Dose-surface histograms as treatment planning tool for prostate conformal therapy

Area of Science:

• Medical Physics
• Radiation Oncology
• Radiotherapy Planning

Background:

• Traditional dose-volume histograms (DVHs) may not accurately reflect biological effects in hollow organs.
• Thin-walled organs like the rectum and bladder are sensitive to irradiated surface area.
• Evaluating radiation dose distribution requires methods sensitive to organ geometry.

Purpose of the Study:

• To introduce and evaluate dose-surface histograms (DSHs) as an alternative to DVHs for prostate treatment planning.
• To compare the efficacy of DSHs and DVHs in assessing radiation effects on hollow organs.
• To explore the application of DSHs in optimizing radiotherapy plans and understanding biological consequences.

Main Methods:

• Development and application of dose-surface histograms (DSHs).
• Comparison of DSHs with traditional dose-volume histograms (DVHs).
• Analysis using idealized geometry models and a cohort of prostate cancer patients.

Main Results:

• Dose-surface histograms provide different and potentially more accurate assessments than DVHs for prostate treatment planning.
• For hollow organs, the percentage of surface area irradiated to high doses can differ significantly from the percentage of volume.
• DSHs revealed differences in ranking treatment plans and calculating high-dose regions in the rectum compared to DVHs.

Conclusions:

• Dose-surface histograms offer valuable new insights for prostate treatment planning, particularly for organs at risk like the rectum.
• DSHs are more appropriate for evaluating biological effects in thin-walled hollow organs.
• The study suggests DSHs can improve the accuracy of treatment plan evaluation and potentially reduce rectal complications.