Use Of 18F-FDG Research Articles

Metastatic Mucinous Adenocarcinoma of Unknown Origin Showing 68Ga-DOTATATE Uptake.

Although the use of 18F-FDG PET/CT is well established in the evaluation of adenocarcinoma, the performance of 18F-FDG PET/CT in mucinous adenocarcinoma is not consistent. 68Ga-DOTATATE uptake can be observed in some non-neuroendocrine tumors as a result of tumor blood flow and somatostatin receptor expression at different levels. For this reason, 68Ga-DOTATATE PET/CT may have a prospective role in the evaluation of mucinous adenocarcinoma. However, there is no published case of mucinous adenocarcinoma with 68Ga-DOTATATE uptake. We present a unique case of metastatic mucinous adenocarcinoma of unknown origin on 68Ga-DOTATATE PET/CT.

Diagnostic Performance of 18F-FDG PET/CT According to Delay After Treatment to Detect Subclinical Recurrence of Head and Neck Squamous Cell Carcinoma.

Head and neck squamous cell carcinoma (HNSCC) remains a malignancy with high rates of locoregional recurrence and poor prognosis for recurrent cases. Early detection of subclinical lesions is challenging but critical for effective patient management. Imaging surveillance after treatment, particularly 18F-FDG PET/CT, has shown promise in the diagnosis of HNSCC recurrence. The aim was to evaluate the diagnostic performance of 18F-FDG PET/CT according to delay after treatment in detecting subclinical recurrence (SCR) in HNSCC patients. Methods: In this retrospective study, all 18F-FDG PET/CT scans were performed at a single center. All adults with histologically proven HNSCC who were treated with curative intent between January 1, 2006, and December 31, 2021, were included. They had a normal clinical examination before each scan. Patients who underwent an intensive follow-up strategy after treatment had 18F-FDG PET/CT with an intravenous contrast agent at 3-6 mo and annually thereafter for 5 y. The primary endpoint was diagnostic performance (positive and negative predictive values, sensitivity, specificity, and accuracy). Results: In total, 2,566 18F-FDG PET/CT scans were performed among 852 patients, with an average of 3 scans per patient. The overall diagnostic performance measures were as follows: positive predictive value (88%), negative predictive value (98%), sensitivity (98%), specificity (89%), and accuracy (93%). There were no significant differences in diagnostic performance over time. The scans detected 126 cases of SCR (14.8%) and 118 cases of metachronous cancer (13.8%). The incidence of SCR decreased over time, with the highest detection rate in the first 2 y after treatment. Positive predictive value improved over time, reaching 90% for the digital Vision 600 system (third period) compared with 76% for the analog Gemini GXLi system (first period, P < 0.001). Multivariate analysis identified advanced stage, high body mass index, and initial PET/CT upstaging as predictive factors for detection of SCR. Conclusion: Our study demonstrates that 18F-FDG PET/CT has high diagnostic performance in detecting SCR during follow-up after treatment of HNSCC, especially in the first 2 y. Advanced tumor stage, initial PET/CT upstaging, and high body mass index were associated with a higher likelihood of SCR detection. The routine use of 18F-FDG PET/CT during follow-up seems justified for patients with HNSCC.

Role of 18F-FDG PET/CT in Head and Neck Squamous Cell Carcinoma: Current Evidence and Innovative Applications.

This article provides an overview of the use of 18F-FDG PET/CT in various clinical scenarios of head-neck squamous cell carcinoma, ranging from initial staging to treatment-response assessment, and post-therapy follow-up, with a focus on the current evidence, debated issues, and innovative applications. Methodological aspects and the most frequent pitfalls in head-neck imaging interpretation are described. In the initial work-up, 18F-FDG PET/CT is recommended in patients with metastatic cervical lymphadenectomy and occult primary tumor; moreover, it is a well-established imaging tool for detecting cervical nodal involvement, distant metastases, and synchronous primary tumors. Various 18F-FDG pre-treatment parameters show prognostic value in terms of disease progression and overall survival. In this scenario, an emerging role is played by radiomics and machine learning. For radiation-treatment planning, 18F-FDG PET/CT provides an accurate delineation of target volumes and treatment adaptation. Due to its high negative predictive value, 18F-FDG PET/CT, performed at least 12 weeks after the completion of chemoradiotherapy, can prevent unnecessary neck dissections. In addition to radiomics and machine learning, emerging applications include PET/MRI, which combines the high soft-tissue contrast of MRI with the metabolic information of PET, and the use of PET radiopharmaceuticals other than 18F-FDG, which can answer specific clinical needs.

Diagnostic value of 18F-FDG PET/CT versus diffusion-weighted MRI in detection of residual or recurrent tumors after definitive (chemo) radiotherapy for laryngeal and hypopharyngeal squamous cell carcinoma: A prospective study.

Despite advances in treatment, residual or recurrent tumors after definitive (chemo) radiotherapy for laryngeal and hypopharyngeal squamous cell carcinoma (SCC) remain a challenge in clinical management and require accurate and timely detection for optimal salvage therapy. This study aimed to compare the diagnostic value of Fluorine 18 (18F) fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and diffusion-weighted magnetic resonance imaging (DW-MRI) in detecting residual or recurrent tumors after definitive (chemo) radiotherapy for laryngeal and hypopharyngeal SCC. A prospective study was conducted on 30 patients who presented with new symptoms after definitive (chemo) radiotherapy for laryngeal (n = 21) and hypopharyngeal (n = 9) carcinoma. Both 18F-FDG PET/CT and DW-MRI were performed and histopathologic analysis served as the standard of reference. Histopathology showed 20 patients as positive and 10 as negative for tumors. 18F-FDG PET/CT detected all tumors correctly but was falsely positive in one case. DW-MRI detected tumors in 18 out of 20 positive patients and correctly excluded tumors in all negative patients. The sensitivity and specificity of 18F-FDG PET/CT were 100% and 90%, respectively, while the values for DW-MRI were 90% and 100%, respectively. The study concludes that 18F-FDG PET/CT is slightly superior to DW-MRI in detecting residual or recurrent tumors after definitive (chemo) radiotherapy for laryngeal and hypopharyngeal SCC. The combined use of 18F-FDG PET/CT and DW-MRI can potentially improve specificity in therapy response evaluation.

Detecting Metastatic Patterns of Oligometastatic Breast Cancer: A Comparative Analysis of 18F-FDG PET/CT and Conventional CT Imaging.

Metastasis-directed therapy has the potential to improve progression-free and overall survival in oligometastatic disease (OMD). For breast cancer, however, randomized trials have failed so far to confirm this finding. Because the concept of metastasis-directed therapy in OMD is highly dependent on the accuracy of the imaging modality, we aimed to assess the impact of 18F-FDG PET/CT on the definition of OMD in breast cancer patients. Methods: Eighty patients with a total of 150 18F-FDG PET/CT images (between October 2006 and January 2022) were enrolled in this retrospective study at the Technical University of Munich. The inclusion criteria were OMD, defined as 1-5 distant metastases, at the time of 18F-FDG PET/CT. For the current study, we systemically compared the metastatic pattern on 18F-FDG PET/CT with conventional CT. Results: At the time of 18F-FDG PET/CT, 21.3% of patients (n = 32) had a first-time diagnosis of metastatic disease, 40.7% (n = 61) had a previous history of OMD, and 38% (n = 57) had a previous history of polymetastatic disease. In 45.3% of cases, the imaging modality (18F-FDG PET/CT vs. conventional CT) had an impact on the assessment of whether OMD was present. An identical metastatic pattern was observed in only 32% of cases.18F-FDG PET/CT detected additional metastases in 33.3% of cases, mostly in the nonregional lymph node system. Conclusion: The use of 18F-FDG PET/CT had a substantial impact on the definition of OMD and detection of metastatic pattern in breast cancer. Our results emphasize the importance of establishing a standardized definition for imaging modalities in future trials and clinical practices related to metastasis-directed therapy in breast cancer patients.

Multiple myeloma: characterization of patients through the analysis of semiquantitative parameters with 18F-FDG PET

BackgroundMultiple myeloma (MM) is the second most common hematological malignancy after non-Hodgkin lymphoma. Recently, the use of 18F-FDG PET/CT has become more and more diffused thanks to its ability to combine functional and morphological information for diagnosis, prognosis assessment, and evaluation of treatment response. This study aims to describe the semiquantitative parameters obtained from 18F-FDG PET/CT in a population of patients with MM. A comparative analysis was performed with existing literature.MethodsThis retrospective study included 50 patients with suspected MM who had undergone whole-body 18F-FDG PET/CT. The semiquantitative parameters obtained from 18F-FDG PET/CT positive scans were analyzed, specifically the number of focal lesions (FLs), the SUVmax of the “hottest” lesion, the ratio between SUVmax of the bone marrow and the spleen (marrow-to-spleen SUVmean ratio), marrow-to-spleen SULpeak ratio, and MTV.ResultsOf the total cohort of 50 patients submitted to 18F-FDG PET/CT for suspected MM, 39 subjects resulted affected by MM. The 11 negative 18F-FDG PET/CT scans of the remaining subjects were not included. 59% of patients were males, and mean age (SD) was 65 ± 7.8 years. Based on the number of FLs, the entire cohort was divided into three groups: 14 patients in group A with more than 10 lesions; 5 patients in group B had a number of lesions between 5 and 10; and 24 patients in group C presented with less than 5 lesions.ConclusionsSemiquantitative parameters obtained through 18F-FDG PET can be useful in the assessment of staging criteria for MM, as the metabolic activity of lesions is higher in patients with extensive disease at the time of diagnosis. The predictive and prognostic relevance of these parameters as well as their role in guiding the therapeutic process toward ASCT worths further research.

Determining the usefulness of systematic 18F-FDG PET/CT for the management of invasive fungal infection (PETIFI project): a prospective national multicentre cohort study protocol

IntroductionThe evaluation of staging and activity of invasive fungal infection (IFI) is used to adjust the type and duration of antifungal therapy (AT). Typically anatomy-based imaging is used. Positron emission...

Assessing the Performance of 18F-FDG PET/CT in Bladder Cancer: A Narrative Review of Current Evidence.

Lymph node (LN) involvement is a crucial determinant of prognosis for patients with bladder cancer, and an accurate staging is of utmost importance to better identify timely and appropriate therapeutic strategies. To improve the accuracy of LN detection, as an alternative to traditional methods such as CT or MRI, 18F-FDG PET/CT has been increasingly used. 18F-FDG PET/CT is also used in post-treatment restaging after neoadjuvant chemotherapy. The aim of this narrative literature review is to provide an overview of the current evidence on the use of 18F-FDG PET/CT in the diagnosis, staging, and restaging of bladder cancer, with a particular focus on its sensitivity and specificity for the detection of LN metastasis. We aim to provide clinicians with a better understanding of 18F-FDG PET/CT's potential benefits and limitations in clinical practice. We designed a narrative review starting from a wide search in the PubMed/MEDLINE and Embase databases, selecting full-text English articles that have examined the sensibility and specificity of PET/CT for nodal staging or restaging after neoadjuvant therapy in patients with bladder cancer. The extracted data were analyzed and synthesized using a narrative synthesis approach. The results are presented in a tabular format, with a summary of the main findings of each study. Twenty-three studies met the inclusion criteria: fourteen studies evaluated 18F-FDG PET/CT for nodal staging, six studies examined its accuracy for restaging after neoadjuvant therapy, and three studies evaluated both applications. To date, the use of F-18 FDG PET/TC for detection of LN metastasis in bladder cancer is controversial and uncertain: some studies showed low accuracy rates, but over the years other studies have reported evidence of high sensitivity and specificity. 18F-FDG PET/CT provides important incremental staging and restaging information that can potentially influence clinical management in MIBC patients. Standardization and development of a scoring system are necessary for its wider adoption. Well-designed randomized controlled trials in larger populations are necessary to provide consistent recommendations and consolidate the role of 18F-FDG PET/CT in the management of bladder cancer patients.

The use of 18F-FDG PET/CT for radiotherapy treatment planning in non-small cell lung cancer: a mini-review

: In the past decades, the technical achievements in radiotherapy treatment planning and delivery, such as the use of intensity-modulated radiotherapy or the use of image-guided radiotherapy, alongside with the significant developments in molecular imaging and especially the use of positron-emission tomography (PET) have significantly improved radiotherapy treatment precision. In non-small cell lung cancer (NSCLC), the use of 18F-fluoro-desoxy-glucose (18F-FDG) positron-emission tomography/computed tomography (18F-FDG-PET/CT) has a high accuracy for diagnostic workup, staging and response assessment but has been also implemented to optimize target volume concepts in NSCLC with high precision. These advances led, in the recent years, to an increased tumor control and improved outcomes. Especially in the context of emerging systemic treatments, such as immune checkpoint blockades (ICBs), the prevention of unnecessary irradiation of the lymphatic system might be very important. In the past years, several prospective randomized studies have been performed, aiming to optimize, standardize and develop new concepts in the target volume delineation especially in locally advanced NSCLC using different approaches. While the PET-Plan trial used a uniform target volume reduction based on the 18F-FDG-PET/CT signal in the experimental arm, the PET boost trial and the RTOG 1106 used the 18F-FDG-PET/CT information to define an additional boost volume for dose escalation. Within this mini-review, we provide an overview on the role of 18F-FDG-PET/CT, the challenges and the benefits, in radiotherapy of NSCLC.

Clinical use of 18F-FDG PET/CT in the differential diagnosis of patients with primary and secondary adenoid cystic carcinoma of the lung: a retrospective cohort study.

BackgroundAdenoid cystic carcinoma (ACC) of the lung (ACCL) is a rare malignancy and includes primary ACCL (PACCL) and secondary ACCL (SACCL) metastasized from the ACC of the head and neck. Fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has been shown to be useful in the differential diagnosis between primary and metastatic lung lesions. This study retrospectively investigated the role of 18F-FDG PET/CT in combination with clinicopathological findings in the management of patients with primary or secondary ACCL.MethodsClinicopathological characteristics and 18F-FDG PET/CT metabolic parameters of 29 patients with PACCL and 11 patients with SACCL with pathological confirmation as gold standard were retrospectively collected. The association between PET/CT metabolic parameters and clinicopathological features was explored. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal maximum standard uptake value (SUVmax) cut-off value to distinguish PACCL from SACCL. The prognostic value of PET/CT metabolic parameters and clinicopathological features was evaluated by Cox regression analysis.ResultsSACCL patients more often presented with multiple ACC lesions in the peripheral lung (81.8% vs. 17.2%, P<0.05) and tended to be asymptomatic compared to patients with PACCL (72.7% versus 27.6%, P<0.05). The SUVmax was significantly higher in PACCL patients compared to SACCL patients (median 4.4 vs. 2.8, P<0.05). Furthermore, at a cut-off value of 3.2 for SUVmax, the sensitivity and specificity of 18F-FDG PET/CT in distinguishing PACCL from SACCL were 82.8% and 72.7%, respectively. Higher SUVmax of ACCL was observed in patients with clinical symptoms, fewer ACC lesions, or larger tumor size (P<0.05). The median PFS of ACCL patients was 71.1 months, and the 12- and 24-month PFS rates were 96.1% and 91.6%, respectively. Univariate Cox regression analysis showed that SACCL from metastasis, lesions located at the peripheral lung or multiple ACC lesions present in the lung, were associated with poorer PFS (P<0.05). However, multivariate Cox regression analysis showed that none of the variables examined were independent predictors of prognosis.ConclusionsThe use of 18F-FDG PET/CT in combination with assessment of clinicopathological features was helpful in distinguishing PACCL from SACCL, which could provide guidance for clinical decision making.

Lack of Adherence to Guideline-Based Imaging Before Subsequent Radiation in Patients with Non-Small Cell Lung Cancer: Impact on Patient Outcomes.

Lung cancer is the leading cause of cancer death within the United States, yet prior studies have shown a lack of adherence to imaging and treatment guidelines in patients with lung cancer. This study evaluated the use of 18F-FDG PET/CT imaging before subsequent radiation therapy (RT) in patients with non-small cell lung cancer (NSCLC), as recommended by National Comprehensive Cancer Network guidelines, and whether the use of this imaging modality impacts cancer-specific survival. Methods: This was a retrospective study of the National Cancer Institute's Surveillance, Epidemiology, and End Results program of Medicare-linked data in patients with NSCLC. Hazard ratios and 95% CIs for overall and cancer-specific survival were estimated for patients diagnosed between 2006 and 2015 who underwent either 18F-FDG PET/CT-based or CT-based imaging before subsequent RT. Results: Significant improvement in cancer-specific survival was found in patients who underwent 18F-FDG PET/CT imaging before subsequent RT, compared with those who underwent CT (hazard ratio, 1.43 [95% CI, 1.32-1.55; P < 0.0001]). Although the National Comprehensive Cancer Network recommends 18F-FDG PET/CT before subsequent RT, 43.6% of patients were imaged with CT alone. Conclusion: Many patients with NSCLC are not being imaged according to national guidelines before subsequent RT, and this omission is associated with a lower cancer-specific survival.

Multimodality radionuclide imaging in fever of unknown origin presenting with a solitary spleen lesion

BackgroundFever of unknown origin (FUO) still represents a serious challenge for clinicians, since it can be related to a wide spectrum of disorders, ranging from infections to malignancies. In this scenario, nuclear medicine can be of value to achieve a correct diagnosis both through positron emission computed tomography (PET/CT) and 99mTc labeled hexamethylpropylene amine oxime (HMPAO) white blood cell (WBC) scintigraphy.Case presentationWe are presenting the case of 65-year-old male, who was referred to our hospital due to prolonged unexplained fever. He was submitted to abdomen ultrasonography (US) that did not disclose relevant pathological findings. Subsequently, he underwent PET/CT scan with 18F-fluorodeoxyglucose (18F-FDG) that revealed an area of increased tracer uptake in splenic inferior pole. In order to solve differential diagnosis between tumor and infection, he was submitted to 99mTc-HMPAO WBC scintigraphy that resulted negative for sites of pathologic radiolabeled cells’ accumulation but revealed a photopenic area in the splenic inferior pole. The pattern of mismatched uptake between 18F-FDG PET/CT and 99mTc-HMPAO WBC scintigraphy was considered highly suspicious for spleen tumor localization. The patient was scheduled for splenectomy and histology resulted positive for non-Hodgkin lymphoma (NHL) of diffuse large B cell type. After splenectomy, a further 18F-FDG PET/CT revealed the appearance of hypermetabolic hepatic lesions. The patient underwent chemotherapy with complete remission.ConclusionNuclear medicine provides valuable tools for differential diagnosis in FUO. In case of patients presenting solitary lesion of the spleen, the combined use of 18F-FDG PET/CT and 99mTc-HMPAO WBC scintigraphy can provide relevant information to aid clinicians to a correct diagnosis.

Whole-body Positron Emission Tomography (WBPET) Scan in All Patients of Breast Cancer: Is This the Way Forward?

Objectives: Globally, breast cancer is the second most frequently diagnosed malignancy just behind lung cancer, accounting for over 2 million cases each year. It is the second most commonly diagnosed cancer worldwide and the most common malignancy among females in India. The role of whole-body positron emission tomography (WBPET) in all cases of breast cancer is still not clear. This pilot study was undertaken to study whether there is any change in the management of breast cancer using WBPET scan in all patients of breast cancer irrespective of the stage? Materials and Methods: We retrospectively reviewed the data of 43 patients with invasive breast cancer who were newly diagnosed at Malignant Disease Treatment Centre at a tertiary care centre in East India. The duration of the study was between June 2020 and March 2021. Patients underwent liver function test, mammography, breast ultrasound, bone scan, and tru-cut needle biopsy to confirm the presence of breast cancer and 18F-fluoro-Dglucose (FDG) positron emission tomography/computed tomography (PET/CT) was studied in all 43 patients before the initiation of any therapy. The primary objective was to find out whether doing a WBPET upstaged the disease and changed our management. The secondary objective was to determine whether hormonal status (oestrogen receptor [ER], progesterone receptor [PR] and human epidermal growth factor receptor 2 [Her2] Neu) and Breast Imaging-Reporting and Database System (BIRADS) score staging had any correlation with metastasis. Results: A total of 43 patients with newly diagnosed breast cancer were studied. The number of patients in Stage IIA (3/43), Stage IIB (4/43), Stage III A (17/43), Stage IIIB (13/43), and Stage IV was (6/33). Out of total 43 patients, in 10 (23%) patients, there was a change in treatment on doing an upfront WBPET scan. There was no correlation between ER, PR, or Her2 Neu positivity or negativity on the upstaging of the disease and change in treatment. Standardised uptake value (SUV) uptake of the primary lesion &gt;7.2 was associated with upstaging and change of treatment. Conclusion: The use of 18F-FDG PET/CT has been shown to bring change in treatment in almost 20% of patients with breast cancer. Although the role of other variables in breast cancer such as hormone status, SUV of the primary lesion, and grade of lesion on BIRADS has also shown some association with change of treatment.

The Use of 18F-FDG PET/CT Metabolic Parameters in Predicting Overall Survival in Patients Undergoing Restaging for Malignant Melanoma

Malignant melanoma is one of the more aggressive cancers in the skin, with an increasing incidence every year. Melanoma has a better prognosis if diagnosed early and survival tends to decrease once the disease has metastasized. Positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) has been used extensively over the past two decades in staging and assessing responses to therapy in patients with melanoma. Metabolic PET parameters have been demonstrated to be independent prognostic factors for progression-free survival (PFS) and overall survival (OS) in different malignancies, melanoma included. In our study, we evaluated the metabolic parameters of 18F-FDG PET/CT (flourodeoxyglucose positron emission tomography/computed tomography) in predicting the overall survival in patients with malignant melanoma who presented for restaging. Metabolic PET parameters (maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG)) of the primary tumor, as well as whole-body MTV and TLG of the metastatic disease, were measured. Survival curves for OS were constructed and mortality rates were determined using the different PET variables. Forty-nine patients who presented for a PET/CT restaging in melanoma were included in this study. We found that non-survivors had significantly higher median MTV (11.86 cm3 vs. 5.68 cm3; p-value = 0.022), TLG (3125 vs. 14; p-value = 0.0357), whole-body MTV (53.9 cm3 vs. 14.4 cm3; p-value = 0.0076) and whole-body TLG (963.4 vs. 114.6; p-value = 0.0056). This demonstrated that high MTV and TLG values of the primary tumor and whole-body TLG as quantified by 18F-FDG PET/CT were prognostic factors for overall survival. The findings may potentially guide clinicians in decision making and identifying patients with a poorer prognosis.

Current situation and cost-effectiveness of 18F-FDG PET/CT for the diagnosis of fever of unknown origin and inflammation of unknown origin: A single-center, large-sample study from China

Purpose18F-FDG PET/CT has an important role in the evaluation of fever of unknown origin (FUO) and inflammation of unknown origin (IUO). Our study was to investigate the current status of the inclusion of 18F-FDG PET/CT within FUO/ IUO diagnostic work-up and evaluate the cost-effectiveness of it in China. MethodsA total of 741 FUO/IUO patients admitted to our hospital from January 2012 to December 2019 were retrospectively reviewed. The clinical characteristic, medical expenses to reach diagnosis and the proportion of definite etiological diagnosis achieved upon hospital discharge were compared between patients examined by 18F-FDG PET/CT (18F-FDG PET/CT group) and patients not examined by 18F-FDG PET/CT (non-18F-FDG PET/CT group). ResultsThe mean age, proportion of critically-ill patients, proportion of rheumatologic diseases, the number of examinations and hospitalisation days to reach diagnosis in the 18F-FDG PET/CT group were significantly higher than those in the non-18F-FDG PET/CT group. The mean medical costs of 18F-FDG PET/CT group were significantly higher than those of non-18F-FDG PET/CT group, whereas the proportion of definite etiological diagnosis achieved upon hospital discharge of 18F-FDG PET/CT group was significantly higher than that of non-18F-FDG PET/CT group. The mean hospitalisation days and mean medical costs before diagnosis were significantly lower in patients who undertook 18F-FDG PET/CT ≤ 7 days after hospital admission than those in patients who undertook 18F-FDG PET/CT > 7 days after hospital admission. Conclusions18F-FDG PET/CT is mostly used in critically-ill and hard-to-diagnose FUO/IUO patients currently in China, which may conceal its cost-effective advantage. While the early use of 18F-FDG PET/CT according to patient characteristics and etiological clues could help to reduce hospitalization stay, limit medical costs, thus producing its diagnostic effect to the great extent.

Diagnostic Significance of 18F-FDG PET/CT Imaging Coupled with Magnetic Resonance Imaging of the Entire Body for Bone Metastases.

Objective To see if 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging paired with MR diffusion imaging can help doctors diagnose bone metastases. Methods From September 2020 to December 2021, a total of 30 individuals with probable bone metastases were recruited for the trial. With an average interval of four days, MAGNETIC resonance whole-body diffusion imaging (MR whole-body diffusion imaging) was performed on each of the 30 patients who had 18F-FDG PET/CT. The SUVmax values of the group with bone metastases were compared to those of the group without bone metastases. In this study, 18F-FDG PET/CT imaging, MR whole-body diffusion imaging, and their combination were examined. The researchers compared the results when 18F-FDG PET/CT imaging, whole-body MRI diffusion scans, and their combination indicated abnormal bone lesions. By comparing the diagnostic efficacy of 18F-FDG PET/CT imaging, MR whole-body diffusion imaging, and their combination, as well as accuracy, sensitivity, and specificity, the three techniques for diagnosing bone metastases will be evaluated for diagnostic usefulness. Results: the SUV max values of patients with bone metastases were significantly different from those of patients without bone metastases, as determined by 18F-FDG PET/CT imaging (P < 0.05). Using 18F-FDG PET/CT imaging, MR whole-body diffusion imaging, and their combined detection of aberrant bone lesions in various areas, we found statistically significant differences. Conclusion The use of 18F-FDG PET/CT imaging in conjunction with MR whole-body diffusion imaging in the diagnosis of bone metastases can be very helpful.

Current Roles of PET/CT in Thymic Epithelial Tumours: Which Evidences and Which Prospects? A Pictorial Review.

Simple SummaryThymic epithelial tumours are uncommon malignancies. Histologically, they may be distinguished in different subtypes and different relapse risk classes. Surgery, sometimes after induction therapy, stays the best treatment option, and long-term results depend on the disease stage and completeness of resection. In this context, 18F FDG PET CT scan has been reported to play different roles in the care strategy of thymic epithelial tumours. In the present review, we analyse current evidences, the use of this imaging tool and future application prospects.Background: The use of 18F FDG PET/CT scan in thymic epithelial tumours (TET) has been reported in the last two decades, but its application in different clinical settings has not been clearly defined. Methods: We performed a pictorial review of pertinent literature to describe different roles and applications of this imaging tool to manage TET patients. Finally, we summarized future prospects and potential innovative applications of PET in these neoplasms. Results: 18FFDG PET/CT scan may be of help to distinguish thymic hyperplasia from thymic epithelial tumours but evidences are almost weak. On the contrary, this imaging tool seems to be very performant to predict the grade of malignancy, to a lesser extent pathological response after induction therapy, Masaoka Koga stage of disease and long-term prognosis. Several other radiotracers have some application in TETs but results are limited and almost controversial. Finally, the future of PET/CT and theranostics in TETs is still to be defined but more detailed analysis of metabolic data (such as texture analysis applied on thymic neoplasms), along with promising preclinical and clinical results from new “stromal PET tracers”, leave us an increasingly optimistic outlook. Conclusions: PET plays different roles in the management of thymic epithelial tumours, and its applications may be of help for physicians in different clinical settings.

18F FDG imaging – response criteria in tumors

With the progress of medical oncology, it became apparent that anatomical imaging is oftentimes insufficient for therapy response evaluation. Hybrid imaging, namely 18F-FDG PET/CT has helped to overcome these limitations. The aim of this paper is to emphasize the utility and impact in clinical use of 18F-FDG PET/CT, and to give an overview of the most important 18F-FDG PET/CT tumor response criteria.We also focus on standardization of hybrid imaging techniques as this is of outmost importance to provide reliable imaging evaluation.

Comparison of PSF and Non PSF BLOB based reconstructed image in Time-of-Flight PET/CT

Hybrid PET/CT imaging with the use of 18F FDG is a widely used imaging technique with major indications in oncology for staging, re-staging and monitoring response to therapy. There is a major issue of partial volume effect in PET images which affects image quality as well as quantitative accuracy in small lesions. Multiple attempts have been made to resolve these issues. The aim of our study was to look into impact of Point‐spread-function (PSF) on reconstructed attenuation corrected (AC) images of PET/CT and to find out best combination of the number of PSF iterations with regularization level while applying PSF.

Het gebruik van 18F-FDG PET/CT ter evaluatie van multipel myeloom

The use of 18F-FDG PET/CT to evaluate patients with multiple myeloma. Detection of bone lesions are important to diagnose multiple myeloma. In this study we investigate the role of an 18F-FDG PET/CT exam. Fifteen newly diagnosed multiple myeloma patients were included in this retrospective study. A 18F-FDG PET/CT was performed at diagnosis and after induction therapy. The response of a treatment is examined by semi-quantitative parameters (standardised 18F-FDG uptake values) and volumetric parameters (metabolic tumor volume and total lesion glycolysis). The aim of this study is to evaluate the use of these parameters for response evaluation and risk assessment in multiple myeloma. The prognostic value of an increased metabolic activity of the spleen is also examined. All semi-quantitative and volumetric parameters in this study are useful for response evaluation. Lower values of maximum or mean standardized uptake values (SUVmax, SUVmean) and total lesion glycolysis at diagnosis are prognostic favourable. We could not prove prognostic relevance for a spleen to liver ratio. Due to the small study population, all these results have to be confirmed in a larger patient cohort. 18F-FDG PET/CT is a reliable technique for response evaluation and risk stratification in multiple myeloma. In the future semi-quantitative and volumetric parameters will probably be incorporated in the risk classification systems of multiple myeloma patients.