Authors (including presenting author) :
KWONG SWM, KAM CYC, CHAN CMA, LEUNG KPA
Affiliation :
Physiotherapy Department, Queen Elizabeth Hospital
Introduction :
Breast cancer is the most common cancer and the third leading cause of cancer deaths among females in Hong Kong. The number of breast cancer cases with operation and adjuvant radiation therapy (RT) performed at the Queen Elizabeth Hospital (QEH) has been increasing. Despite RT reducing the risk of cancer-related mortality and the chance of local recurrence, radiation increases the risk of cardiac exposure and complications. Deep inspiration breath-hold (DIBH) is a technique that takes advantage of a more desirable position of the heart during inspiration to minimize heart doses from RT for left-sided breast cancer patients. With adequate prior education and training to master this technique, it was adopted to reduce cardiac exposure during RT.
Objectives :
To evaluate the efficacy of DIBH technique on promoting accurate maintenance of desirable chest wall volume during RT and successful rate for completion for entire radiation therapy in left-sided breast cancer patients.
Methodology :
Patients with left-sided breast cancer and pending RT at the QEH referred for physiotherapy training were recruited. All received three sessions of DIBH training educated by experienced physiotherapists. Incentive spirometry was utilized to assist in performing DIBH on a RT-positioning simulation board. The use of spirometry allows continuous monitoring of airflow throughout the respiratory cycle and stopping airflow at a set threshold volume, allowing the patient to hold their breath at the desired volume. Outcome measures included (1) airflow volume as shown in spirometry, (2) Forced Vital Capacity, and (3) post-RT complications if any. Measurements were taken before and after RT. Direct or phone interviews, medical record checking were performed at three months follow-up to explore if the patients had any post-RT complications.
Result & Outcome :
From March 2018 to December 2020, 52 patients referred for DIBH training were reviewed. Airflow volume was preserved after RT. All patients received DIBH training were able to maintain the desirable chest wall volume during RT and completed the entire course of RT successfully. Our results demonstrated that the DIBH intervention program was effective in assisting successful completion of RT for left-sided breast cancer patients with the heart maintained in favourable position to minimise radiation exposure. There were no post-RT complications recorded. Therefore it may enhance clinical safety and outcome. DIBH is easy to learn with the use of incentive spirometry and the RT-positioning simulation board. Further studies are needed to determine the optimal lung volume to reduce cardiac exposure without compromising target RT dose to left breast.
