Optimal scan time for fluorine-18 fluorodeoxyglucose positron emission tomography in breast cancer

Eur J Nucl Med. 1999 Mar;26(3):226-30. doi: 10.1007/s002590050381.


Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) has proven useful in the differentiation of various tumour entities, including breast cancer. In patients with primary breast cancer we performed a 3-h imaging protocol to examine possible improvements in tumour detectability and image contrast. Twenty-nine patients with primary breast cancer with a diameter of >/=2 cm that was demonstrated to be malignant by biopsy or surgery were injected with 370-740 MBq 18F-FDG and scanned in the prone position. Data were acquired 0-40 min, 1.5 h and 3.0 h after injection. After correction for measured attenuation, decay and scatter and iterative reconstruction, standardised uptake values (SUVs) and tumour-to-non-tumour and tumour-to-organ ratios were calculated. Visual analysis was performed using transverse, sagittal and coronal slices as well as 3D reprojection images. Tumour-to-non-tumour and tumour-to-organ ratios were significantly higher for the 3-h images than for the 1.5-h images. SUVs did not increase to the same extent. Lesion detectability was 83% in 1.5-h images compared to 93% in 3-h images. We conclude that tumour contrast in breast cancer is improved by starting the PET acquisition at 3 h p.i. rather than at 1.5 h p.i.

MeSH terms

  • Adult
  • Breast Neoplasms / diagnostic imaging*
  • Case-Control Studies
  • Female
  • Fluorine Radioisotopes*
  • Fluorodeoxyglucose F18*
  • Humans
  • Image Processing, Computer-Assisted
  • Middle Aged
  • Prospective Studies
  • Radiopharmaceuticals
  • Time Factors
  • Tomography, Emission-Computed*


  • Fluorine Radioisotopes
  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18