Deep inspiration breath-hold volumetric modulated arc radiotherapy decreases dose to mediastinal structures in locally advanced lung cancer

Abstract

The phase III dose escalation trial RTOG 0617 [4] showed that heart dose parameters were correlated to death in a multivariate analysis and in a dose escalation trial by Cannon et al.[5] serious late toxicity from central and perihilar structures was encountered. In breast cancer radiotherapy a large population-based case-control study showed an increased risk of major cardiac events with increasing heart dose [6]. During deep inspiration breath-hold (DIBH), the lungs are inflated and the heart displaced caudally and these anatomical changes can be exploited to achieve a lower radiation dose to the intra-thoracic normal tissue. Several reports have shown that DIBH radiotherapy (RT) is a feasible alternative and has the potential of decreasing the lung dose in conventional three-dimensional conformal radiotherapy (3D-CRT) [7][8][9] and also with volumetric modulated arc therapy (VMAT) [10]. Furthermore, DIBH RT does not acquire a lot of time [11] or economical resources for implementation.We previously reported preliminary results from the first 10 patients included in this study and found a statistically significant reduction of mean lung dose with DIBH 3D-CRT as well as with VMAT in patients with locally advanced NSCLC [12]. The combination of DIBH and VMAT reduced these parameters further and DIBH mitigated the low dose bath induced by VMAT.Most previous studies have focused on dose to the lungs and none of them have reported on dose to bronchi and trachea. In this final report, we examine if DIBH-VMAT holds potential to decrease doses to mediastinal organs at risk (OAR) compared to free breathing (FB) VMAT. Material and methodsSeventeen patients with locally advanced NSCLC were included prospectively from April 2012 to September 2013. Inclusion criteria were ability to perform a voluntary breathhold for 20 seconds and to follow the audio-visual coaching instructions. All patients were treated in FB. The delineations and treatment planning was performed retrospectively.The study was approved by the local ethical committee (H-2-2011-153). Patient characteristics are listed in Supplementary Table 1S (available online at http://www.informahealthcare. com).The patients were audio visually coached to hold their breath at a comfortable level of deep inspiration for 20 seconds at a time during a 15-minute session. The Realtime Position Management TM system (VarianV R Medical Systems) was used to track and record the respiratory signal. The planning procedure included a FB positron emission tomography (PET)/computed tomography (CT) (with 18-Fluorodeoxyglucose tracer), a respiration correlated CT (4D-CT) and three consecutive audio-visual coached DIBH-CT scans (for registration of intra-fraction variation). The mid-ventilation phase (MidV) [13] of the 4D-CT was selected for the FB plan and the first acquired DIBH-CT for the DIBH plan.To minimize observer variations, the gross tumor volume (GTV) delineations were performed after a strict protocol, with the same radiologist contouring on both the MidV and the DIBH-CT fo...

Role of Real-World Data in Assessing Cardiac Toxicity After Lung Cancer Radiotherapy

“…Of note, most studies in lung cancer investigate the link between outcomes and planned dose (as opposed to delivered dose). However, the set-up uncertainties and anatomical motion impacts the dose received by the heart and heart sub-structures, and thereby the risk of RIHD ( 44 ).…”

Shooting the Star: Mitigating Respiratory Motion in Lung Cancer Radiotherapy

“…Deep inspiration breath-hold (DIBH) is an active respiratory motion management strategy that involves the delivery of radiotherapy during breath-hold. It results in increased lung volume and displacement of the heart and can therefore be used to reduce normal tissue dose [25,26]. Respiratory gating is another active respiratory motion management strategy.…”

Tumour motion management in lung cancer: a narrative review

“…In the deep-inspiration breath-hold (DIBH), the patient attempted a maximum inhalation during simulation and treatment, by using spirometer linked to a video glasses or a screen (20). This technique allows the displacement of heart and lung from the high-dose region (21,22). Rosenzweig et al (23) showed that normal tissue complication in lung decreased with the DIBH technique compared with freebreathing.…”