Benchmark measurements for lung dose corrections for X-ray beams

Area of Science:

• Medical Physics
• Radiation Oncology
• Dosimetry

Background:

• Accurate photon dose calculations in lung tissue are critical for effective radiation therapy.
• Low-density lung tissue significantly attenuates and scatters radiation, complicating dose calculations.
• Existing benchmark data for lung dosimetry are limited, particularly for diverse geometries and densities.

Purpose of the Study:

• To provide a comprehensive set of reference measurements for photon dose calculations in lung-equivalent materials.
• To establish benchmark data across a range of lung densities and phantom configurations.
• To support the validation and improvement of treatment planning systems used in lung cancer radiotherapy.

Main Methods:

• Measurements were performed using 4 and 15 MV X-ray beams.
• Dose data were collected in lung-like materials with densities of 0.015, 0.18, and 0.31 gcm-3, as well as in water-like plastic.
• Various phantom geometries were used, including layered, finite lung cross-section, mediastinum, and tumor-in-lung simulations.

Main Results:

• Central axis depth dose data were reported for all tested conditions.
• The influence of field size, lung geometry, and distance in/behind the lung on dose distribution was investigated.
• A comprehensive dataset was generated serving as a benchmark for photon dose calculations in lung.

Conclusions:

• The provided reference measurements offer valuable data for validating photon dose calculations in lung.
• These benchmark data are essential for enhancing the accuracy of radiation dose delivery in lung cancer treatment.
• The study contributes to improving treatment planning and patient outcomes in radiotherapy for thoracic malignancies.