Ba D. Nguyen

Usefulness of PET/CT Imaging in Systemic IgG4-related Sclerosing Disease. A Report of Three Cases

Autoimmune pancreatitis is the pancreatic manifestation of a novel clinicopathological disorder called systemic IgG4-related sclerosing disease. Beside the pancreas, this entity affects other sites (salivary glands, orbit, lung, thyroid, gallbladder, biliary tree system, kidney, abdominal aorta, retroperitoneum, prostate, and lymph node) by infiltration with IgG4-positive plasma cells. Several case reports and small case series have demonstrated the utility of integrated positron emission tomography/computed tomography (PET/CT) in monitoring therapy and documenting relapse and flare-up of autoimmune pancreatitis. However, there are no reports on the usefulness of PET/CT in selecting extrapancreatic sites for tissue sampling. We herein demonstrate the clinical utility of integrated PET/CT in 3 cases of systemic IgG4-related sclerosing disease for targeting extrapancreatic biopsy sites.

Image-Guided Radiotherapy for Prostate Cancer: A Prospective Trial of Concomitant Boost Using Indium-111–Capromab Pendetide (ProstaScint) Imaging

PURPOSE To evaluate, in a prospective study, the use of (111)In-capromab pendetide (ProstaScint) scan to guide the delivery of a concomitant boost to intraprostatic region showing increased uptake while treating the entire gland with intensity-modulated radiotherapy for localized prostate cancer. METHODS AND MATERIALS From September 2002 to November 2005, 71 patients were enrolled. Planning pelvic CT and (111)In-capromab pendetide scan images were coregistered. The entire prostate gland received 75.6 Gy/42 fractions, whereas areas of increased uptake in (111)In-capromab pendetide scan received 82 Gy. For patients with T3/T4 disease, or Gleason score ≥8, or prostate-specific antigen level >20 ng/mL, 12 months of adjuvant androgen deprivation therapy was given. In January 2005 the protocol was modified to give 6 months of androgen deprivation therapy to patients with a prostate-specific antigen level of 10-20 ng/mL or Gleason 7 disease. RESULTS Thirty-one patients had low-risk, 30 had intermediate-risk, and 10 had high-risk disease. With a median follow-up of 66 months, the 5-year biochemical control rates were 94% for the entire cohort and 97%, 93%, and 90% for low-, intermediate-, and high-risk groups, respectively. Maximum acute and late urinary toxicities were Grade 2 for 38 patients (54%) and 28 patients (39%) and Grade 3 for 1 and 3 patients (4%), respectively. One patient had Grade 4 hematuria. Maximum acute and late gastrointestinal toxicities were Grade 2 for 32 patients (45%) and 15 patients (21%), respectively. Most of the side effects improved with longer follow-up. CONCLUSION Concomitant boost to areas showing increased uptake in (111)In-capromab pendetide scan to 82 Gy using intensity-modulated radiotherapy while the entire prostate received 75.6 Gy was feasible and tolerable, with 94% biochemical control rate at 5 years.

Salivary duct carcinoma with perineural spread to facial canal: F-18 FDG PET/CT detection.

Salivary duct carcinoma is a highly aggressive malignancy targeting predominantly the parotid gland. It frequently involves the extracranial portion of the facial nerve and has a propensity to metastasize through the temporal bone via perineural spread. The authors present a case of treated parotid malignancy with F-18 FDG PET/CT detecting abnormal radiotracer uptake within the facial canal from perineural tumor recurrence. The positive PET/CT finding was confirmed by subsequent MR examination. Postradiation PET/CT surveillance showed resolution of the perineural metastasis with unfortunate distant ischial bone dissemination.

Choroidal and extraocular muscle metastases from non-small-cell lung carcinoma: F-18 FDG PET/CT imaging.

Lung carcinoma may metastasize to the orbit involving predominantly the choroidal layers. Secondary malignancy targeting extraocular muscles is uncommon. The authors present a case of recurrent non–small-cell lung cancer with serial F-18 FDG PET/CT examinations showing successive right choroidal and medial rectus muscle tumor dissemination.

18F-FDG PET/CT Imaging of the Pancreas: Spectrum of Diseases

Since the introduction of integrated positron emission tomography-computed tomography (PET/CT), it has a great impact on the field of oncology. Comparing to other conventional scanners, only PET/CT is capable of providing important information on accurate detecting, staging/restaging, and post-therapeutic monitoring of many cancers. Many studies have demonstrated that PET/CT changes the management in approximately 30% of all cancer patients. Because 2-((18)F)-fluoro-2-deoxy-D-glucose (FDG) is a nonspecific tracer, understanding the PET/CT limitations and pitfalls for various pancreatic conditions can lead to more accurate interpretation of PET/CT images, which ultimately would impact patient care. As a result, it is important for radiologists and other clinicians to familiarize themselves with a wide spectrum of pancreatic PET/CT findings simulating cancer from benign entities.

Endotracheal metastasis from squamous cell cancer of the head and neck: PET/CT imaging.

Lung cancer is the main malignancy with frequent endotracheal and endobronchial dissemination. Extrapulmonary sources of airway metastasis are less common, predominantly seen with breast, colorectal, and renal neoplasms. Head and neck cancer represents only a small fraction of tumors with tracheal luminal metastasis. We present 2 such rare cases with F-18 FDG PET/CT imaging. These 2 companion cases show in one instance an obvious hypermetabolic endotracheal lesion and in the other one a discrete airway metastasis overlooked by chest CT and diagnosed by PET with coregistered CT.

Methotrexate-induced and Epstein-Barr virus-associated B-cell lymphoma of the spine: MR and PET/CT imaging.

Methotrexate, used as a disease-modifying agent in the treatment of rheumatoid arthritis and other connective tissue diseases, may depress the immune system and increase the already high risk of Epstein–Barr virus infection in this immune-challenged patient population. The combined impact of methotrexate and Epstein– Barr virus may induce lymphoproliferative disorders involving skin, lung, nodes and central nervous system. The authors present a case of dermatomyositis with methotrexate-related and Epstein–Barr-associated thoracic spinal and paraspinal diffuse large B-cell lymphoma.

Practical applications of nuclear medicine in imaging breast cancer.

The rise in incidence, morbidity, and mortality of breast cancer has triggered multiple imaging efforts to detect this malignancy early, stage it accurately, and monitor it with precision in the posttherapeutic course. Among different imaging modalities, nuclear medicine provides an important contribution to the clinical management of breast cancer. This article discusses four practical applications based on the use of radionuclides in the evaluation of breast malignancy, focusing on scintimammography, preoperative tumor localization procedure using radioactive seeds, sentinel nodal scintigraphy, and F-18 fluorodeoxyglucose positron emission tomography/computed tomography.

Bilateral and multifocal Warthin's tumors of parotid glands: PET/CT imaging.

Unilateral hypermetabolic lesion of parotid gland demonstrated on PET/CT imaging may originate from a large spectrum of benign or malignant processes, such as adenoma, Warthins tumor, oncocytic neoplasm, lymphoma, and primary or secondary malignancy of the gland. Bilateral and multifocal parotid gland disease is less common but possible because of the known characteristics of Warthins tumors. The authors present such a case that was incidentally documented during PET/CT evaluation of solitary pulmonary nodule.

Occult colon cancer with initial cutaneous metastatic manifestation: PET/CT detection.

Skin metastasis as initial clinical presentation of occult internal organ malignancy is of rare occurrence, predominantly encountered in breast and lung cancer. The search for the occult causative primary malignancy is usually difficult with conventional anatomy-based cross-sectional imaging. The authors present a case of cecal cancer with thoracic and abdominal cutaneous metastasis demonstrated by PET/CT.