title: High occurrence of aberrant lymph node spread on magnetic resonance lymphography in prostate cancer patients with a biochemical recurrence after radical prostatectomy.
abstract: OBJECTIVE
  To investigate the pattern of lymph node spread in prostate cancer patients with a biochemical recurrence after radical prostatectomy, eligible for salvage radiotherapy; and to determine whether the clinical target volume (CTV) for elective pelvic irradiation in the primary setting can be applied in the salvage setting for patients with (a high risk of) lymph node metastases.
  
  
  METHODS
  The charts of 47 prostate cancer patients with PSA recurrence after prostatectomy who had positive lymph nodes on magnetic resonance lymphography (MRL) were reviewed. Positive lymph nodes were assigned to a lymph node region according to the guidelines of the Radiation Therapy Oncology Group (RTOG) for delineation of the CTV for pelvic irradiation (RTOG-CTV). We defined four lymph node regions for positive nodes outside this RTOG-CTV: the para-aortal, proximal common iliac, pararectal, and paravesical regions. They were referred to as aberrant lymph node regions. For each patient, clinical and pathologic features were recorded, and their association with aberrant lymph drainage was investigated. The distribution of positive lymph nodes was analyzed separately for patients with a prostate-specific antigen (PSA) <1.0 ng/mL.
  
  
  RESULTS
  MRL detected positive aberrant lymph nodes in 37 patients (79%). In 20 patients (43%) a positive lymph node was found in the pararectal region. Higher PSA at the time of MRL was associated with the presence of positive lymph nodes in the para-aortic region (2.49 vs. 0.82 ng/mL; p = 0.007) and in the proximal common iliac region (1.95 vs. 0.59 ng/mL; p = 0.009). There were 18 patients with a PSA <1.0 ng/mL. Ten of these patients (61%) had at least one aberrant positive lymph node.
  
  
  CONCLUSIONS
  Seventy-nine percent of the PSA-recurrent patients had at least one aberrant positive lymph node. Application of the standard RTOG-CTV for pelvic irradiation in the salvage setting therefore seems to be inappropriate.
authors.affiliation: Department of Radiation Oncology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands. H.Meijer@rther.umcn.nl
authors.forename: Hanneke J M
authors.initials: HJ
authors.lastname: Meijer
authors.forename: Emile N
authors.initials: EN
authors.lastname: van Lin
authors.forename: Oscar A
authors.initials: OA
authors.lastname: Debats
authors.forename: J Alfred
authors.initials: JA
authors.lastname: Witjes
authors.forename: Paul N
authors.initials: PN
authors.lastname: Span
authors.forename: Johannes H A M
authors.initials: JH
authors.lastname: Kaanders
authors.forename: Jelle O
authors.initials: JO
authors.lastname: Barentsz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003911:Dextrans; D018572:Disease-Free Survival; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D012307:Risk Factors; D016879:Salvage Therapy
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; C097921:ferumoxtran-10; D017430:Prostate-Specific Antigen