Venkatesh Rangarajan MD, Presenter: Nothing to Disclose

Sneha Ashok Shah MD, Abstract Co-Author: Nothing to Disclose

Anshu Rajneesh MBBS, Abstract Co-Author: Nothing to Disclose

Nilendu Chandrakant Purandare MBBS, Abstract Co-Author: Nothing to Disclose

Abhishek Arora, Abstract Co-Author: Nothing to Disclose

1) To assess lesion detectability and characterization by 99mTc MDP-Planar scan, SPECT, and SPECT/CT,18F Fluoride PET & PET/CT in patients with a known malignancy. 2) To study the incremental benefit of these modalities over conventional Planar bone scan in lesion detection and characterisation.

96 patients (53 breast ca, 43 other malignancies) who were referred for a bone scan were included in the prospective study.They underwent 99mTc MDP Planar scan, SPECT & SPECT/CT on the same day. The patients underwent a 18 F Fluoride PET/CT scan (140Kv, 110mAs), 45 minutes after injection of 370MBq of 18 F Fluoride on the subsequent day.Scans were read by three nuclear physicians and one radiologist.On planar,SPECT images lesions were classified as benign,malignant or equivocal as per scintigraphic principles.On SPECT-CT & fluoride PET-CT lesions were classified as metastatic (osteoblastic, osteolytic, mixed), benign (degenerative, other benign) or equivocal based on the morphological appearance on the corresponding CT images.

Fluoride PET/CT detected the 564 lesions – 529 metastatic (278 osteoblastic,58 osteolytic,192 mixed) lesions and 31 benign ( 22 degenrative,9 other benign) lesions with 5 equivocal studies. Of the 356 lesions that MDP SPECT/CT detected, 317 were metastatic (223 osteoblatsic, 17 osteolytic, 73 mixed) lesions, 13 were benign, but 36 lesions remained equivocal. Only 328 lesions were picked up by planar MDP scan of which 278 were identified as metastatic, 22 as benign and 27 were equivocal.

1) 18 F Fluoride PET/CT detects most number of skeletal lesions and has the highest discriminatory power to differentiate between benign and malignant.2) It has the least number of equivocal lesions,compared to 99mTc MDP planar, SPECT& SPECT/CT studies due to the increased sensitivity of fluoride over MDP and also due to the morphological detail provided by CT.  

The incremental value of 18 F Fluoride PET-CT may benefit and impact the clinical management of patients at high risk for skeletal metastases.

Rangarajan, V, Shah, S, Rajneesh, A, Purandare, N, Arora, A, Assessment of Skeletal Lesions Using 99mTc MDP Planar, SPECT, SPECT/CT, 18 F Fluoride PET, and PET/CT.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8014825.html