title: PET-based dose painting in non-small cell lung cancer: Comparing uniform dose escalation with boosting hypoxic and metabolically active sub-volumes.
abstract: OBJECTIVE
  We compared two imaging biomarkers for dose-escalation in patients with advanced non-small cell lung cancer (NSCLC). Treatment plans boosting metabolically active sub-volumes defined by FDG-PET or hypoxic sub-volumes defined by HX4-PET were compared with boosting the entire tumour.
  
  
  METHODS
  Ten NSCLC patients underwent FDG- and HX4-PET/CT scans prior to radiotherapy. Three isotoxic dose-escalation plans were compared per patient: plan A, boosting the primary tumour (PTVprim); plan B, boosting sub-volume with FDG >50% SUVmax (PTVFDG); plan C, boosting hypoxic volume with HX4 tumour-to-background >1.4 (PTVHX4).
  
  
  RESULTS
  Average boost volumes were 507 ± 466 cm(3) for PTVprim, 173 ± 127 cm(3) for PTVFDG and 114 ± 73 cm(3) for PTVHX4. The smaller PTVHX4 overlapped on average 87 ± 16% with PTVFDG. Prescribed dose was escalated to 87 ± 10 Gy for PTVprim, 107 ± 20 Gy for PTVFDG, and 117 ± 15 Gy for PTVHX4, with comparable doses to the relevant organs-at-risk (OAR). Treatment plans are available online (https://www.cancerdata.org/10.1016/j.radonc.2015.07.013).
  
  
  CONCLUSIONS
  Dose escalation based on metabolic sub-volumes, hypoxic sub-volumes and the entire tumour is feasible. Highest dose was achieved for hypoxia plans, without increasing dose to OAR. For most patients, boosting the metabolic sub-volume also resulted in boosting the hypoxic volume, although to a lower dose, but not vice versa.
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, The Netherlands. Electronic address: aniek.even@maastro.nl.
authors.forename: Aniek J G
authors.initials: AJ
authors.lastname: Even
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, The Netherlands.
authors.forename: Judith
authors.initials: J
authors.lastname: van der Stoep
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, The Netherlands.
authors.forename: Catharina M L
authors.initials: CM
authors.lastname: Zegers
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, The Netherlands.
authors.forename: Bart
authors.initials: B
authors.lastname: Reymen
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, The Netherlands; Institute of Radiooncology, Helmholtz-Zentrum Dresden-Rossendorf, Germany.
authors.forename: Esther G C
authors.initials: EG
authors.lastname: Troost
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, The Netherlands.
authors.forename: Philippe
authors.initials: P
authors.lastname: Lambin
authors.affiliation: Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, The Netherlands.
authors.forename: Wouter
authors.initials: W
authors.lastname: van Elmpt
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D015687:Cell Hypoxia; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods
keywords: Dose painting; FDG; HX4; NSCLC; Positron emission tomography; Radiotherapy