Lessons learned using an MRI-only workflow during high-dose-rate brachytherapy for prostate cancer

Area of Science:

• Oncology
• Radiotherapy
• Medical Imaging

Background:

• High-dose-rate brachytherapy is a standard treatment for prostate cancer.
• External beam radiotherapy often follows brachytherapy.
• Accurate catheter placement and treatment planning are crucial for effective brachytherapy.

Purpose of the Study:

• To evaluate an MRI-only workflow for catheter insertion and treatment planning in prostate cancer brachytherapy.
• To observe clinical outcomes of this novel technique.

Main Methods:

• Prospective clinical trial involving 40 patients with intermediate or high-risk prostate cancer.
• Multiparametric MRI with stereotactic navigation for guided brachytherapy catheter insertion.
• MRI-based treatment planning was performed post-insertion.

Main Results:

• MRI restaged 35% of patients, identifying higher disease stages.
• Catheter insertion was adjusted in 6 patients based on MRI findings (extracapsular extension or seminal vesicle invasion).
• Low toxicities were observed (Grade ≥2 GU: 20% acute, 15% late; Grade ≥2 GI: 7% late).

Conclusions:

• An MRI-only workflow can alter brachytherapy catheter insertion and dose-planning strategies.
• The technique is feasible but needs optimization for broader clinical use.
• MRI visualization of tumor and anatomy impacts treatment decisions.