Extended-field bone marrow sparing radiotherapy for primary chemoradiotherapy in cervical cancer patients with para-aortic lymphadenopathy: Volumetric-modulated arc therapy versus helical tomotherapy.
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.
['Chen|Jenny Ling-Yu|JL|', 'Wang|Miao-Ci|MC|', 'Huang|Yu-Sen|YS|', 'Huang|Chao-Yuan|CY|', 'Pan|Chun-Kai|CK|', 'Hsu|Che-Yu|CY|', 'Lan|Keng-Hsueh|KH|', 'Kuo|Sung-Hsin|SH|']
D000328:Adult D000368:Aged D001853:Bone Marrow D059248:Chemoradiotherapy D005260:Female D006801:Humans D000072281:Lymphadenopathy D008875:Middle Aged D058958:Organs at Risk D011880:Radiotherapy Planning, Computer-Assisted D050397:Radiotherapy, Intensity-Modulated D014057:Tomography, X-Ray Computed D002583:Uterine Cervical Neoplasms
extended-field bone marrow sparing Cervical cancer volumetric-modulated arc therapy helical tomotherapy