A Dosimetric Comparison of Accelerated Partial Breast Irradiation Techniques: Multicatheter Interstitial Brachytherapy, Three-Dimensional Conformal Radiotherapy, and Supine Versus Prone Helical Tomotherapy

Prone versus supine positioning for whole and partial-breast radiotherapy: A comparison of non-target tissue dosimetry

“…We found the effects of prone positioning upon both heart and LAD doses to be variable between patients, consistent with previous studies (10,14). Around two-thirds of patients planned for WBI benefited from prone positioning, with mean improvements in heart-NTD mean , LAD-NTD mean and LAD max of 0.4Gy, 7.0Gy and 4.9Gy respectively.…”

“…However, studies using conventional tangential-field arrangements have failed to show an overall benefit of prone positioning on cardiac dosimetry (11,14). Furthermore, a study comparing distances between anterior pericardium and chest-wall on supine CT-images and prone MRI (15) found prone positioning to systematically displace supero-lateral aspects of heart-tissue closer to chest-wall, such that prone positioning might be detrimental where target tissues include chest-wall and/or deeply-lying breast tissue.…”

“…The combination of prone positioning and PBI is particularly attractive in terms of reducing normal-tissue toxicity. A dosimetric comparison of accelerated PBI techniques (14) found that brachytherapy & prone tomotherapy resulted in least Prone breast dosimetry Kirby page 4 dose to lung and non-target ipsilateral breast tissue (compared with supine 3D-conformal-RT and tomotherapy). However, heart doses again varied between patients, prone tomotherapy benefiting only women with larger breasts and/or lesions further from chest-wall.…”

The UK HeartSpare Study (Stage IB): Randomised comparison of a voluntary breath-hold technique and prone radiotherapy after breast conserving surgery

“…Breath-holding techniques reduce heart doses [8][9][10][11] be as effective at heart-sparing and as reproducible as breath-holding treatment with the active breathing coordinator™ (ABC) (Elekta, Crawley, UK) [7]. Additional benefits, including shorter treatment setup times and lower implementation costs, are likely to establish this technique as the standard of care for many left-sided women in the UK.…”

“…However, there remains a group of largerbreasted women in whom the relative benefits of breath-hold versus prone positioning are unknown. Previous work has shown that, although the prone position moves the heart closer to the chest wall under gravity [8], larger breasts fall further forward, allowing for shallower tangential radiotherapy beam placement [9,10] and therefore significantly reduced cardiac doses in largerbreasted women [11].…”