An interventional study of CONVIVO system and Conventional histologic evaluation in Glioblastoma, Glial Tumor and Brain Metastases, sponsored by Dartmouth-Hitchcock Medical Center. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-06.
Sponsored by Dartmouth-Hitchcock Medical Center · Not applicable, Interventional, and Diagnostic
The primary objective of this study is to evaluate the diagnostic performance of the CONVIVO confocal endomicroscope in discriminating between normal and abnormal tissue in vivo during brain tumor surgery. The interpretation of intraoperative images obtained in situ will be tested against conventional histologic evaluation of targeted biopsies from imaged tissue. The study team hypothesize that there will be a high degree of correlation between images obtained with the CONVIVO system and conventional histologic interpretation.
The surgical resection of brain tumors is an integral component of modern neuro-oncology. . Extent of resection has been found to be associated with increased overall and progression free survival, with the greatest benefit occurring in the setting of a complete or gross total resection. Unfortunately, there are a number of obstacles unique to brain tumors that may limit the extent of resection. A number of advancements in neurosurgical oncology have emerged to improve the extent of tumor resection while decreasing operative morbidity and mortality. Confocal reflectance microscopy is a routine technique used to visualize tissues without fixation or staining used in classical histological techniques. Laser scanning confocal microscopy (LSCM) is an optical fluorescence imaging modality used for imaging thick in vivo and ex vivo tissues. Clinically available confocal endomicroscopy systems contain lasers with precise excitation wavelengths and dichroic filters for detecting appropriate emission wave lengths. The studies completed to date do not evaluate the ability of confocal microscopy to discriminate between normal and abnormal tissue at the margins during surgical resection. This is the first of such in vivo feasibility studies that aims to demonstrate this claim of the CONVIVO system.
The images acquired with the CONVIVO system following administration of fluorescein will be compared to conventional histologic specimens from corresponding biopsies. This is a planned single center study. This study is designed to assess the diagnostic accuracy of the CONVIVO system compared with gold-standard histopathology in tissue that has already been identified for resection. The device will not be used to inform surgical decision making, nor will tissue that would not otherwise be resected be biopsied for research purposes.
This study will rely on study investigators, all physicians at Dartmouth-Hitchcock, to identify subjects. Written consent is required for participation in the study.. There are no specific medical risks to patients associated with the use of CONVIVO. It is not anticipated that there are immediate or direct benefits to patients participating in this study. The CONVIVO imaging data acquired during the procedure will be initially stored on the device's hard drive and later securely uploaded to an encrypted Dartmouth-Hitchcock server. Patients will have the ability to maintain their privacy with minimal disruption or contact by the study team. Additionally, the PI or other investigators will have interactions with the patient as part of their routine clinical care. Participants are free to withdraw from participation in the study at any time upon request.
1,920 studies on the registry are indexed under Glioblastoma; 450 are open to participants now.
This study's planned enrollment of 30 is below the median of 36 across 1,618 interventional studies indexed under Glioblastoma.
Browse Glioblastoma studies →Dartmouth-Hitchcock Medical Center is the lead sponsor of 472 studies on the registry; 68 are open to participants now.
Of its 30 completed or terminated interventional studies of FDA-regulated products, 20 (67%) have results posted.
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Exclusion Criteria:
During tumor resection, study investigators trained in the use of the system will determine when the CONVIVO imaging system will be used for in vivo¬ imaging. At this point 5 mg/kg of fluorescein will be administered intravenously by an anesthesia provider over one minute.Approximately 2-5 minutes following administration of FNa in situ imaging will be performed by the participating surgeon ensuring proper technique.
Diagnostic Test: CONVIVO system
Following image acquisition, the tissue region imaged with the CONVIVO system will then be biopsied using biopsy forceps. This will be passed immediately off the surgical field as a research specimen and provided to a member of the research team to be prepared for conventional histologic evaluation. The specimen will be labeled with the deidentified subject and sample number. This sequence will then be repeated for each successive sample.
Other: Conventional histologic evaluation
Approximately 2-5 minutes following administration of FNa in situ imaging will be performed by the participating surgeon ensuring proper technique. Prior to entering the surgical field, the probe will be covered in a disposable sterile sheath that is manufactured with quality assurance for this purpose. The probe will gently be held against the tissue interface while imaging occurs. Again this will only be in regions that would normally be resected or sampled in routine clinical care. Following image acquisition, a neuropathologist present in the operating room, will review and capture each image.
Following image acquisition, the tissue region imaged with the CONVIVO system will then be biopsied using biopsy forceps. This will be passed immediately off the surgical field as a research specimen and provided to a member of the research team to be prepared for conventional histologic evaluation. The specimen will be labeled with the deidentified subject and sample number. This sequence will then be repeated for each successive sample.
Diagnostic performance of CONVIVO in discriminating between normal and abnormal tissue
Concordance between in vivo imaging with the CONVIVO system and conventional histologic assessment.The diagnostic performance of the CONVIVO system will be assessed with respect to classification as "normal" or "abnormal" tissue. The interpretation of intraoperative images obtained in situ will be tested against conventional histologic evaluation of targeted biopsies from imaged tissue. Pertinent tumors include all intracranial neoplasms including low and high grade glial neoplasms, glioneuronal tumors, cerebral metastasis, meningioma, schwannoma, and pituitary lesions.
Time frame: On day of Surgery, Day 0
Degree of concordance with histologic diagnosis
Degree of concordance between in vivo imaging with the CONVIVO system and conventional histologic assessment or frozen with respect to histologic diagnosis.
Time frame: On day of surgery, Day 0
Sensitivity and Specificity of CONVIVO system
Sensitivity and specificity analysis of CONVIVO using area under the curve and receiver operating characteristics. Conventional histopathology will be the gold-standard.
Time frame: On day of surgery, Day 0
Rate of uninterpretable or non-diagnostic imaging with the CONVIVO system.
Rate of uninterpretable or non-diagnostic imaging with the CONVIVO system. During the resection the PI or other investigators may image tissue that is ultimately not biopsied. For example at the end of resection if there is a region of interest that cannot be safely resected, the CONVIVO system can be used to image the tissue without obtaining a corresponding tissue specimen for histology. During image acquisition it will be noted and documented by the research team that there is not a corresponding tissue specimen.
Time frame: On day of surgery, Day 0
Correlation between intra-operative confocal microscopy and co-registered MRI points.
MRI characteristics will include (i) the presence or absence of contrast enhancement; (ii) signal intensity on T2 weighted images; (iii) perfusion based and spectroscopy imaging; (iv) diffusion weighted sequences.
Time frame: On day of surgery, Day 0
Correlation between visible yellow-light fluorescence (560 nm filter) and intraoperative confocal microscopy.
Following image coregistration, the 560 yellow light filter on the Kinevo microscope will be used to determine the visible fluorescence in the region that was interrogated and classified from 0 to 4 based upon the fluorescence intensity. This will be recorded by the research team. The degree of visible fluorescence will be graded as 0-no fluorescence, 1- weak intensity, 2-moderate intensity, 3-strong intensity.
Time frame: On day of surgery, Day 0
Correlation between visible blue-light fluorescence and quantitative fluorescence measurements
If the participant has also received 5-ALA, the 400 nm blue light filter will then be selected and the visible fluorescence of PPIX will also be classified from 0 to 4 based upon the fluorescence intensity. The degree of visible fluorescence will be graded as 0-no fluorescence, 1- weak intensity, 2- moderate intensity, 3-strong intensity.
Time frame: On day of surgery, Day 0
Extent of tumor resection
Extent of resection has been found to be associated with increased overall and progression free survival, with the greatest benefit occurring in the setting of a complete or gross total resection. Postoperative MRI is obtained as appropriate, as it relates to extent of resection.
Time frame: 2 Days after surgery up to one month.
Adverse events related to the administration of fluorescein
Record adverse events as reported by participant or observed by investigator related to the administration of fluorescein
Time frame: Day of surgery (Day 0), 2 Days after surgery up to one month.
Time to interpretation of imaging and histology
Time to pathologic interpretation of intraoperative imaging compared to conventional interpretation of histology.Currently, the frozen section provides intraoperative histopathological analysis of brain tumors. Though useful, this process is time consuming and requires the cutting, freezing, and staining of several biopsies.
Time frame: Day of surgery (Day 0), and up to one week
Ability to discriminate between viable tumor and pseudoprogression or "treatment effect" using the CONVIVO system.
The WHO criteria for the diagnosis of Glioblastoma (GBM) - cell density, cellular pleomorphism, increased mitoses, microvascular proliferation and trpalisading or ischemic necrosis - were all detectable by Confocal EndoMicroscope (CEM). Identification of the infiltration zone or the center of the tumor was possible based upon assessments of cell density comparing the center and border specimens. Additional aspects, e.g. apoptotic figures in perinecrotic pseudopalisading tumor cells, and important histological structures such as giant cells, fibrillary tumor matrix and blood vessels were also visible with CEM. Typical features of CEM in patients with histologically proven meningioma were also seen.
Time frame: Day of surgery (Day 0) and up to one month
Plan to share: No — There are no plans at this time to share IPD.
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