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Author Liu, H. ♦ Wentworth, S. ♦ Sintay, B. ♦ Wiant, D.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword APPLIED LIFE SCIENCES ♦ RADIATION PROTECTION AND DOSIMETRY ♦ ANIMAL TISSUES ♦ BEAM POSITION ♦ BIOMEDICAL RADIOGRAPHY ♦ DOSIMETRY ♦ HEART ♦ IMAGES ♦ MAMMARY GLANDS ♦ METRICS ♦ NEOPLASMS ♦ PATIENTS ♦ POSITIONING ♦ RADIATION DOSES ♦ RADIOTHERAPY ♦ REVIEWS
Abstract Purpose: Deep inspiration breath hold (DIBH) for left-sided breast cancer has been shown to reduce heart dose. Surface imaging helps to ensure accurate breast positioning, but does not guarantee a reproducible breath hold (BH) at DIBH treatments. We examine the effects of variable BH positions for DIBH treatments. Methods: Twenty-Five patients with free breathing (FB) and DIBH scans were reviewed. Four plans were created for each patient: 1) FB, 2) DIBH, 3) FB-DIBH – the DIBH plans were copied to the FB images and recalculated (image registration was based on breast tissue), and 4) P-DIBH – a partial BH with the heart shifted midway between the FB and DIBH positions. The FB-DIBH plans give “worst case” scenarios for surface imaging DIBH, where the breast is aligned by surface imaging but the patient is not holding their breath. Students t-tests were used to compare dose metrics. Results: The DIBH plans gave lower heart dose and comparable breast coverage versus FB in all cases. The FB-DIBH plans showed no significant difference versus FB plans for breast coverage, mean heart dose, or maximum heart dose (p >= 0.10). The mean heart dose differed between FB-DIBH and FB by < 2 Gy for all cases, the maximum heart dose differed by < 2 Gy for 21 cases. The P-DIBH plans showed significantly lower mean heart dose than FB (p = 0.01). The mean heart doses for the P-DIBH plans were < FB for 22 cases, the maximum dose < FB for 18 cases. Conclusions: A DIBH plan delivered to a FB patient set-up with surface imaging will yield similar dosimetry to a plan created and delivered FB. A DIBH plan delivered with even a partial BH can give reduced heart dose compared to FB techniques when the breast tissue is well aligned.
ISSN 00942405
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-06-15
Publisher Place United States
Journal Medical Physics
Volume Number 42
Issue Number 6


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