Radiobiological depth of subcutaneous induration

Area of Science:

• Oncology
• Radiation Oncology
• Medical Physics

Background:

• Postmastectomy radiotherapy can cause side effects like subcutaneous induration.
• Understanding dose-response relationships is crucial for optimizing radiotherapy.
• Previous studies have explored various factors influencing radiation-induced tissue reactions.

Purpose of the Study:

• To investigate the incidence of subcutaneous induration in breast cancer patients treated with postmastectomy radiotherapy.
• To correlate the incidence of induration with the biological effective dose (BED) at varying depths.
• To identify the most representative depth for assessing radiation dose related to subcutaneous induration.

Main Methods:

• Analysis of 23 breast cancer patients who received postmastectomy radiotherapy.
• Correlation of subcutaneous induration incidence with BED at different tissue depths.
• Utilizing an alpha/beta ratio of 2 Gy for dose calculation.
• Assessment of dose at depths ranging from the skin surface downwards.

Main Results:

• Subcutaneous induration incidence was successfully correlated with BED.
• An alpha/beta ratio of 2 Gy provided the best fit for the observed data.
• The most representative depth for assessing the dose related to subcutaneous induration was determined to be 2 mm.
• This 2 mm depth is located near the interface between subcutaneous fat and dermis.

Conclusions:

• The incidence of subcutaneous induration is dependent on the biological effective dose of radiotherapy.
• A depth of 2 mm, representing the subcutaneous fat/dermis interface, is critical for evaluating radiation dose in relation to induration.
• These findings can inform radiotherapy planning to minimize subcutaneous induration in breast cancer patients.