Which imaging method to choose for detection of bone metastases in high risk prostate cancer patients?

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Jambor I, Kuisma A, Ramadan S, Huovinen R, Sandell M, Kajander S, Kemppainen J, Kauppila E, Auren J, Merisaari H, Saunavaara J, Noponen T, Minn H, Aronen HJ, Seppänen M. Acta Oncol. 2016;55(1):59-67. doi: 10.3109/0284186X.2015.1027411. PubMed PMID: …

Jambor I, Kuisma A, Ramadan S, Huovinen R, Sandell M, Kajander S, Kemppainen J, Kauppila E, Auren J, Merisaari H, Saunavaara J, Noponen T, Minn H, Aronen HJ, Seppänen M. Acta Oncol. 2016;55(1):59-67. doi: 10.3109/0284186X.2015.1027411. PubMed PMID: 25833330.

Short summary 

  • Prospective, (2011-2013) comparative study, regarding diagnostic accuracy of methods for detecting bone mets in high risk patients (breast- and prostate cancer).
  • Imaging methods:
    1. 99m-Tc-HDP planar Bone Scintigraphy (BS)
    2. 99m-Tc-HDP SPECT
    3. 99m-Tc-HDP SPECT/CT
    4. 18-F-NaF PET/CT
    5. 1.5T Whole body MRI with DWI (wbMRI+DWI).
  • All imaging done within 2 weeks.
  • Evaluation by 5 individual modality specific readers
  • Reference: consensus and follow-up.
  • Follow-up time: 6 – 32 months (min.-max).
  • Findings compared on patient-, region- and lesion-level. 

Conclusion

wbMRI+DWI showed similar diagnostic accuracy to 18-F-NaF PET/CT and outperformed 99m-Tc-HDP- SPECT/CT and 99m-Tc-HDP-BS.

Patient cohort

53pt. (26 breast/27prostate).

The New and the Good

  • First prospective clinical trial directly comparing the diagnostic accuracy of these 5 modalities including DWI for detection of bone metastases in these high risk patients.

  • Economic aspects have been evaluated (Table IV) . Reading times for multiplanar examinations are equal, 18-F-NaF PET/CT cost X4 €; 1,5T wbMRI+DWI has longer acquisition time (x2).

Limitations

  • Approx. 50% of the patients were on hormone therapy when imaged. 12 breast- and 16-prostate- cancer had only clinical and laboratory follow-up (no imaging follow-up).

  • No histological confirmation of lesions. Follow-up is a mix, but in line with many other clinical studies. 

Possible consequences for clinical practice

Choice of imaging modality may change patient management (in the PCa-cohort, in 2/27 patients chemotherapy was started due to discovery of bone metastasis by SPECT/CT, 18-F-NaF PET/CT and wbMRI+DWI). In one PCa patient, liver or mesenteric metastases were discovered by wbMRI+DWI, which changed treatment for this patient. Therefore, adequate imaging is important in detetion of bone metastases and clinical referrers should be informed on the adequate modality. 

Personal comment

Although there was an inconsistency in the follow-up of patients, which is a limitation of this study, BS and SPECT should not be recommended as adequate imaging tools to detect metastases in PCa patients. Equivocal lesions lead to a delay in treatment decisions and extra costs by additional examinations to rule out or confirm a lesion.  So, again I think why not start with wbMRI+DWI routinely for this setting?