The probability of correct target dosage: dose-population histograms for deriving treatment margins in radiotherapy

Herk, Marcel van; Remeijer, P.; Rasch, Coen R. N.; Lebesque, Joos V.

doi:10.1016/s0360-3016(00)00518-6

Cited by 1,328 publications

(1,259 citation statements)

References 34 publications

Supporting

Mentioning

1,215

Contrasting

Unclassified

Order By: Relevance

“…Therefore, the geometric uncertainties for patient realignment are taken from their publication (8) . The geometric uncertainties for current treatment procedure, no realignment, are taken from the study of van Herk et al (7) The data are believed to represent the clinical situation at our center because we have the same patient management: full bladder without rectum balloon. The magnitude of geometric uncertainties will affect the simulation results.…”

Section: Discussionmentioning

confidence: 99%

“…For the treatment without patient realignment, that is, the full uncertainty situation, the standard deviations were taken from Table 1 of the paper by van Herk et al (7) The reduced uncertainty data (i.e., after online correction with a 3‐mm action level) were taken from Table 3 of the paper by Chung et al, (8) the “center of mass” data. Two hundred histories were calculated for each treatment plan with a calculation time of 6 h to 7 h on a Pentium IV 2.66 GHz PC.…”

Section: Methodsmentioning

confidence: 99%

“…All the parameters used in the calculations are shown in Table 2. The results of the simulations have been summarized as dose‐population histograms (DPH) (7) . Similar to a DVH, each point on the cumulative DPH represents the percentage of patients who receive at least a certain dose.…”

Section: Methodsmentioning

confidence: 99%

“…( 1 – 6 ) Commonly, the margin is approximately 1 cm with a smaller posterior margin to achieve better rectal sparing. A more generic approach has been suggested by van Herk, (7) who proposed linking the PTV margin with systematic and random errors.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

PTV margin for dose‐escalated radiation therapy of prostate cancer with daily online realignment using internal fiducial markers: Monte Carlo approach and dose population histogram (DPH) analysis

Zhang

Moiseenko

Liu

2006

J Applied Clin Med Phys

View full text Add to dashboard Cite

Using internal fiducial markers and electronic portal imaging (EPI) to realign patients has been shown to significantly reduce positioning uncertainties in prostate radiation treatment. This creates the possibility of decreasing the planning target volume (PTV) margin added on the clinical target volume (CTV), which in turn may allow for dose escalation. We compared the outcome of two plans: 70 Gy/35 fx, 10‐mm PTV margin without patient realignment (Reference Plan) and 78 Gy/39 fx, 5‐mm PTV margin with patient realignment (Escalated Plan). Four‐field‐oblique (gantry angles 35°, 90°, 270°, 325°) beam arrangement was used. Monte Carlo code was used to simulate the daily organ motion. Dose to each organ was calculated. Tumor control probability (TCP) and the effective dose to critical organs false(Defffalse) were calculated using the biologically normalized dose‐volume histograms. By comparing the biological factors, we found that the prescription dose can be escalated to 78 Gy/39 fx with a 5‐mm PTV margin when using internal fiducial markers and EPI. Based on the available dose‐response data for intermediate risk prostate patients, this will result in a 20% increase of local control and significantly reduced rectal complications provided that less serial dose‐volume behavior of rectum is proven.PACS number: 87.50.‐a

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

PTV margin for dose‐escalated radiation therapy of prostate cancer with daily online realignment using internal fiducial markers: Monte Carlo approach and dose population histogram (DPH) analysis

Zhang

Moiseenko

Liu

2006

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…Because day‐to‐day setup variations were random, it was necessary to use a mathematical calculation of the probability distribution that considers the number of fractions 18. The dose distribution within the PTV on the periphery location was more inhomogeneous in the robust optimization plan than in the PTV‐based optimization plan.…”

Section: Discussionmentioning

confidence: 99%

Efficacy of robust optimization plan with partial‐arc VMAT for photon volumetric‐modulated arc therapy: A phantom study

Miura

Ozawa

Nagata

2017

J Applied Clin Med Phys

View full text Add to dashboard Cite

This study investigated position dependence in planning target volume (PTV)‐based and robust optimization plans using full‐arc and partial‐arc volumetric modulated arc therapy (VMAT). The gantry angles at the periphery, intermediate, and center CTV positions were 181°–180° (full‐arc VMAT) and 181°–360° (partial‐arc VMAT). A PTV‐based optimization plan was defined by 5 mm margin expansion of the CTV to a PTV volume, on which the dose constraints were applied. The robust optimization plan consisted of a directly optimized dose to the CTV under a maximum‐uncertainties setup of 5 mm. The prescription dose was normalized to the CTV D99% (the minimum relative dose that covers 99% of the volume of the CTV) as an original plan. The isocenter was rigidly shifted at 1 mm intervals in the anterior‐posterior (A‐P), superior‐inferior (S‐I), and right‐left (R‐L) directions from the original position to the maximum‐uncertainties setup of 5 mm in the original plan, yielding recalculated dose distributions. It was found that for the intermediate and center positions, the uncertainties in the D99% doses to the CTV for all directions did not significantly differ when comparing the PTV‐based and robust optimization plans (P > 0.05). For the periphery position, uncertainties in the D99% doses to the CTV in the R‐L direction for the robust optimization plan were found to be lower than those in the PTV‐based optimization plan (P < 0.05). Our study demonstrated that a robust optimization plan's efficacy using partial‐arc VMAT depends on the periphery CTV position.

show abstract

Radiation Therapy, Quality Assurance in

Gejerman

Hanley

2006

Encyclopedia of Medical Devices and Instrumentation

View full text Add to dashboard Cite

A prerequiste to a successful radiation oncology prgram is accurate treatment planning and consistent treatment delivery. The Nuclear Regulatory Commission and most state regulatory bodies have published quality assurance guidelines requiring interval testing of the simulation, treatment planning, and treatment delivery process. Recognizing the challenge of ensuring proper maintenance and use of increasingly complicated systems, the American Assiciation of Physicists (AAPM) published a series of comprehensive quality assurance guidelines that can be applied to X‐ray and CT simulators, treatment planning systems, and linear accelerators. Comprehensive quality assurance must encompass both systematic and random uncertainity in treatment planning and delivery to minimize their occurrence. The many factors that contribute to target dilineation uncertanity including acquisition parameters, organ motion, imaging modality, image fusion, and intra‐observer variablity should all be examined closely for their contributions to treatment uncertainities. To minimize treatment inaccuracies, it is essential that each radiation oncology department establishes a “quality system” or quality assurance program to provide the organizational structure, responsibilities, procedures, processes, and resources for assuring the quality of patient management.

show abstract

The probability of correct target dosage: dose-population histograms for deriving treatment margins in radiotherapy

Cited by 1,328 publications

References 34 publications

PTV margin for dose‐escalated radiation therapy of prostate cancer with daily online realignment using internal fiducial markers: Monte Carlo approach and dose population histogram (DPH) analysis

PTV margin for dose‐escalated radiation therapy of prostate cancer with daily online realignment using internal fiducial markers: Monte Carlo approach and dose population histogram (DPH) analysis

Efficacy of robust optimization plan with partial‐arc VMAT for photon volumetric‐modulated arc therapy: A phantom study

Radiation Therapy, Quality Assurance in

Contact Info

Product

Resources

About