MRI-guided Pelvic Radiation Therapy: A Primer for Radiologists.

Area of Science:

• Oncology
• Radiology
• Medical Physics

Background:

• Radiation therapy (RT) is a cornerstone of cancer treatment, with half of all cancer patients receiving it.
• The integration of Magnetic Resonance Imaging (MRI) into RT workflows has introduced MRI-guided RT (MRIgRT).

Purpose of the Study:

• To familiarize radiologists with the applications of MRI in planning pelvic RT.
• To discuss various RT techniques and the impact of MRIgRT on treatment paradigms.
• To review clinical experience and evidence for MRIgRT in prostate, cervical, and bladder cancers.

Main Methods:

• Discussion of current clinical experience and evidence for MRIgRT.
• Illustration of treated cases.
• Highlighting benefits like real-time adaptation and sparing organs at risk.

Main Results:

• MRIgRT provides superior soft-tissue contrast and motion visualization for pelvic tumors compared to CT.
• Real-time adaptive RT is achievable, allowing for precise targeting and sparing of organs at risk.
• MRIgRT demonstrates potential to decrease treatment toxicity and improve oncologic outcomes.

Conclusions:

• MRIgRT is particularly beneficial for mobile pelvic structures and offers advanced adaptive treatment capabilities.
• Future directions include biologically driven adaptive RT using functional MRI and radiogenomics.
• Radiologists must be knowledgeable about MRIgRT's role in modern radiation oncology.