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. 2022 Aug;12(8):4239-4247.
doi: 10.21037/qims-21-1101.

Analysis of deep inspiration breath-hold technique to improve dosimetric and clinical advantages in postoperative intensity-modulated radiation therapy for thymomas

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Analysis of deep inspiration breath-hold technique to improve dosimetric and clinical advantages in postoperative intensity-modulated radiation therapy for thymomas

Danfang Yan et al. Quant Imaging Med Surg. 2022 Aug.

Abstract

Background: Radiation therapy is one of the essential treatment modalities for invasive thymomas. Clinically, respiratory motion poses a challenge for the radiotherapy of thoracic tumors. One method to address this issue is to train patients to hold their breath at the end of deep inspiration. The purpose of this retrospective cohort study was to investigate the dosimetric and clinical advantages of the deep inspiration breath-hold (DIBH) technique in postoperative intensity-modulated radiation therapy (IMRT) for thymomas.

Methods: Thymoma patients undergoing postoperative IMRT were included. Each patient underwent two computed tomography (CT) scans, one under free breath (FB) and the other under DIBH. Dosimetric parameters of organs at risk (OARs) were evaluated in three series plans. Dose analysis and volume comparisons were conducted during FB-3 mm (FB with 3 mm internal target volume margin), FB-10 mm (FB with 10 mm internal target volume margin), and DIBH and compared using a paired sample Student's t-test. Normal tissue complication probabilities (NTCP) for lungs and heart were calculated and compared.

Results: The total lung volume significantly increased by 31% (4,216±198 vs. 2,884±166 mL) and the heart volume reduced by 12% (552±25 vs. 636±35 mL) between DIBH acquisitions compared to FB. A significant improvement was observed in all the dosimetric parameters (Dmean, V20, V5) of the lung on DIBH compared to FB-3 mm (54%±2.85% vs. 47%±2.90%, P<0.001; 15%±1.37% vs. 12%±1.32%, P=0.004; and 10.28±0.58 vs. 8.76±0.57 Gy, P<0.001, respectively), as well as in the Dmax and D2% of the esophagus and spine. The lung volume increment was related to a reduction in the mean dose of lungs, with a correlation coefficient of r=0.27, P=0.03. The NTCP values for pneumonitis significantly reduced with DIBH compared to the FB state (0.6% vs. 1.1%, P<0.001).

Conclusions: The radiation dose to the OARs can be significantly reduced by using the DIBH technique in postoperative IMRT for thymomas. The increased volume of lungs using DIBH acquisitions can significantly reduce the incidence of pneumonitis.

Keywords: Thymomas; deep inspiration breath-hold (DIBH); intensity-modulated radiation therapy (IMRT); pneumonitis.

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Conflict of interest statement

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-21-1101/coif). The authors have no conflicts of interest to declare.

Figures

Figure 1
Figure 1
The ITV and PTV margin in FB and DIBH. ITV, internal target volume; PTV, planning target volume; FB, free breath; DIBH, deep inspiration breath hold.

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References

    1. Engels EA, Pfeiffer RM. Malignant thymoma in the United States: demographic patterns in incidence and associations with subsequent malignancies. Int J Cancer 2003;105:546-51. 10.1002/ijc.11099 - DOI - PubMed
    1. Marx A, Weis CA, Ströbel P. Thymomas. Pathologe 2016;37:412-24. 10.1007/s00292-016-0223-3 - DOI - PubMed
    1. Mariano C, Ionescu DN, Cheung WY, Ali RH, Laskin J, Evans K, Carolan H, Murray N. Thymoma: a population-based study of the management and outcomes for the province of British Columbia. J Thorac Oncol 2013;8:109-17. 10.1097/JTO.0b013e318276241c - DOI - PubMed
    1. Gomez D, Komaki R. Technical advances of radiation therapy for thymic malignancies. J Thorac Oncol 2010;5:S336-43. 10.1097/JTO.0b013e3181f20ea2 - DOI - PubMed
    1. Marchand V, Zefkili S, Desrousseaux J, Simon L, Dauphinot C, Giraud P. Dosimetric comparison of free-breathing and deep inspiration breath-hold radiotherapy for lung cancer. Strahlenther Onkol 2012;188:582-9. 10.1007/s00066-012-0129-9 - DOI - PubMed