Extended-field bone marrow sparing radiotherapy for primary chemoradiotherapy in cervical cancer patients with para-aortic lymphadenopathy: Volumetric-modulated arc therapy versus helical tomotherapy

Article type: Research Article

Authors: Chen, Jenny Ling-Yu^{a; b; c} | Wang, Miao-Ci^b | Huang, Yu-Sen^{a; d; *} | Huang, Chao-Yuan^b | Pan, Chun-Kai^{a; e} | Hsu, Che-Yu^b | Lan, Keng-Hsueh^b | Kuo, Sung-Hsin^b

Affiliations: [a] Department of Radiology, National Taiwan University College of Medicine, Taipei, Taiwan | [b] Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan | [c] Department of Oncology, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, Taiwan | [d] Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan | [e] Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan

Correspondence: [*] Corresponding author: Yu-Sen Huang, M.D. Ph.D., Department of Radiology, National Taiwan University College of Medicine, No. 7, Chung-Shan S. Rd, Taipei 100, Taiwan. Tel.: 886 2 2312 3456, ext 62643; E-mail: [email protected].

Abstract: BACKGROUND:Extended-field (EF) bone marrow-sparing (BMS) radiotherapy is attracting interest for cervical cancer patients with para-aortic lymphadenopathy. OBJECTIVE:To compare dosimetric quality of volumetric-modulated arc therapy (VMAT) vs. helical tomotherapy (HT) during EF BMS radiotherapy. METHODS:HT dose-volume histogram parameters including (1) coverage, homogeneity, and conformity of target volumes, (2) sparing of organs-at-risk, (3) monitor units, and (4) estimated treatment time were compared with those of VMAT in 20 cervical cancer patients who underwent EF BMS radiotherapy. The pelvic and para-aortic regions received 45-Gy dose (25 fractions), with simultaneous integrated boost of 55 Gy (25 fractions) for pelvic and para-aortic lymphadenopathy, followed by a parametrial boost of 9 Gy (5 fractions). RESULTS:The HT-based and VMAT techniques achieved adequate and similar target volume coverage with good dose homogeneity and conformity, while sparing all organs-at-risk, including the rectum, bladder, bowel, bone marrow, femoral head, kidney, and spinal cord. The HT treatment plan had significantly higher monitor units (p < 0.001) and longer estimated treatment times (p < 0.001). CONCLUSIONS:VMAT and HT plans are suitable for EF BMS radiotherapy, which can achieve adequate target volume coverage while sufficiently sparing normal tissue. In addition, VMAT, compared to HT planning, yielded shorter estimated treatment times.

Keywords: Cervical cancer, extended-field bone marrow sparing, volumetric-modulated arc therapy, helical tomotherapy

DOI: 10.3233/XST-190593

Journal: Journal of X-Ray Science and Technology, vol. 28, no. 1, pp. 111-124, 2020