Role of 18 F-FDG-PET/CT in an AML-M5a Subtype Patient with Rare Constellation of Hemophagocytic Lymphohistiocytosis & Bilateral Multiple Breast Chloromas.

We report a treated case of acute myeloid leukemia (AML-M5a subtype) with monocytic differentiation (AMoL) presenting with fever and body pains. Initial 18 F-FDG-PET/CT ( 18 F-flurodeoxyglucose positron emission tomography/computed tomography) identified multiple lymph nodal, and marrow lesions. Biopsy confirmed hemophagocytic lymphohistiocytosis (HLH). Post HLH treatment, follow-up PET/CT demonstrated unsuspected FDG avid bilateral breast lesions ( n = 5), which proved to be chloromas, that is, extranodal manifestation of AML. 18 F-FDG-PET/CT has helped not only in identifying the various sites of disease involvement but also in guiding the sites for biopsy. Finally, 18 F-FDG-PET/CT was useful in monitoring therapy response for both these coexisting pathologies, which are said to be resistant to treatment based on FLT3-ITD tyrosine kinase-3 internal tandem duplication mutation positivity and high-grade AML status. This case represents a rare constellation of different etiologies that needed to be differentiated. It also emphasizes the challenges in interpreting PET/CT findings, especially in difficult clinical scenarios. Disease distribution in HLH/presence of chloromas, etc., can mimic stage IV lymphoma in a known case of AML. So the nuclear medicine physician should be aware of the different complications in the background of AML, especially in patients with poor prognostic factors.

18F-FDG PET imaging for treatment response assessment and management guidance in patients with skull base osteomyelitis.

OBJECTIVE: The objective of this study is to evaluate the role of hybrid 18F-FDG PET for treatment response assessment and management guidance in patients with skull base osteomyelitis. MATERIALS AND METHODS: Retrospectively, 33 patients, with at least a baseline and follow-up PET (computed tomography/MRI) scan, were included. Parameters like standardized uptake value (SUV) max, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) (initial, follow-up, percentage change) were analysed and outcomes based on 18F-FDG PET reports were classified into resolution (a), partial response (b), progression (c) and stable disease (d). The clinical course and response on anatomical imaging were also compared with 18F-FDG PET. RESULTS: There was mild correlation between initial SUV with ESR (0.338) and CRP (0.384). Moderate correlation was seen between follow-up SUV and CRP (0.619), percentage change in SUV max (PC SUV) with percentage change in ESR (0.456) and CRP (0.668). Mean PC SUV was 70% (a), 35% (b), -40% (c) and -18% (d), respectively. 48% (16/33) (resolution, progression, stable disease) patients had clear management change with 18F-FDG PET with either escalation or stopping of antibiotics/antifungals. Management decision in partial response group (52%, 17/33) was taken clinically. On retrospective PC SUV analysis, treatment continuation group (8 patients) showed 20% decrease, whereas the group that was only monitored further (9 patients) had 48% reduction in SUV. CONCLUSION: 18F-FDG PET showed a moderate association with clinical markers used in follow-up of patients with skull base osteomyelitis and is a reliable investigation for assessment of disease status. This can be used as a guide along with clinical evaluation for de-escalation of treatment.

18 F-FDG Whole-Body PET-MR in Primary Hepatic Lymphoma Mimicking Focal Nodular Hyperplasia.

Primary hepatic lymphomas are rare hepatic malignancies which are often misdiagnosed preoperatively. Early accurate diagnosis is essential as the patients can be treated successfully with chemotherapy, eluding the need for surgery. We present a case of primary hepatic lymphoma which mimicked as focal nodular hyperplasia with normal biochemical tumor markers, and 18 F-fluorodeoxyglucose ( 18 F-FDG) whole-body positron emission magnetic resonance showed intense FDG uptake in the large hepatic lesion. The patient subsequently underwent right hepatectomy, and histopathology revealed diffuse large B cell lymphoma.

Atypical Presentation of Marginal Zone Lymphoma as Isolated Diffuse Bone Marrow Involvement: Utility of F-18 FDG PET/CT in Diagnosis and Response Assessment.

Non-Hodgkin's lymphoma (NHL) with secondary bone marrow involvement is relatively common. However, isolated involvement of bone marrow in marginal zone type of NHL is atypical and rare. Here, we describe a patient of atypical marginal zone lymphoma with isolated bone marrow involvement who presented with weight loss and bicytopenia, where F-18 FDG PET/CT (fluorine-18-labeled fluorodeoxyglucose positron emission tomography with computed tomography) imaging played a pivotal role in establishing the diagnosis when conventional imaging modalities were unremarkable. The patient was successfully treated with systemic chemotherapy (rituximab, cyclophosphamide, prednisolone) and achieved complete remission, as demonstrated by a follow-up F-18 FDG PET/CT scan.

Recurrent Intra Articular Osteochondroma of Left 4th Finger.

Osteochondromas are common benign bone tumors arising from metaphyseal region of long bones. They are notorious for undergoing malignant transformation. We present a case of a middle aged woman with recurrent episodes of swelling in the middle of left 4th finger post excision. Bone scan was performed to look for any malignant transformation of finger lesion and also to rule out skeletal metastases due to recent onset bone pains. 99m Tc MDP (Technetium methylene diphosphonate) bone scan demonstrated a focal hot spot in middle of left 4th finger along the radial side. There was no evidence of skeletal metastases. Surgery is usually curative (70-90%). Limb sparing wide local excision is treatment of choice.

Early Demonstration of Spontaneous Perinodal Lymphangiogenesis by Lymphoscintigraphy after Vascularized Lymph Node Transplantation - A Pilot Study.

Background: Despite the lymphatic system being so important and extensive, the field of lymphatic diseases, research is still very young. Lymphedema is a progressively debilitating condition with no known "cure." Specific pathologies that could benefit from improved lymphatic drainage by advanced super surgical techniques or engineered tissue transfer are being sought. Microsurgical techniques like lymphovenous bypass and anastomosis have spurred interest as they tend to physiologically restore the damaged lymphatic channels and may be a key to permanent cure. The latest in the field is vascularized lymph node transfer (VLNT), indicated in post mastectomy or other post operative settings producing disruption of regional lymphatic channels and draining lymph nodes. Autologous healthy lymph nodes are transferred along with surrounding fat and vascular pedicle to the affected limb in a bid to promote lymphangiogenesis. Lymphoscintigraphy (LS) is a simple, noninvasive nuclear technique used in identifying upper or lower limb lymphatic dysfunction and obstruction with a high degree of sensitivity. Quantitative LS is extremely useful in follow-up assessment of lymphedema postmanual lymphatic drainage (MLD) or other forms of medical management. Aim: We hypothesize that LS can document perinodal lymphangiogenesis post VLNT. Material and Methods: Three cases of acquired lymphedema (suspected filariasis and postmastectomy conditions) who underwent VLNT in our institute were prospectively studied with LS. The imaging findings highlight the subtle lymphatic regeneration along with the vascularized graft in all three patients during the early postoperative period. Conclusion: This is the first (pilot) study documenting early spontaneous perinodal lymphangiogenesis after VLNT in human subjects.99mTc Nanocolloid LS has been found to be incremental in demonstrating early lymphangiogenesis.

68Ga-DOTANOC PET/CT in Multiple Endocrine Neoplasia 1 With Associated Adrenocortical Carcinoma.

ABSTRACT: Multiple endocrine neoplasia 1 (MEN1) syndrome is an autosomal dominant syndrome comprising a triad of pancreatic, pituitary, and parathyroid tumors. Adrenal cortical carcinoma occurs rarely in MEN1 syndrome. Here, we have presented a case of a 62-year-old woman with adrenal mass and elevated serum parathormone levels, who underwent 68Ga-DOTANOC PET/CT. 68Ga-DOTANOC PET/CT showed intense tracer concentration in the left adrenal mass and lesions in the liver, pancreas, and peritoneum. Biopsy of the peritoneal deposit revealed metastatic adrenocortical carcinoma, and further genetic testing showed MEN1 mutation.

Utility of Fluorine-18-Labeled Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Diagnosis of Erdheim-Chester Disease with Multisystemic Involvement.

Erdheim‒Chester disease (ECD) is a rare non-Langerhans' cell histiocytic proliferative disorder of unknown origin with multisystemic predilection. It commonly affects adults in the fifth-seventh decades of life, with male preponderance, and has nonspecific clinical manifestations. Presence of characteristic radiological findings and demonstration of CD68 positive xanthogranulomatous infiltrates in histology clinches the diagnosis. Nevertheless, being a nonmalignant condition, it might be fatal due to multiorgan dysfunction. Hence, timely diagnosis and initiation of treatment with corticosteroids, immunosuppressants, or tyrosine kinase inhibitors are of paramount importance. We present a case of ECD with multisystemic involvement, who was initially evaluated for the left lung mass and treated as tuberculosis, where fluorine-18-labeled fluorodeoxyglucose positron emission tomography/computed tomography aided in targeting the metabolically active site for biopsy as well as assessing the multisystemic involvement.

Clinicopathological features and outcome of thyroglobulin elevation and negative iodine scintigraphy (TENIS) patients with negative neck ultrasound: Experience from a thyroid carcinoma clinic in India.

Management of differentiated thyroid carcinoma (DTC) patients with thyroglobulin (Tg) elevation and negative iodine scintigraphy (TENIS) and negative neck ultrasound scan causes considerable diagnostic and therapeutic dilemma, especially in resource-poor settings. The aim of this study was to evaluate clinicopathological features and outcome of TENIS patients with negative neck US attending a thyroid cancer clinic in India. From a DTC database of 722 containing 193 TENIS patients, subjects with negative neck US and negative Tg antibody (TgAb) were selected retrospectively and analyzed using appropriate statistical methods. The study group included 64 patients (male - 17, female - 47, mean age - 44.7 ± 12.8 years) with 54 papillary and 10 follicular thyroid carcinomas, American Thyroid Association (ATA) recurrence risk categorization (2009) - low - 16, intermediate - 28, and high - 2 0. Most of the patients became TENIS within 1 year of diagnosis with median Tg level of 6.5 ng/mL (1.2-996 ng/mL) and mean follow-up of 7.8 years. On follow-up, Tg dropped spontaneously in 27 patients, more among the low and intermediate-risk categories. For those with high or increasing Tg level, further imaging (fluorodeoxyglucose positron emission tomography/computed tomography) was done and 14 out of 18 were positive. Treatment included empiric radioactive iodine therapy-16, external beam radiation therapy (EBRT)-7, and lymph node dissection (LND)-10. A favorable outcome was seen in 36 patients and unfavorable in 28. Distant metastases were associated with unfavorable outcome and poor survival. Progression-free survival was significantly better in the Tg group of <10 at the time of TENIS (111 months) compared to the Tg group >10 (72 months). Tg level dropped spontaneously in nearly half the patients, especially if levels were <10 and more so among the low-risk category. Distant metastasis was predictive of unfavorable outcomes. Along with Tg level, the ATA risk category might help to predict clinical course and reduce unnecessary expensive imaging in resource-poor settings.

Precision Radiotherapy: 18F-FDG PET-based radiotherapy planning in Head and Neck cancers.

Precision medicine is gaining importance in this era of molecular imaging where the molecular features of a disease can be noninvasively assessed and treated with personalized medicine. This is especially suited for head and neck cancers (HNCa). Early stage HNCa are ideally managed with radiotherapy (RT) or surgery. Head and neck (HN) is a complex region and its tumors respond to RT differently due to dissimilar structures and moving organs such as tongue. Radiation oncologists are always in the process of trying and investigating newer RT techniques in order to achieve precise and targetted therapy to tumour/s. One such innovation is Intensity modulated RT (IMRT) using 3 Dimensional conformal RT (3DCRT). This 3DCRT resizes the radiation beams to match the shape of the tumor. Such focused dose escalation may improve local control in HNCa. Image guided RT in conjunction with IMRT is the most advanced form of RT planning being used these days. Simulation computerized tomography (CT) images are usually incorporated into RT planning module. But limitations of CT such as poor soft tissue contrast than magnetic resonance imaging and inability to clearly define solid / cystic / necrotic areas and viable tumour exist. Functional imaging such as Positron Emission Tomography (PET) has established its superiority over CT in delineating the actual site and extent of HN tumors. A combination of IMRT with BTV (Biological Tumour Volume) may be the most ideal technique to deliver a homogeneous radiation boost to tumour. This review shall discuss PET based RT planning, challenges, practical tips, and how to optimize therapy with the least side effects to the normal surrounding tissues.

Predictive value of sentinel lymph node imaging and biopsy in early cervical cancers: correlation with scintigraphic uptake patterns and histology.

AIM: This study was designed to 1) assess the feasibility, standardization of sentinel lymph node imaging (SLNI) and biopsy in early cervical cancers and also to determine the detection rates. 2) To analyze the SLN uptake pattern and correlate the findings with the histological grades of tumor. MATERIALS AND METHODS: 52 early cervical cancer patients underwent same-day Tc sulfur colloid (filtered) SLNI and biopsy with gamma probing. Patients underwent radical hysterectomy, para-aortic and pelvic lymphadenectomy irrespective of sentinel lymph node biopsy (SLNB) findings. We analyzed the colloid transit times, uptake pattern, lymphatic groups involved and histology. RESULTS: A total of 203 hot nodes (100% detection rate) were detected and harvested. Study showed 100% sensitivity, specificity, and negative predictive value. Internal iliac nodes were predominantly involved. Lymphatic uptake patterns were graded and correlated with tumor histology (Ki index). Transit time was relatively prolonged in patients with aggressive tumors. CONCLUSION: SLNI and biopsy in early cervical malignancies are feasible with high detection rate. Scintigraphic patterns of nodal uptake were relevant and found to correlate with the tumor histological grades. We found that nonfocal nodal uptake patterns were mainly encountered in patients with tumors having higher Ki index. Immunohistochemistry further facilitated identification of lymph nodal metastases. The visual grading system, implemented in this study provides a good indication of the degree of impairment of lymphatic drainage. Higher visual scintigraphic grade denotes greater lymphatic tumor burden.

Gamma Probe-Guided Surgery in Postoperative Recurrent Osteoid Osteoma of Left Index Finger.

Osteoid osteomas are painful benign osteoblastic tumors that usually affect the metaphysis or diaphysis of long bones. Hands are rarely involved. Identification of recurrent lesion by anatomical imaging modalities is a challenge especially in postoperative setting. Diagnosis of osteoid osteoma is based on typical clinical signs, radiographs, bone scintigraphy, thin-slice computed tomography, or magnetic resonance imaging. Atypical locations, multicentricity of nidus, or incomplete excision of the nidus result in a high rate of recurrence. Here we present a case of recurrent osteoid osteoma at an unusual site in left index finger and was operated under gamma probe guidance.

Does myocardial viability detection improve using a novel combined 99mTc sestamibi infusion and low dose dobutamine infusion in high risk ischemic cardiomyopathy patients?

OBJECTIVE: Early identification of viable myocardium in ischemic cardiomyopathy (ICM) patients is essential for early intervention and better clinical outcome. 99mTechnetium (99mTc) sestamibi gated myocardial perfusion imaging (gMPI) is a well-established technique for myocardial viability evaluation. Detection of potentially viable segments is a predictor of hibernating myocardium. ICM patients with hibernation have a better prognosis after revascularization. We used a novel infusion technique to determine better viability detection preoperatively in challenging situations. Like thallium, does prolonged availability of sestamibi in circulation with additional low dose dobutamine steady infusion (DS Inf) facilitate improved myocardial viability? METHODS: A total of 58 ICM patients with infarct and left ventricular ejection fraction (LVEF) <45% underwent 99mTc sestamibi bolus injection followed by slow intravenous infusion single-photon emission computed tomography (SPECT) using a 2 day protocol. After acquiring the second set of 99mTc sestamibi infusion images, a third SPECT gMPI was performed during DS Inf. RESULTS: A 17-segment myocardial model was used; 52 of 58 patients (548/986 segments) demonstrated perfusion defects (nonviable myocardium) on bolus study. Only 24 patients demonstrated viable segments by standard bolus imaging protocol. The slow MIBI infusion study demonstrated 158 viable segments (12 ICM patients), while combined infusion (99mTc sestamibi+DS Inf) exhibited an additional 6 patients with improved myocardial viability. Thus, 18 high risk patients benefited by this novel infusion technique to demonstrate viable myocardium on SPECT. There was a significantly higher sensitivity (p=0.05) and positive predictive value (p=0.01) in viability identification with the combined DS Inf technique. In dysfunctional segments, the rate of concordance for detecting viability between infusion and bolus techniques was 65%. Paired t test showed statistically significant improvement in viability detection with combined infusion compared to the bolus study (p=0.001). CONCLUSION: This novel infusion technique was shown to be feasible and incremental in viability detection in ICM patients with severe left ventricular dysfunction. It is a robust tool to guide revascularization, in high risk ICM patients. This study also showed that patients with large transmural MI demonstrated no significant improvement in myocardial perfusion status using either protocol.

Dual Thyroid Ectopia and Heterotopic Thyroid Autotransplantation.

Ectopic thyroid gland can be detected at any age. It is a developmental defect that results from abnormal migration of the primitive thyroid bud. Dual ectopia is very rare, and only a few cases have been reported in literature. Patients with thyroid ectopia may be either euthyroid or hypothyroid. Concept of thyroid autotransplantation is based on restoring euthyroidism and is an attempt to preserve the autoregulatory mechanism of hormone production. This is a case of dual ectopia who underwent heterotopic thyroid autotranplantation. Images demonstrate hypertrophy of the transplanted thyroid tissue with gradual restoration of thyroid trapping function.

Asymptomatic Large Pulmonary Arteriovenous Malformation Masquerading as a Metastatic Deposit in a Patient with Papillary Thyroid Carcinoma.

Adult cases of congenital arteriovenous malformation (AVM) of the mediastinum are extremely rare, and because of their varied clinical presentations, they pose a diagnostic challenge. There is no reported association of pulmonary AVM and papillary thyroid carcinoma. We describe a 38-year-old female with a large right lung AVM, multinodular goiter, and high serum thyroglobulin (Tg) with papillary thyroid carcinoma. The lung mass was believed to represent a pulmonary metastatic deposit due to high Tg value. Whole body I-131 scan and FDG PETMR imaging were performed as part of the workup.

Zosteriform cutaneous metastases from an occult primary malignancy of lung identified by whole-body FDG PETCT imaging.

Cutaneous metastasis may be the first evidence of internal malignancy or a sign of recurrence of malignancy and is considered a grave prognostic sign. There are various morphological variants of cutaneous metastases, with the most common being solitary to multiple erythematous infiltrating papules and nodules and the rarer variants being carcinoma erysipeloides, carcinoma en cuirasse, carcinoma telangiectaticum, alopecia neoplastica, metastasis to the inframammary crease, and zosteriform pattern. FDG PETCT is an established imaging modality in the identification of an unknown primary malignancy and also has an important role in the therapeutic decision-making.

Role of FDG PET/CT in Baastrup's disease.

Baastrup's disease is a benign condition, which presents as chronic low back pain. It is also known as "kissing spine syndrome" and refers to close approximation of adjacent spinous processes producing inflammation and back pain. This condition is often misdiagnosed, resulting in incorrect treatment and persistence of symptoms. Diagnosis of Baastrup's disease is verified with clinical examination and imaging studies. Conventionally, clinicians resort to magnetic resonance imaging (MRI) of spine rather than X-ray or computed tomography (CT) in the evaluation of back pain. MRI can additionally identify flattening, sclerosis, enlargement, cystic lesions, and bone edema at the articulating surfaces of the two affected spinous processes. Studies have reported that (18)Fluorine fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT) can detect a bursitis or an inflammation as a form of stress reaction despite a negative MRI and (99m)Tc Methylene diphosphonate (MDP) bone scan. PET/CT is usually not a recommended investigation for this condition. However, this case report highlights the benefit of FDG-PET/CT in identifying the site of inflammatory pathology. It is also known to identify the exact site of inflammation where steroid or local anesthetic injection can be administered to alleviate pain, especially in patients with multilevel vertebral involvement.

Coronary Stent Infection Successfully Diagnosed Using 18F-Flurodeoxyglucose Positron Emission Tomography Computed Tomography.

Infection of coronary stents is extremely rare. We report a case of a 60-year-old gentleman with recurrent fever after acute stent occlusion and reintervention. A coronary angiogram showed an occluded stented segment and the blood cultures were positive for infection. The presence of inflammation in the stented region was confirmed using 18F-flurodeoxyglucose positron emission tomography computed tomography. The patient underwent surgery and the diagnosis was proven by examination of the surgical material. This article highlights the need to have a high index of suspicion of stent infection, and the use of 18F-flurodeoxyglucose positron emission tomography computed tomography along with coronary angiogram in aiding the diagnosis.