Treatment planning and evaluation of gated radiotherapy in left-sided breast cancer patients using the CatalystTM/SentinelTM system for deep inspiration breath-hold (DIBH)

Abstract

BackgroundThere is a potential for adverse cardiovascular effects in long-term breast cancer survivors following adjuvant radiotherapy (RT). For this purpose, the deep inspiration breath-hold technique (DIBH) has been introduced into clinical practice, to maximally reduce the radiation dose to the heart. However, there are a variety of DIBH delivery techniques, patient positioning and visual patient feedback mechanisms. The aim of the present study was to evaluate the application of radiotherapy in DIBH using the CatalystTM/SentinelTM system, with a special emphasis on treatment planning and dosimetric plan comparison in free breathing (FB) and DIBH.Patients and methodsA total of 13 patients with left-sided breast cancer following breast conserving surgery were included in this prospective clinical trial. For treatment application the CatalystTM/SentinelTM system (C-RAD AB, Uppsala, Sweden) was used and gating control was performed by an audio-visual patient feedback system. CT and surface data were acquired in FB and DIBH and dual treatment plans were created using Pencil Beam and Collapsed Cone Convolution. Dosimetric output parameters of organs at risk were compared using Wilcoxon signed-rank test. Central lung distance (CLD) was retrieved from iViewTM portal images during treatment delivery.ResultsThe system contains a laser surface scanner (SentinelTM) and an optical surface scanner (CatalystTM) interconnected to the LINAC systems via a gating interface and allows for a continuous and touchless surface scanning. Overall, 225 treatment fractions with audio-visual guidance were completed without any substantial difficulties. Following initial patient training and treatment setup, radiotherapy in DIBH with the CatalystTM/SentinelTM system was time-efficient and reliable. Following dual treatment planning for all patients, nine of 13 patients were treated in DIBH. In these patients, the reduction of the mean heart dose for DIBH compared to FB was 52 % (2.73 to 1.31 Gy; p = 0.011). The maximum doses to the heart and LAD were reduced by 59 % (47.90 to 19.74 Gy; p = 0.008) and 75 % (38.55 to 9.66 Gy; p = 0.008), respectively. In six of the nine patients the heart completely moved out of the treatment field by DIBH. The standard deviation of the CLD varied between 0.12 and 0.29 cm (mean: 0.16 cm).ConclusionThe CatalystTM/SentinelTM system enabled a fast and reliable application and surveillance of DIBH in daily clinical routine. Furthermore, the present data show that using the DIBH technique during RT could significantly reduce high dose areas and mean doses to the heart.Trial registration DRKS: DRKS00010929 registered on 5. August 2016.

Does deep inspiration breath-hold prolong life? Individual risk estimates of ischaemic heart disease after breast cancer radiotherapy

“…There are different strategies for implementing the DIBH technique in terms of used equipment, required accessories, intra-fractional monitoring and patient feedback systems. Several studies have confirmed the substantial impact of DIBH on dosimetric endpoints, such as mean heart or ipsilateral lung dose [6,[14][15][16]. The dose reduction in our study (35%, interquartile range: 23-46%) was slightly lower than the range reported in the literature (38-67%).…”

“…Patients were immobilized in a supine position on a positioning device (Wing-STEP Ò , IT-V, Austria), with both arms elevated above the head. The DIBH manoeuvre during CT simulation and treatment delivery was performed using the surface-based Catalyst TM /Sentinel TM system as described elsewhere [6]. The system enables a continuous optical surface scanning with automated treatment delivery using an audio-visual patient feedback system.…”

“…Abbreviations: BC, breast cancer; DIBH, deep inspiration breath-hold; FB, free breathing; IHD, ischaemic heart disease; RNI, regional nodal irradiation; YLL, expected years of life lost. significant reduction of cardiac dose exposure [6]. Even though, in some countries, DIBH is already routinely applied, it cannot be extensively used in most other countries.…”

Comparison of initial patient setup accuracy between surface imaging and three point localization: A retrospective analysis

“…This ability to manually manipulate marks highlights the need for an alternative method. For treatments like lung Stereotactic Body Radiation Therapy (SBRT) and the treatment of breast cancer with deep inspiration breath hold, where surface imaging technologies are already being utilized, the question becomes are tattoos necessary?11 Clinically, regardless of the pre‐imaging verification setup method, it is assumed that patients are being positioned correctly due to the 3D volumetric imaging. It is important and should be noted that this study is not advocating for a complete removal of subcutaneous tattoos in radiation therapy but rather to evaluate an alternative solution for primary setup that may be preferable for specific clinics and patients.…”

Low‐cost Kinect Version 2 imaging system for breath hold monitoring and gating: Proof of concept study for breast cancer VMAT radiotherapy

“…This may be achieved by reducing the radiation dose to the heart from radiotherapy. One approach to achieving this is deep inspiration breath‐hold, using either equipment‐assisted or voluntary inspiration breath‐hold (VIBH) techniques 6, 7…”