Deep inspiration breath-hold (DIBH) technique applied in right breast radiotherapy to minimize liver radiation

Abstract

A right-sided breast cancer patient (stage T1N0M0) was referred for post-surgical radiotherapy to minimize risk of local tumour recurrence. During the CT simulation and intensity-modulated radiotherapy planning process undertaken in free breathing, it was apparent that an unusually large volume of normal liver tissue (134 cc) was in the high-dose region of the tangential radiation field. This raised concern for risk of liver side effects and was considered suboptimal for this excellent prognosis patient. A deep inspiration breath-hold (DIBH) technique using three-dimensional (3D) surface monitoring—primarily developed and applied in left breast cancer to displace cardiac tissue from the target field—was investigated to determine potential benefit to optimize radiotherapy delivery. Resimulation of DIBH resulted in considerable displacement of the liver, reducing the volume of liver tissue in the target field by 63% (to 50 cc) and the mean liver dose by 46% (to 2.6 Gy). As the patient was deemed suitable for the DIBH technique, treatment was delivered according to the DIBH plan. A total of 40.05 Gy in 15 fractions was successfully delivered in the DIBH position using a technique that incorporated 3D body surface imaging with automated radiation beam hold-off when out of tolerance. Additional advantages were optimal set up without extensive immobilization and the elimination of respiratory motion. Acute mild skin erythema was the only side effect experienced—no liver sequalae were experienced by the patient up to 6 months after treatment. DIBH treatment may improve liver sparing in other similar right breast cancer patients.

Dose reduction to organs at risk with deep-inspiration breath-hold during right breast radiotherapy: a treatment planning study

“…While the clinical significance of hepatic dose during right-breast radiotherapy remains to be established, it is in the best interests of patients, and in alignment with the ‘as low as reasonably achievable’ (ALARA) principle, to reduce dose to all potential organs at risk as much as possible. Our data, alongside previous studies [13, 14, 29], clearly demonstrates a role for DIBH in reducing hepatic dose which is achieved through increasing the superior-inferior separation between the CTV and the liver as the lungs expand (Fig. 4).…”

“…Early data suggests cardiac and pulmonary benefits for right-breast cancer patients when RNI is also prescribed [12, 13]. Liver-sparing is also reported [13, 14], however, data remains limited.…”

An effective deep-inspiration breath-hold radiotherapy technique for left-breast cancer: impact of post-mastectomy treatment, nodal coverage, and dose schedule on organs at risk

“…At the time of simulation, radiographers determined patient benefit and capability for DIBH technique using previously described criteria, 24 as outlined in Table 1 . The screening method was designed to be a quick and pragmatic way of determining patients who demonstrated obvious heart risk (heart within FB RT treatment field), easily performed good DIBH technique, and showed clear benefit of the DIBH technique (heart moves away from RT treatment field in DIBH).…”

The volume of liver irradiated during modern free-breathing breast radiotherapy: Implications for theory and practice

“…The upper range of liver exposure evident in the current participants could also be minimised for standard local breast tangents. 10 Leveraging the inherent stability of DIBH can reduce cranio-caudal intrafraction hepatic motion from 19mm to 1-5mm, 25,26 reduce liver volume by 63% (134cm 3 to 50cm 3 ) and mean liver dose by 46% (from 4.8 to 2.6 Gy) compared to a free breathing plan 10 and deliver superior ipsilateral and total lung dosimetry. 27,28 The range of maximum liver dose in the current study was surprisingly large for left-sided treatments.…”