High-dose-rate Brachytherapy Monotherapy in Patients With Localised Prostate Cancer: Dose Modelling and Optimisation...

Area of Science:

• Oncology
• Medical Physics
• Radiotherapy

Background:

• Interstitial high-dose-rate brachytherapy (HDR-BT) is a key treatment for localized prostate cancer.
• Optimizing HDR-BT requires careful consideration of dose, fractionation, and overall treatment time.
• Patient risk stratification is crucial for tailoring effective treatment protocols.

Purpose of the Study:

• To optimize therapy regime variables for prostate cancer HDR-BT using Response Surface Methodology (RSM) and Artificial Neural Network (ANN) models.
• To identify treatment parameters that maximize biochemical free survival (BFS).
• To compare the efficacy of RSM and ANN in optimizing HDR-BT protocols.

Main Methods:

• A meta-analysis of 31 studies involving 5651 prostate cancer patients (low, intermediate, and high-risk).
• Calculation of biologically effective dose (BEDef) based on dose per fraction and treatment schedule.
• Application of RSM and ANN models to optimize BEDef and patient risk level for maximum BFS.

Main Results:

• Optimal schedule for low-risk patients: 26 Gy in 2 fractions over 1 day (BEDef = 251 Gy), achieving 97% BFS.
• Optimal schedule for intermediate/high-risk patients: 38 Gy in 4 fractions over 2 days (BEDef = 279 Gy), achieving 94% BFS (intermediate) and 90% BFS (high).
• RSM and ANN models yielded highly concordant optimal treatment parameters.

Conclusions:

• RSM and ANN models effectively determine optimal HDR-BT parameters for prostate cancer.
• The models provide feasible selections for optimal treatment regimes, enhancing patient outcomes.
• Optimized HDR-BT protocols can significantly improve BFS across different risk groups.