MRI versus 68Ga-PSMA PET/CT for gross tumour volume delineation in radiation treatment planning of primary prostate cancer

  • Constantinos Zamboglou
  • Gesche Wieser
  • Steffen Hennies
  • Irene Rempel
  • Simon Kirste
  • Martin Soschynski
  • Hans Christian Rischke
  • Tobias Fechter
  • Cordula A. Jilg
  • Mathias Langer
  • Philipp T. Meyer
  • Michael Bock
  • Anca-Ligia Grosu
Original Article

DOI: 10.1007/s00259-015-3257-5

Cite this article as:
Zamboglou, C., Wieser, G., Hennies, S. et al. Eur J Nucl Med Mol Imaging (2016) 43: 889. doi:10.1007/s00259-015-3257-5

Abstract

Purpose

Multiparametric magnetic resonance imaging (mpMRI) is widely used in radiation treatment planning of primary prostate cancer (PCA). Focal dose escalation to the dominant intraprostatic lesions (DIPL) may lead to improved PCA control. Prostate-specific membrane antigen (PSMA) is overexpressed in most PCAs. 68Ga-labelled PSMA inhibitors have demonstrated promising results in detection of PCA with PET/CT. The aim of this study was to compare 68Ga-PSMA PET/CT with MRI for gross tumour volume (GTV) definition in primary PCA.

Methods

This retrospective study included 22 patients with primary PCA analysed after 68Ga-PSMA PET/CT and mpMRI. GTVs were delineated on MR images by two radiologists (GTV-MRIrad) and two radiation oncologists separately. Both volumes were merged leading to GTV-MRIint. GTVs based on PET/CT were delineated by two nuclear medicine physicians in consensus (GTV-PET). Laterality (left, right, and left and right prostate lobes) on mpMRI, PET/CT and pathological analysis after biopsy were assessed.

Results

Mean GTV-MRIrad, GTV-MRIint and GTV-PET were 5.92, 3.83 and 11.41 cm3, respectively. GTV-PET was significant larger then GTV-MRIint (p = 0.003). The MRI GTVs GTV-MRIrad and GTV-MRIint showed, respectively, 40 % and 57 % overlap with GTV-PET. GTV-MRIrad and GTV-MRIint included the SUVmax of GTV-PET in 12 and 11 patients (54.6 % and 50 %), respectively. In nine patients (47 %), laterality on mpMRI, PET/CT and histopathology after biopsy was similar.

Conclusion

Ga-PSMA PET/CT and mpMRI provided concordant results for delineation of the DIPL in 47 % of patients (40 % – 54 % of lesions). GTV-PET was significantly larger than GTV-MRIint. 68Ga-PSMA PET/CT may have a role in radiation treatment planning for focal radiation to the DIPL. Exact correlation of PET and MRI images with histopathology is needed.

Keywords

PSMA Prostate cancer MRI Radiation therapy 

Funding information

Funder NameGrant NumberFunding Note
Piramal
    GE
      German Cancer Consortium (DKTK)

        Copyright information

        © Springer-Verlag Berlin Heidelberg 2015

        Authors and Affiliations

        • Constantinos Zamboglou
          • 1
          • 2
        • Gesche Wieser
          • 3
        • Steffen Hennies
          • 4
        • Irene Rempel
          • 5
        • Simon Kirste
          • 1
          • 2
        • Martin Soschynski
          • 5
        • Hans Christian Rischke
          • 1
        • Tobias Fechter
          • 1
          • 2
        • Cordula A. Jilg
          • 6
        • Mathias Langer
          • 5
        • Philipp T. Meyer
          • 2
          • 3
        • Michael Bock
          • 2
          • 5
        • Anca-Ligia Grosu
          • 1
          • 2
        1. 1.Department of Radiation OncologyUniversity Medical Center FreiburgFreiburgGermany
        2. 2.German Cancer Consortium (DKTK)HeidelbergGermany
        3. 3.Department of Nuclear MedicineUniversity Medical Center FreiburgFreiburgGermany
        4. 4.Department of Radiation OncologyUniversity Medical Center GöttingenGöttingenGermany
        5. 5.Department of RadiologyUniversity Medical Center FreiburgFreiburgGermany
        6. 6.Department of UrologyUniversity Medical Center FreiburgFreiburgGermany

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