title: Can We Spare the Pancreas and Other Abdominal Organs at Risk? A Comparison of Conformal Radiotherapy, Helical Tomotherapy and Proton Beam Therapy in Pediatric Irradiation.
abstract: OBJECTIVE
  Late abdominal irradiation toxicity during childhood included renal damage, hepatic toxicity and secondary diabetes mellitus. We compared the potential of conformal radiotherapy (CRT), helical tomotherapy (HT) and proton beam therapy (PBT) to spare the abdominal organs at risk (pancreas, kidneys and liver- OAR) in children undergoing abdominal irradiation.
  
  
  METHODS
  We selected children with abdominal tumors who received more than 10 Gy to the abdomen. Treatment plans were calculated in order to keep the dose to abdominal OAR as low as possible while maintaining the same planned target volume (PTV) coverage. Dosimetric values were compared using the Wilcoxon signed-rank test.
  
  
  RESULTS
  The dose distribution of 20 clinical cases with a median age of 8 years (range 1-14) were calculated with different doses to the PTV: 5 medulloblastomas (36 Gy), 3 left-sided and 2 right-sided nephroblastomas (14.4 Gy to the tumor + 10.8 Gy boost to para-aortic lymphnodes), 1 left-sided and 4 right-sided or midline neuroblastomas (21 Gy) and 5 Hodgkin lymphomas (19.8 Gy to the para-aortic lymphnodes and spleen). HT significantly reduced the mean dose to the whole pancreas (WP), the pancreatic tail (PT) and to the ipsilateral kidney compared to CRT. PBT reduced the mean dose to the WP and PT compared to both CRT and HT especially in midline and right-sided tumors. PBT decreased the mean dose to the ispilateral kidney but also to the contralateral kidney and the liver compared to CRT. Low dose to normal tissue was similar or increased with HT whereas integral dose and the volume of normal tissue receiving at least 5 and 10 Gy were reduced with PBT compared to CRT and HT.
  
  
  CONCLUSIONS
  In children undergoing abdominal irradiation therapy, proton beam therapy reduces the dose to abdominal OAR while sparing normal tissue by limiting low dose irradiation.
authors.affiliation: Department of Radiation Oncology, Institut de Cancérologie de l'Ouest, boulevard Jacques Monod, Saint Herblain, 44800 France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Jouglar
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret, 3 rue Frédéric Combemale, Lille, 59000 France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Wagner
authors.affiliation: Department of Medical Physics, Institut de Cancérologie de l'Ouest, boulevard Jacques Monod, Saint Herblain, 44800 France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Delpon
authors.affiliation: Department of Statistics, Institut de Cancérologie de l'Ouest, boulevard Jacques Monod, Saint-Herblain, 44800 France.
authors.forename: Loïc
authors.initials: L
authors.lastname: Campion
authors.affiliation: Department of Radiology, Institut de Cancérologie de l'Ouest, boulevard Jacques Monod, Saint-Herblain, 44800 France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Meingan
authors.affiliation: Department of Radiation Oncology, Institut de Cancérologie de Lorraine, 6 Avenue de Bourgogne, Vandœuvre-lès-Nancy, 54519 France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Bernier
authors.affiliation: Department of Radiation Oncology, Institut de Cancérologie de l'Ouest, boulevard Jacques Monod, Saint Herblain, 44800 France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Demoor-Goldschmidt
authors.affiliation: Department of Radiation Oncology, Institut de Cancérologie de l'Ouest, boulevard Jacques Monod, Saint Herblain, 44800 France.
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Mahé
authors.affiliation: Department of Medical Physics, Centre Oscar Lambret, 3 rue Frédéric Combemale, Lille, 59000 France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lacornerie
authors.affiliation: Department of Radiation Oncology, Institut de Cancérologie de l'Ouest, boulevard Jacques Monod, Saint Herblain, 44800 France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Supiot
mesh_terms: D034841:Abdominal Cavity / Q000528:radiation effects*; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007668:Kidney / Q000528:radiation effects; D008099:Liver / Q000528:radiation effects; D008297:Male; D058958:Organs at Risk; D010179:Pancreas / Q000528:radiation effects; D061766:Proton Therapy / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D020266:Radiotherapy, Conformal / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*