PMID- 35523741
OWN - NLM
STAT- MEDLINE
DCOM- 20220510
LR  - 20220510
IS  - 2224-5839 (Electronic)
IS  - 2224-5820 (Linking)
VI  - 11
IP  - 4
DP  - 2022 Apr
TI  - The effects of intestinal air cavity on dose distribution of volume modulated arc 
      therapy for cervical cancer.
PG  - 1326-1335
LID - 10.21037/apm-22-66 [doi]
AB  - BACKGROUND: This study explored the effects of air cavity on the dose 
      distribution of radiotherapy in patients after extensive hysterectomy. In 
      patients who have an air cavity in the intestines near the planning target volume 
      (PTV), the photon beams may interact with the air cavity to cause electron 
      disequilibrium (ED), resulting in a reduction in the absorbed dose by the 
      surrounding tissues. In this paper, the electron density assignment (EDA) of the 
      air cavity was used to simulate the disappearance of the intestinal gas, and the 
      effects of the intestinal air cavity on the volume modulated arc therapy (VMAT) 
      results were examined. METHODS: A total of 21 patients who underwent VMAT after 
      extensive hysterectomy were enrolled in this retrospective analysis. The dose 
      parameters from the selected treatment plan were used the experimental reference. 
      The treatment plan of the reference group was copied, and the intestinal air 
      cavity structure was identified using the computed tomography (CT) simulation 
      image. The electron density value of the intestine near the cavity was measured 
      and averaged according to the intestinal electron density value recommended by 
      International Commission Radiological Units (ICRU) report No. 46. The averaged 
      value was assigned to the air cavity structure. Subsequently, the treatment plan 
      was re-calculated without changing other parameters, and the resulting treatment 
      plan was defined as the experimental group. The dose parameters of the PTV and 
      organs at risk (OAR) in the 2 groups were assessed, and the influence of the 
      intestinal air cavity on the VMAT dose distribution in cervical cancer patients 
      was analyzed. RESULTS: The minimum dose (D98) and the maximum dose (D2) of the 
      PTV was significantly different between the experimental group and the control 
      group (P<0.05), however, mean dose of the PTV was comparable between the 2 
      groups. The dose parameters of OARs were not significantly different between the 
      two groups except the bone structural organs. CONCLUSIONS: When the intestinal 
      air cavity is large and related to the target area, the intestinal air cavity 
      should be intervened, and the patient should be treated with radiotherapy after 
      the intestinal gas decreases.
FAU - Chang, Xiaobin
AU  - Chang X
AD  - Department of Radiation Oncology, Shaanxi Provincial Tumor Hospital, Affiliated 
      Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, China.
FAU - Yuan, Yuan
AU  - Yuan Y
AD  - Department of Gynaecological Oncology, Shaanxi Provincial Tumor Hospital, 
      Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, 
      China.
FAU - Wang, Guoqing
AU  - Wang G
AD  - Department of Gynaecological Oncology, Shaanxi Provincial Tumor Hospital, 
      Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, 
      China.
FAU - Hu, Lijuan
AU  - Hu L
AD  - Department of Gynaecological Oncology, Shaanxi Provincial Tumor Hospital, 
      Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, 
      China.
FAU - Zhou, Min
AU  - Zhou M
AD  - Department of Gynaecological Oncology, Shaanxi Provincial Tumor Hospital, 
      Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, 
      China.
FAU - Liu, Huijuan
AU  - Liu H
AD  - Department of Radiation Oncology, Shaanxi Provincial Tumor Hospital, Affiliated 
      Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, China.
FAU - Pan, Libo
AU  - Pan L
AD  - Department of Computed Tomography, Shaanxi Provincial Tumor Hospital, Affiliated 
      Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, China.
FAU - Wang, Jing
AU  - Wang J
AD  - Department of Gynaecological Oncology, Shaanxi Provincial Tumor Hospital, 
      Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, 
      China.
LA  - eng
PT  - Journal Article
PL  - China
TA  - Ann Palliat Med
JT  - Annals of palliative medicine
JID - 101585484
SB  - IM
MH  - Female
MH  - Humans
MH  - Intestines
MH  - Radiotherapy Dosage
MH  - Radiotherapy Planning, Computer-Assisted/methods
MH  - *Radiotherapy, Intensity-Modulated/methods
MH  - Retrospective Studies
MH  - *Uterine Cervical Neoplasms/radiotherapy
OTO - NOTNLM
OT  - Volume modulated arc therapy (VMAT)
OT  - air cavity
OT  - cervical cancer
OT  - dose distribution
EDAT- 2022/05/07 06:00
MHDA- 2022/05/11 06:00
CRDT- 2022/05/06 22:52
PHST- 2021/10/15 00:00 [received]
PHST- 2022/03/10 00:00 [accepted]
PHST- 2022/05/06 22:52 [entrez]
PHST- 2022/05/07 06:00 [pubmed]
PHST- 2022/05/11 06:00 [medline]
AID - 10.21037/apm-22-66 [doi]
PST - ppublish
SO  - Ann Palliat Med. 2022 Apr;11(4):1326-1335. doi: 10.21037/apm-22-66.