Gregory T. Kennedy, MD from Penn Medicine speaks about Targeted Intraoperative Molecular Imaging for Localizing Nonpalpable Tumors and Quantifying Resection Margin Distances.
Link to Abstract:
https://jamanetwork.com/journals/jamasurgery/article-abstract/2783502
Points to Remember:
A Question –
Can intraoperative molecular imaging correctly predict resection margin adequacy and locate nonpalpable, visually occult tumors?
Conclusions –
Intraoperative molecular imaging identified 83 percent of nonpalpable, nonvisible lesions in this nonrandomized open-label trial of 40 adults with a T1 pulmonary lesion radiographically suspicious for a nonpalpable cancer, and intraoperative molecular imaging–calculated margins were nearly identical to those reported on final pathology.
Defined –
Intraoperative molecular imaging can enhance surgical care of nonpalpable tumors across the area of surgical oncology by detecting occult tumors and cancer-positive margins that may have been overlooked by traditional surgical techniques.
Abstract:
Importance Across all solid tumor types, complete – (R0) resection is the most important predictive marker for survival. In nonpalpable tumors or in situ illness, achieving sufficient tumor removal with proper margins is extremely difficult. Previous approaches to this problem have been time-consuming, inefficient, or unsuccessful.
The goal is to
To see how well intraoperative molecular imaging (IMI), a new technique that uses a fluorescent tracer targeted to malignant cells, can locate optically occult, nonpalpable tumors and measure margin lengths during resection.
Participants, Design, and Setting –
Patients were enrolled in this nonrandomized open-label study of IMI employing a folate receptor-targeted fluorescent tracer at a single referral site between May 2017 and June 2020. Patients who had a tiny (T1) lung lesion that was suspected of malignant neoplasms and had radiographic characteristics suggestive of a nonpalpable lesion were eligible.
Interventions (interventions) –
A folate receptor-targeted near-infrared tracer was injected into the patients prior to surgery. Surgeons utilized thoracoscopic vision and palpation to detect lesions during surgery. The lesion was detected in situ using IMI, and the lesions were visualized ex vivo. IMI evaluated the margins before comparing them to the results of the final histopathologic study.
Main Indicators and Outcomes –
The primary objectives were whether IMI could (1) locate nonpalpable lung lesions in situ and (2) measure margin distance using final pathology as a criteria. Patient demographics and lesion characteristics were collected prospectively.
Observations –
26 (65%) of the 40 patients were female, with a median (interquartile range) age of 66.5 (62-72). Conventional surgical techniques were able to locate 22 of the 40 lesions (55%) whereas IMI was able to locate 36 of the 40 lesions (90 percent ). IMI detected 15 (83.3 percent) of the 18 nonpalpable lesions. The mean signal-to-background ratio was more than 2 in both palpable and nonpalpable lesions. For 39 of the 40 patients, an IMI margin could be determined (95 percent ). With a median (interquartile range) difference of 1.3 (0.7-2.0) mm, IMI margins were substantially equal to final pathological margins (R2 = 0.9593). IMI discovered two clinically unacceptable margins in nonpalpable tumors that would have resulted in a significant risk of recurrence.
Conclusions and Implications –
To our knowledge, this is the first clinical application of IMI for nonpalpable tumors, and it establishes the efficacy of IMI in detecting occult illness and tumor-positive margins in the area of surgical oncology.