TOPLINE:

Specimen PET-CT imaging is associated with improved intraoperative margin assessment (IMA) during breast-conserving surgery for early breast cancer. In patients with invasive ductal carcinoma, success rates for addressing positive margins increased from 83.3% without IMA to 95.2% with specimen PET-CT.

METHODOLOGY:

• Reoperation for positive margins increases physical and psychological burden, compromises cosmetic outcomes, delays adjuvant therapy, and increases healthcare costs, making accurate and efficient IMA of substantial importance to reduce reoperations. But existing IMA methods have limitations: Frozen sections and cytology provide high diagnostic accuracy but are limited by prolonged turnaround time, labor intensiveness, and costs, while specimen radiography is less accurate but easier to implement.
• Researchers conducted an interventional, multicenter, nonrandomized clinical trial from June 2022 to March 2025 across six European breast cancer centers in Belgium, Germany, and Italy, with a 2-week postoperative follow-up.
• A total of 148 female patients with early-stage breast cancer scheduled for breast-conserving surgery were included, with a median age of 65 years and median preoperative tumor size of 17 mm.
• Patients received an intravenous injection of low-dose 18F-FDG, followed by tumor excision and intraoperative specimen imaging using a dedicated specimen PET-CT scanner.
• Surgeons interpreted PET-CT images intraoperatively and excised additional tissue when margins appeared suspicious to achieve final negative margins, with optional use of standard-of-care IMA techniques.
• The primary outcome measured the success rate of specimen PET-CT in addressing positive margins for the invasive component in patients with invasive ductal carcinoma, while secondary outcomes included success rates in other breast cancer subtypes, final positive margin rates, reoperation rates, and diagnostic performance using histopathology as a reference standard.

TAKEAWAY:

• For the invasive component of invasive ductal carcinoma, success rates increased from 83.3% (70 of 84 patients) without IMA to 86.9% (73 of 84 patients) with routine margin assessment and to 95.2% (80 of 84 patients) with specimen PET-CT (P < .001 vs no IMA).
• Across all study groups, success rates for invasive and/or in situ disease improved from 76.4% (113 of 148 patients) without IMA to 81.8% (121 of 148 patients) with routine IMA and to 91.9% (136 of 148 patients) with specimen PET-CT (P < .001 vs no IMA; P = .009 vs standard-of-care IMA).
• Specimen PET-CT demonstrated sensitivity of 74% (26 of 35) and specificity of 68% (77 of 113) for addressing invasive and/or in situ margin involvement, with a positive predictive value of 42% (26 of 62) and a negative predictive value of 90% (77 of 86).
• Intraclass correlation coefficient for the average of four surgeon raters was 0.82 (95% CI, 0.77-0.86), indicating good interobserver agreement and consistent ratings, with no adverse events related to study-specific procedures or device use reported.

IN PRACTICE:

In an invited commentary, published in JAMA Surgery, Marissa Howard-McNatt, MD, noted that the authors of the study “found that specimen PET-CT improved the assessment of positive margins” in their study participants. She also urged caution about embracing specimen PET-CT by pointing out that “there are a number of competing and new methods in this field” and several unanswered questions about specimen PET-CT and limitations of the study.

Howard-McNatt wrote: “I feel that future studies using PET-CT imaging should be” [prospective randomized clinical trials, and this method should be] “compared with other techniques such as radiofrequency spectroscopy, fluorescent imaging, or cavity shaved margins. Also, the cost of PET-CT scan is not stated in the article. Because this study was performed in Europe, would the cost of the unit be more or less expensive in the US?”

“PET-CT imaging is one of the emerging methods, but only more vigorous studies and time will determine if it is the answer to our quest,” she concluded.

SOURCE:

The study was led by Menekse Göker, MD, Cancer Research Institute Ghent, Ghent, Belgium. It was published online on June 17 in JAMA Surgery.

LIMITATIONS:

Subgroup analyses were underpowered, and intraoperative interpretation of cavity shaves was not included, potentially underestimating device performance. The absence of positive margins in the neoadjuvant therapy group precluded evaluation in this subgroup. The study was not powered to demonstrate superiority vs standard-of-care IMA. Additionally, 18F-FDG uptake may interfere with sentinel lymph node mapping using 99mTc-nanocolloid, although adequate training mitigated this issue. Pregnant staff members were not present in the operating room due to occupational radiation limits.

DISCLOSURES:

XEOS Medical NV provided funding to participating centers for study-related costs. Göker disclosed receiving funding from XEOS Medical for AURA 10 during the conduct of the study. Markus Hahn, MD, disclosed receiving personal fees from the Department of Women’s Health during the conduct of the study. Oreste Davide Gentilini, MD, disclosed receiving fees per patient from XEOS Medical and honoraria from XEOS Medical for chairing a sponsored symposium during the conduct of the study, as well as lecture fees from MSD, AstraZeneca, Eli Lilly and Company, BD, Bayer, and Applied Medical for lectures outside the submitted work. Additional disclosures are noted in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.