Dosimetric comparisons of IMRT planning using MCO and DMPO techniques

Area of Science:

• Radiation Oncology
• Medical Physics
• Cancer Treatment

Background:

• Intensity-modulated radiotherapy (IMRT) is a precise radiation therapy technique.
• Treatment planning optimization aims to maximize tumor coverage while minimizing dose to organs at risk (OARs).
• Direct machine parameter optimization (DMPO) is a standard method for IMRT planning.

Purpose of the Study:

• To evaluate the efficacy of multi-criteria optimization (MCO) compared to DMPO for IMRT planning.
• To assess improvements in OAR protection and optimization efficiency using MCO.
• To analyze dose distribution, DVH, optimization time, and monitor units (MUs) for MCO and DMPO plans.

Main Methods:

• Twenty IMRT patients (10 prostate, 10 lung cancer) were selected.
• Treatment plans were initially created using DMPO.
• New plans were generated using MCO with identical objectives and constraints.
• Plans were compared based on dose distribution, DVH, optimization time, and MUs.

Main Results:

• Both MCO and DMPO plans met clinical requirements.
• MCO provided superior protection for the rectum, bladder, and small bowel in prostate cancer patients.
• MCO reduced optimization time by 58% (prostate) and 59% (lung) compared to DMPO.
• MCO also improved protection for the lung, heart, and spinal cord in lung cancer patients.
• Monitor units increased by 32% (prostate) and 11% (lung) with MCO.

Conclusions:

• MCO is an effective method for IMRT planning, offering better OAR sparing than DMPO.
• MCO significantly reduces the time required for treatment plan optimization.
• MCO presents a valuable alternative for improving IMRT plan quality and efficiency.