PMID- 34628271
OWN - NLM
STAT- MEDLINE
DCOM- 20211102
LR  - 20211102
IS  - 1724-191X (Electronic)
IS  - 1120-1797 (Linking)
VI  - 90
DP  - 2021 Oct
TI  - Dosimetric effect of variable rectum and sigmoid colon filling during carbon ion 
      radiotherapy to sacral chordoma.
PG  - 123-133
LID - S1120-1797(21)00311-2 [pii]
LID - 10.1016/j.ejmp.2021.09.012 [doi]
AB  - PURPOSE: Carbon ion radiotherapy (CIRT) is sensitive to anatomical density 
      variations. We examined the dosimetric effect of variable intestinal filling 
      condition during CIRT to ten sacral chordoma patients. METHODS: For each patient, 
      eight virtual computed tomography scans (vCTs) were generated by varying the 
      density distribution within the rectum and the sigmoid in the planning computed 
      tomography (pCT) with a density override approach mimicking a heterogeneous 
      combination of gas and feces. Totally full and empty intestinal preparations were 
      modelled. In addition, five different intestinal filling conditions were modelled 
      by a mixed density pattern derived from two combined and weighted Gaussian 
      distributions simulating gas and feces respectively. Finally, a patient-specific 
      mixing proportion was estimated by evaluating the daily amount of gas detected in 
      the cone beam computed tomography (CBCT). Dose distribution was recalculated on 
      each vCT and dose volume histograms (DVHs) were examined. RESULTS: No target 
      coverage degradation was observed at different vCTs. Rectum and sigma dose 
      degradation ranged respectively between: [-6.7; 21.6]GyE and [-0.7; 15.4]GyE for 
      D(50%); [-377.4; 1197.9] and [-95.2; 1027.5] for AUC; [-1.2; 10.7]GyE and [-2.6; 
      21.5]GyE for D(1%). CONCLUSIONS: Variation of intestinal density can greatly 
      influence the penetration depth of charged particle and might compromise dose 
      distribution. In particular cases, with large clinical target volume in very 
      close proximity to rectum and sigmoid colon, it is appropriate to evaluate the 
      amount of gas present in the daily CBCT images even if it is totally included in 
      the reference planning structures.
CI  - Copyright (c) 2021 Associazione Italiana di Fisica Medica. Published by Elsevier 
      Ltd. All rights reserved.
FAU - Ricotti, R
AU  - Ricotti R
AD  - Bioengineering Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy. Electronic address: 
      rosalinda.ricotti@cnao.it.
FAU - Pella, A
AU  - Pella A
AD  - Bioengineering Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy.
FAU - Mirandola, A
AU  - Mirandola A
AD  - Medical Physics Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy.
FAU - Fiore, M R
AU  - Fiore MR
AD  - Radiation Oncology Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy.
FAU - Chalaszczyk, A
AU  - Chalaszczyk A
AD  - Radiation Oncology Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy.
FAU - Paganelli, C
AU  - Paganelli C
AD  - Department of Electronics Information and Bioengineering, Politecnico di Milano, 
      Milano, Italy.
FAU - Antonioli, L
AU  - Antonioli L
AD  - Bioengineering Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy.
FAU - Vai, A
AU  - Vai A
AD  - Medical Physics Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy.
FAU - Tagaste, B
AU  - Tagaste B
AD  - Bioengineering Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy.
FAU - Belotti, G
AU  - Belotti G
AD  - Department of Electronics Information and Bioengineering, Politecnico di Milano, 
      Milano, Italy.
FAU - Rossi, M
AU  - Rossi M
AD  - Department of Electronics Information and Bioengineering, Politecnico di Milano, 
      Milano, Italy.
FAU - Ciocca, M
AU  - Ciocca M
AD  - Medical Physics Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy.
FAU - Orlandi, E
AU  - Orlandi E
AD  - Radiation Oncology Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy.
FAU - Baroni, G
AU  - Baroni G
AD  - Bioengineering Unit, Clinical Department, National Center for Oncological 
      Hadrontherapy (CNAO), Pavia, Italy; Department of Electronics Information and 
      Bioengineering, Politecnico di Milano, Milano, Italy.
LA  - eng
PT  - Journal Article
DEP - 20211007
PL  - Italy
TA  - Phys Med
JT  - Physica medica : PM : an international journal devoted to the applications of 
      physics to medicine and biology : official journal of the Italian Association of 
      Biomedical Physics (AIFB)
JID - 9302888
SB  - IM
MH  - *Chordoma/diagnostic imaging/radiotherapy
MH  - Colon, Sigmoid/diagnostic imaging
MH  - Cone-Beam Computed Tomography
MH  - *Heavy Ion Radiotherapy
MH  - Humans
MH  - Radiotherapy Dosage
MH  - Radiotherapy Planning, Computer-Assisted
MH  - Rectum/diagnostic imaging
OTO - NOTNLM
OT  - Bowel filling variation
OT  - Carbon ion radiotherapy
OT  - Density variation
OT  - Dose perturbation
OT  - Intestinal gas
OT  - Sacral chordoma
OT  - Variable filling
EDAT- 2021/10/11 06:00
MHDA- 2021/11/03 06:00
CRDT- 2021/10/10 21:04
PHST- 2021/04/26 00:00 [received]
PHST- 2021/08/13 00:00 [revised]
PHST- 2021/09/23 00:00 [accepted]
PHST- 2021/10/11 06:00 [pubmed]
PHST- 2021/11/03 06:00 [medline]
PHST- 2021/10/10 21:04 [entrez]
AID - S1120-1797(21)00311-2 [pii]
AID - 10.1016/j.ejmp.2021.09.012 [doi]
PST - ppublish
SO  - Phys Med. 2021 Oct;90:123-133. doi: 10.1016/j.ejmp.2021.09.012. Epub 2021 Oct 7.