Study on dosimetric parameters for stereotactic radiosurgery and intensity-modulated radiotherapy

Area of Science:

• Radiation Oncology
• Medical Physics

Background:

• Stereotactic radiosurgery (SRS) and intensity-modulated radiation therapy (IMRT) are advanced radiation techniques.
• Comparing their dosimetric parameters is crucial for optimizing treatment planning.

Purpose of the Study:

• To compare the dosimetric parameters of IMRT and SRS using patient data.
• To evaluate the efficacy of IMRT versus SRS for different lesion types.

Main Methods:

• Six patients treated with SRS underwent IMRT replanning.
• Dosimetric parameters including conformity index, homogeneity index, and organ-at-risk doses were calculated and compared.
• Data were analyzed based on lesion complexity and isocenter count.

Main Results:

• IMRT demonstrated superior conformality and dose homogeneity, especially for multiple-isocenter cases.
• Critical structure sparing was better with IMRT, but nontarget tissue doses were higher.
• IMRT matched SRS for spherical lesions but outperformed SRS for irregular lesions.

Conclusions:

• IMRT is a viable alternative to SRS, offering advantages for irregular-shaped targets.
• IMRT provides better critical structure sparing and dose distribution for complex cases.
• Treatment selection should consider lesion characteristics for optimal outcomes.