Multi-institutional study of the variability in target delineation for six targets commonly treated with radiosurgery

Abstract

This study showed that the variability in the contouring was much higher than expected and therefore further work in standardizing the contouring practice in radiosurgery is warranted.

Use of MRI increases interobserver agreement on gross tumor volume for imaging‐diagnosed canine intracranial meningioma

“…The concordance index increased to 0.15 for this dog with the addition of MR imaging for gross tumor delineation from 4.4 to 10.7 mm for tumor volumes delineated on CT, 7 from 6.5 to 11.0 mm for tumor volumes delineated on MRI, 7 and from 4.1 to 5.3 mm for tumors volumes delineated on fused CT-MRI. 19 Our results for CT-MRI (maximum, 10.8 mm) are again comparable to the values reported in the human studies, however we found greater maximum COV differences for volumes delineated on CT only (maximum, 17.0 mm).…”

“…7 A CI of 0.22 was reported for a group of 32 observers delineating one meningioma in a human patient using fused CT-MRI images. 19 Our results for CT-MRI (median, 0.21) are comparable to these human studies, however the CI for GTV delineated on CT alone (median, 0.11) is lower in our study.…”

“…The COV differences provide a measure of agreement on location of the tumor volume. The two previously mentioned human studies 7,19 reported the maximum translational difference between any two observers, corresponding to the upper value for the range in our study. The maximum COV differences for human patients ranged F I G U R E 7 Transverse, sagittal, and dorsal fused MRI and CT images of the same dog as in Figure 6.…”

ESTRO ACROP guideline for target volume delineation of skull base tumors

“…In addition, there has been a renewed interest in using particle therapy for such tumors due to technological advances in the delivery of proton and carbon ion RT 5 [15][16][17]. Along with greater accuracy of dose delivery and patient repositioning, more improvements in imaging techniques such as new sequences in MRI or novel tracers for PET-imaging have enabled tumor spatial accuracy, contributing to reduce inter-observer variability in target delineation [18][19][20]. As for other steps in the treatment planning process, an accurate delineation of tumor volumes and OARs is mandatory for a precise calculation of the spatial dose distribution, and for choosing the optimal radiation dose and fractionation schedule.…”

Simultaneous Truth and Performance Level Estimation Method for Evaluation of Target Contouring in Radiosurgery

“…The success with respect to treatment outcome and normal tissue toxicity of stereotactic radiosurgery, delivered in one large fraction of radiation and without margins, relies on the accuracy in contouring the target and the organs-at-risk (OAR). However, despite its key role in the success of treatment, the delineation of the target and OARs in radiosurgery appears to vary considerably between practitioners and this could have unwanted clinical implications (1)(2)(3). This state of the affairs points towards the need of harmonising the clinical practice with respect to contouring the various structures in radiosurgery through standardisation.…”