Audiovisual biofeedback guided breath-hold improves lung tumor position reproducibility and volume consistency

Abstract

PurposeRespiratory variation can increase the variability of tumor position and volume, accounting for larger treatment margins and longer treatment times. Audiovisual biofeedback as a breath-hold technique could be used to improve the reproducibility of lung tumor positions at inhalation and exhalation for the radiation therapy of mobile lung tumors. This study aimed to assess the impact of audiovisual biofeedback breath-hold (AVBH) on interfraction lung tumor position reproducibility and volume consistency for respiratory-gated lung cancer radiation therapy.MethodsLung tumor position and volume were investigated in 9 patients with lung cancer who underwent a breath-hold training session with AVBH before 2 magnetic resonance imaging (MRI) sessions. During the first MRI session (before treatment), inhalation and exhalation breath-hold 3-dimensional MRI scans with conventional breath-hold (CBH) using audio instructions alone and AVBH were acquired. The second MRI session (midtreatment) was repeated within 6 weeks after the first session. Gross tumor volumes (GTVs) were contoured on each dataset. CBH and AVBH were compared in terms of tumor position reproducibility as assessed by GTV centroid position and position range (defined as the distance of GTV centroid position between inhalation and exhalation) and tumor volume consistency as assessed by GTV between inhalation and exhalation.ResultsCompared with CBH, AVBH improved the reproducibility of interfraction GTV centroid position by 46% (P = .009) from 8.8 mm to 4.8 mm and GTV position range by 69% (P = .052) from 7.4 mm to 2.3 mm. Compared with CBH, AVBH also improved the consistency of intrafraction GTVs by 70% (P = .023) from 7.8 cm3 to 2.5 cm3.ConclusionsThis study demonstrated that audiovisual biofeedback can be used to improve the reproducibility and consistency of breath-hold lung tumor position and volume, respectively. These results may provide a pathway to achieve more accurate lung cancer radiation treatment in addition to improving various medical imaging and treatments by using breath-hold procedures.

Current status of proton therapy techniques for lung cancer

“…The inter-fractional variations were measured using repeated CT scans [82,83], daily CBCT [84] for lung cancer patients, and repeated MRI imaging [85] for healthy volunteers. The inter-fractional variations were larger than intra-fractional variations [79,[84][85][86]. ABC devices assisted BH was more stable than self-controlled BHs.…”

“…Patient compliance is important for the reproducibility of DIBH treatment. A moderate and comfortable level of breath holding with the aid of visual feedback increases reproducibility and thus, the consistency in the breath-hold lung tumor position and volume can be achieved [79].…”

Positional repeatability and variation in internal and external markers during volumetric-modulated arc therapy under end-exhalation breath-hold conditions for pancreatic cancer patients

“…In the inter-fraction subanalyses, positional variation improved during the 3rd 5-day treatment section (day 11–15), compared to that during the 1st 5-day treatment section (day 1–5). According to Lee et al ., BH training before treatment improved the positional consistency of lung tumors [ 18 ]. To further improve the positional consistency of pancreatic cancer motion during the 1st BH session within the first few days after beginning treatment, sufficient BH training of the patient would be useful.…”

Positional repeatability and variation in internal and external markers during volumetric-modulated arc therapy under end-exhalation breath-hold conditions for pancreatic cancer patients

“…In contrast, several studies have reported that visual feedback provided high repeatability of BH (12,17,19). Given the visual feedback, it may have improved the positional repeatability and variation.…”

“…BH training before treatment improved the positional consistency of lung tumors (17). To further improve the positional consistency of pancreatic cancer motion during the 1st BH session within the first few days after beginning treatment, sufficient training of the patient in BH would be useful.…”