Chadwick Wright

Radiation Pneumonitis Following Yttrium-90 Radioembolization: Case Report and Literature Review

Radiation-induced pneumonitis (RP) is a rare complication of radioembolization with yttrium-90 ((90)Y) microspheres. The present report describes a case of RP in a patient with liver metastases from a gastrointestinal stromal tumor after radioembolization with (90)Y glass microspheres. This patient developed clinical, functional, and radiographic findings consistent with RP, with near-complete pulmonary parenchymal recovery and no clinical evidence of relapse or progressive decline in pulmonary function over a 9-month period. As clinical use of radioembolization expands, rare adverse events such as RP may become more frequent. It is essential that interventional radiologists, radiation/medical oncologists, and nuclear medicine physicians recognize this potential complication.

Phase contrast and time-of-flight magnetic resonance angiography of the intracerebral arteries at 1.5, 3 and 7 T

PURPOSE Time-of-flight (ToF) and phase contrast (PC) magnetic resonance angiographies (MRAs) are noninvasive applications to depict the cerebral arteries. Both approaches can image the cerebral vasculature without the administration of intravenous contrast. Therefore, it is used in routine clinical evaluation of cerebrovascular diseases, e.g., aneurysm and arteriovenous malformations. However, subtle microvascular disease usually cannot be resolved with standard, clinical-field-strength MRA. The purpose of this study was to compare the ability of ToF and PC MRA to visualize the cerebral arteries at increasing field strengths. MATERIALS AND METHODS The Institutional Review Board-approved study included eight healthy volunteers (age: 36 ± 10 years; three female, five male). All subjects provided written informed consent. ToF and PC MRAs were obtained at 1.5, 3 and 7T. Signal intensities of the large, primary vessels of the Circle of Willis were measured, and signal-to-noise ratios were calculated. Visualization of smaller first- and second-order branch arteries of the Circle of Willis was also evaluated. RESULTS The results show that both ToF and PC MRAs allow the depiction of the large primary vessels of the Circle of Willis at all field strengths. Ultrahigh field (7T) provides only small increases in the signal-to-noise ratio in these primary vessels due to the smaller voxel size acquired. However, ultrahigh-field MRA provides better visualization of the first- and second-order branch arteries with both ToF and PC approaches. Therefore, ultrahigh-field MRA may become an important tool in future neuroradiology research and clinical care.

Intraoperative Use of a Portable Large Field of View Gamma Camera and Handheld Gamma Detection Probe for Radioguided Localization and Prediction of Complete Surgical Resection of Gastrinoma: Proof of Concept

BACKGROUND Surgical management of Zollinger-Ellison syndrome (ZES) relies on localization and resection of all tumor foci. We describe the benefit of combined intraoperative use of a portable large field of view gamma camera (LFOVGC) and a handheld gamma detection probe (HGDP) for indium-111 ((111)In)-pentetreotide radioguided localization and confirmation of gastrinoma resection in ZES. STUDY DESIGN Five patients (6 cases) with (111)In-pentetreotide-avid ZES were evaluated. Patients were injected with (111)In-pentetreotide for diagnostic imaging the day before surgery. Intraoperatively, an HGDP and LFOVGC were used to localize (111)In-pentetreotide-avid lesions, guide resection, assess specimens for (111)In-pentetreotide activity, and to verify lack of abnormal post-resection surgical field activity. RESULTS Large field of view gamma camera imaging and HGDP-assisted detection were helpful for localization and guided resection of tumor and removal of (111)In-pentetreotide-avid tumor foci in all cases. In 3 of 5 patients (3 of 6 cases), these techniques led to detection and resection of additional tumor foci beyond those detected by standard surgical techniques. The (111)In-pentetreotide-positive or-negative specimens correlated with neuroendocrine tumors or benign pathology, respectively. In one patient with mild residual focal activity on post-resection portable LFOVGC imaging, thought to be artifact, had recurrence of disease in the same area 5 months after surgery. CONCLUSIONS Real-time LFOVGC imaging and HGDP use for surgical management of gastrinoma improve success of localizing and resecting all neuroendocrine tumor-positive tumor foci, providing instantaneous navigational feedback. This approach holds potential for improving long-term patient outcomes in patients with ZES.

Theranostic Imaging of Yttrium-90.

This paper overviews Yttrium-90 (90Y) as a theranostic and nuclear medicine imaging of 90Y radioactivity with bremsstrahlung imaging and positron emission tomography. In addition, detection and optical imaging of 90Y radioactivity using Cerenkov luminescence will also be reviewed. Methods and approaches for qualitative and quantitative 90Y imaging will be briefly discussed. Although challenges remain for 90Y imaging, continued clinical demand for predictive imaging response assessment and target/nontarget dosimetry will drive research and technical innovation to provide greater clinical utility of 90Y as a theranostic agent.

Feasibility of a multimodal 18F-FDG-directed lymph node surgical excisional biopsy approach for appropriate diagnostic tissue sampling in patients with suspected lymphoma

Background18F-FDG PET/CT imaging is widely utilized in the clinical evaluation of patients with suspected or documented lymphoma. The aim was to describe our cumulative experience with a multimodal 18F-FDG-directed lymph node surgical excisional biopsy approach in patients with suspected lymphoma.MethodsThirteen patients (mean age 51 (±16;22–76) years), with suspected new or suspected recurrent lymphoma suggested by 18F-FDG-avid lesions seen on prior diagnostic whole-body PET/CT imaging, were injected IV with 18F-FDG prior to undergoing same-day diagnostic lymph node surgical excisional biopsy in the operating room. Various 18F-FDG detection strategies were used on the day of surgery, including, (1) same-day pre-resection patient PET/CT; (2) intraoperative gamma probe assessment; (3) clinical scanner specimen PET/CT imaging of whole surgically excised tissue specimens; (4) specimen gamma well counts; and/or (5) same-day post-resection patient PET/CT.ResultsSame-day 18F-FDG injection dose was 14.8 (±2.4;12.5-20.6) millicuries or 548 (±89;463–762) megabecquerels. Sites of 18F-FDG-avid lesions were 4 inguinal, 3 cervical, 3 abdominal/retroperitoneal, 2 axillary, and 1 gluteal region subcutaneous tissue. Same-day pre-resection patient PET/CT was performed on 6 patients. Intraoperative gamma probe assessment was performed on 13 patients. Clinical scanner PET/CT imaging of whole surgically excised tissue specimens was performed in 10 cases. Specimen gamma well counts were performed in 6 cases. Same-day post-resection patient PET/CT imaging was performed on 8 patients. Time from 18F-FDG injection to same-day pre-resection patient PET/CT, intraoperative gamma probe assessment, and same-day post-resection patient PET/CT were 76 (±8;64–84), 240 (±63;168–304), and 487 (±104;331–599) minutes, respectively. Time from 18F-FDG injection to clinical scanner PET/CT of whole surgically excised tissue specimens was 363 (±60;272–446) minutes. Time from 18F-FDG injection to specimen gamma well counts was 591 (±96;420–689) minutes. Intraoperative gamma probe assessment successfully identified 18F-FDG-avid lesions in 12/13 patients. Histopathologic evaluation confirmed lymphoma in 12/13 patients and benign disease in 1/13 patients.ConclusionsA multimodal approach to 18F-FDG-directed lymph node surgical excisional biopsy for suspected lymphoma is technically feasible for guiding appropriate diagnostic tissue sampling of lymph nodes seen as 18F-FDG-avid lesions on diagnostic 18F-FDG PET/CT imaging.

Intraoperative Scintigraphy Using a Large Field-of-View Portable Gamma Camera for Primary Hyperparathyroidism: Initial Experience

Background. We investigated a novel technique, intraoperative 99 mTc-Sestamibi (MIBI) imaging (neck and excised specimen (ES)), using a large field-of-view portable gamma camera (LFOVGC), for expediting confirmation of MIBI-avid parathyroid adenoma removal. Methods. Twenty patients with MIBI-avid parathyroid adenomas were preoperatively administered MIBI and intraoperatively imaged prior to incision (neck) and immediately following resection (neck and/or ES). Preoperative and intraoperative serum parathyroid hormone monitoring (IOPTH) and pathology (path) were also performed. Results. MIBI neck activity was absent and specimen activity was present in 13/20 with imaging after initial ES removal. In the remaining 7/20 cases, residual neck activity and/or absent ES activity prompted excision of additional tissue, ultimately leading to complete hyperfunctioning tissue excision. Postexcision LFOVGC ES imaging confirmed parathyroid adenoma resection 100% when postresection imaging qualitatively had activity (ES) and/or no activity (neck). The mean ± SEM time saving using intraoperative LFOVGC data to confirm resection versus first IOPTH or path result would have been 22.0 ± 2 minutes (specimen imaging) and 26.0 ± 3 minutes (neck imaging). Conclusion. Utilization of a novel real-time intraoperative LFOVGC imaging approach can provide confirmation of MIBI-avid parathyroid adenoma removal appreciably faster than IOPTH and/or path and may provide a valuable adjunct to parathyroid surgery.

Advancing Precision Nuclear Medicine and Molecular Imaging for Lymphoma

PET with fluorodeoxyglucose F 18 (18F FDG-PET) is a meaningful biomarker for the detection, targeted biopsy, and treatment of lymphoma. This article reviews the evolution of 18F FDG-PET as a putative biomarker for lymphoma and addresses the current capabilities, challenges, and opportunities to enable precision medicine practices for lymphoma. Precision nuclear medicine is driven by new imaging technologies and methodologies to more accurately detect malignant disease. Although quantitative assessment of response is limited, such technologies will enable a more precise metabolic mapping with much higher definition image detail and thus may make it a robust and valid quantitative response assessment methodology.

Real-time scintigraphic assessment of intravenous radium-223 administration for quality control.

Radium-223 (223Ra) dichloride is an approved intravenous radiotherapy for patients with osseous metastases from castration-resistant prostate cancer (CRPC). In addition to the therapeutic alpha radiation, there is additional 223Ra radiation generated which produces photons that can be imaged with conventional gamma cameras. No studies have evaluated real-time and quality imaging during intravenous 223Ra administration to verify systemic circulation and exclude 223Ra extravasation at the injection site. A retrospective review was performed for fifteen 223Ra administrations for CRPC patients which were imaged using a large field of view portable gamma camera (LFOVPGC) for the purposes of quality control and patient safety. Dynamic imaging of the chest was performed before, during, and after the 223Ra administration to verify systemic circulation, per institutional clinical protocol. Before and after 223Ra administration, a static image was obtained of the intravenous access site. Dynamic imaging of the chest confirmed systemic administration early during the 1-minute injection period for all patients. There were no cases of focal 223Ra extravasation at the site of intravenous access. These results verify that systemic 223Ra administrations can be quantified with real-time imaging using an LFOVPGC. This simple approach can confirm and quantify systemic circulation of 223Ra early during injection and exclude focal extravasation for the purposes of quality control.

Unusual motion detected on real-time sonography inside a glomus tumor in the thigh

Glomus tumors are rare and many have been reported to have a hypervascular appearance on color or power Doppler sonography. We report a pathologically proven case of superficial glomus tumor within the thigh with no detectable color flow signals on color or power Doppler sonography. In addition, real‐time sonography showed spontaneous motions within the tumor, which were not synchronized with vascular or respiratory motions, and misled the presurgical diagnosis of a suspected parasite in a patient who had direct contact with multiple animal species. The etiology of this internal motion remains hypothetical but, if reconfirmed, this finding may be a useful adjunctive sign for the diagnosis of glomus tumors.

Advancing theranostics with tumor-targeting peptides for precision otolaryngology

Worldwide, about 600,000 head and neck squamous cell carcinoma (HNSCC) are detected annually, many of which involve high risk human papilloma virus (HPV). Surgery is the primary and desired first treatment option. Following surgery, the existence of cancer cells at the surgical margin is strongly associated with eventual recurrence of cancer and a poor outcome. Despite improved surgical methods (robotics, microsurgery, endoscopic/laparoscopic, and external imaging), surgeons rely only on their vision and touch to locate tumors during surgery. Diagnostic imaging systems like computed tomography (CT), magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT) and positron-emission tomography (PET) are too large, slow and costly to use efficiently during most surgeries and, ultrasound imaging, while fast and portable, is not cancer specific. This purpose of this article is to review the fundamental technologies that will radically advance Precision Otolaryngology practices to the benefit of patients with HNSCC. In particular, this article will address the potential for tumor-targeting peptides to enable more precise diagnostic imaging while simultaneously advancing new therapeutic paradigms for next generation image-guided surgery, tumor-specific chemotherapeutic delivery and tumor-selective targeted radiotherapy (i.e., theranostic).