PMID- 19544808
OWN - NLM
STAT- MEDLINE
DCOM- 20090715
LR  - 20181201
IS  - 0094-2405 (Print)
IS  - 0094-2405 (Linking)
VI  - 36
IP  - 5
DP  - 2009 May
TI  - Characterization of a mini-multileaf collimator in a proton beamline.
PG  - 1886-94
AB  - A mini-multileaf collimator (MMLC) was mounted as a field shaping collimator in a 
      proton beamline at the Massachusetts General Hospital. The purpose is to evaluate 
      the device's dosimetric and mechanical properties for the use in a proton 
      beamline. For this evaluation, the authors compared MMLC and brass aperture 
      shaped dose distributions with regard to lateral and depth dose properties. The 
      lateral fall off is generally broader with the MMLC, with difference varying with 
      proton range from 0.2 to 1.2 mm. Central axis depth dose curves did not show a 
      difference in peak-to-entrance ratio, peak width, distal fall off, or range. 
      Two-dimensional dose distributions to investigate the conformity of MMLC shaped 
      doses show that the physical leaf width of approximately 2.5 mm does not have a 
      significant impact. All differences seen in dose distribution shaped by the MMLC 
      versus brass apertures were shown to be clinically insignificant. Measured 
      neutron doses of 0.03-0.13 mSv/Gy for a closed brass beam block (depending on 
      range) are very low compared to the previously published data. Irradiation of the 
      tungsten MMLC, however, produced 1.5-1.8 times more neutrons than brass 
      apertures. Exposure of the staff resulting from activation of the device is below 
      regulatory limits. The measurements established an equivalency between aperture 
      and MMLC shaped dose distributions.
FAU - Daartz, J
AU  - Daartz J
AD  - Department of Radiation Oncology, Francis H. Burr Proton Therapy Center, 
      Massachusetts General Hospital, Boston, Massachusetts 02114, USA. 
      jdaartz@partners.org
FAU - Bangert, M
AU  - Bangert M
FAU - Bussiere, M R
AU  - Bussiere MR
FAU - Engelsman, M
AU  - Engelsman M
FAU - Kooy, H M
AU  - Kooy HM
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Med Phys
JT  - Medical physics
JID - 0425746
RN  - 0 (Protons)
SB  - IM
MH  - Computer-Aided Design
MH  - Equipment Design
MH  - Equipment Failure Analysis
MH  - *Proton Therapy
MH  - *Radiometry
MH  - Radiosurgery/*instrumentation
MH  - Radiotherapy Dosage
MH  - Reproducibility of Results
MH  - Sensitivity and Specificity
EDAT- 2009/06/24 09:00
MHDA- 2009/07/16 09:00
CRDT- 2009/06/24 09:00
PHST- 2009/06/24 09:00 [entrez]
PHST- 2009/06/24 09:00 [pubmed]
PHST- 2009/07/16 09:00 [medline]
AID - 10.1118/1.3116382 [doi]
PST - ppublish
SO  - Med Phys. 2009 May;36(5):1886-94. doi: 10.1118/1.3116382.