Evaluation of treatment plans using target and normal tissue DVHs is no longer appropriate

Abstract

OVERVIEWIt is standard practice to evaluate dose distributions in different tissues, organs, and tumors through visualization of dosevolume histograms (DVHs) and/or analysis of quantities derived from DVHs. The DVH does not contain spatial information and has several other shortcomings, however, and some have suggested that evaluation of treatment plans using DVHs is no longer appropriate. This is the claim debated in this month's Point/Counterpoint.

Dose accumulation to assess the validity of treatment plans with reduced margins in radiotherapy of head and neck cancer

“…However, a full analysis of the dose delivered to each voxel (Table 2) highlighted potentially clinically significant underdosage in many cases both for 3 mm and 5 mm margin expansions. DVH metrics inherently lack spatial information regarding the dose distribution within a volume of interest [31] and commonly refer to percentages instead of absolute volumes. Specifically for larger target volumes, underdosage of the high-and intermediate-risk target volumes may not be detected by using DVH metrics as criterion.…”

“…The CTV coverage was quantified using D 99% to enable direct comparison of our results with those reported by van Kranen et al [19]. However, DVH metrics inherently lack spatial information regarding the dose distribution within a volume of interest [31] and specifically for large target volumes, a clinically relevant loss in sub-volume coverage may not be detected. Therefore, CTV coverage was also assessed by recording the number of voxels where D plan and D acc were less than 95% of D presc at the 95% level of confidence.…”

SPIDERplan: A tool to support decision-making in radiation therapy treatment plan assessment

“…Different scoring indexes based on traditional DVH information, or any other relevant physical or biological quantities like EUD, TCP, NTCP, etc. 29 may be set up. This flexibility confers to SPIDERplan the possibility to be easily adapted to new situations that are recurrent in the clinical routine.…”

Mathematical Modelling of Dose Planning in High Dose-Rate Brachytherapy

“…Future research be to prefer to use radiobiological indices, which directly estimate the treatment effects. However, more clinical development is needed before radiobiological models can replace the current physical ones, see the discussion in [83] on this subject. At the same time, there is room for improvements in radiobiological optimization models for dose planning, both in the modelling and in algorithms and solution methods.…”