title: Standardized treatment planning methodology for passively scattered proton craniospinal irradiation.
abstract: BACKGROUND
  As the number of proton therapy centers increases, so does the need for studies which compare proton treatments between institutions and with photon therapy. However, results of such studies are highly dependent on target volume definition and treatment planning techniques. Thus, standardized methods of treatment planning are needed, particularly for proton treatment planning, in which special consideration is paid to the depth and sharp distal fall-off of the proton distribution. This study presents and evaluates a standardized method of proton treatment planning for craniospinal irradiation (CSI).
  
  
  METHODS
  We applied our institution's planning methodology for proton CSI, at the time of the study, to an anatomically diverse population of 18 pediatric patients. We evaluated our dosimetric results for the population as a whole and for the two subgroups having two different age-specific target volumes using the minimum, maximum, and mean dose values in 10 organs (i.e., the spinal cord, brain, eyes, lenses, esophagus, lungs, kidneys, thyroid, heart, and liver). We also report isodose distributions and dose-volume histograms (DVH) for 2 representative patients. Additionally we report population-averaged DVHs for various organs.
  
  
  RESULTS
  The planning methodology here describes various techniques used to achieve normal tissue sparing. In particular, we found pronounced dose reductions in three radiosensitive organs (i.e., eyes, esophagus, and thyroid) which were identified for optimization. Mean doses to the thyroid, eyes, and esophagus were 0.2%, 69% and 0.2%, respectively, of the prescribed dose. In four organs not specifically identified for optimization (i.e., lungs, liver, kidneys, and heart) we found that organs lateral to the treatment field (lungs and kidneys) received relatively low mean doses (less than 8% of the prescribed dose), whereas the heart and liver, organs distal to the treatment field, received less than 1% of the prescribed dose.
  
  
  CONCLUSIONS
  This study described and evaluated a standardized method for proton treatment planning for CSI. Overall, the standardized planning methodology yielded consistently high quality treatment plans and perhaps most importantly, it did so for an anatomically diverse patient population.
authors: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors: Annelise
authors: A
authors: Giebeler
authors: Wayne D
authors: WD
authors: Newhauser
authors: Richard A
authors: RA
authors: Amos
authors: Anita
authors: A
authors: Mahajan
authors: Kenneth
authors: K
authors: Homann
authors: Rebecca M
authors: RM
authors: Howell
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D061888:Craniospinal Irradiation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D017785:Photons / Q000627:therapeutic use*; D010934:Planning Techniques; D011379:Prognosis; D061766:Proton Therapy; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal; D011522:Protons
chemical_list: D011522:Protons
references: Nat Rev Cancer. 2011 Jun;11(6):438-48
references: 21593785
references: J Natl Cancer Inst. 2010 Apr 7;102(7):450-3
references: 20339139
references: Radiat Oncol. 2012 Jul 24;7:116
references: 22828073
references: Int J Radiat Oncol Biol Phys. 2001 Apr 1;49(5):1429-38
references: 11286851
references: Int J Cancer. 2007 Nov 15;121(10):2233-40
references: 17557301
references: Phys Med Biol. 2008 Mar 21;53(6):1545-62
references: 18367787
references: Cancer J. 2009 Jul-Aug;15(4):319-24
references: 19672149
references: Phys Med Biol. 2010 Dec 7;55(23):7067-80
references: 21076189
references: Radiother Oncol. 2007 May;83(2):123-32
references: 17499374
references: Technol Cancer Res Treat. 2003 Oct;2(5):445-7
references: 14529309
references: Int J Radiat Oncol Biol Phys. 2007 Feb 1;67(2):620-9
references: 17236979
references: J Clin Oncol. 2007 Mar 10;25(8):965-70
references: 17350945
references: Int J Radiat Oncol Biol Phys. 2005 Oct 1;63(2):362-72
references: 16168831
references: Int J Radiat Oncol Biol Phys. 2011 Nov 1;81(3):637-46
references: 20932690
references: Int J Radiat Oncol Biol Phys. 2007 Nov 15;69(4):1193-8
references: 17967308
references: Phys Med Biol. 2008 May 7;53(9):2327-44
references: 18421122
references: Ann Intern Med. 2009 Oct 20;151(8):556-65
references: 19755348
references: Med Phys. 2009 Sep;36(9):4068-83
references: 19810479
references: Technol Cancer Res Treat. 2003 Oct;2(5):389-99
references: 14529304
references: Cancer J. 2009 Jul-Aug;15(4):298-305
references: 19672146
references: Radiother Oncol. 2007 May;83(2):110-22
references: 17502116
references: Int J Radiat Oncol Biol Phys. 2002 Nov 1;54(3):824-9
references: 12377335
references: Phys Med Biol. 2009 Apr 21;54(8):2277-91
references: 19305036
references: J Radiol Prot. 2009 Jun;29(2A):A171-84
references: 19454800
references: Acta Oncol. 2011 Aug;50(6):806-16
references: 21767178
references: Phys Med Biol. 2007 Aug 7;52(15):4569-84
references: 17634651
references: Cancer J. 2004 Nov-Dec;10(6):386-90
references: 15701271
references: Int J Radiat Oncol Biol Phys. 2004 Mar 1;58(3):727-34
references: 14967427
references: Phys Med Biol. 1984 May;29(5):553-66
references: 6330772
references: Nat Rev Clin Oncol. 2010 Jan;7(1):37-43
references: 19949433