ESTRO 2024 - Abstract Book

S4356

Physics - Intra-fraction motion management and real-time adaptive radiotherapy

ESTRO 2024

Total twenty-three patients who succeed with CPAP method have difference level of CPAP positive pressure. Most of patients (19 person) can tolerate CPAP pressure up to 14 cmH2O, 3 patients can tolerate CPAP pressure up to 12 cmH2O, and only 1 patient can tolerate pressure with 10 cmH2O. We found that the patient tolerance in CPAP pressure should not exceed 14 cmH2O which is dependent on individual patient tolerate. The results showed the mean heart dose was decreased in the patients who succeed DIBH with CPAP method compared to FB technique. The level of CPAP pressure related to the dose overlayed to the heart. Not only mean heart dose was reduced by using high CPAP pressure in DIBH, but Heart V25%, mean LAD, and max LAD were also decreased from 5.28Gy(FB) to 3.46Gy(CPAP), 7.25%(FB) to 3.57%(CPAP), 25.27Gy(FB) to 16.99Gy(CPAP), and 44.84Gy(FB) to 31.69Gy(CPAP), respectively. The CPAP pressure between 12 to 14 cmH2O was also effective to control mean heart dose within 4 Gy.

Conclusion:

CPAP is a method using the passively pressurized the patient’s lungs into the certain pressure and then take a deep breath to separate heart from chest wall by increasing lung volume. This method was more reliable success for simulation especially in the groups of elderly patient or patient who failed in DIBH. Our study was demonstrated the ability to decrease the mean heart dose by increasing lung volume using CPAP method. The optimal CPAP positive pressure level to reduce the mean heart dose less than 4 Gy could be 12 to 14 cmH2O. The use of CPAP application was associated significant dosimetric and volumetric reducing mean heart dose compared with FB. the CPAP pressure 12 cmH2O is suitable for patient tolerate throughout treatment. CPAP method could be an effective, simple, and safe option to implement in most left-sided breast cancer radiation.

Keywords: CPAP, DIBH, mean heart dose

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