title: Pelvic lymph node dissection for nodal oligometastatic prostate cancer detected by 68Ga-PSMA-positron emission tomography/computerized tomography.
abstract: BACKGROUND
  The first evaluation of pelvic extended lymph node dissection (pLND) in oligometastatic prostate cancer (PCa) detected by (68)Ga-PSMA PET/CT.
  
  
  METHODS
  Retrospective analysis of 35 PCa patients underwent (68)Ga-PSMA PET/CT affected by biochemical recurrence (BCR) after curative treatment (n = 23) or before primary therapy of high-risk PCa (n = 12). We performed pLND associated with pathologic imaging in 17 men with nodal oligometastatic PCa.
  
  
  RESULTS
  Indicative lesions for PCa in PET/CT were detected in 91.4% (32 of 35) of patients. Nodal, bone, visceral (pulmonary), and within the prostate suspected disease were detected in 72% (23 of 32), 16% (5 of 32), 6% (2 of 32), and 47% (15 of 32) of patients, respectively. Median serum PSA in patients with pathological radiotracer uptake in recurrent and high-risk PCa patients was 2.9 ng/ml (range 0.18-30) and 19.5 ng/ml (range 6-90), respectively. The median number of removed lymph nodes with pLND in recurrent and high-risk PCa was 10 (range 4-17) and 12 (range 8-29) per patient and the median number of positive lymph nodes was 1 (range 1-2) and 3 (2-3) per patient, respectively. In total, two false positive and one false-negative lymph node were found. Diagnostic accuracies per nodal lesion in total of 213 removed nodes: sensitivity, 94%; specificity, 99%; positive predictive value (PPV), 89%, and negative predictive value (NPV), 99.5%. After pLND, 53% (9 of 17) of patients received androgen deprivation therapy and/or radiation therapy and hormonal therapy, while 47% (8 of 17) of patients remained free of any post-surgery therapy. Follow-up PSA remained less than 0.2 ng/ml in 82% (14 of 17) of patients. After pLND, immediate BCR (PSA never measured less than 0.2 ng/ml) in 18% (3 of 17) of patients was recorded.
  
  
  CONCLUSIONS
  This represents the first study of pLND in the setting of nodal oligometastatic PCa detected by (68)Ga-PSMA PET/CT. The use of (68)Ga-PSMA PET/CT could be to improve the accuracy for the detection of nodal micrometastases. These promising findings need validation in larger studies.
authors.affiliation: Department of Urology, University Medical Center Goettingen, Goettingen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Hijazi
authors.affiliation: Department of Nuclear Medicine, University Medical Center Goettingen, Goettingen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Meller
authors.affiliation: Department of Urology, University Medical Center Goettingen, Goettingen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Leitsmann
authors.affiliation: Department of Urology, University Medical Center Goettingen, Goettingen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Strauss
authors.affiliation: Department of Nuclear Medicine, University Medical Center Goettingen, Goettingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Meller
authors.affiliation: Department of Radiology, University Medical Center Goettingen, Goettingen, Germany.
authors.forename: C O
authors.initials: CO
authors.lastname: Ritter
authors.affiliation: Department of Radiology, University Medical Center Goettingen, Goettingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Lotz
authors.affiliation: Institute of Pathology, University Medical Center Goettingen, Goettingen, Germany.
authors.forename: H-U
authors.initials: HU
authors.lastname: Schildhaus
authors.affiliation: Department of Urology, University Medical Center Goettingen, Goettingen, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Trojan
authors.affiliation: Department of Nuclear Medicine, University Medical Center Goettingen, Goettingen, Germany.
authors.forename: C O
authors.initials: CO
authors.lastname: Sahlmann
mesh_terms: D000368:Aged; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: 68Ga-PSMA PET/CT; PSMA; biochemical recurrence; pelvic lymph node dissection; prostate cancer