Keywords:
Breast, Radioprotection / Radiation dose, Cardiac, CT, CT-High Resolution, Radiation therapy / Oncology, Complications, Radiation effects, Cancer, Dosimetric comparison, Image guided radiotherapy
Authors:
A. Parasuramar, M. Borg, A. DeSmit; SA/AU
DOI:
10.1594/ranzcr2017/R-0124
Purpose
Breast cancer remains the most common cancer to target women in Australia (1).
Adjuvant radiotherapy (RT) has become the mainstay treatment after breast conserving surgery for invasive cancer and post-mastectomy radiotherapy,
boasting a reduction of local recurrence from 26% to 7% at 5 years follow-up.
As with any treatment,
radiation therapy has its side-effects – multiple studies have linked left breast irradiation to increased cardiac mortality and morbidity (2–4).
Darby et al.
found that the relative risk for ischaemic heart disease increased by 7.4% for every 1 Gray (Gy) increase in mean heart dose in a population base study involving 2168 patients (2).
Deep Inspiration Breath Hold (DIBH) has been widely recognized as an effective means of reducing radiation exposure to the heart without compromising the therapeutic dose to breast cancer tissue (5–14)
One of the most common methods is via the spirometry-based Active Breathing Coordinator (ABC) system made by Elekta (Stockholm,
Sweden).
One of the difficulties with this system is its cost,
not only in the machine itself but with new mouthpieces and specialized training for staff.
For some years this prevented widespread implementation of the Breath Hold Technique.
The Voluntary Breath Hold (VBH) was then conceived as a simple and inexpensive alternative to the ABC DIBH.
Our study looks to compare the efficacy of two different techniques of DIBH investigated at Adelaide Radiotherapy Centre – Active breathing coordinator (Elekta) and Voluntary breath hold with dosimetric endpoints.