A brachytherapy plan evaluation tool for interstitial applications

Area of Science:

• Medical Physics
• Radiation Oncology
• Biostatistics

Background:

• Radiobiological metrics like tumor control probability (TCP) and normal tissue complication probability (NTCP) are crucial for assessing brachytherapy plan quality.
• Current clinical and research application of these metrics remains limited.
• There is a need for accessible tools to implement these advanced evaluation methods.

Purpose of the Study:

• To implement and evaluate two indigenous plan evaluation modules, Brachy_TCP and Brachy_NTCP.
• To compute TCP and NTCP from dose-volume histograms (DVHs) for interstitial brachytherapy plans.
• To assess the predictive capability of these metrics against clinical outcomes in cervical cancer patients.

Main Methods:

• Developed Brachy_TCP and Brachy_NTCP modules for calculating TCP and NTCP from DVHs.
• Applied the computation module to ten cervical cancer patients using biologically effective equivalent uniform dose (BEEUD).
• Correlated estimated TCP/NTCP values with clinical follow-up data, including acute toxicity grading (CTCAE v4.0).

Main Results:

• The developed modules successfully computed TCP and NTCP for interstitial brachytherapy plans.
• An outcome score derived from clinical follow-up showed a correlation with the estimated TCP and NTCP values.
• The biologically effective equivalent uniform dose (BEEUD) formalism demonstrated effectiveness in predicting treatment complexities and disease control.

Conclusions:

• The Brachy_TCP and Brachy_NTCP modules provide a viable method for evaluating brachytherapy plans.
• The study quantifies the predictive ability of TCP/NTCP estimates by correlating them with clinical outcomes.
• BEEUD-based formalism is effective for predicting treatment outcomes and disease control in brachytherapy.