Whole-body Positron Emission Tomography-computed Tomography Research Articles

The Utility of Whole Body 18F-FDG PET-CT in Diagnosing Isolated Cardiac Sarcoidosis: The Western Australian Cardiac Sarcoid Study

It is reported that up to 29-52% of patients with cardiac sarcoidosis (CS) may have isolated cardiac sarcoidosis (ICS). The wide variation in prevalence may be related to the diagnostic methods for assessing extracardiac involvement. Whole-body 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) imaging is a useful and increasingly used technique for screening for extracardiac involvement in cases of suspected ICS. This study aims to determine the rate of isolated cardiac involvement with clinically manifest CS using cardiac 18F-FDG PET-CT. We performed a retrospective analysis of data in the West Australian Cardiac Sarcoid (WACaS) Database. After cardiologist review and workup, all cases of proven or probable CS, based on either current Heart Rhythm Society criteria for the diagnosis of CS or local expert consensus were included. Only patients who underwent whole body 18F-FDG PET-CT were included in the final analysis. Fifty-two (52) cases of CS were identified. Data on symptoms, imaging findings, treatment and outcomes were collected. Of the 42 patients who underwent diagnostic 18F-FDG PET-CT, 32 demonstrated changes consistent with CS. Of the 32, 69% were male, mean age 50 years at diagnosis. Only 3/32 (9.4%) patients had ICS. Pulmonary involvement occurred in 91% with varied involvement in other organs. The mean number of extracardiac sites at diagnosis was 2.2. This study demonstrates the utility of 18F-FDG PET-CT in diagnosing extracardiac organ involvement in cases of CS. With the use of this modality, ICS may be rarer than previously reported.

Comparison of Efficacy of Positron Emission Tomography/Computed Tomography with Contrast-Enhanced Computed Tomography in Pretreatment Evaluation of Head and Neck Cancers: An Institutional Experience

Abstract Introduction: Head and neck squamous cell carcinomas (SCCs) constitute 5.4% of all cancers worldwide, and 23% of all cancers in males and 6% of all cancers in females diagnosed in India. Lots of ambiguity exists in primary, nodal, and metastatic workup of these patients, especially in developing countries. Aim: The study was designed to compare the accuracy of whole-body positron emission tomography/computed tomography (WBPET/CT) scan with contrast-enhanced CT (CECT) face and neck as pretreatment evaluation for staging workup and management decision and to confirm the nodal findings on imaging with fine-needle aspiration cytology (FNAC). Design: It was a single-institute, prospective, observational, interventional study over a 2-year period. All cases of SCC of upper aerodigestive tract who were scheduled for definitive treatment concurrent chemoradiotherapy or radiotherapy were evaluated with routine investigations followed by imaging in the form of CECT face and neck and 18F-fluorodeoxyglucose (FDG) WBPET/CT. Results: In the 40 enrolled patients, all underwent CECT face and neck and WBPET/CT. During initial workup, biopsy was taken from primary site and FNAC was done from neck nodes for diagnosis and for staging. In 40 patients, CECT neck showed nodal metastasis in 39 patients; however, FNAC came positive in 38 cases. PET/CT showed nodal metastasis in 38 patients; however, FNAC came positive in 38 cases. Any node with Standardized uptake value (SUV) >2.5 was taken as suspicious lesion and FNAC was done. Sensitivity of CECT and PET/CT was 97.36% and 100%, respectively, while the specificity was 0% and 100%, respectively. Positive predictive value calculated for CECT and WBPET was 94.87% and 100%, respectively, while the negative predictive value for CECT and WBPET was 0% and 100%, respectively. Conclusion: In head and neck SCC, FDG-PET/CT is more accurate than CECT in staging of the neck.

Prognostic Relevance of Medullary Abnormalities in the Appendicular Skeleton Detected By Positron Emission Tomography-Computed Tomography in Patients with Newly Diagnosed Multiple Myeloma

Background: Positron emission tomography-computed tomography (PET-CT) is a valuable tool in the initial evaluation of myeloma and related disorders. However, the prognostic value of PET-CT has not been fully elucidated. We recently reported the prognostic significance of medullary abnormalities in the appendicular skeleton (AS) detected by multidetector computed tomography (MDCT) in patients with multiple myeloma (MM) [Blood Adv, 2018. 2(9): p.1032-39].The study reported that medullary abnormalities in AS detected by MDCT showed different fluourodeoxyglucose-avidity ranging from entirely negative to diffusely positive on concurrently performed PET-CT, despite the presence of unequivocal infiltration of abnormal lesions in AS on MDCT. We further investigate the prognostic relevance of medullary abnormalities in AS by PET-CT in symptomatic MM.Methods: We identified a total of 211 consecutive patients with newly diagnosed, symptomatic MM diagnosed and treated between April 2008 and February 2018 at Kameda Medical Center, Kamogowa-shi, Japan. They were evaluated with pretreatment whole-body PET-CT. We included only patients who had been treated with novel agents. PET-CT imaging was performed as previously reported [Blood, 2011. 118(23): p.5989-95]. PET-CT positivity and negativity were also defined as previously described.Results: Median age of the patients was 73.5 years [interquartile range (IQR): 66.3-80.3 years). There were 129 (61.1%) patients who showed abnormal findings on PET-CT. Consistent with previous reports, known high-risk PET-CT findings including the presence of >3 systemic focal lesions (FLs), maximum standardized uptake value (SUVmax) >4.2, and extramedullary disease were observed in 91 (43.1%), 97 (46.0%), and 11 (5.2%) patients, respectively. Receiver operating characteristic analysis determined the optimal cutoff value of AS focal lesions (AS-FLs) on PET-CT as 3. We then divided patients into two groups with ≤3 or >3 AS-FLs (Fig. 1). There were 35 (16.6%) patients with >3 AS-FLs, and their levels of clonal circulating plasma cells and prevalence of del(17p) and t(14;16) were higher than those in patients without AS-FLs. Patients with >3 AS-FLs showed significantly shorter progression-free survival (PFS) and overall survival (OS) than those without [median PFS: 12.8 and 35.6 months, respectively; P < 0.001, and median OS: 33.4 months and not reached (NR), respectively; P < 0.001]. Patients with 1-3 AS-FLs did not show significant differences in PFS and OS compared to patients with no AS-FL (Fig. 2). In addition, this finding retained its prognostic value for PFS and OS in multivariate analysis [hazard ratio (HR); 2.35, 95% confidence interval (CI); 1.42-3.88; P < 0.001 for PFS, and HR; 2.86, 95% CI; 1.60-5.09; P < 0.001 for OS] (Table 1). As previously described, we observed that the known high-risk PET findings including the presence of >3 systemic FLs and SUVmax> 4.2 had an unfavorable prognostic impact. Patients with >3 AS-FLs showed significantly shorter PFS and OS than those without, even among patients with >3 systemic FLs (Fig. 3) or SUVmax> 4.2 (Fig. 4). Furthermore, we identified 108 and 42 patients with focal/scattered and diffuse marrow pattern on MDCT, respectively. There were 16 (14.8%) and 19 (45.2%) patients with >3 AS-FLs observed on PET-CT with focal/scattered and diffuse marrow pattern on MDCT, respectively. These patients showed shorter PFS and OS than those without AS-FLs among patients with the same AS marrow pattern on MDCT.Conclusions: To the best of our knowledge, ours is the first study to demonstrate that the presence of >3 FLs in AS detected by pretreatment PET-CT was robustly predictive of unfavorable survival independent of known risk factors, including existing high-risk PET-CT findings in patients with newly diagnosed MM. The findings in AS may potentially complement and improve the prognostic performance of PET-CT. Further systematic studies are warranted for the validation of our results and development of more accurate prognostic systems incorporating cross-sectional imaging. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Whole-body 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) for staging locally advanced breast cancer: A prospective study from a tertiary cancer centre in south India.

Background & objectives:Locally advanced breast cancer (LABC) is associated with substantial risk of occult metastases. The patients with LABC have high rate of systemic relapse, suggesting inadequacy of the current conventional staging in detecting the occult metastatic spread. 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) is a new modality in the staging of breast cancer patients. Hence, this study was conducted to evaluate the role of 18F-FDG PET/CT in initial staging of LABC and to compare it with conventional methods.Methods:This prospective study included biopsy-confirmed female patients diagnosed with LABC meeting the selection criteria and attending surgical, medical and radiation oncology departments of a tertiary care centre in south India, from April 2013 to December 2014. Conventional workup included serum chemistry, mammogram, bone scan, contrast-enhanced CT (CECT) chest and upper abdomen and ultrasound abdomen and pelvis. All patients following conventional workup underwent 18F-FDG PET/CT.Results:In this study, 61 women with LABC underwent both conventional workup and 18F-FGD PET/CT. The 18F-FDG PET/CT, in comparison to conventional workup, revealed unsuspected N3 nodal disease in 11 more patients, revealed distant metastasis in seven more patients and also detected extra sites of metastasis in five patients. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT to detect distant metastasis were 95, 98, 95, 98 and 97 per cent, respectively, whereas the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of conventional imaging to detect distant metastasis were 65, 93, 81, 84 and 84 per cent, respectively.Interpretation & conclusions:The 18F-FDG PET/CT was found to be more accurate than conventional imaging for staging and modified stage and treatment in 30 and 38 per cent of patients, respectively. It was particularly useful in detecting occult distant metastasis and N3 nodal disease with an added advantage of examining whole body in single session. However, CECT chest was superior over 18F-FDG PET/CT for detecting pulmonary metastasis.

One Pulmonary Lesion, 2 Synchronous Malignancies.

Introduction. Mantle cell lymphoma (MCL) comprises approximately 3% to 10% of all non-Hodgkin lymphomas. Although there is an increased risk for secondary malignancies after treatment among non-Hodgkin lymphomas survivors, a synchronous diagnosis of primary lung cancer arising in conjunction with lymphoma at the same site has rarely been reported. We report an unusual case of primary lung adenocarcinoma with coexistent MCL within the same lung lesion. Case Presentation. A 55-year-old female with newly diagnosed stage IV-B MCL was referred for workup of a right upper lobe cavitary lesion detected during lymphoma staging. A whole-body positron-emission tomography-computed tomography scan revealed diffuse adenopathy but also identified a cavitary right upper lobe lesion atypical for lymphoma. Bronchoscopy was unremarkable with cytology (on lavage) negative for malignancy. At 2 months, a computed tomography scan of the chest showed a persistent lesion. A video-assisted thoracoscopic wedge resection was performed. Histopathological examination revealed a lepidic predominant, well-differentiated adenocarcinoma (stage T1a) and foci of lymphoid infiltrate within and adjacent to the adenocarcinoma consistent with lung involvement by MCL. Discussion. Synchronous presentation of primary lung adenocarcinoma and lymphoma at a single site is exceedingly rare. Nonresolving pulmonary lesions with features atypical for lymphoma should be viewed with caution and worked up comprehensively to rule out occult second malignancies, in order to guide a prompt diagnosis and appropriate treatment.

Malignant mesothelioma of the tunica vaginalis testis: A case report and literature review.

Malignant mesothelioma of the tunica vaginalis testis is an extremely rare tumor without specific clinical manifestations, mainly including hydrocele formation and a painless mass. We herein present the case of a patient with hydrocele of the left testis, without any other complaints. Tunica vaginalis subinvolution was performed, and postoperative pathological examination revealed a malignant mesothelioma arising from the left tunica vaginalis testis. Whole-body positron emission tomography-computed tomography (PET-CT) and subsequent abdominal and pelvic magnetic resonance imaging (MRI) revealed no evidence of local lymphadenopathy. Radical left orchiectomy was performed after the pathological diagnosis. The pathological examination after the second surgery demonstrated that the tumor had invaded the adjacent periorchium and spermatic cord, but there was no evidence of local lymph node metastasis. Pemetrexed and cisplatin were administered at a dose of 900 and 130 mg, respectively, on the first day of a 28-day cycle. After 6 months of therapy, the disease had not progressed on abdominal and pelvic PET-CT and MRI. The patient was still followed up in our urology outpatient clinic at the time of the present report. Although testicular hydrocele is a common and easily diagnosed condition, detailed medical history and physical examination are required. Thus, when clinicians encounter patients with testicular hydrocele, a variety of possible causes must be considered, including testicular or paratesticular tumors, even rare tumors such as mesothelioma of the tunica vaginalis testis.

Non traumatic vertebral lesions: incremental utility of PET-CT over MRI and FNAC in a suggested diagnostic algorithm

Objective: To prospectively compare positron emission tomography-computed tomography (PET-CT) with conventional magnetic resonance imaging (MRI) and FNAC for diagnosis of non- traumatic vertebral lesions fracture in countries like India where tuberculosis is endemic.Methods: Fifty four patients with non-traumatic spontaneous vertebral lesions were prospectively studied. All patients underwent CEMRI focusing on the spinal lesions, whole-body PET-CT and FNAC.Results were then analysed and compared with final diagnosis obtained either by FNAC or clinical follow up.Results: Out of total 54 patients, FNAC from the spinal lesion could establish diagnosis in 36 patients (26 TB, 1 Fungal and 9 tumors). Of the remaining 18 patients, diagnosis could be established in 7 utilizing FNAC from other sites as dictated by PET-CT. In the remanining11 patients, the diagnosis and management was decided on the concordance of MRI and PET-CT.Conclusion: All three investigations have their own advantages and pitfalls and they complement each other in reaching the final diagnosis. MRI has a better pick up rate (than PET-CT) for inflammatory lesions. PET-CT on the other hand has better sensitivity for malignant vertebral disease. Diagnosis was established if FNAC was conclusive. In cases where FNAC was inconclusive, an additional 38.9% patients’ diagnosis could be established by FNAC from other sites of involvement as dictated by PET-CT. This was an incremental utility of PET–CT. When even this fails, there were two possible scenarios—MRI and PET-CT in concordance with each other. In such a scenario, the combined report of MRI and PET-CT was relied upon. The last sub group (where MRI and PET-CT were discordant and FNAC was inconclusive) still remains achilles’ heel. Wide bore biopsy may help in establishing diagnosis in such group.

Higher breast cancer conspicuity on dbPET compared to WB-PET/CT

ObjectivesThe purpose of this study was to evaluate lesion detectability of a dedicated breast positron-emission tomography (dbPET) scanner for breast cancers with an updated reconstruction mode, comparing it to whole-body positron-emission tomography/computed tomography (WB-PET/CT). Materials and methodsA total of 179 histologically-proven breast cancer lesions in 150 females who underwent both WB-PET/CT and dbPET with 18F-fluorodeoxyglucose were retrospectively analyzed. The patient/breast/lesion-based sensitivities based on visual analysis were compared between dbPET and WB-PET/CT. For lesions visible on both PET images, SUVmax values of the tumors were measured, and tumor-to-background ratios (T/B ratios) of SUVmax were compared between the two scans. Subgroup analyses according to clinical tumor stage, histopathology and histological grade were also performed. ResultsPatient/breast/lesion-based sensitivities were 95%, 95%, and 92%, respectively, for dbPET, and 95%, 94%, and 88%, respectively, for WB-PET/CT. Mean±standard deviation SUVmax values of FDG-avid tumors were 13.0±9.7 on dbPET and 6.4±4.8 on WB-PET. T/B ratios were also significantly higher in dbPET than in WB-PET/CT (8.1±7.1 vs. 5.1±4.5). In the subgroup analysis, no significant differences in sensitivities between dbPET and WB-PET/CT were found. However, T/B ratios of dbPET were significantly higher than those of WB-PET/CT in cT1c, cT2, cT3, invasive cancer, invasive carcinoma of no special type, mucinous carcinoma and Grades 1–3. ConclusionNo significant differences in sensitivities were identified between dbPET using an updated reconstruction mode and WB-PET/CT; however, T/B ratios of dbPET were significantly higher than those of WB-PET/CT, indicating higher tumor conspicuity on dbPET.

Bone metastasis from lung cancer identified by genetic profiling.

Cancer metastasis remains responsible for the vast majority of cases of cancer-related morbidity and mortality. Metastasis, by its definition, is the spread of cancer from the primary site to the distant tissues. Advancing the scientific and clinical understanding of cancer metastasis is a high priority. The prerequisite requirement for pathological consistency may be compromised during metastasis. The present study reports the case of a cancer patient with different pathological types. The patient presented with pain in the neck and right hip, as well as weight loss. He underwent whole-body positron emission tomography-computed tomography, which identified a mass in the lung and abnormal metabolism of the bone. Biopsies of the ilium and lung were performed and he was shown to have lung adenocarcinoma and bone squamous carcinoma. The morphology and immunohistochemical patterns were completely different, while each lesion harbored an identical genetic profile. The bone lesion was identified to be a metastasis from the lung cancer. The patient was prescribed an epithelial growth factor receptor inhibitor, which resulted in a partial response in the lung mass and alleviation of the patient's bone pain. Through this case study, we advocate the importance of using genetic testing in addition to pathological assessment.

Prostate-Specific Membrane Antigen Is a Potential Antiangiogenic Target in Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) is a rare tumor type with a poor prognosis and few therapeutic options. Assess prostate-specific membrane antigen (PSMA) expression as a potential novel therapeutic target for ACC. Expression of PSMA was evaluated in benign and malignant adrenal tumors and 1 patient with metastatic ACC. This study took place at a tertiary referral center. Fifty adrenal samples were evaluated, including 16 normal adrenal glands, 16 adrenocortical adenomas, 15 primary ACC, and 3 ACC metastases. Demographics, PSMA expression levels via real-time quantitative polymerase chain reaction and immunohistochemistry and whole-body positron emission tomography-computed tomography standardized uptake values for 1 patient. qPCR demonstrated an elevated level of PSMA in ACC relative to all benign tissues (P < .05). Immunohistochemistry localized PSMA expression to the neovasculature of ACC and confirmed overexpression of PSMA in ACC relative to benign tissues both in intensity and percentage of vessels stained (78% of ACC, 0% of normal adrenal, and 3.27% of adenoma-associated neovasculature; P < .001). Those with more than 25% PSMA-positive vessels were 33 times more likely to be malignant than benign (odds ratio, P < .001). Whole-body positron emission tomography-computed tomography imaging showed targeting of anti-PSMA Zr89-J591 to 5/5 of the patient's multiple lung masses with an average measurement of 3.49 ± 1.86 cm and a standardized uptake value of 1.4 ± 0.65 relative to blood pool at 0.8 standardized uptake value. PSMA is significantly overexpressed in ACC neovasculature when compared with normal and benign adrenal tumors. PSMA expression can be used to image ACC metastases in vivo and may be considered as a potential diagnostic and therapeutic target in ACC.

Visual Vignette

Case presentation: A 38-year-old male was admitted with a 4-year history of paroxysmal headache, erectile dysfunction, and fatigue. He also reported dizziness, generalized muscle aches, and weakness. On physical examination, the patient was afebrile. His heart rate and blood pressure were 95 beats per minute and 90/50 mm Hg. respectively. The sodium level was 171 mmol/L, potassium level 3.5 mmol/L, chloride level 135 mmol/L, plasma osmotic pressure 339 mOsm/kgH2O, and urine osmotic pressure 362 mOsm/kgH2O. A pituitary function assessment revealed secondary hypocortisolism and hypogonadotropic hypogonadism. A visual field examination showed no significant abnormalities. Pituitary magnetic resonance imaging (MRI) revealed a large mass in the hypothalamic area and right posterior horn of lateral ventricle with thickening of the pituitary stalk, which was about 6 mm (Fig. 1). Whole-body positron emission tomography-computed tomography using 18F-fluorodexoyglucose showed mild lymph node uptake (Fig. 2 involving the neck, mediastinum, right armpit, supratrochlear area, and groin bilaterally). His erythrocyte sedimentation rate and high-sensitivity C-reactive protein and serum angiotensin-converting enzyme (sACE) levels were in normal ranges. Left inguinal lymph node biopsy revealed epithelioid granulomas. What is the diagnosis?

Melanoma of unknown primary origin coexisting with early-onset multifocal basal cell carcinoma.

Melanoma of unknown primary origin coexisting with early-onset multifocal basal cell carcinoma.

Diagnostic value of whole-body diffusion-weighted magnetic resonance imaging for detection of primary and metastatic malignancies: A meta-analysis

PurposeTo perform a meta-analysis to evaluate the diagnostic performance of whole-body diffusion-weighted magnetic resonance imaging (WB-DWI) technique in detection of primary and metastatic malignancies compared with that of whole-body positron emission tomography/computed tomography (WB-PET/CT). Materials and methodsSearch Pubmed, MEDLINE, EMBASE and Cochrane Library database from January 1984 to July 2013 for studies comparing WB-DWI with WB-PET/CT for detection of primary and metastatic malignancies. Methodological quality was assessed by the quality assessment of diagnostic studies (QUADAS) instrument. Sensitivities, specificities, predictive values, diagnostic odds ratio (DOR) and areas under the summary receiver operator characteristic curve (AUC) were calculated. Potential threshold effect, heterogeneity and publication bias were investigated. ResultThirteen eligible studies were included, with a total of 1067 patients. There was no significant threshold effect. WB-DWI had a similar AUC (0.966 (95% CI, 0.940–0.992) versus 0.984 (95% CI, 0.965–0.999)) with WB-PET/CT. No significant difference was detected between AUC of WB-DWI and WB-PET/CT. WB-DWI had a pooled sensitivity of 0.897 (95% CI, 0.876–0.916) and a pooled specificity of 0.954 (95% CI, 0.944–0.962). WB-PET/CT had a pooled sensitivity of 0.895 (95% CI, 0.865–0.920) and a pooled specificity of 0.975 (95% CI, 0.966–0.981). Heterogeneity was found to stem primarily from data type (per lesion versus per patient), MR sequence (DWIBS only and DWIBS with other sequence), and primary lesion type (single type and multiple type). The Deeks's funnel plots suggested the absence of publication bias. ConclusionWB-DWI has similar, good diagnostic performance for the detection of primary and metastatic malignancies compared with WB-PET/CT. DWIBS with other MR sequences could further improve the diagnostic performance. More high-quality studies regarding comparison of WB-DWI and WB-PET/CT and combination of them in detecting malignancies are still needed to be conducted.

Vulnerable plaque detection: The role of 18-fluorine fluorodeoxyglucose in identifying high risk patients

Positron emission tomography computed tomography (PET-CT) is a combined functional and structural multi modality imaging tool that can be utilized to detect vulnerable and atherosclerotic plaques. In this study we observe the prevalence of active and calcified plaques in selected arteries during whole-body 18F-FDG PET-CT and correlate the findings with risk factors in developing coronary artery disease. There was a significant relationship between patients with high body mass index and vulnerable plaques. We concluded that 18F-FDG PET-CT can be utilized in detecting focal high FDG uptake within vascular plaque in early recognition of high risk patients having vascular accidents.

Accuracy of 18-FDG PET/CT in the Differential Diagnosis of Malignant and Benign Pleural Diseases

Integrated whole-body 18-fluorodeoxyglucose positron emission tomography-computed tomography (PET/CT) is a non-invasive imaging technique for identifying several types of malignant diseases. We evaluated the role of PET/CT in distinguishing malignant from benign pleural diseases. Thirty patients, who had pleural abnormalities on computed tomography (CT), such as thickening, fluid with suspicion of malignant pleural mesothelioma or any other malignancy underwent PET/CT. Maximum standardized uptake values (SUVmax) were calculated separately for pleural thickening and pleural fluid and compared with pathological results obtained by video thoracoscopy. Twenty-two patients with pleural thickening and 25 patients with pleural fluid were assessed with regard to the accuracy of PET/CT. The overall sensitivity,specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT was 81.8%, 54.5%, 64.3%, 75%, and 68.2% for pleural thickening and it was 100%, 56.5%, 41.1%, 100%, and 60% for patients with pleural fluid. When the pleural thickening was evaluated, the SUVmax values were higher in the malignant pleural diseases than in the benign pleural diseases but the difference was not statistically significantly (p = 0.063). When the pleural fluid was evaluated, the SUVmax values were also higher in the malignant pleural diseases than in the benign pleural diseases and the difference was statistically significantly (p= 0.03). The accuracy of PET/CT for detecting malignant pleural fluids was high. However, PET/CT was not adequate to make the differential diagnosis of pleural malignancies especially in case of pleural thickening because of its relatively low sensitivity,specificity,PPV, and NPV. A tissue biopsy is necessary to determine the diagnosis.

Current Concepts in MRI of Focal and Diffuse Malignancy of Bone Marrow

Bone marrow is a ubiquitous component of musculoskeletal imaging studies. The ability to identify and characterize pathology accurately in the bone marrow can be challenging given the broad spectrum of imaging features of normal bone marrow. Knowledge regarding the ability to differentiate normal from abnormal marrow has been enhanced with MR imaging with numerous techniques available to aid in distinguishing benign from malignant lesions in the bone marrow. T1-weighted fast spin echo (FSE) and fluid-sensitive sequences, fat-saturated T2-weighted FSE, and short tau inversion recovery provide valuable tools for the evaluation of a focal bone marrow lesion. Gadolinium enhancement, chemical shift, diffusion-weighted, and MR spectroscopy imaging are additional tools available for focal bone marrow lesion evaluation. Whole-body MRI and fluorodeoxyglucose positron emission tomography-computed tomography have evolved to be useful studies for staging and monitoring of therapeutic response in whole-body imaging. The relative advantages and disadvantages of the whole-body techniques are reviewed for metastases, myeloma, and lymphoma.

Comparison of FDG whole-body PET/CT and gadolinium-enhanced whole-body MRI for distant malignancies in patients with malignant tumors: a meta-analysis

We performed a meta-analysis to compare the performance of whole-body positron emission tomography/computed tomography (WB-PET/CT) with that of whole-body magnetic resonance imaging (WB-MRI) for the overall assessment of distant malignancies in patients with malignant tumors. We performed a meta-analysis of 13 available articles (1239 patients). We calculated sensitivities, specificities, positive likelihood ratios, and negative likelihood ratios, and constructed summary receiver operating characteristic curves using bivariate regression models for WB-PET/CT and WB-MRI, respectively. Across nine studies (1070 patients), WB-PET/CT have similar patient-based sensitivity (0.85 versus 0.85) and specificity (0.96 versus 0.97) with WB-MRI. Across 5 studies (210 patients), WB-PET/CT have similar lesion-based sensitivity (0.85 vs 0.88) and specificity (0.90 vs 0.89) with WB-MRI. Across four studies (511 patients), the combined use may have higher patient-based sensitivity (0.89) than WB-PET/CT (0.82) and WB-MRI (0.81) alone. Both WB-PET/CT and WB-MRI have good diagnostic performance for the overall assessment of distant malignancies in patients with malignant tumors. The combined use may provide more added value than WB-PET/CT and WB-MRI alone.

The role of magnetic resonance imaging and positron emission tomography-computed tomography combined in differentiating benign from malignant lesions contributing to vertebral compression fractures

Background:Obtaining tissue confirmation of the underlying pathology is the gold standard for establishing the etiology of nontraumatic vertebral compression fractures. However, newer investigative modalities such as the magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT) combined potentially offer the ability to distinguish between benign and malignant lesions, thereby circumventing the need for invasive tissue diagnostic/biopsy procedures.Methods:Twenty-four patients with nontraumatic, spontaneous vertebral compression fractures were prospectively studied. After clinical evaluation, all patients underwent MRI (with/without contrast) focusing on the spinal lesion, followed by whole-body PET-CT. This was followed by fine needle aspiration cytology (FNAC) of the lesion to confirm the diagnosis. The sensitivity and specificity of MRI and PET-CT studies were calculated for benign vs. malignant lesions.Results:The sensitivity/specificity of MRI for benign lesions were 78.57%/90%, while the sensitivity/specificity values of PET-CT for benign disease were 92.8%/90% respectively. Alternatively, the sensitivity/specificity of MRI for malignant lesions were 90%/78.57%, while the sensitivity/specificity of PET-CT for malignant disease were 90%/92.8%, respectively. Furthermore, the sensitivity for diagnosing malignant lesions utilizing both studies together was 100%, but the algorithm was not specific. Additionally, the specificity for MRI and PET-CT combined was 100% for benign lesions. PET-CT also helped in monitoring responses to empirical antitubercular treatment (ATT) therapy. Of interest, FNAC was inconclusive in four cases in which PET-CT findings helped further in either obtaining a tissue diagnosis from another location or institution of empirical therapy in suspected cases of tuberculosis.Conclusions:The specificity for MRI and PET-CT combined was 100% for benign lesions. Unfortunately, the specificity for MRI and PET-CT combined was not 100% for malignant vertebral lesions, though it was sensitive. The PET-CT scan was an extremely useful tool when FNAC from the affected site proved inconclusive. It gave additional information regarding the overall extent of disease, while identifying other locations amenable to FNAC. Furthermore, in countries where tuberculosis is endemic, the empirical response to ATT therapy could be monitored utilizing PET-CT.

Nasal Tip Cutaneous Metastases Secondary to Lung Carcinoma: Three Case Reports and a Review of the Literature

Cutaneous metastatic carcinoma of the nose is a rare presentation associated with lung cancer. We report here 3 cases of cutaneous metastatic carcinoma of the nose that originated from lung cancer. Two men, age 61 and 76 years, with lung cancers were referred for evaluation of a tumour on the tip of the nose. The third patient, a 57-year-old man, had developed a rosacea-like tumour on the tip of the nose; although he had no history of internal cancer, whole-body positron-emission tomography-computed tomography revealed a primary lung cancer. Skin biopsies of all 3 cases showed metastatic squamous cell carcinoma, and all primary lung cancers were squamous cell carcinomas. Only 3 patients are described here, and further reports are needed to substantiate this interesting phenomenon. When an elderly patient presents to dermatology with a tumour on the nose with or without known internal cancer, it is necessary to approach the diagnosis with caution.

Imaging Therapeutic PARP Inhibition In Vivo through Bioorthogonally Developed Companion Imaging Agents

A number of small-molecule poly (ADP-ribose) polymerase (PARP) inhibitors are currently undergoing advanced clinical trials. Determining the distribution and target inhibitory activity of these drugs in individual subjects, however, has proven problematic. Here, we used a PARP agent for positron emission tomography-computed tomography (PET-CT) imaging ((18)F-BO), which we developed based on the Olaparib scaffold using rapid bioorthogonal conjugation chemistries. We show that the bioorthogonal (18)F modification of the parent molecule is simple, highly efficient, and well tolerated, resulting in a half maximal inhibitory concentration (IC(50)) of 17.9 ± 1.1 nM. Intravital imaging showed ubiquitous distribution of the drug and uptake into cancer cells, with ultimate localization within the nucleus, all of which were inhibitable. Whole-body PET-CT imaging showed tumoral uptake of the drug, which decreased significantly, after a daily dose of Olaparib. Standard (18)F-fludeoxyglucose imaging, however, failed to detect such therapy-induced changes. This research represents a step toward developing a more generic approach for the rapid codevelopment of companion imaging agents based on small-molecule therapeutic inhibitors.