scholarly journals Dosimetric comparison of deep inspiration breath hold and free breathing technique in stereotactic body radiotherapy for localized lung tumor using Flattening Filter Free beam

2018 ◽  
Vol 24 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Karthick Raj Mani ◽  
Md. Anisuzzaman Bhuiyan ◽  
Md. Mahbub Alam ◽  
Sharif Ahmed ◽  
Mostafa Aziz Sumon ◽  
...  

Abstract Aim: To compare the dosimetric advantage of stereotactic body radiotherapy (SBRT) for localized lung tumor between deep inspiration breath hold technique and free breathing technique. Materials and methods: We retrospectively included ten previously treated lung tumor patients in this dosimetric study. All the ten patients underwent CT simulation using 4D-CT free breathing (FB) and deep inspiration breath hold (DIBH) techniques. Plans were created using three coplanar full modulated arc using 6 MV flattening filter free (FFF) bream with a dose rate of 1400 MU/min. Same dose constraints for the target and the critical structures for a particular patient were used during the plan optimization process in DIBH and FB datasets. We intend to deliver 50 Gy in 5 fractions for all the patients. For standardization, all the plans were normalized at target mean of the planning target volume (PTV). Doses to the critical structures and targets were recorded from the dose volume histogram for evaluation. Results: The mean right and left lung volumes were inflated by 1.55 and 1.60 times in DIBH scans compared to the FB scans. The mean internal target volume (ITV) increased in the FB datasets by 1.45 times compared to the DIBH data sets. The mean dose followed by standard deviation (x̄ ± σx̄) of ipsilateral lung for DIBH-SBRT and FB-SBRT plans were 7.48 ± 3.57 (Gy) and 10.23 ± 4.58 (Gy) respectively, with a mean reduction of 36.84% in DIBH-SBRT plans. Ipsilateral lung were reduced to 36.84% in DIBH plans compared to FB plans. Conclusion: Significant dose reduction in ipsilateral lung due to the lung inflation and target motion restriction in DIBH-SBRT plans were observed compare to FB-SBRT. DIBH-SBRT plans demonstrate superior dose reduction to the normal tissues and other critical structures.

2019 ◽  
Vol 18 (02) ◽  
pp. 169-174
Author(s):  
N. Munirathinam ◽  
P. N. Pawaskar

AbstractAimThe aim of this study is to evaluate the influence of flattened and flattening filter-free (FFF) beam 6 MV photon beam for liver stereotactic body radiation therapy by using volumetric modulated arc therapy (VMAT) technique in deep inspiration breath hold (DIBH) and free breathing condition.Materials and methodsEight liver metastasis patients (one to three metastasis lesions) were simulated in breath hold and free breathing condition. VMAT-based treatment plans were created for a prescription dose of 50 Gy in 10 fractions, using a 230° coplaner arc and 60° non-coplanar arc for both DIBH and free breathing study set. Treatment plans were evaluated for planning target volume (PTV) dose coverage, conformity and hot spots. Parallel and serial organs at risk were compared for average and maximum dose, respectively. Dose spillages were evaluated for different isodose volumes from 5 to 80%.ResultMean D 98% (dose received by 98% target volume) for FFF in DIBH, flattened beam in DIBH, FFF in free breathing and flatten beam in free breathing dataset were 48·9, 47·81, 48·5 and 48·3 Gy, respectively. D 98% was not statistically different between FFF and flatten beam (p = 0·34 and 0·69 for DIBH and free breathing condition). PTV V 105% (volume receiving 105% dose) for the same set were 3·76, 0·25, 1·2 and 0·4%, respectively. Mean heterogeneity index for all study sets and beam models varies between 1·05 and 1·07. Paddik conformity index using unflattened and flattened beam in DIBH at 98% prescription dose were 0·91 and 0·79, respectively. Maximum variation of isodose volume was observed for I-5%, which was ranging between 2288·8 and 2427·2 cm3. Increase in isodose value shows a diminishing difference in isodose volumes between different techniques. DIBH yields a significant reduction in the chest wall dose compared with free breathing condition. Average monitor units for FFF beam in DIBH, flattened beam in DIBH, FFF beam in free breathing CT dataset and flattened beam in free breathing CT dataset were 1318·6 ± 265·1, 1940·3 ± 287·6, 1343·3 ± 238·1 and 2192·5 ± 252·6 MU.ConclusionDIBH and FFF is a good combination to reduce the treatment time and to achieve better tumour conformity. No other dosimetric gain was observed for FFF in either DIBH or free breathing condition.


2020 ◽  
Vol 61 (3) ◽  
pp. 431-439 ◽  
Author(s):  
Chih-Shen CHANG ◽  
Chia-Hsin CHEN ◽  
Kuo-Chi LIU ◽  
Chia-Sheng HO ◽  
Miao-Fen CHEN

Abstract The deep inspiration breath-hold (DIBH) technique has been utilized to reduce the cardiac dose in left-sided breast cancer (BC) patients undergoing radiotherapy. Further investigation of the parameters for selecting which patients will benefit most from DIBH is essential. We performed dosimetric comparisons for 21 patients with left-sided BC who had both computed tomography (CT)-based free-breathing (FB) and DIBH plans. The doses to the heart and left anterior descending artery (LAD) and any reduction due to the DIBH technique were analysed. Based on CTFB plans, dosimetric analysis revealed that the irradiation doses to the heart and LAD were significantly correlated with the target volume, the ipsilateral lung volume (ILV) and the total lung volume (TLV). When patients had an ILV ≥ 950 cm3 or a TLV ≥ 2200 cm3, the irradiation doses to the heart and LAD were significantly decreased. Furthermore, the reduction in the mean heart dose (MHD) was correlated to the difference in lung volume between FB and DIBH. The difference in ILV between DIBH and FB of 1.8 indicated that the patients obtained more benefit from the DIBH technique. The data suggest that lung volume (ILV and TLV) measured on a CT-simulation scan and the difference between FB and DIBH could be utilized to help select patients for DIBH.


2020 ◽  
Vol 21 (12) ◽  
pp. 280-287
Author(s):  
Sarah B. Wisnoskie ◽  
Xiaoying Liang ◽  
Andrew O. Wahl ◽  
Nathan R. Bennion ◽  
Andrew D. Granatowicz ◽  
...  

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Michał Falco ◽  
Bartłomiej Masojć ◽  
Agnieszka Macała ◽  
Magdalena Łukowiak ◽  
Piotr Woźniak ◽  
...  

Abstract Background Patients with left breast cancer who undergo radiotherapy have a non-negligible risk of developing radiation-induced cardiovascular disease (CVD). Cardioprotection can be achieved through better treatment planning protocols and through respiratory gating techniques, including deep inspiration breath hold (DIBH). Several dosimetric studies have shown that DIBH reduces the cardiac dose, but clinical data confirming this effect is limited. The aim of the study was to compare the mean heart dose (MHD) in patients with left breast cancer who underwent radiotherapy at our institution as we transitioned from non-gated free-breathing (FB) radiotherapy to gated radiotherapy (FB-GRT), and finally to DIBH. Patients and methods Retrospective study involving 2022 breast cancer patients who underwent radiotherapy at West Pomeranian Oncology Center in Szczecin from January 1, 2014 through December 31, 2017. We compared the MHD in these patients according to year of treatment and technique. Results Overall, the MHD for patients with left breast cancer in our cohort was 3.37 Gy. MHD values in the patients treated with DIBH were significantly lower than in patients treated with non-gated FB (2.1 vs. 3.48 Gy, p < 0.0001) and gated FB (3.28 Gy, p < 0.0001). The lowest MHD values over the four-year period were observed in 2017, when nearly 85% of left breast cancer patients were treated with DIBH. The proportion of patients exposed to high (> 4 Gy) MHD values decreased every year, from 40% in 2014 to 7.9% in 2017, while the percentage of patients receiving DIBH increased. Conclusions Compared to free-breathing techniques (both gated and non-gated), DIBH reduces the mean radiation dose to the heart in patients with left breast cancer. These findings support the use of DIBH in patients with left breast cancer treated with radiotherapy.


Sign in / Sign up

Export Citation Format

Share Document