Alterations of the three-phase bone scan after sympathectomy

Area of Science:

• Nuclear Medicine
• Radiology
• Pain Management

Background:

• Reflex sympathetic dystrophy (RSD) is a complex pain condition.
• Three-phase bone scan (TPBS) is a diagnostic tool used in evaluating RSD.
• Surgical or chemical sympathectomy is a treatment option for RSD.

Purpose of the Study:

• To evaluate changes in three-phase bone scan (TPBS) patterns in patients diagnosed with reflex sympathetic dystrophy (RSD).
• To assess these TPBS alterations before and after undergoing surgical or chemical sympathectomy.
• To determine if TPBS changes correlate with the success of sympathectomy in relieving pain.

Main Methods:

• TPBS was performed using 99technetium dimethylphosphonate intravenously.
• Scans were analyzed by blinded and non-blinded reviewers using a standardized visual grading system.
• Data from 14 patients (10 women, 4 men) with 17 pre- and 30 post-procedure scans were analyzed.

Main Results:

• All three phases of TPBS showed significant enhancement post-sympathectomy in 11 of 14 patients.
• This enhancement pattern was similar to that observed in florid RSD.
• Increased uptake appeared within 24 hours, normalizing in some by 3 months, but remaining abnormal in others at 12 months.
• Only 33% of sympathectomies resulted in long-term symptom relief.

Conclusions:

• Post-sympathectomy TPBS alterations are indistinguishable from early RSD findings.
• These TPBS changes do not correlate with the effectiveness of sympathectomy for pain relief.
• The study discusses mechanisms behind TPBS alterations and potential reasons for sympathectomy failure.