Old Dog with New Tricks: 99mTc-sestamibi SPECT-CT for Renal Mass Differentiation

Small renal masses have historically presented a diagnostic challenge for radiologists and urologists. MRI and CT have a limited capability to differentiate benign and malignant small solid renal masses. The relatively poor negative predictive value of renal biopsy limits the ability to avoid surgical resection in small renal masses with negative biopsy. 99mTc-sestamibi SPECT-CT can be an important tool in directing the management of patients with renal masses.We present the analysis of 99mTc-sestamibi uptake patterns in patients with small renal masses who underwent further characterization of these masses with 99mTc-sestamibi SPECT-CT. Pertinent interpretation points in differentiating renal cell carcinoma from benign renal masses such as oncocytoma or angiomyolipoma with 99mTc-sestamibi SPECT-CT are illustrated via these patient cases.We believe that this exhibit showcases an area in which 99mTc-sestamibi SPECT-CT can significantly aid patient care. The use of this nuclear medicine study in patients with small renal masses will allow clinicians to be more selective when deciding if a renal mass requires excision. The viewer of this exhibit will have a full knowledge of how 99mTc-sestamibi SPECT-CT can be utilized to provide more definite characterization of small solid renal masses.https://scholarlycommons.henryford.com/merf2019edu/1000/thumbnail.jp

F-18 Fluciclovine Positron Emission Tomography: The New Kid On The Block

Introduction: F-18 Fluciclovine (AxuminTM) is a new positron emission tomography (PET) agent used for patients suspected of having prostate cancer recurrence based on prostate specific antigen (PSA) levels following prior treatment of prostate cancer. This presentation provides a case-based discussion on what the clinician needs to know, including a background on AxuminTM, how to interpret an AxuminTM study, and pitfalls to be aware of during interpretation. Goals and Objectives: Understand the indications for the use of F-18 Fluciclovine. Gain a basic understanding on the mechanism of localization of F-18 Fluciclovine. Learn the normal biodistribution and how to interpret an F-18 Fluciclovine study as well as understanding common pitfalls to interpretation. Discussion: This presentation will discuss the indications, mechanism of localization, normal distributions, and a suggested interpretation criteria for F-18 Fluciclovine PET studies. A brief discussion will be made comparing F-18 Fluciclovine with other nuclear medicine agents used in prostate cancer imaging. Cases presented will illustrate cases of metastatic disease in the setting of biochemical recurrence as well as interesting cases of false positive studies. There will also be a discussion on pitfalls to interpretation. Conclusion: F-18 Fluciclovine is a new and effective PET agent that can be used to diagnose local recurrent or distant metastatic disease in patients with a history of prostate cancer. Knowledge of pitfalls as well as potential false positive and false negative uptake patterns is crucial for accurate diagnosis in these patients.https://scholarlycommons.henryford.com/merf2019edu/1003/thumbnail.jp

Laparoscopic Port-Site Metastasis From Prostate Cancer on 18F-Fluciclovine PET/CT

Laparoscopic port-site metastasis from prostate cancer is a rare complication after radical prostatectomy and pelvic lymph node dissection. We report a case of port-site metastasis from prostate cancer identified on F-fluciclovine PET/CT for a patient with evidence of biochemical recurrence. Final pathology after targeted ultrasound and biopsy of the mass in the right abdominal wall revealed prostatic adenocarcinoma

Hardware infection

A 70-year-old man underwent a T9-T10 facetectomy with instrumented back fusion. Postoperatively, he developed a bowel obstruction and was found to have a rectal squamous cell carcinoma. Emergency resection was performed followed by chemoradiation. A follow-up PET/CT was obtained 4 months’ status post-resection, which demonstrated suspicious uptake around the thoracic spine hardware. The ordering physician was notified of a potential hardware infection, but at that time, the patient was asymptomatic and had been recently seen in clinic without any evidence to suggest infection. Within 1 week following the PET/CT, the patient presented with a new abscess and drainage from his incision site. Erythrocyte sedimentation rate and C-reactive protein were both elevated. Cultures from the abscess grew methicillin-resistant Staphylococcus aureus. The patient was taken back to the OR for debridement and hardware removal. He eventually made a full recovery after a prolonged course of antibiotics

Incidental Uptake of 18F-Fluciclovine by Type AB Thymoma

ABSTRACT: Biochemical recurrence of prostate cancer, detected by a rising PSA, may reflect intraprostatic or extraprostatic recurrence. 18F-Fluciclovine (Axumin), a synthetic amino acid substrate in tumor metabolism, has frequently been used for to localize recurrent prostate cancers. We present a 71-year-old man with biochemical recurrence of prostate cancer but no convincing imaging findings on 18F-fluciclovine PET/CT. Of note, however, was an incidental uptake within the anterior mediastinum, which was found on biopsy to be a type AB thymoma. With this, we stress that awareness of false-positive uptake patterns is crucial for accurate diagnosis of recurrent prostate cancer

Extraosseous multiple myeloma

A 52-year-old woman presented with a 1-year complaint of unexplained/undesired weight loss of 13 lbs. Additional symptoms derived on review of systems included chills, night sweats, fatigue, and pain at the base of her tongue. Standard laboratory values demonstrated slight anemia and increase in serum creatinine. Subsequent biopsy of the base of tongue spot demonstrated amyloid deposition. Urine protein electrophoresis demonstrated elevated free lambda light chain, and bone-marrow biopsy demonstrated elevated levels of clonal plasma cells, consistent with diagnosis of multiple myeloma with associated amyloidosis. The patient then underwent high-dose chemotherapy followed by allogenic stem cell transplantation with stabilization of the disease process. On follow-up examinations after initial therapy, the patient complained of new areas of nodularity involving the tongue, eyelids, and lower abdomen. The left lower abdomen was biopsied and pathologic results demonstrated myeloma/plasmacytoma. Additional involvement of the heart and GI tract was noted during the patient’s workup

18 -FDG uptake in pulmonary dirofilariasis

Solitary pulmonary nodules are a common finding on chest radiography and CT. We present the case of an asymptomatic 59-year-old male found to have a 13 mm left upper lobe nodule on CT scan. The patient was asymptomatic and the CT was performed to follow up mediastinal and hilar lymphadenopathy that had been stable on several previous CT scans. He had a history of emphysema and reported a 15 pack-year smoking history. PET-CT was performed which demonstrated mild 18-FDG uptake within the nodule. Given his age and smoking history, malignancy was a consideration and he underwent a wedge resection. Pathological examination revealed a necrobiotic granulomatous nodule with a central thrombosed artery containing a parasitic worm with internal longitudinal ridges and abundant somatic muscle, consistent with pulmonary dirofilariasis. Dirofilaria immitis, commonly known as the canine heartworm, rarely affects humans. On occasion it can be transmitted to a human host by a mosquito bite. There are two major clinical syndromes in humans: pulmonary dirofilariasis and subcutaneous dirofilariasis. In the pulmonary form, the injected larvae die before becoming fully mature and become lodged in the pulmonary arteries