Repeated quantitative bone scintigraphy in patients with prostatic carcinoma treated with orchiectomy

Abstract

Bone scintigraphy was performed in 16 men with newly diagnosed prostatic carcinoma before orchiectomy as well as 2 weeks and 2 months after operation. The uptake in the lower thoracic and lumbar vertebrae was registered up to 240 min after injection of 99mTc-MDP and was then calculated for each patient and vertebra. The relative standard deviation in measured uptake due to measuring technique was estimated to be +/- 7%. In eight patients, who had normal bone scintigraphies before orchiectomy, there were no changes in the uptake values after operation. The remaining eight patients had widespread metastatic involvement prior to treatment. Six of these patients showed a so called "flare phenomenon" in the abnormal vertebrae which means an initial increase in uptake after operation followed by a decreased uptake in response to therapy. One patient had a continuously increased uptake in all the abnormal vertebrae which correlated well with the clinical progression of the disease, while in another patient both reactions were seen. Thus, repeated quantitative bone scintigraphies using 99mTc-MDP can be made in a reproducible way and can be a useful tool to follow a patient's response to treatment.

18F-fluoride PET: changes in uptake as a method to assess response in bone metastases from castrate-resistant prostate cancer patients treated with 223Ra-chloride (Alpharadin)

“…However, it has been shown that the bone scan is limited in its sensitivity to measure treatment effect, with only 52% of responders showing scintigraphic improvement and 62% of non-responders showing scintigraphic deterioration at 6 to 8 months in one early study of patients with breast cancer [6]. In an attempt to increase sensitivity of response measurement, some authors have described various semi-quantitative means of following bone metastases with bone scintigraphy [7-10], but others have found no advantage over visual interpretation [11] and quantitative methods have not gained acceptance into routine practice.…”

Quantitative Bone Scintigraphy in Prostatic Carcinoma - Long-Term Response to Treatment

“…The count rate from " m T c -M D P was determined over the lower thoracic and lumbar spine. In most of the patients with skeletal metastases the flare phenomenon, with an increase in count rate two weeks after orchiectomy followed by a decrease after two months, was seen as response to treatment (23,24,25,26). A further decrease below the preoperative level was seen after six months (24,25).…”

Age-related Normal Uptake of 99mTc-MDP in the Lower Spine

“…A background ROI was chosen between the projection of the kidney and crista iliaca in order to correct for soft tissue activity in front of and behind the vertebrae (14,15). To calculate the uptake in a vertebra, measurements on a trunk simulating phantom containing a human like vertebra (made of epoxy mixed with C a H P 0 4 corresponding to a bone mineral content of 10% and a known activity of 99m Tc-MDP) were performed (14). The sensitivity of the gamma camera system was determined to 74 counts per second and MBq for " m T c in the vertebrae of interest.…”