PMID- 18313530
OWN - NLM
STAT- MEDLINE
DCOM- 20080506
LR  - 20161124
IS  - 0360-3016 (Print)
IS  - 0360-3016 (Linking)
VI  - 70
IP  - 4
DP  - 2008 Mar 15
TI  - Comparison of different strategies to use four-dimensional computed tomography in 
      treatment planning for lung cancer patients.
PG  - 1229-38
LID - 10.1016/j.ijrobp.2007.11.042 [doi]
AB  - PURPOSE: To discuss planning target volumes (PTVs) based on internal target 
      volume (PTVITV), exhale-gated radiotherapy (PTVGating), and a new proposed 
      midposition (PTVMidP; time-weighted mean tumor position) and compare them with 
      the conventional free-breathing CT scan PTV (PTVConv). METHODS AND MATERIALS: 
      Respiratory motion induces systematic and random geometric uncertainties. Their 
      contribution to the clinical target volume (CTV)-to-PTV margins differs for each 
      PTV approach. The uncertainty margins were calculated using a 
      dose-probability-based margin recipe (based on patient statistics). Tumor motion 
      in four-dimensional CT scans was determined using a local rigid registration of 
      the tumor. Geometric uncertainties for interfractional setup errors and tumor 
      baseline variation were included. For PTVGating, the residual motion within a 30% 
      gating (time) window was determined. The concepts were evaluated in terms of 
      required CTV-to-PTV margin and PTV volume for 45 patients. RESULTS: Over the 
      patient group, the PTVITV was on average larger (+6%) and the PTVGating and 
      PTVMidP smaller (-10%) than the PTVConv using an off-line (bony anatomy) setup 
      correction protocol. With an on-line (soft tissue) protocol the differences in 
      PTV compared with PTVConv were +33%, -4%, and 0, respectively. CONCLUSIONS: The 
      internal target volume method resulted in a significantly larger PTV than 
      conventional CT scanning. The exhale-gated and mid-position approaches were 
      comparable in terms of PTV. However, mid-position (or mid-ventilation) is easier 
      to use in the clinic because it only affects the planning part of treatment and 
      not the delivery.
FAU - Wolthaus, Jochem W H
AU  - Wolthaus JW
AD  - Department of Radiation Oncology, The Netherlands Cancer Institute-Antoni van 
      Leeuwenhoek Hospital, Amsterdam, The Netherlands.
FAU - Sonke, Jan-Jakob
AU  - Sonke JJ
FAU - van Herk, Marcel
AU  - van Herk M
FAU - Belderbos, Jose S A
AU  - Belderbos JS
FAU - Rossi, Maddalena M G
AU  - Rossi MM
FAU - Lebesque, Joos V
AU  - Lebesque JV
FAU - Damen, Eugene M F
AU  - Damen EM
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Int J Radiat Oncol Biol Phys
JT  - International journal of radiation oncology, biology, physics
JID - 7603616
SB  - IM
MH  - Calibration
MH  - Female
MH  - Humans
MH  - Lung Neoplasms/*diagnostic imaging/pathology/radiotherapy
MH  - Male
MH  - Movement
MH  - Radiotherapy Dosage
MH  - Radiotherapy Planning, Computer-Assisted/*methods
MH  - *Respiration
MH  - Retrospective Studies
MH  - Time Factors
MH  - Tomography, X-Ray Computed/*methods
MH  - *Tumor Burden
EDAT- 2008/03/04 09:00
MHDA- 2008/05/07 09:00
CRDT- 2008/03/04 09:00
PHST- 2007/08/09 00:00 [received]
PHST- 2007/10/03 00:00 [revised]
PHST- 2007/11/09 00:00 [accepted]
PHST- 2008/03/04 09:00 [pubmed]
PHST- 2008/05/07 09:00 [medline]
PHST- 2008/03/04 09:00 [entrez]
AID - S0360-3016(07)04592-0 [pii]
AID - 10.1016/j.ijrobp.2007.11.042 [doi]
PST - ppublish
SO  - Int J Radiat Oncol Biol Phys. 2008 Mar 15;70(4):1229-38. doi: 
      10.1016/j.ijrobp.2007.11.042.