves represent the plan with no shift with maximum positional offsets.

Bottom Line: Advanced techniques are less tolerant to poor implementation than are standard techniques.Mis-administrations are more difficult to detect and can possibly lead to poor outcomes for some patients.Some of the major challenges in the above areas are discussed.

View Article: PubMed Central - PubMed

Affiliation: University of Wisconsin Radiation Oncology Physics 600 Highland Ave., K4/B100 - 0600 Madison, USA.

ABSTRACT
During the last decade, there has been an explosion of new radiation therapy planning and delivery tools. We went through a rapid transition from conventional three-dimensional (3D) conformal radiation therapy to intensity-modulated radiation therapy (IMRT) treatments, and additional new techniques for motion-adaptive radiation therapy are being introduced. These advances push the frontiers in our effort to provide better patient care; and with the addition of IMRT, temporal dimensions are major challenges for the radiotherapy patient dosimetry and delivery verification. Advanced techniques are less tolerant to poor implementation than are standard techniques. Mis-administrations are more difficult to detect and can possibly lead to poor outcomes for some patients. Instead of presenting a manual on quality assurance for radiation therapy, this manuscript provides an overview of dosimetry verification tools and a focused discussion on breath holding, respiratory gating and the applications of four-dimensional computed tomography in motion management. Some of the major challenges in the above areas are discussed.

No MeSH data available.


Related in: MedlinePlus