NOPR results say sodium fluoride PET changes management of prostate cancer

After waiting patiently for sodium F-18 fluoride PET/CT data to come out of the National Oncological PET Registry (NOPR), clinicians are now clear that that the scan benefits patients by changing their course of care, at the very least, 12 percent of the time, according to a review published March 10 in the Journal of Nuclear Medicine.

The U.S. is expected to report about 233,000 new cases of prostate cancer this year alone. It is the number one killer in cancers affecting men and the most prevalent besides skin cancer among the male population. In 2014, an estimated 29,480 men are expected to die of the disease.

George M. Segall, MD, from Stanford University in Palo Alto, Calif., reviewed the first number crunching to come out of this arm of NOPR, which happen to aim solely at prostate cancer data, accounting for 67 percent of all of the 20,238 patients enrolled in the registry from Feb. 11, 2010, until April 17 of last year. This set of data, however, is pulled from 3,531 bone scans from 3,396 registered prostate cancer patients.

After a bone scan to detect metastatic prostate cancer has been deemed appropriate, clinicians choose between sodium F-18 fluoride PET, carbon-11 choline PET and the more conventional technetium-99m (Tc-99m) diphosphonate planar or SPECT scan.

According to the literature of previous studies cited in the report, sodium fluoride PET was found to be 100 percent sensitive compared to SPECT at 92 percent sensitivity and Tc-99m diphosphonate, which was found to be only 54 percent sensitive for bone metastases. Other studies corroborated these numbers closely.  

The newly published NOPR data revealed that sodium fluoride PET/CT’s impact was significant, especially in terms of replacing other imaging modalities in about half of the cases.

“The study shows that sodium F-18 fluoride PET/CT substantially affected intended management across three groups of patients: initial staging, suspected first skeletal metastasis and suspected progression of known skeletal metastatic disease,” wrote Segall. Importantly, when the intended patient management was deemed either treatment or nontreatment, that intended clinical decision was changed about 44 to 52 percent of the time after sodium fluoride PET/CT.

“After adjustment for those cases for which the pre-PET plan—including other advanced imaging—may have led to the same changes in intended management, the impact of sodium F-18 fluoride on intended management was still 12 percent to 16 percent,” he added.

It is yet unknown what the change in management would be subsequent to sodium fluoride imaging if the patient had already had a Tc-99m diphosphonate scan. Another comparison from the literature included a study involving 526 bone lesions: 163 not malignant and 363 found to be malignant that added C-11 choline to the mix.

“Sensitivity and specificity were, respectively, 51 percent and 82 percent for Tc-99m diphosphonate bone scanning, 85 percent and 91 percent for C-11 choline, and 93 percent and 54 percent for sodium F-18 fluoride,” noted Segall.

The major conclusion of this preliminary review was that both C-11 choline and sodium F-18 fluoride performed better than Tc-99m diphosphonate, but C-11 choline’s major disadvantage is its exceedingly short half-life of about 20 minutes.

Further studies will need to be conducted to weigh the pros and cons of these techniques for improved prostate cancer patient care.