The added value of multislice SPECT/CT in patients with equivocal bony metastasis from carcinoma of the prostate.
OBJECTIVE
The purpose of this study was to investigate the additional value of single photon emission computed tomography/computed tomography (SPECT/CT) over whole-body planar bone scintigraphy and SPECT in prostate cancer patients in terms of diagnostic confidence, inter-reviewer agreement and the possible impact on the clinical management.


METHODS
This was a retrospective review of 40 consecutive prostate cancer patients (mean age 71 years) who underwent (99m)Tc-methylene diphosphonate (MDP) whole-body planar bone scintigraphy, SPECT and SPECT/CT between April 2006 and April 2008. The images were evaluated by two independent reviewers; inter-reviewer agreement was evaluated using a weighted kappa score. Each focus of abnormal increased tracer uptake was recorded using a 4-point diagnostic confidence scale. Institutional Review Board approval was obtained.


RESULTS
Fifty lesions on planar bone scintigraphy in the 40 patients were evaluated. On reporting the planar study and SPECT scans, reviewers rated 61% of lesions as equivocal. On reporting the SPECT/CT scans only 8% of lesions were rated as equivocal, 24% were rated as malignant and 68% as benign. Weighted kappa scores for inter-reviewer agreement were 0.43 for bone scintigraphy, 0.56 for SPECT and 0.87 for SPECT/CT. All were significant at p < 0.0001. Follow-up imaging confirmed the SPECT/CT diagnoses in 14 patients.


CONCLUSIONS
The addition of SPECT/CT resulted in a significant reduction of equivocal reports; a definitive diagnosis was given in the majority of the patients due to the improved diagnostic confidence compared to planar or SPECT imaging alone in prostate cancer patients with suspected bone metastases.
Helyar
Vincent
V
School of Medicine, King's College London, The Flat, Poundisford Lodge, Poundisford, Taunton, Somerset TA3 7AE, UK. vincent.helyar@doctors.net.uk
Mohan
Hosahalli K
HK
Barwick
Tara
T
Livieratos
Lefteris
L
Gnanasegaran
Gopinath
G
Clarke
Susan E M
SE
Fogelman
Ignac
I
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000556:secondary*; D000368:Aged; D000369:Aged, 80 and over; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary*; D003937:Diagnosis, Differential; D050815:Fractures, Compression / Q000175:diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010347:Patient Care Planning; D011471:Prostatic Neoplasms / Q000473:pathology*; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000175:diagnosis; D013125:Spinal Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D015899:Tomography, Emission-Computed, Single-Photon; D036542:Tomography, Spiral Computed; D051598:Whole Body Imaging