A planning study of simultaneous integrated boost with forward IMRT for multiple brain metastases

Area of Science:

• Radiation Oncology
• Medical Physics

Background:

• Brain metastases require precise radiation delivery to maximize tumor control and minimize toxicity.
• Intensity-modulated radiation therapy (IMRT) offers advanced dose shaping capabilities.

Purpose of the Study:

• To evaluate the dose conformity and feasibility of whole-brain radiotherapy (WBRT) with a simultaneous integrated boost (SIB) using forward IMRT.
• To assess the treatment delivery time for this technique in patients with 1 to 3 brain metastases.

Main Methods:

• Forward IMRT plans were generated for 10 patients with 1-3 brain metastases.
• Prescribed doses: 30 Gy to the whole brain (PTVwbrt) and 40 Gy to metastases (PTVboost) in 10 fractions.
• Evaluated dose conformity using conformation number and assessed treatment delivery time.

Main Results:

• 100% of PTVboost received at least 95% of the prescribed dose in all cases.
• Hot spots were within PTVboost and less than 110% of the prescribed dose.
• 99.2% to 100% of PTVwbrt received at least 95% of the prescribed dose.
• Mean conformation number was 0.682, and mean treatment delivery time was 2.79 minutes.

Conclusions:

• Whole-brain radiotherapy with SIB by forward IMRT is a feasible technique for patients with 1-3 brain metastases.
• The method achieves excellent dose conformity and has a short treatment delivery time.