Multifocal Burkholderia cepacia Infection in Postrenal Transplantation Fever : Role of 18 F-FDG PET/CT in Treatment Optimization.

ABSTRACT: Nosocomial Burkholderia cepacia infection in the clinical setting of postrenal transplantation pyrexia of unknown origin and the role of 18 F-FDG PET/CT in treatment optimization in such situation is presented in this report. The consequence of fastidious infection by nosocomial colonizing organisms like B. cepacia can be catastrophic in immunocompromised postrenal transplant individuals causing severe urinary tract infection. In the presented case, following 2 weeks of IV antibiotics, the patient didn't show clinical response, and FDG PET scan recognized multifocal infective sites early, likely representing immune reconstitution inflammatory syndrome and timely appropriate and optimal treatment salvaged the renal graft.

Assessing Krenning's score on 68 Ga-DOTATATE PET-CT and miPSMA score on 68 Ga-PSMA-11 PET-CT in TENIS: a comparison with FDG PET/CT and examining the feasibility of targeted radionuclide therapy.

OBJECTIVES: The objective of this study was to assess receptor expression in metastatic differentiated thyroid carcinoma patients with progressive elevated thyroglobulin and negative iodine scintigraphy, we used 68 Ga-DOTATATE [Gallium-68 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotate (DOTATATE)] (Krenning's score) and 68 Ga-PSMA-11 (Gallium-68 prostate-specific membrane antigen-11) PET-computed tomography (CT) [molecular imaging prostate-specific membrane antigen (miPSMA) score]. Patients with Krenning's score 3 and above and miPSMA score 2 and above were considered to determine the incidence of patients, who would qualify for treatment with 177 Lu-DOTATATE/PSMA [Lutetium-177 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotate (DOTATATE)/prostate-specific membrane antigen]-based therapy. In addition, we compared 68 Ga-DOTATATE and 68 Ga-PSMA-11 PET-CT with 2-deoxy-2-[F-18]fluoroglucose ( 18 F-FDG) PET-CT (using maximum standardized uptake value). MATERIALS AND METHODS: A total of 74 patients with histopathologically proven metastatic differentiated thyroid carcinoma with thyroglobulin elevation and negative iodine scintigraphy syndrome were studied retrospectively. They all had 18 F-FDG, 68 Ga-DOTATATE, and 68 Ga-PSMA-11 PET-CT scans available for undertaking this analysis. The lesions detected by 68 Ga-DOTATATE and 68 Ga-PSMA-11 were evaluated using Krenning's and miPSMA scores. In addition, quantitative comparisons of maximum standardized uptake values for 68 Ga-DOTATATE and 68 Ga-PSMA-11, as well as with 18 F-FDG, were conducted. RESULTS: Patient-wise analysis revealed positivity rates of 40.5% for 68 Ga-DOTATATE, 41.89% for 68 Ga-PSMA-11, and 75.67% for 18 F-FDG. Among the 74 patients, 14 (18.91%) were deemed eligible for 177 Lu-DOTATATE/PSMA-617 therapy based on Krenning's score of 3 and above both/either miPSMA score of 2 and above on 68 Ga-DOTATATE or 68 Ga-PSMA-11 PET-CT. Within this subgroup, seven out of 74 patients (9.45%) were eligible for 177 Lu-DOTATATE therapy, and nine out of 74 patients (12.16%) were eligible for 177 Lu-PSMA-targeted therapy. Four patients were eligible for both therapies. CONCLUSION: Among thyroglobulin elevation and negative iodine scintigraphy patient's subgroup, 9.45% could qualify for 177 Lu-DOTATATE and 12.16% for 177 Lu-PSMA-617. Four were eligible for both therapies. Given the lack of effective therapies, this subset of patients warrants consideration for radionuclide therapy exploration.

18 F-Fluorodeoxyglucose Uptake in Bilateral Diaphragmatic Crura: A Relatively Uncommon Benign Variant Noted in a Treated Case of Extraosseous Paraspinal Ewing's Sarcoma.

A toddler was diagnosed with extraosseous Ewing's sarcoma, primary large epidural paraspinal soft tissue in the lumbar region encasing the cord and neural foramen from D12-L1 to L4-L5. After eight cycles of induction chemotherapy with vincristine, doxorubicin, and cyclophosphamide alternating with etoposide and ifosfamide, 18 F-FDG positron emission tomography/computed tomography ( 18 F-FDG-PET/CT) scan confirmed no active disease. Later external beam radiotherapy (EBRT) at D10-L5 was completed. At 3 months follow-up, 18 F-FDG-PET/CT reconfirmed no residual/active disease; however, a new incidental finding of diffuse benign bilateral diaphragmatic 18 F-FDG uptake was noted in the clinically asymptomatic patient, which remained unexplained.

Concomitant Bilateral Inferior Gluteal Lymph Node Involvement in Metastatic Prostate Adenocarcinoma Detected on 68 Gallium-Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography.

An unusual and unique case of prostate adenocarcinoma with involvement of bilateral inferior gluteal lymph nodes is reported. The patient was a 42-year-old male, with conventional prostatic adenocarcinoma (Gleason score: 5 + 4 = 9), who, during disease progression with rising serum prostate specific antigen levels following medical androgen deprivation therapy, demonstrated new prostate-specific membrane antigen expressing metastatic intermuscular deposits in the bilateral gluteal region, subsequently proven to be bilateral inferior gluteal nodal metastasis. A therapeutic implication to this may be that these nodes usually fall beyond the range covered by the therapeutic radiation field coverage where external radiotherapy is the advocated modality of choice and are not easily reachable through standard surgical procedures. As a result, they could have an impact on the way patients are clinically treated and on their prognosis.

Rare Presentations of Differentiated Thyroid Cancer Exposing Dr Jekyll and Mr Hyde Nature of an Otherwise Indolent Disease: Case Series.

ABSTRACT: Differentiated thyroid carcinoma (DTC) usually manifests as an indolent cancer with good prognosis. However, rarely uncommon sites of metastatic involvement can worsen the prognosis and require aggressive therapeutic approach. Here in, we describe 5 patients (3 women and 2 men) harboring rare sites of metastatic involvement from DTC including the adrenals, colon, kidneys, urinary bladder, brachial plexus, and superior vena cava with contiguous right atrial involvement. The awareness of such rare sites of involvement from DTC is imperative for treating clinicians to plan individualistic approach in management including multiprong therapies for better patient care.

Normal physiological distribution and tumor localization of 64 CuCl 2 in different human malignancies along with semiquantitative scoring: a comparative evaluation with 18 Fluorodeoxyglucose ( 18 FDG) PET-CT.

OBJECTIVE: This study aimed to explore 64-Copper-Chloride ( 64 CuCl 2 ) PET-CT in various malignancies and demonstrate a head-to-head comparison of uptake on 64 CuCl 2 PET/computed tomography (CT) and 18 fluorodeoxyglucose ( 18 FDG)-PET/CT scans for different malignancies, with an emphasis on 18 FDG nonavid malignancies. METHODS: Fifty-three patients diagnosed with various biopsy-proven malignancies (except prostate cancer) were recruited in this prospective study. All the patients underwent both 64 CuCl 2 PET/CT and 18 FDG-PET/CT. 64 CuCl 2 PET/CT was acquired at 1, 3 and 24 h time points. We studied the physiological biodistribution of 64 CuCl 2 in the various organs, corroborated the uptake of 64 CuCl 2 with various types of malignancies and comparison of their uptake with 18 FDG-PET/CT and their correlation with each other in various lesions. RESULTS: The biodistribution study showed that the liver concentrated 64 CuCl 2 the most out of all the organs, followed by the pancreas and large intestine. Liver and intestinal activity increased subsequently with delayed imaging, and the washout of 64 CuCl 2 was noted in the pancreas in delayed images and followed a hepatobiliary excretion of tracer over a period of time. In lesion-wise analysis, it was noted that the primary neuroendocrine tumor, melanoma and renal/urothelial malignancy group showed more uptake of 64 CuCl 2 , than that in metastasis and vice-versa was noted in lung and soft tissue malignancies. Comparing it with 18 FDG, it was seen that FDG showed more uptake in lesions and showed no significant correlation (Kappa value: 0.089) with the uptake of 64 CuCl 2 in the lesion-wise comparison. CONCLUSION: 64 CuCl 2 PET/CT did not show any added advantage over 18 FDG-PET/CT in the evaluation of the studied malignancies, both primary and their metastasis. Biodistribution studies showed the liver as the organ with maximum uptake, which implies it may hinder the detection of abdominal or hepatic involvement of the disease.

Sellar-Parasellar and Petrous Bone Metastasis from Differentiated Thyroid Carcinoma: Imaging Characteristics and Follow-Up Profile Post Radioiodine Therapy.

Sella turcica and petrous bone metastasis from differentiated thyroid carcinoma are rare clinical entities, with only a few limited cases reported to date. Two cases, one of sella turcica metastasis and the other of petrous bone metastasis from carcinoma of the thyroid gland, are presented. The cases diagnosed to have arisen from poorly differentiated thyroid carcinoma and follicular carcinoma of thyroid, respectively, subsequently underwent total thyroidectomy, radioiodine (RAI) scans and RAI therapies with iodine-131, external radiotherapy, and levothyroxine suppression with follow-up. Their clinical symptoms gradually subsided, with reduction in serum thyroglobulin, and finally resulted in disease stabilization. With the multimodality therapeutic approach, both patients are alive to date, with 48- and 60-month survival post diagnosis, respectively.

"Stocking Pattern Metabolic Captivity" of Legs on 18 F-FDG PET-CT in Necrotizing Fasciitis: Potential Complimentary Role in Differential Diagnosis and Assessment of Disease Extent in a Life-Threatening Condition.

A rare and fatal life-threatening case of necrotizing fasciitis (initially presenting with skin-deep superficial lesions and clinical suspicion of paraneoplastic syndrome) is described, who was finally diagnosed with the help of fluorodeoxyglucose-positron emission tomography (FDG-PET)/computed tomography (CT) as more extensive infectious process. A 36-year-old male presented with bilaterally symmetrical cutaneous lesions involving lower limbs that rapidly progressed to ulcerative lesions and pancytopenia. In view of suspicion of paraneoplastic manifestation, the patient underwent 18 F-FDG-PET/CT to rule out any underlying malignancy. The FDG-PET/CT findings confirmed hypermetabolism circumferentially along the fasciae of bilateral lower extremities while sparing muscles and subcutaneous fat from below the knee till toe with diffused hypermetabolic marrow, and no evidence of focal disease suggesting malignancy. Biopsy turned out to be superficial necrolytic fasciitis. The patient's condition deteriorated and, 20 days following the scan, the patient succumbed secondary to severe pancytopenia and hypotension. The case raises the importance of high degree of suspicion and prompt diagnosis of this condition, where FDG-PET/CT imaging can play a valuable complimentary role. Such awareness could be lifesaving due to early optimal treatment in the disease course.

Role of PET/Computed Tomography in Elderly Thyroid Cancer: Tumor Biology and Clinical Management.

PET/computed tomography (CT) studies can be potentially useful in elderly thyroid carcinoma patients for exploring the disease biology, especially in metastatic setting and thereby directing appropriate therapeutic management on case-to-case basis, adopting nuclear theranostics, and disease prognostication. With the availability of multiple PET radiopharmaceuticals, it would be worthwhile to evolve and optimally use FDG and the other non-fluorodeoxyglucose and investigational PET/CT tracers as per the clinical situation and need and thereby define their utilities in a given case scenario. In this regard, (I) differentiated thyroid carcinoma (DTC) including radioiodine refractory disease, poorly differentiated thyroid cancer (PDTC) and TENIS, (II) medullary thyroid carcinoma (MTC), (III) anaplastic carcinoma and (IV) Primary thyroid lymphoma (PTL) should be viewed and dealt separately.

An Unusual FDG-PET/CT Documentation in Aleukemic Leukemia Cutis: Atypical Penile, Scrotal, and Leg Muscles Involvement.

Aleukemic leukemia cutis (ALC) is a rare condition with a relatively poor prognosis, clinically presenting as skin and subcutaneous nodules commonly involving head and neck region with discrete atypical leukemic cells infiltrating in the skin on histopathology. The lesions on the genital area skin are seldom reported. A 49-year-old male presented with joint pains and multiple subcutaneous nodules clinically with biopsy proving it as leukemia cutis. Bone marrow aspiration and biopsy were suggestive of normocellular myeloid preponderant bone marrow with mild increase in eosinophils. The 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) revealed metabolically active FDG avid ill-defined soft tissue attenuation involving the entire length of penile shaft with central necrotic area, diffuse scrota skin thickening, and lateral compartment muscles of left leg, in addition to multiple hypermetabolic metastatic lymph nodes, and diffuse hypermetabolic marrow in humerii and femora. Despite prompt investigations and initiation of management, the patient succumbed in 15 days post-FDG PET/CT. The present report depicts an atypical case of ALC, with FDG PET-CT showing extensive and unusual sites of disease involvement, emphasizing its potential role in ALC.

Chest Wall Mass as the Dominant Presentation of Low-Grade B-Cell Non-Hodgkin's Lymphoma: A Case Report.

Low-grade B cell non-Hodgkin's lymphoma with dominant presentation of chest wall mass is presented in this report. The patient, a 65-year-old woman, presented with pain, rising skin temperature and redness, and swelling on the right lower chest wall. The histopathological examination revealed non-Hodgkin's lymphoma; the staging fluorodeoxyglucose-positron emission tomography/computed tomography demonstrated stage IVE disease, with hypermetabolic active disease in the right anterolateral chest wall in the form of large soft tissue mass and subcutaneous tissue with underlying bony erosion with extension into right anterior cardiophrenic space and superiorly up to right second costosternal region along the right internal mammary vessels. This was along with hypermetabolic active right axillary, right supraclavicular and left inguinal lymphadenopathy, and thickened hypermetabolic posterior right pleura with ametabolic right-sided pleural effusion. Bone marrow biopsy revealed uninvolved bone marrow. On follow-up after eight cycles of R-CHOP chemotherapy, the mass had completely resolved on contrast-enhanced computed tomography.

Differential tumor biology between locoregional and distant metastasis in a patient with TENIS with TKI-resistant aggressive recurrent disease: a comparative evaluation with FDG, 68Ga-DOTATATE and 68Ga-PSMA-11 PET-CT.

The molecular PET-CT imaging profile of an interesting case of differentiated thyroid carcinoma, later transformed into with thyroglobulin elevation and negative iodine scintigraphy (TENIS) with tyrosine kinase inhibitor (TKI) resistant recurrent aggressive disease, is presented. The patient was evaluated to assess SSTR-2 or PSMA expression to explore the possibility of any effective targeted nuclear therapy. 18F-FDG, 68Ga-DOTATATE and 68Ga-PSMA-11 PET/CT was performed, which revealed tracer avidity in all 3 scans in the extensive loco-regional disease of large ill-defined retropharyngeal and retro-tracheal soft tissue eroding cricoid cartilage, extending into tracheal lumen and left sided strap muscles. On the contrary, there was no definite uptake in the multiple bilateral lung nodules, the scan findings indicating a differential tumor biology between loco-regional and distant metastasis.

Prostate-Specific Membrane Antigen Expression in Patients With Differentiated Thyroid Cancer With Thyroglobulin Elevation and Negative Iodine Scintigraphy Using 68Ga-PSMA-HBED-CC PET/CT.

PURPOSE OF THE REPORT: Prostate-specific membrane antigen (PSMA) is a member of superfamily of zinc-dependent exopeptidases that is robustly expressed in prostate cancer cells and nonprostatic solid tumor neovasculature including microvessels of thyroid tumors. Its expression in differentiated thyroid cancer (DTC) has been confirmed in many recent studies, but systematic studies exploring PSMA expression in patients with DTC with thyroglobulin elevation and negative iodine scintigraphy (TENIS) are lacking. The aim of the present study was to evaluate the role of PSMA scan in TENIS patients with DTC. METHODS: Nine consecutive patients with DTC with proven TENIS syndrome (6 men and 3 women with age range 29-68 years and mean age of 48 years) underwent 18F-FDG PET/CT as per the institution protocol. Thereafter, they were subjected to 68Ga-PSMA-HBED-CC PET/CT as per the institution protocol within a week of FDG PET imaging. Prostate-specific membrane antigen expression (SUVmax) in the lesions was compared with 18F-FDG PET and CT scan findings. RESULTS: In 5 of 9 patients with TENIS, the metastatic lesions showed PSMA expression. A total of 14 lesions were seen on the CT scan. Prostate-specific membrane antigen PET detected 9 of 14 lesions (64.28%) (SUVmax ranging from 10.1 to 45.67; median SUVmax of 16.31), whereas FDG PET was positive in 11 of 14 lesions (78.57%). The lesions that showed PSMA uptake was localized to bones (5 of 9) and lungs (4 of 9). Two lesions that were localized to iliac crest and acetabulum were missed on FDG PET but were seen on CT and PSMA PET scan. CONCLUSIONS: The results of this pilot study indicate that 68Ga-HBED-CC-PSMA PET/CT demonstrates PSMA expression in TENIS patients with lesions being localized to the bones and lungs. 68Ga-PSMA PET/CT could be useful for the identification of TENIS patients who might benefit from PSMA-targeted radionuclide therapy.

Evidence of Prostate-Specific Membrane Antigen Expression in Metastatic Differentiated Thyroid Cancer Using 68Ga-PSMA-HBED-CC PET/CT.

PURPOSE OF THE REPORT: Prostate-specific membrane antigen (PSMA) overexpression is not restricted to prostate cancer, but it has also been demonstrated in gliomas, lung cancer, and in tumor neovasculature. Systematic studies exploring PSMA uptake in thyroid tumors are lacking. The aim of this pilot study was to assess PSMA expression in patients with metastatic differentiated thyroid cancer (mDTC). MATERIALS AND METHODS: Ten patients of mDTC harboring 32 lesions (5 men; age range, 38-65 years; mean age, 50 years) underwent prospective evaluation with radioiodine (I), F-FDG PET, and Ga-PSMA-HBED-CC PET scans as per the institution protocol. PSMA expression (SUVmax) was compared with F-FDG and I scan findings in all patients. RESULTS: Lesions were radioiodine avid in 8 patients, whereas 2 were classified as thyroglobulin elevation with negative iodide scintigraphy (TENIS) patients. All patients with iodine-avid metastatic disease showed substantial PSMA uptake. PSMA PET detected 30/32 total lesions (93.75%; SUVmax ranging from 4.86 to 101.81 with median SUVmax of 31.35), whereas FDG PET/CT was positive in 23/32 lesions (81.85%). Twenty-one (70%) of 30 lesions that showed PSMA expression were localized to the bones. PSMA localized a lesion in each of the 2 TENIS patients similar to FDG PET scan. CONCLUSIONS: Ga-PSMA-HBED-CC PET/CT is a potentially useful imaging modality in patients of mDTC with most (70%) of PSMA expressing metastasis being localized to the bones. PSMA PET/CT could be useful for identifying patients with limited therapeutic options (eg, TENIS) who might benefit from PSMA-targeted radionuclide therapy.

Role of fluorine-18 fluorodeoxyglucose positron emission tomography in a case of renal cell carcinoma to differentiate tumor thrombus from bland thrombus.

Tumor thrombus is a rare complication of many solid tumors. We present a case of renal cell carcinoma whose baseline contrast-enhanced computerized tomography (CT) revealed an heterogeneously enhancing mass in the upper half of right kidney with tumor thrombus in the right renal vein extending to suprarenal inferior vena cava (IVC), crossing the cavoatrial junction and reaching up to the right atrium (Grade IV). Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT imaging revealed large irregular right renal mass, hypermetabolic tumor thrombus extending from the right renal vein to suprarenal IVC reaching up to the right atrium. There was no FDG uptake noted in the infrarenal IVC and bilateral iliofemoral venous thrombi. Thus, 18F-FDG PET/CT was not only helpful in the staging, but was also helpful in differentiating tumor thrombus from bland thrombus in our patient.

Postoperative distal ureteric and bladder cuff recurrence in a Grade I renal transitional cell carcinoma diagnosed and restaged by fluorodeoxyglucose positron emission tomography-computed tomography.

A 56-year-old male having Grade I transitional cell carcinoma (TCC) of left kidney, postleft nephrectomy and upper 1/3(rd) ureterectomy presented with painless hematuria. Restaging fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) revealed abnormal linear FDG uptake in the lower 2/3(rd) of the left ureter and in the bladder adjacent to the left vesicoureteric junction, no locoregional adenopathy nor distant metastases (Figures 1 and 2- left column). Patient underwent left lower ureterectomy with partial cystectomy. Postoperative histopathology was TCC. Instillation of Bacillus Calmette-Guérin injection in the bladder was done postoperatively. A follow-up FDG PET/CT scan performed 3 months postoperatively was revealed no abnormal focal FDG uptake in the whole body revealing disease free status. FDG PET was helpful in diagnosing tumor recurrence in the distal remnant ureter. This case attempts to highlight the role of FDG PET/CT in follow-up, residual and recurrence evaluation.

Abnormal extraosseous activity in both lungs and stomach in pre-transplant 99mTc-MDP bone scan disappearing after renal transplant.

A chronic kidney disease male patient presenting with bone pains, fever, weakness, and clinically ascites was subjected to four technetium-99m-methylene diphosphonate (Tc99m-MDP) bone scans, two before renal transplant and two after renal transplants. Pretransplant bone scan revealed metabolic bone disease with focal insufficiency fractures. Marked extraosseous activity in both lungs and stomach was also visualized. On regular hemodialysis (HD) after 4 months, repeat pretransplant bone scan showed persistent uptake in lungs and stomach, representing altered calcium metabolism with microcalcifications. He underwent human leukocyte antigen (HLA) matched live donor renal transplantation, started on immune-suppression and steroids. Posttransplant bone scan at 20 days revealed no definite interval change, but bone scan performed approximately 17 months posttransplant showed resolving metabolic bone disease and the tracer uptake in the lungs and stomach was no more visualized. Patient clinically followed-up until the date (February 2013) is asymptomatic with serum creatinine of 1.5 mg/dl, no bone scan done.

Post re-anastomosis demonstration of regain in function in non-visualized upper half of kidney in a dual arterial allogenic renal graft on renal scintigraphy.

A young male patient with end stage renal disease underwent renal allograft having dual arterial supply. Immediate post-operative urine output dropped, an urgent Technetium-99m-mercaptoacetyltriglycine ((99m)Tc-MAG3) renogram revealed non-visualized upper-half and the preserved perfusion and parenchymal function of the small transplant kidney. Patient was re-explored and re-anastomosis was performed. A renogram at 24h post re-anastomosis revealed increase in the size of renal allograft, with preserved perfusion to the upper-half of transplant. Transplant kidney biopsy of the Upper-half showed acute tubular necrosis. 99mTc-MAG3renogram at 10 days post re-vascularization remains unchanged with persistent improvement at 2 months follow-up. We conclude that early recognition of renal functional loss allows early management and the high probability of salvaging the renal function.

Febrile renal transplant recipient with discordant findings of (99m)Tc-Leukoscan (Sulesomab) and (67)Ga-citrate scan in pyelonephritis.

Nuclear medicine techniques like (99m)Tc-Leukoscan and (67)Ga-citrate scan have been used in localizing infectious pathologies in renal transplant patients. We present an interesting case of febrile renal transplant with discordant findings of tracer uptake in the transplant kidney on (99m)Tc-Leukoscan and (67)Ga-citrate scan.