The LightPath® and 68Ga-RM2 in Breast Cancer Study
Status:
Not yet recruiting
Trial end date:
2023-11-01
Target enrollment:
Participant gender:
Summary
This study is a prospective, open-label study to examine the performance of the LightPath®
Imaging System using the PET tracer 68Ga-RM2 in patients scheduled for and/or undergoing wide
local excision (WLE) with or without sentinel lymph node biopsy (SLNB) or complete axillary
lymph node dissection(cALND) for breast cancer with an ER-positive invasive primary cancer.
The study consists of 3 sequential groups:
Group 1 (N=20 patients): Torso, i.e. base of skull to thighs, PET/CT imaging and axillary
gamma probe measurements (using a collimator) of 68Ga-RM2 to: determine the optimal scan
time-window post-injection; to extrapolate the optimal dose for resolution against axillary
background signal on gamma probe measurements (first 6 patients); and the value of 68Ga-RM2
PET/CT imaging for breast cancer staging (all 20 patients).
Group 2 (N=10 patients): Intraoperative LightPath® imaging with 68Ga-RM2 to familiarise site
with procedure and interpretation of intraoperative scans,validate the dose and timings
determined from Group 1, and optimise LightPath® Imaging parameters such as acquisition
resolution and duration. Group 2 scans will acquire LightPath® images of both intact and
incised cancer specimens for post-operative standardised, controlled assessment. Group 2 will
use the optimal scan time-window and 68Ga-RM2 activity extrapolated from at least the first 6
patients in Group 1. The dose of 68Ga-RM2 will be determined to optimise the intra-operative
imaging and axillary gamma probe measurements.
Group 3 (N=50 patients): Intraoperative LightPath® imaging with 68Ga-RM2 to measure agreement
between LightPath® images and post-operative histopathology. Group 3 scans will acquire
LightPath® images of intact and incised cancer specimens for post-operative standardised,
controlled assessment. Group 3 will use the optimal scan time-window and 68Ga-RM2 activity
extrapolated from the first 6 patients in Group 1 with the optimised imaging parameters, and
dose developed from Group 2.
The intraoperative LightPath® Images will be used to inform the surgeons about detectable
residual cancer in an attempt to achieve better guided cancer surgery and complete tumour
excision with clear WLE resection margins
The study site will use the local criteria considered standard of care to guide decisions to
act on positive margins. Lightpoint Medical will provide guidance to act on LightPath® Images
in the Instructions forUse (IFU). It will be at the Investigator's discretion to choose
whether to act based upon the intraoperative LightPath® Images.
In Group 3,the resection margin status of the WLE specimen, cavity shavings (if any) and the
metastatic status of axillary (sentinel) lymph nodes as measured with the LightPath® Imaging
System will be compared with histopathology results. A positive margin on histology will be
defined as
- Invasive carcinoma: positive: ink on tumour; close: <1mm; negative ≥1mm
- Ductal carcinoma in situ (DCIS)or pleomorphic lobular carcinoma in situ (LCIS) (if
present): positive: ink on tumour; close: <2mm; negative ≥2mm.