PMID- 18077031
OWN - NLM
STAT- MEDLINE
DCOM- 20080605
LR  - 20080121
IS  - 0167-8140 (Print)
IS  - 0167-8140 (Linking)
VI  - 86
IP  - 1
DP  - 2008 Jan
TI  - A study of tumor motion management in the conformal radiotherapy of lung cancer.
PG  - 77-85
AB  - PURPOSE: To assess the benefit derived from the reduction of planning target 
      volumes (PTVs) afforded by tumor motion management in treatment planning for lung 
      cancer. METHODS: We use a simple formula that combines measurements of tumor 
      motion and set-up error for 7 patients to determine PTVs based on the following 
      scenarios: standard uniform 15 mm margin, individualized PTVs (no gating), 
      spirometry-based gating, and active breath-control (ABC). We compare the percent 
      volumes of lung receiving at least 20 Gy (V20) for a standard prescription, and 
      the maximum tolerated doses (MTDs) at fixed V20. In anticipation of improvements 
      in set-up accuracy, we repeat the analysis assuming a reduced set-up margin of 
      3mm. RESULTS: Relative to the standard, the average percent reductions in V20 
      (+/- 1 standard deviation) for the ungated and gated scenarios are 17+/-5 and 
      21+/-8; the percent gains in MTD are 25+/-12 and 33+/-11, respectively. For the 
      3mm set-up margin, the corresponding results for V20 are 28+/-7 and 36+/-7, and 
      for MTD are 57+/-23 and 79+/-31. CONCLUSIONS: Any form of motion management 
      provides a benefit over the use of a standard margin. The benefit derived from 
      gating compared to the use of ungated individualized PTVs increases with tumor 
      mobility but is generally modest. While motion management may benefit patients 
      with highly mobile tumors, we expect efforts to reduce set-up error to be of 
      greater overall significance. The practical limit for lung PTV margins is likely 
      around 4-5mm, provided set-up error can be reduced sufficiently.
FAU - Burnett, Stuart S C
AU  - Burnett SS
AD  - Toronto-Sunnybrook Regional Cancer Centre, Canada.
FAU - Sixel, Katharina E
AU  - Sixel KE
FAU - Cheung, Patrick C F
AU  - Cheung PC
FAU - Hoisak, Jeremy D P
AU  - Hoisak JD
LA  - eng
PT  - Journal Article
PL  - Ireland
TA  - Radiother Oncol
JT  - Radiotherapy and oncology : journal of the European Society for Therapeutic 
      Radiology and Oncology
JID - 8407192
SB  - IM
MH  - Humans
MH  - Lung Neoplasms/*radiotherapy
MH  - *Movement
MH  - Radiotherapy Dosage
MH  - *Radiotherapy Planning, Computer-Assisted
MH  - *Radiotherapy, Conformal
MH  - *Respiration
EDAT- 2007/12/14 09:00
MHDA- 2008/06/06 09:00
CRDT- 2007/12/14 09:00
PHST- 2007/08/20 00:00 [received]
PHST- 2007/11/06 00:00 [accepted]
PHST- 2007/12/14 09:00 [pubmed]
PHST- 2008/06/06 09:00 [medline]
PHST- 2007/12/14 09:00 [entrez]
AID - S0167-8140(07)00565-8 [pii]
AID - 10.1016/j.radonc.2007.11.017 [doi]
PST - ppublish
SO  - Radiother Oncol. 2008 Jan;86(1):77-85. doi: 10.1016/j.radonc.2007.11.017.