PMID- 18077033
OWN - NLM
STAT- MEDLINE
DCOM- 20081105
LR  - 20161124
IS  - 0167-8140 (Print)
IS  - 0167-8140 (Linking)
VI  - 87
IP  - 3
DP  - 2008 Jun
TI  - Simultaneous tumour dose escalation and liver sparing in Stereotactic Body 
      Radiation Therapy (SBRT) for liver tumours due to CTV-to-PTV margin reduction.
PG  - 432-8
AB  - PURPOSE: To quantify potential benefits of CTV-to-PTV margin reduction for SBRT 
      of liver tumours, as allowed by enhanced treatment precision. MATERIALS AND 
      METHODS: For 14 patients plans were generated for the clinical margin and for 3 
      tighter margins. An in-house developed algorithm was used to optimise beam 
      directions, shapes, and weights for generation of the plan with the highest 
      isocenter dose (D(iso)), while keeping the minimum PTV dose at least 65%xD(iso) 
      and strictly adhering to all imposed hard OAR constraints. Each plan contains 10 
      optimal beam directions, automatically selected from up to 252 coplanar and 
      non-coplanar input directions. RESULTS: Apart from the expected tumour dose 
      escalation (D(iso), EUD(PTV), gEUD(PTV)) with decreasing margin, a simultaneous 
      improved sparing of the normal liver (D33%, D50%, D(mean)) was also observed. The 
      smaller the margin was, the bigger both effects were. For renormalized plans with 
      D(iso) equal to the clinical value (3x19.2Gy), and a margin reduction of 50% 
      (2.5mm laterally, 5mm longitudinally), normal liver D33% and D50% reduced on 
      average by 22% (maximum 38%), and 26% (maximum 47%), respectively. CONCLUSIONS: 
      Using an algorithm for beam direction, shape and weight optimisation, large 
      increases in the therapeutic ratio of liver plans could be obtained for reduced 
      margins.
FAU - Molinelli, Silvia
AU  - Molinelli S
AD  - Department of Radiation Oncology, Erasmus MC - Daniel den Hoed Cancer Center, 
      Rotterdam, The Netherlands. silvia.molinelli@pv.infn.it
FAU - de Pooter, Jacco
AU  - de Pooter J
FAU - Mendez Romero, Alejandra
AU  - Mendez Romero A
FAU - Wunderink, Wouter
AU  - Wunderink W
FAU - Cattaneo, Mauro
AU  - Cattaneo M
FAU - Calandrino, Riccardo
AU  - Calandrino R
FAU - Heijmen, Ben
AU  - Heijmen B
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080220
PL  - Ireland
TA  - Radiother Oncol
JT  - Radiotherapy and oncology : journal of the European Society for Therapeutic 
      Radiology and Oncology
JID - 8407192
SB  - IM
MH  - Algorithms
MH  - Humans
MH  - Liver/radiation effects
MH  - Liver Neoplasms/diagnostic imaging/*surgery
MH  - *Radiosurgery/methods
MH  - Radiotherapy Dosage
MH  - *Radiotherapy Planning, Computer-Assisted
MH  - Tomography, X-Ray Computed
EDAT- 2007/12/14 09:00
MHDA- 2008/11/06 09:00
CRDT- 2007/12/14 09:00
PHST- 2007/06/12 00:00 [received]
PHST- 2007/11/13 00:00 [revised]
PHST- 2007/11/14 00:00 [accepted]
PHST- 2007/12/14 09:00 [pubmed]
PHST- 2008/11/06 09:00 [medline]
PHST- 2007/12/14 09:00 [entrez]
AID - S0167-8140(07)00587-7 [pii]
AID - 10.1016/j.radonc.2007.11.015 [doi]
PST - ppublish
SO  - Radiother Oncol. 2008 Jun;87(3):432-8. doi: 10.1016/j.radonc.2007.11.015. Epub 
      2008 Feb 20.