title: Distribution of prostate nodes: a PET/CT-derived anatomic atlas of prostate cancer patients before and after surgical treatment.
abstract: BACKGROUND
  In order to define adequate radiation portals in nodal positive prostate cancer a detailed knowledge of the anatomic lymph-node distribution is mandatory. We therefore systematically analyzed the localization of Choline PET/CT positive lymph nodes and compared it to the RTOG recommendation of pelvic CTV, as well as to previous work, the SPECT sentinel lymph node atlas.
  
  
  METHODS
  Thirty-two patients being mostly high risk patients with a PSA of 12.5 ng/ml (median) received PET/CT before any treatment. Eighty-seven patients received PET/CT for staging due to biochemical failure with a median PSA of 3.12 ng/ml. Each single PET-positive lymph node was manually contoured in a "virtual" patient dataset to achieve a 3-D visualization, resulting in an atlas of the cumulative PET positive lymph node distribution. Further the PET-positive lymph node location in each patient was assessed with regard to the existence of a potential geographic miss (i.e. PET-positive lymph nodes that would not have been treated adequately by the RTOG consensus on CTV definition of pelvic lymph nodes).
  
  
  RESULTS
  Seventy-eight and 209 PET positive lymph nodes were detected in patients with no prior treatment and in postoperative patients, respectively. The most common sites of PET positive lymph nodes in patients with no prior treatment were external iliac (32.1 %), followed by common iliac (23.1 %) and para-aortic (19.2 %). In postoperative patients the most common sites of PET positive lymph nodes were common iliac (24.9 %), followed by external iliac (23.0 %) and para-aortic (20.1 %). In patients with no prior treatment there were 34 (43.6 %) and in postoperative patients there were 77 (36.8 %) of all detected lymph nodes that would not have been treated adequately using the RTOG CTV. We compared the distribution of lymph nodes gained by Choline PET/CT to the preexisting SPECT sentinel lymph node atlas and saw an overall good congruence.
  
  
  CONCLUSIONS
  Choline PET/CT and SPECT sentinel lymph node atlas are comparable to each other. More than one-third of the PET positive lymph nodes in patients with no prior treatment and in postoperative patients would not have been treated adequately using the RTOG CTV. To reduce geographical miss, image based definition of an individual target volume is necessary.
authors.affiliation: Department of Radiation Oncology, Klinikum der Universität, Ludwig-Maximilians-University (LMU), Marchioninistrasse 15, 81377, Munich, Germany. Nina-Sophie.Hegemann@med.uni-muenchen.de.
authors.forename: Nina-Sophie
authors.initials: NS
authors.lastname: Hegemann
authors.affiliation: Department of Nuclear Medicine, Klinikum der Universität, Ludwig-Maximilians-University (LMU), Marchioninistrasse 15, 81377, Munich, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Wenter
authors.affiliation: Department of Radiation Oncology, Klinikum der Universität, Ludwig-Maximilians-University (LMU), Marchioninistrasse 15, 81377, Munich, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Spath
authors.affiliation: Department of Radiation Oncology, Klinikum der Universität, Ludwig-Maximilians-University (LMU), Marchioninistrasse 15, 81377, Munich, Germany.
authors.forename: Nadia
authors.initials: N
authors.lastname: Kusumo
authors.affiliation: Department of Radiation Oncology, Klinikum der Universität, Ludwig-Maximilians-University (LMU), Marchioninistrasse 15, 81377, Munich, Germany.
authors.forename: Minglun
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Nuclear Medicine, Klinikum der Universität, Ludwig-Maximilians-University (LMU), Marchioninistrasse 15, 81377, Munich, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Bartenstein
authors.affiliation: Department of Nuclear Medicine, Klinikum der Universität, Ludwig-Maximilians-University (LMU), Marchioninistrasse 15, 81377, Munich, Germany.
authors.forename: Wolfgang P
authors.initials: WP
authors.lastname: Fendler
authors.affiliation: Department of Urology, Klinikum der Universität, Ludwig-Maximilians-University (LMU), Marchioninistrasse 15, 81377, Munich, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Stief
authors.affiliation: Department of Radiation Oncology, Klinikum der Universität, Ludwig-Maximilians-University (LMU), Marchioninistrasse 15, 81377, Munich, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Belka
authors.affiliation: Department of Radiation Oncology, Klinikum der Universität, Ludwig-Maximilians-University (LMU), Marchioninistrasse 15, 81377, Munich, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Ganswindt
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002794:Choline / Q000737:chemistry; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D049268:Positron-Emission Tomography; D011184:Postoperative Period; D057234:Preoperative Period; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D011857:Radiographic Image Interpretation, Computer-Assisted; D012306:Risk; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: D002794:Choline
keywords: Anatomic atlas; Choline PET/CT; Lymph node metastases; Prostate cancer