Abstract
Rationale: In early-stage breast cancer, the primary treatment option for the majority of women is breast-conserving surgery (BCS). There is a clear need for more accurate techniques to assess resection margins intraoperatively, as on average 20% of patients require further surgery to achieve clear margins. Cerenkov luminescence imaging (CLI) combines optical and molecular imaging by detecting light emitted by 18F-fluorodeoxyglucose (18F-FDG). Its high-resolution and small size imaging equipment makes CLI a promising technology for intraoperative margin assessment. A first-in-human study was conducted to evaluate the feasibility of 18F-FDG CLI for intraoperative assessment of tumor margins in BCS. Methods: Twenty-two patients with invasive breast cancer received 5 MBq/kg 18F-FDG 45-60 min prior to surgery. Sentinel lymph node biopsy (SLNB) was performed using an increased technetium-99m (99mTc)-nanocolloid activity of 150 MBq to facilitate nodal detection against the gamma-probe background signal (cross-talk) from 18F-FDG. The cross-talk and 99mTc dose required was evaluated in two lead-in studies. Immediately after excision, specimens were imaged intraoperatively in an investigational CLI imaging system. The first 10 patients were used to optimize the imaging protocol; the remaining 12 patients were included in the analysis dataset. CLI images from incised BCS specimens were analyzed postoperatively by two surgeons blinded to the histopathology results, and mean radiance and margin distance were measured. Agreement between margin distance on CLI and histopathology was assessed. Radiation doses to staff were measured. Results: Ten of the 12 patients had an elevated tumor radiance on CLI. Mean radiance and tumor-to-background ratio were 560 ± 160 photons/s/cm2/sr and 2.41 ± 0.54, respectively. All 15 assessable margins were clear on CLI and histopathology. Agreement in margin distance and inter-rater agreement was good (κ = 0.81 and 0.912, respectively). Sentinel lymph nodes (SLNs) were successfully detected in all patients. Radiation dose to staff was low; surgeons received a mean dose of 34 ± 15 μSv per procedure. Conclusion: Intraoperative 18F-FDG CLI is a promising, low-risk technique for intraoperative assessment of tumor margins in breast-conserving surgery. A randomized controlled trial will evaluate the impact of this technique on re-excision rates.
- Molecular Imaging
- Oncology: Breast
- Optical
- Radiation Safety
- 18F-FDG
- Breast-conserving surgery
- Cerenkov luminescence imaging
- Sentinel lymph node biopsy
- Tumor margins
- Copyright © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.