Diagnosis of Primary Scrotal Lymphedema Using 99mTc-Sulfur Colloid Lymphoscintigram: Correlation With MR Lymphangiogram.

ABSTRACT: We report a case of a 19-year-old man who presented with severe scrotal swelling. His medical history was notable for severe global edema at birth. Most areas of swelling had resolved by adolescence with exception of the scrotum and the left lower extremity. 99mTc-filtered sulfur colloid lymphoscintigraphy of the lower extremities demonstrated prominent dermal backflow into the superficial scrotum and thighs, which were confirmed on the SPECT/CT images, and correlated with findings on MR lymphangiogram. Lymphoscintigram and MR lymphangiogram may provide complementary information to aid diagnosis and management of primary scrotal lymphedema.

Identification of Acute Mesenteric Ischemia on 18F-FDG PET/CT.

ABSTRACT: Acute mesenteric ischemia resulting in bowel necrosis is a surgical emergency. First identification of acute mesenteric ischemia with FDG PET/CT is uncommon, because patients with bowel ischemia are usually diagnosed by other imaging methods such as CT. Nevertheless, prompt imager recognition of the PET/CT findings of mesenteric ischemia and necrosis is critical for proper triage of the patient to potentially lifesaving interventions. We present a 39-year-old woman with portal vein thrombosis who was sent for 18F-FDG PET/CT evaluation of a suspected pancreatic head neoplasm but was unexpectedly found to have ischemic and necrotic small bowel secondary to mesenteric venous infarction.

Thumb Metacarpal-Trapezoid Impingement as an Etiology of Pain After Trapeziectomy and Basal Joint Soft Tissue Arthroplasty: A Case Series.

PURPOSE: To report a poorly described etiology for pain after trapeziectomy and soft tissue basal joint arthroplasty, diagnosed with the aid of nuclear imaging. METHODS: Five patients (4 women and 1 man), average age 62 years (range, 59-65 years) presented with pain an average of 7 months (range, 2-11 months) after basal joint arthroplasty. The dominant hand was involved in all cases. Advanced imaging including 25 mCi 99mTc methylene diphosphonate bone scintigraphy and single-photon emission computed tomography (CT) showed intense tracer uptake between the base of the thumb metacarpal and residual trapezoid. Computed tomography scans confirmed abutment between these bones. The symptoms were attributed to this finding, and revision surgery consisting of excision of the trapezoid and arthrodesis of the index and middle finger carpometacarpal joints was performed. RESULTS: Mean follow-up was 40 months (range, 12-60 months). Grip strength improved from a mean of 10.5 to 23 kg, and lateral pinch strength improved from a mean of 3 to 6.75 kg. Radiographic fusion of the index finger metacarpal to capitate was confirmed in 4 of 5 patients; it was indeterminate in one patient who was completely pain-free. Radiographic fusion of long finger carpometacarpal joints was indeterminate in 3 patients. Patient-Rated Wrist Evaluation pain scores improved from 35 to 6, Patient-Rated Wrist Evaluation function scores from 78 to 14, and Quick-Disabilities of the Arm, Shoulder, and Hand scores from 37 to 18. CONCLUSIONS: Impingement between the base of the thumb metacarpal and remaining trapezoid should be considered a potential source of pain after trapeziectomy and soft tissue arthroplasty. Advanced imaging (bone scintigraphy and single-photon emission CT and standard CT) are helpful to confirm the diagnosis. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Nuclear Medicine and Molecular Imaging in Nodal Staging and Surveillance of Ocular Melanoma: Case Reports and Review of the Literature.

Ocular melanoma (OM) is a rare noncutaneous malignancy and consists of 2 different subtypes based on the anatomic location in the eye: uveal melanoma and conjunctival melanoma. Like cutaneous melanoma, OM benefits from nuclear medicine and molecular imaging in nodal staging and clinical management. Through the illustration of 2 distinctive cases, we aim to demonstrate the complementary roles of standard lymphoscintigraphy, advanced SPECT/CT, 18F-FDG PET/CT, and 18F-FDG PET/MRI in accurate nodal staging and surveillance of OM. We also review the epidemiology, existing staging guidelines, and management of uveal melanoma and conjunctival melanoma.

Advanced Nuclear Medicine and Molecular Imaging in the Diagnosis of Cardiomyopathy.

OBJECTIVE. The purpose of this article is to summarize the protocol, interpretation, and diagnostic performance of nuclear medicine and molecular imaging in imaging two distinctive, underdiagnosed cardiomyopathies: cardiac amyloidosis and cardiac sarcoidosis. CONCLUSION. Emerging new radiotracers and advanced molecular imaging modalities enable us to noninvasively characterize certain types of cardiomyopathies, including cardiac amyloidosis and cardiac sarcoidosis, with great confidence. We expect to improve recognition and promote the application of such advanced techniques in the imaging and management of these potentially lethal cardiomyopathies.

Nodular Fat-Sparing Hepatic Parenchyma as 11C-Choline-Avid Finding on PET/CT.

Focal nodular fat sparing of the liver may show, on PET/CT imaging, prominent tracer uptake over a background of less metabolic features of steatosis. This finding, already reported with F-FDG, may mimic primary or secondary neoplasms of the liver. The authors present an additional case of nodular fat-sparing hepatic parenchyma exhibiting C-choline avidity during PET/CT assessment for biochemical recurrence of prostate cancer.

Molecular Imaging in Diagnosis of Tumor-induced Osteomalacia.

Tumor induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by overproduction of fibroblast growth factor 23 (FGF23) secreted by benign mesenchymal neoplasm. Due to its nonspecific clinical presentation or lack of awareness, the diagnosis of TIO is often significantly delayed resulting in patients' prolonged physical suffering or psychological distress. Successful detection or complete surgical resection of the causative tumor typically leads to rapid resolution of symptoms or reversal of biochemical imbalance. Nuclear medicine and molecular imaging have been playing a promising role as the first-line imaging modalities in the diagnosis and localization of occult FGF23 secreting mesenchymal tumor, especially with the emerging whole-body, head-to-toe Ga68-DOTATATE PET/CT technique. Combined focused diagnostic CT and/or MRI are imperative for accurate delineation of tumor and surgical guidance.

"Migratory" Pattern of Corticosteroid-Related Multifocal Bone Infarction on Bone Scintigraphy.

We present serial bone scintigraphy examinations in a 38-year-old woman who presented with posterior left rib pain in the setting of adrenal insufficiency secondary to pituitary damage as a result of radiation treatment for orbital sarcoma.

99mTc-Sulfur Colloid Bone Marrow Scintigraphy in Diagnosis of Diffuse Pulmonary Extramedullary Hematopoiesis Secondary to Myelofibrosis.

Our objective was to define the role of combined 99mTc-sulfur colloid bone marrow (SC BM) scintigraphy, SPECT or SPECT/CT, and chest CT in diagnosing diffuse pulmonary extramedullary hematopoiesis (PEMH) in patients with myelofibrosis. Methods: We retrospectively reviewed 99mTc-SC BM scintigraphy scans performed at our institution for the diagnosis of diffuse PEMH, as well as accompanying chest CT and SPECT/CT imaging findings. Relevant clinical information, including respiratory manifestations, pulmonary hypertension, and subjective response to whole-lung radiation therapy, was also summarized. Results: Twenty-two myelofibrosis patients with 27 99mTc-SC BM scintigraphy scans were diagnosed with diffuse PEMH. In 21 patients (95%) with accompanying chest CT and SPECT/CT scans, the most common CT findings were ground-glass opacity, interstitial infiltration, and pleural effusion. Of 20 patients (91%) who underwent 2-dimensional echocardiography studies, 12 (55%) were diagnosed with pulmonary hypertension. All 12 patients exhibited the aforementioned nonspecific CT imaging findings, with 8 (66%) of them presenting with respiratory symptoms, including dyspnea, shortness of breath, and cough. In the remaining 8 patients, without pulmonary hypertension, half had similar respiratory symptoms. Fourteen patients (64%) of this cohort received whole-lung radiation therapy, of whom 7 (50%) experienced symptom relief after therapy. Conclusion: Nonspecific respiratory symptoms should raise concern about pulmonary hypertension and diffuse PEMH in patients with advanced-stage myelofibrosis. Combined 99mTc-SC BM scintigraphy and SPECT/CT is a promising noninvasive imaging tool to diagnose this rare clinical entity.Key Words: hematology; respiratory; SPECT/CT; pulmonary hematopoiesis; Tc-99m sulfur colloid scintigraphy; myelofibrosis.

A Prospective Trial of Intensity Modulated Radiation Therapy (IMRT) Incorporating a Simultaneous Integrated Boost for Prostate Cancer: Long-term Outcomes Compared With Standard Image Guided IMRT.

PURPOSE: This report describes the long-term outcomes of a prospective trial of intensity modulated radiation therapy (IMRT), integrating a 111In capromab pendetide (ProstaScint) scan-directed simultaneous integrated boost (SIB) for localized prostate cancer. METHODS AND MATERIALS: Seventy-one patients with T1N0M0 to T4N0M0 prostate cancer were enrolled, and their ProstaScint and pelvic computed tomography scans were coregistered for treatment planning. The entire prostate received 75.6 Gy in 42 fractions with IMRT, whereas regions of increased uptake on ProstaScint scans received 82 Gy as an SIB. Patients with intermediate- and high-risk disease also received 6 months and 12 months of adjuvant hormonal therapy, respectively. RESULTS: The study enrolled 31 low-, 30 intermediate-, and 10 high-risk patients. The median follow-up was 120 months (range, 24-150 months). The 10-year biochemical control rates were 85% for the entire cohort and 84%, 84%, and 90% for patients with low-, intermediate-, and high-risk disease, respectively. The 10-year survival rate of the entire cohort was 69%. Pretreatment prostate-specific antigen level >10 ng/mL and boost volume of >10% of the prostate volume were significantly associated with poorer biochemical control and survival. The outcomes were compared with those of a cohort of 302 patients treated similarly but without the SIB and followed up for a median of 91 months (range, 6-138 months). The 5- and 10-year biochemical control rates were 86% and 61%, respectively, in patients without the SIB compared with 94% and 85%, respectively, in patients in this trial who received the SIB (P=.02). The cohort that received an SIB did not have increased toxicity. CONCLUSIONS: The described IMRT strategy, integrating multiple imaging modalities to administer 75.6 Gy to the entire prostate with a boost dose of 82 Gy, was feasible. The addition of the SIB was associated with greater biochemical control but not toxicity. Modern imaging technology can be used to locally intensify the dose to tumors and spare normal tissues, producing very favorable long-term biochemical disease control.

Pilot study: Evaluation of dual-energy computed tomography measurement strategies for positron emission tomography correlation in pancreatic adenocarcinoma.

We sought to determine whether dual-energy computed tomography (DECT) measurements correlate with positron emission tomography (PET) standardized uptake values (SUVs) in pancreatic adenocarcinoma, and to determine the optimal DECT imaging variables and modeling strategy to produce the highest correlation with maximum SUV (SUVmax). We reviewed 25 patients with unresectable pancreatic adenocarcinoma seen at Mayo Clinic, Scottsdale, Arizona, who had PET-computed tomography (PET/CT) and enhanced DECT performed the same week between March 25, 2010 and December 9, 2011. For each examination, DECT measurements were taken using one of three methods: (1) average values of three tumor regions of interest (ROIs) (method 1); (2) one ROI in the area of highest subjective DECT enhancement (method 2); and (3) one ROI in the area corresponding to PET SUVmax (method 3). There were 133 DECT variables using method 1, and 89 using the other methods. Univariate and multivariate analysis regression models were used to identify important correlations between DECT variables and PET SUVmax. Both R2 and adjusted R2 were calculated for the multivariate model to compensate for the increased number of predictors. The average SUVmax was 5 (range, 1.8-12.0). Multivariate analysis of DECT imaging variables outperformed univariate analysis (r = 0.91; R2 = 0.82; adjusted R2 = 0.75 vs. r < 0.58; adjusted R2 < 0.34). Method 3 had the highest correlation with PET SUVmax (R2 = 0.82), followed by method 1 (R2 = 0.79) and method 2 R2 = 0.57). DECT thus has clinical potential as a surrogate for, or as a complement to, PET in patients with pancreatic adenocarcinoma.

Incarcerated inguinal hernia from metastatic pleural mesothelioma: PET/CT imaging.

PET/CT provides a comprehensive staging, post-therapeutic surveillance, and outcome prognosis of malignant pleural mesothelioma based on its hypermetabolic behavior. This ability of PET may allow the monitoring, prediction, and detection of uncommon distant gastrointestinal clinical manifestations of this disease. The authors present a case of PET/CT imaging of pleural mesothelioma disseminating to the abdomen and pelvis, inducing an incarcerated inguinal hernia.

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.

Can lymphatic drainage of head and neck melanoma be predicted?

BACKGROUND: The lymphatic drainage patterns of the head and neck (H&N) is complex. Therefore, identification of the sentinel lymph node (SLN) for H&N melanoma can be challenging. METHODS: Retrospective review of a prospectively collected melanoma database, from February 1997 through October 2008, identified 137 patients with H&N melanoma. All underwent pre-operative lymphoscintigraphy, and after 2007, patients underwent single photon emission computed tomography combined with computed tomography (SPECT/CT). RESULTS: The mean number of SLNs per patient was 2.6. An SLN was successfully identified in 97% of patients, and in 9%, the SLN was positive for metastatic disease. The majority of patients (88%) drained to a unilateral level. Bilateral drainage occurred in 10%, with only two patients draining outside of the neck. The majority of patients (58%) had an SLN in level IIa (jugulodigastric lymph nodes). The regional recurrence rate was 4%, which all occurred prior to the use of SPECT/CT. DISCUSSION: Utilization of SPECT/CT and knowledge of common lymphatic drainage patterns in neck lymph node levels can assist the surgeon in properly locating and excising the SLN with minimal morbidity, limiting unnecessary dissections, as well as reducing false negative results.

Multifocal Langerhans cell histiocytosis with infiltrative pelvic lesions: PET/CT imaging.

Langerhans cell histiocytosis is essentially a pediatric disorder with a large spectrum encompassing focal lytic osseous eosinophilic granuloma, chronic multifocal Hand-Schuller-Christian lesions, and fulminant disseminated Letterer-Siwe syndrome. However, adult involvement is not uncommon. The authors present a case of multifocal Langerhans cell histiocytosis in a 47-year-old woman. The PET/CT-depicted infiltrative features of soft tissue and osseous pelvic lesions with obstructive uropathy are unusual for this disease.