[Necrosis of the tongue as a clinical manifestation of giant cell arteritis]

An 83-year-old male patient presented due to a 3-week history of swelling of the tongue with tongue pain on eating, yellowish plaques, and a gray-brown lesion in the anterior portion of the tongue. Sudden loss of vision in the left eye and temporal headache occurred 3 days before presentation. Due to elevated C‑reactive protein, sonography of the supraaortic arteries as well as positron emission tomography/computed tomography was performed. Imaging revealed inflammation of the great arteries as well as a halo sign on ultrasound of the temporal artery. Thus, a diagnosis of giant cell arteritis with necrosis of the tongue was made. Immunosuppressive therapy with glucocorticoids was initiated. Necrosis of the tongue is a rare manifestation of giant cell arteritis that requires immediate immunosuppressive therapy to prevent further complications to the tongue (e.g., complete necrosis of the tongue, superinfection, tongue amputation).

Incidentally found parotid gland lesion in 18F-FDG PET/CT for staging evaluation of patients with hepatocellular carcinoma: remote possibility of metastatic tumor or second primary salivary gland malignancy

OBJECTIVES

We primarily aimed to evaluate whether parotid incidental lesion (PIL) in 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for staging evaluation of patients with hepatocellular carcinoma (HCC) would represent a possibility of extrahepatic metastasis or second primary malignancy (SPM). Additionally, we explored the incidence of PIL in HCC patients and examined any associated risk factors.

METHODS

We retrospectively analyzed patients with HCC who underwent 18F-FDG PET/CT at our institution from 2010 to 2022. The pathological findings of PILs in HCC patients were investigated for confirmatory identification of the risk of HCC metastasis or SPM in parotid gland. Healthy controls received 18F-FDG PET/CT for health screening were also enrolled to compare the incidence of PILs with HCC patients. Various parameters associated with patient demographics and characteristics of HCC were analyzed to find the related factors of PILs.

RESULTS

A total of 17,674 patients with HCC and 2,090 healthy individuals who had undergone 18F-FDG PET/CT scans were enrolled in the analyses. Among the 54 HCC patients who underwent pathological confirmation for PILs, benign primary parotid tumor was most commonly observed (n = 43 [79.6%]); however, no malignant lesions were detected, including HCC metastasis. The incidence of PILs was higher in patients diagnosed with HCC compared with the control group (485 [2.7%] vs. 23 [1.1%], p = 0.002). Analysis for the risk factors for PILs revealed that patient age, sex, and positive viral markers were significantly associated with the incidence of PILs in patients with HCC (all p < 0.001).

CONCLUSIONS

Our study demonstrates that PILs are more frequently identified in patients with HCC on 18F-FDG PET/CT. However, no malignant PIL, including extrahepatic metastasis of HCC, was identified. Therefore, the presence of PIL should not impede or delay the treatment process for patients with HCC. Additionally, we suggested that for future swift and straightforward differential diagnoses of PIL, the development of additional protocols within the PET/CT imaging could be beneficial.

Evidence of brain metabolism redistribution from neocortex to primitive brain structures in early acute COVID-19 respiratory syndrome

BACKGROUND

Neuropsychiatric sequelae of COVID-19 have been widely documented in patients with severe neurological symptoms during the chronic or subacute phase of the disease. However, it remains unclear whether subclinical changes in brain metabolism can occur early in the acute phase of the disease. The aim of this study was to identify and quantify changes in brain metabolism in patients hospitalized for acute respiratory syndrome due to COVID-19 with no or mild neurological symptoms.

RESULTS

Twenty-three non-intubated patients (13 women; mean age 55.5 ± 12.1 years) hospitalized with positive nasopharyngeal swab test (RT-PCR) for COVID-19, requiring supplemental oxygen and no or mild neurological symptoms were studied. Serum C-reactive protein measured at admission ranged from 6.43 to 189.0 mg/L (mean: 96.9 ± 54.2 mg/L). The mean supplemental oxygen demand was 2.9 ± 1.4 L/min. [18F]FDG PET/CT images were acquired with a median of 12 (4-20) days of symptoms. After visual interpretation of the images, semiquantitative analysis of [18F]FDG uptake in multiple brain regions was evaluated using dedicated software and the standard deviation (SD) of brain uptake in each region was automatically calculated in comparison with reference values of a normal database. Evolutionarily ancient structures showed positive SD mean values of [18F]FDG uptake. Lenticular nuclei were bilaterally hypermetabolic (> 2 SD) in 21/23 (91.3%) patients, and thalamus in 16/23 (69.6%), bilaterally in 11/23 (47.8%). About half of patients showed hypermetabolism in brainstems, 40% in hippocampi, and 30% in cerebellums. In contrast, neocortical regions (frontal, parietal, temporal and occipital lobes) presented negative SD mean values of [18F]FDG uptake and hypometabolism (< 2 SD) was observed in up to a third of patients. Associations were found between hypoxia, inflammation, coagulation markers, and [18F]FDG uptake in various brain structures.

CONCLUSIONS

Brain metabolism is clearly affected during the acute phase of COVID-19 respiratory syndrome in neurologically asymptomatic or oligosymptomatic patients. The most frequent finding is marked hypermetabolism in evolutionary ancient structures such as lenticular nucleus and thalami. Neocortical metabolism was reduced in up to one third of patients, suggesting a redistribution of brain metabolism from the neocortex to evolutionary ancient brain structures in these patients.

Transfer learning-based PET/CT three-dimensional convolutional neural network fusion of image and clinical information for prediction of EGFR mutation in lung adenocarcinoma

BACKGROUND

To introduce a three-dimensional convolutional neural network (3D CNN) leveraging transfer learning for fusing PET/CT images and clinical data to predict EGFR mutation status in lung adenocarcinoma (LADC).

METHODS

Retrospective data from 516 LADC patients, encompassing preoperative PET/CT images, clinical information, and EGFR mutation status, were divided into training (n = 404) and test sets (n = 112). Several deep learning models were developed utilizing transfer learning, involving CT-only and PET-only models. A dual-stream model fusing PET and CT and a three-stream transfer learning model (TS_TL) integrating clinical data were also developed. Image preprocessing includes semi-automatic segmentation, resampling, and image cropping. Considering the impact of class imbalance, the performance of the model was evaluated using ROC curves and AUC values.

RESULTS

TS_TL model demonstrated promising performance in predicting the EGFR mutation status, with an AUC of 0.883 (95%CI = 0.849-0.917) in the training set and 0.730 (95%CI = 0.629-0.830) in the independent test set. Particularly in advanced LADC, the model achieved an AUC of 0.871 (95%CI = 0.823-0.919) in the training set and 0.760 (95%CI = 0.638-0.881) in the test set. The model identified distinct activation areas in solid or subsolid lesions associated with wild and mutant types. Additionally, the patterns captured by the model were significantly altered by effective tyrosine kinase inhibitors treatment, leading to notable changes in predicted mutation probabilities.

CONCLUSION

PET/CT deep learning model can act as a tool for predicting EGFR mutation in LADC. Additionally, it offers clinicians insights for treatment decisions through evaluations both before and after treatment.

Development and Internal Validation of a Novel Nomogram Predicting the Outcome of Salvage Radiation Therapy for Biochemical Recurrence after Radical Prostatectomy in Patients without Metastases on Restaging Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography

Background and objective

Owing to the greater use of prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) in patients with biochemical recurrence (BCR) of prostate cancer (PCa) after robot-assisted radical prostatectomy (RARP), patient selection for local salvage radiation therapy (sRT) has changed. Our objective was to determine the short-term efficacy of sRT in patients with BCR after RARP, and to develop a novel nomogram predicting BCR-free survival after sRT in a nationwide contemporary cohort of patients who underwent PSMA PET/CT before sRT for BCR of PCa, without evidence of metastatic disease.

Methods

All 302 eligible patients undergoing PCa sRT in four reference centers between September 2015 and August 2020 were included. We conducted multivariable logistic regression analysis using a backward elimination procedure to develop a nomogram for predicting biochemical progression of PCa, defined as prostate-specific antigen (PSA) ≥0.2 ng/ml above the post-sRT nadir within 1 yr after sRT.

Key findings and limitations

Biochemical progression of disease within 1 yr after sRT was observed for 56/302 (19%) of the study patients. The final predictive model included PSA at sRT initiation, pathological grade group, surgical margin status, PSA doubling time, presence of local recurrence on PSMA PET/CT, and the presence of biochemical persistence (first PSA result ≥0.1 ng/ml) after RARP. The area under the receiver operating characteristic curve for this model was 0.72 (95% confidence interval 0.64-0.79). Using our nomogram, patients with a predicted risk of >20% had a 30.8% chance of developing biochemical progression within 1 yr after sRT.

Conclusions

Our novel nomogram may facilitate better patient counseling regarding early oncological outcome after sRT. Patients with high risk of biochemical progression may be candidates for more extensive treatment.

Patient summary

We developed a new tool for predicting cancer control outcomes of radiotherapy for patients with recurrence of prostate cancer after surgical removal of their prostate. This tool may help in better counseling of these patients with recurrent cancer regarding their early expected outcome after radiotherapy.

Primary diffuse large B-cell lymphoma of the cecum

When found in the cecum or rectosigmoid junction, primary colorectal B-cell lymphoma is a rare malignant non-Hodgkin's lymphoma often associated with an unfavorable prognosis. Due to the nonspecific clinical symptoms, these uncommon tumors are often left undefined or misdiagnosed, resulting in delays in treatment and adverse patient outcomes. Contrast-enhanced computed tomography is the most commonly used medical imaging process for primary colorectal lymphoma, but due to the rarity of this disorder, accurate imaging diagnosis remains a clinical challenge. In this article, we report the case of a 70-year-old male who was diagnosed with primary B-cell lymphoma of the cecum. We focus on improving diagnosis through the utilization of radiological imaging modalities, particularly computed tomography (CT) and fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18-F-FDG PET/CT). While imaging modalities are important in recognizing colonic lymphomas, there are no pathognomonic imaging features for lymphoma; therefore, biopsy remains necessary for diagnostic confirmation.

Differentiation of early relapse and late relapse in intermediate- and high-risk neuroblastoma with an 18F-FDG PET/CT-based radiomics nomogram

OBJECTIVES

To develop and validate an 18F-FDG PET/CT-based radiomics nomogram for differentiating early relapse and late relapse of intermediate- and high-risk neuroblastoma (NB).

METHODS

A total of eighty-five patients with relapsed NB who underwent 18F-FDG PET/CT were retrospectively evaluated. All selected patients were randomly assigned to the training set and the validation set in a 7:3 ratio. Tumors were segmented using the 3D slicer, followed by radiomics features extraction. Features selection was performed using random forest, and the radiomics score was constructed by logistic regression analysis. Clinical risk factors were identified, and the clinical model was constructed using logistic regression analysis. A radiomics nomogram was constructed by combining the radiomics score and clinical risk factors, and its performance was evaluated by receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA).

RESULTS

Finally, the 12 most important radiomics features were used for modeling, with an area under the curve (AUC) of 0.835 and 0.824 in the training and validation sets, respectively. Age at diagnosis and International Neuroblastoma Pathology Classification were determined as clinical risk factors to construct the clinical model. In addition, the nomogram achieved an AUC of 0.902 and 0.889 for identifying early relapse in the training and validation sets, respectively, which is higher than the clinical model (AUC of 0.712 and 0.588, respectively). The predicted early relapse and actual early relapse in the calibration curves were in good agreement. The DCA showed that the radiomics nomogram was clinically useful.

CONCLUSION

Our 18F-FDG PET/CT-based radiomics nomogram can well predict early relapse and late relapse of intermediate- and high-risk NB, which contributes to follow-up and management in clinical practice.

18F-FDG PET/CT-Based Radiomics Nomogram for Prediction of Bone Marrow Involvement in Pediatric Neuroblastoma: A Two-Center Study

RATIONALE AND OBJECTIVES

To assess the predictive ability of an 18F-FDG PET/CT-based radiomics nomogram for bone marrow involvement in pediatric neuroblastoma.

MATERIALS AND METHODS

A total of 241 neuroblastoma patients who underwent 18F-FDG PET/CT at two medical centers were retrospectively evaluated. Data from center A (n = 200) were randomized into a training cohort (n = 140) and an internal validation cohort (n = 60), while data from center B (n = 41) constituted the external validation cohort. For each patient, two regions of interest were defined using the tumor and axial skeleton. The clinical factors and radiomics features were derived to construct the clinical and radiomics models. The radiomics nomogram was built by combining clinical factors and radiomics features. The area under the receiver operating characteristic curves (AUCs) were used to assess the performance of the models.

RESULTS

Radiomics models created from tumor and axial skeleton achieved AUCs of 0.773 and 0.900, and the clinical model had an AUC of 0.858 in the training cohort. By incorporating clinical risk factors and axial skeleton-based radiomics features, the AUC of the radiomics nomogram in the training cohort, internal validation cohort, and external validation cohort was 0.932, 0.887, and 0.733, respectively.

CONCLUSION

The axial skeleton-based radiomics model performed better than the tumor-based radiomics model in predicting bone marrow involvement. Moreover, the radiomics nomogram showed that combining axial skeleton-based radiomics features with clinical risk factors improved their performance.

Role of PSMA-targeted PET-CT in renal cell carcinoma: a systematic review and meta-analysis

Fluoro-deoxy glucose positron emission tomography/computed tomography (PET/CT), the workhorse of nuclear medicine, has limited utility for renal cell carcinoma (RCC), particularly clear cell variant. Thus, various other tracers have been tried for evaluation of RCC. One of the most promising targets for radiotracers is prostate-specific membrane antigen (PSMA) expressed in abundance in carcinoma-associated neo-vasculature. Thus, we tried to review and analyse the role of PSMA-targeted PET/CT in evaluation of RCC. Databases like PubMed, EMBASE and SCOPUS were searched for original studies published on PSMA-targeted PET/CT in RCC till 30 September 2023. Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) checklist was used to assess the included studies. Pooled sensitivity and specificity were calculated and represented with 95% confidence intervals (95%CI). Heterogeneity in the studies was assessed by I-square index. Pooled sensitivity and specificity of PSMA-targeted PET/CT for detection of local disease estimates were 87.2% (95%CI: 77-94%) and 100% (95%CI: 92.9-100%), respectively. Pooled sensitivity and specificity for detection of local recurrent disease are 100% (95%CI: 71.5-100%) and 100% (95%CI: 89.4-100%), respectively. Pooled sensitivity and specificity for detection of metastatic disease are 92% (95%CI: 86.2-96%) and 96.9% (95%CI: 83.8-99.9%), respectively. Pooled sensitivity of PSMA-targeted PET/CT for detection of clear cell renal cell carcinoma (ccRCC) and non-ccRCC are 94.7% (95%CI: 88-98.3%) and 75% (95%CI: 35-96.8%), respectively. PSMA-targeted PET-CT demonstrated better diagnostic efficacy for the detection of recurrent RCC. Whilst for staging RCC, it had higher specificity but lower sensitivity. Thus, it can serve as a non-invasive adjuvant tool to conventional imaging in the evaluation of staging of RCC, particularly clear cell variant.

Parotid metastasis of rare lung adenocarcinoma: A case report

BACKGROUND

Lung cancer (LC) is the leading cause of malignancy-related deaths worldwide. The most common sites of metastasis include the nervous system, bone, liver, respiratory system, and adrenal glands. LC metastasis in the parotid gland is very rare, and its diagnosis presents a challenge. Here, we report a case of parotid metastasis in primary LC.

CASE SUMMARY

The patient was a 74-year-old male who was discovered to have bilateral facial asymmetry inadvertently two years ago. The right earlobe was slightly swollen and without pain or numbness. Computed tomography (CT) examination showed bilateral lung space-occupying lesions. Pulmonary biopsy was performed and revealed adenocarcinoma (right-upper-lung nodule tissue). Positron emission tomography-CT examination showed: (1) Two hypermetabolic nodules in the right upper lobe of the lung, enlarged hypermetabolic lymph nodes in the right hilar and mediastinum, and malignant space-occupying lesion in the right upper lobe of the lung and possible metastasis to the right hilar and mediastinal lymph nodes; and (2) multiple hypermetabolic nodules in bilateral parotid glands. Parotid puncture biopsy was performed considering lung adenocarcinoma metastasis. Gene detection of lung biopsy specimens revealed an EGFR gene 21 exon L858R mutation.

CONCLUSION

This case report highlights the challenging diagnosis of parotid metastasis in LC given its rare nature. Such lesions should be differentiated from primary tumors of the parotid gland. Simple radiological imaging is unreliable, and puncture biopsy is needed for final diagnosis of this condition.

Skeletal involvement in Erdheim-Chester disease: Multimodality imaging features and association with the BRAFV600E mutation

OBJECTIVE

The aim of this study was to characterize the distribution of skeletal involvement in Erdheim-Chester disease (ECD) by using radiography, computed tomography (CT), 18F-FDG positron emission tomography/computed tomography (PET/CT), and bone scans, as well as looking for associations with the BRAFV600E mutation.

MATERIAL AND METHODS

Prospective study of 50 consecutive patients with biopsy-confirmed ECD who had radiographs, CT, 18F-FDG PET/CT, and Tc-99m MDP bone scans. At least two experienced radiologists with expertise in the relevant imaging studies analyzed the images. Summary statistics were expressed as the frequency with percentages for categorical data. Fisher's exact test, as well as odds ratios (OR) with 95 % confidence intervals (CI), were used to link imaging findings to BRAFV600E mutation. The probability for co-occurrence of bone involvement at different locations was calculated and graphed as a heat map.

RESULTS

All 50 cases revealed skeletal involvement at different regions of the skeleton. The BRAFV600E mutation, which was found in 24 patients, was correlated with femoral and tibial involvement on 18F-FDG PET/CT and bone scan. The appearance of changes on the femoral, tibial, fibular, and humeral involvement showed correlation with each other based on heat maps of skeletal involvement on CT.

CONCLUSION

This study reports the distribution of skeletal involvement in a cohort of patients with ECD. CT is able to detect the majority of ECD skeletal involvement. Considering the complementary nature of information from different modalities, imaging of ECD skeletal involvement is optimized by using a multi-modality strategy.

Impact of Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography on Prostate Cancer Salvage Radiotherapy Management: Results from a Prospective Multicenter Randomized Phase 3 Trial (PSMA-SRT NCT03582774)

BACKGROUND

Both imaging and several prognostic factors inform the planning of salvage radiotherapy (SRT). Prostate-specific membrane antigen positron emission tomography (PSMA-PET) can localize disease unseen by other imaging modalities.

OBJECTIVE

To evaluate the impact of PSMA-PET on biochemical recurrence-free survival rate after SRT.

DESIGN, SETTING, AND PARTICIPANTS

This prospective randomized, controlled, phase 3 clinical trial randomized 193 patients with biochemical recurrence of prostate cancer after radical prostatectomy to proceed with SRT (control arm, n = 90) or undergo a PSMA-PET/computed tomography (CT) scan prior to SRT planning (investigational arm, n = 103) from June 2018 to August 2020. Any other approved imaging modalities were allowed in both arms (including fluciclovine-PET).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

This is a secondary endpoint analysis: impact of PSMA-PET on SRT planning. Case-report forms were sent to referring radiation oncologists to collect the management plans before randomization and after completion of SRT. The relative frequency (%) of management changes within each arm were compared using chi-square and Fisher's exact tests.

RESULTS AND LIMITATIONS

The delivered SRT plan was available in 178/193 patients (92.2%; 76/90 control [84.4%] and 102/103 PSMA-PET [99%]). Median prostate-specific antigen levels at enrollment was 0.30 ng/ml (interquartile range [IQR] 0.19-0.91) in the control arm and 0.23 ng/ml (IQR 0.15-0.54) in the PSMA-PET arm. Fluciclovine-PET was used in 33/76 (43%) in the control arm. PSMA-PET localized recurrence(s) in 38/102 (37%): nine of 102 (9%) outside of the pelvis (M1), 16/102 (16%) in the pelvic LNs (N1, with or without local recurrence), and 13/102 (13%) in the prostate fossa only. There was a 23% difference (95% confidence interval [CI] 9-35%, p = 0.002) of frequency of major changes between the control arm (22% [17/76]) and the PSMA-PET intervention arm (45% [46/102]). Of the major changes in the intervention group, 33/46 (72%) were deemed related to PSMA-PET. There was a 17.6% difference (95% CI 5.4-28.5%, p = 0.005) of treatment escalation frequency between the control arm (nine of 76 [12%]) and the intervention arm (30/102 [29%]). Treatment de-escalation occurred in the control and intervention arms in eight of 76 (10.5%) and 12/102 (11.8%) patients, and mixed changes in zero of 76 (0%) and four of 102 (3.9%) patients, respectively.

CONCLUSIONS

In this prospective randomized phase 3 study, PSMA-PET findings provided information that initiated major management changes to SRT planning in 33/102 (33%) patients. The final readout of the primary endpoint planned in 2025 may provide evidence on whether these changes result in improved outcomes.

PATIENT SUMMARY

Prostate-specific membrane antigen positron emission tomography leads to management changes in one-third of patients receiving salvage radiotherapy for post-radical prostatectomy biochemical recurrence of prostate cancer.

The potential of 18F-FDG PET/CT metabolic parameter-based nomogram in predicting the microvascular invasion of hepatocellular carcinoma before liver transplantation

PURPOSE

Microvascular invasion (MVI) is a critical factor in predicting the recurrence and prognosis of hepatocellular carcinoma (HCC) after liver transplantation (LT). However, there is a lack of reliable preoperative predictors for MVI. The purpose of this study is to evaluate the potential of an 18F-FDG PET/CT-based nomogram in predicting MVI before LT for HCC.

METHODS

83 HCC patients who obtained 18F-FDG PET/CT before LT were included in this retrospective research. To determine the parameters connected to MVI and to create a nomogram for MVI prediction, respectively, Logistic and Cox regression models were applied. Analyses of the calibration curve and receiver operating characteristic (ROC) curves were used to assess the model's capability to differentiate between clinical factors and metabolic data from PET/CT images.

RESULTS

Among the 83 patients analyzed, 41% were diagnosed with histologic MVI. Multivariate logistic regression analysis revealed that Child-Pugh stage, alpha-fetoprotein, number of tumors, CT Dmax, and Tumor-to-normal liver uptake ratio (TLR) were significant predictors of MVI. A nomogram was constructed using these predictors, which demonstrated strong calibration with a close agreement between predicted and actual MVI probabilities. The nomogram also showed excellent differentiation with an AUC of 0.965 (95% CI 0.925-1.000).

CONCLUSION

The nomogram based on 18F-FDG PET/CT metabolic characteristics is a reliable preoperative imaging biomarker for predicting MVI in HCC patients before undergoing LT. It has demonstrated excellent efficacy and high clinical applicability.

Frequency of Screening for Cardiac Allograft Vasculopathy: Warranty Period of Initial Low Risk Positron Emission Tomography

AIMS

The short-term risk of moderate-severe cardiac allograft vasculopathy (CAV) after a low-risk positron emission tomography/computed tomography (PET/CT) is unknown and therefore there is no guidance on how frequently to perform screening. The aim of this study was to assess the rate of progression to moderate-severe CAV as part of an annual screening program.

METHODS AND RESULTS

Patients with no history of CAV 2/3 and a low-risk result on initial screening PET/CT (CAV 0/1) were enrolled in the study. The primary outcome was the progression to CAV 2/3 as part of an annual screening program (within 6-18 months of initial scan). PET CAV results were graded according to a published and externally validated diagnostic criteria for CAV.Over the study period, 231 patients underwent an initial PET/CT and had a subsequent evaluation for CAV. In this cohort, 4.3% of patients progressed to CAV 2/3 at a median of 374 days (IQR 363 - 433). Initial PET CAV grade was the most significant patient characteristic associated with progression of CAV, with 17% of patients with PET CAV 1 progressing to CAV 2/3 compared to 1.6% with PET CAV 0 (OR 12.4, 95%CI 3.06-50.3).

CONCLUSION

The rate of progression to moderate-severe CAV at 1 year after the lowest-risk PET/CT is low, but approximately 1/6 patients with PET CAV 1 progress to CAV 2/3. Annual screening with PET/CT for select patients with PET CAV 0 may not be warranted. The optimal screening interval awaits confirmation of our findings in multicenter registries.

Erythrodermic mycosis fungoides: A case report

BACKGROUND

Mycosis fungoides is the most common primary cutaneous T-cell lymphoma, whereas generalized erythroderma is rare. In this report, we describe a case of mycosis fungoides with generalized erythroderma using complete clinical data and [18F]fluoroDglucose positron emission tomography/computed tomography (18F-FDG PET/CT) images.

CASE SUMMARY

Systemic skin redness with desquamation for three years confirmed mycosis fungoides within one month. The patient underwent left axillary lymphadenectomy biopsy; pathological biopsy suggested abnormal T-cell lesions consistent with mycosis fungoides involving lymph nodes. The patient received methotrexate, 5 mg twice weekly, as part of their chemotherapy regimen. Patients January half after discharge, no obvious cause of high fever, left axillary lymph nodes with red heat pain, and rupture entered our hospital for treatment.

CONCLUSION

The 18F-FDG PET/CT is essential for early diagnosis and timely treatment.

Reliability of predicting low-burden (≤ 2) positive axillary lymph nodes indicating sentinel lymph node biopsy in primary operable breast cancer - a retrospective comparative study with PET/CT and breast MRI

BACKGROUND

Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging in early breast cancer patients with low-burden axillary metastasis (≤ 2 positive nodes). This study aimed to determine the diagnostic performances of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and breast magnetic resonance imaging in detecting axillary lymph node (ALN) metastases and the reliability to predict ALN burden.

METHODS

A total of 275 patients with primary operable breast cancer receiving preoperative PET/CT and upfront surgery from January 2001 to December 2022 in a single institution were enrolled. A total of 244 (88.7%) of them also received breast MRI. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT and breast MRI were assessed. The predictive values to determine ALN burden were evaluated using radio-histopathological concordance.

RESULTS

PET/CT demonstrated a sensitivity of 53.4%, specificity of 82.1%, PPV of 65.5%, NPV of 73.5%, and accuracy of 70.9% for detecting ALN metastasis, and the corresponding values for MRI were 71.8%, 67.8%, 56%, 80.8%, and 69.2%, respectively. Combining PET/CT and MRI showed a significantly higher PPV than MRI (72.7% vs 56% for MRI alone, p = 0.037) and a significantly higher NPV than PET/CT (84% vs 73.5% for PET/CT alone, p = 0.041). For predicting low-burden axillary metastasis (1-2 positive nodes), the PPVs were 35.9% for PET/CT, 36.7% for MRI, and 55% for combined PET/CT and MRI. Regarding patients with 0-2 positive ALNs in imaging, who were indicated for SLNB, the predictive correctness was 96.1% for combined PET/CT and MRI, 95.7% for MRI alone, and 88.6% for PET/CT alone.

CONCLUSIONS

PET/CT and breast MRI exhibit high predictive values for identifying low-burden axillary metastasis in patients with operable breast cancer with ≦ 2 positive ALNs on imaging.

Primary Pleural Epithelioid Angiosarcoma with Lung and Bone Metastases: A Case Report

Introduction

Primary pleural epithelial angiosarcoma (EAS) is an extremely rare tumor with no specific clinical symptoms. Clinical data on primary pleural EAS are limited, and misdiagnosis often occurs.

Case Presentation

The present study reports the case of a 31-year-old patient diagnosed with primary pleural EAS with lung and bone metastases. The patient presented with persistent right chest pain for 5 months and dyspnea for 2 months. Chest computed tomography (CT) scan revealed right hydropneumothorax, diffuse thickening of the right pleura, passive atelectasis, and scattered nodules in the left lung. A medical thoracoscopic pleural biopsy revealed a vasogenic tumor. To further confirm the diagnosis, positron emission tomography/CT (PET/CT) examination was recommended to determine the biopsy site after multidisciplinary discussion. Increased 18F-FDG uptake in the right pleura and hypermetabolic nodules in the right chest wall, first lumbar vertebrae, second sacral vertebrae, and bilateral iliac crest was detected via PET/CT. CT-guided chest wall and lung biopsies were performed. Immunohistochemistry of specific markers was performed according to remote consultation with a pathologist, and tumor cells with strong positive expression of CD31, CD34, and ETS-related genes led to the final diagnosis of primary pleural EAS.

Conclusion

Primary pleural EAS should be considered for hydropneumothorax of an unknown cause. PET/CT can accurately locate the lesion. The pathological examination is the basis for primary pleural EAS diagnosis. Moreover, multidisciplinary discussion and remote expert consultation can improve the diagnosis rate of primary pleural EAS.

Decoding polymyalgia rheumatica, the role of Nuclear Medicine Imaging

Polymyalgia rheumatica (PMR) is an inflammatory joint disease that presents in patients older than 50 years with prolonged morning pain and stiffness in the shoulder and hip joints and neck. The lack of specific clinical findings, laboratory signs, biomarkers and established imaging methods makes it difficult to diagnose patients with this disease. 18F-FDG PET/CT is a functional imaging technique that is an established tool in oncology and has also proven useful in the field of inflammatory diseases. The aim of this paper is to present literature evidence on the use of molecular imaging methods such as PET/CT for early diagnosis, assessment of disease activity and therapeutic response in PMR. At the same time, the advantages, disadvantages and contraindications of other methods are considered.

The prognostic value of FIGO staging defined by combining MRI and [18F]FDG PET/CT in patients with locally advanced cervical cancer

The last version of the FIGO classification recommended imaging tools to complete the clinical assessment of patients with cervical cancer. However, the preferable imaging approach is still unclear. We aimed to explore the prognostic power of Magnetic Resonance Imaging (MRI), contrast-enhanced Computed Tomography (ceCT), and [18F]-Fluorodeoxyglucose Positron Emission Tomography ([18F]FDG-PET)/CT in patients staged for locally advanced cervical cancer (LACC, FIGO stages IB3-IVA). Thirty-six LACC patients (mean age 55.47 ± 14.01, range 31-82) were retrospectively enrolled. All of them underwent MRI, ceCT and [18F]FDG-PET/CT before receiving concurrent chemoradiotherapy. A median dose of 45 Gy (range 42-50.4; 25-28 fractions, 5 fractions per week, 1 per day) was delivered through the external-beam radiation therapy (EBRT) on the pelvic area, while a median dose of 57.5 Gy (range 16-61.1; 25-28 fractions, 5 fractions per week, 1 per day) was administered on metastatic nodes. The median doses for brachytherapy treatment were 28 Gy (range 28-30; 4-5 fractions, 1 every other day). Six cycles of cisplatin or carboplatin were administered weekly. The study endpoints were recurrence-free survival (RFS) and overall survival (OS). Metastatic pelvic lymph nodes at MRI independently predicted RFS (HR 13.271, 95% CI 1.730-101.805; P = 0.027), while metastatic paraaortic lymph nodes at [18F]FDG-PET/CT independently predicted both RFS (HR 11.734, 95% CI 3.200-43.026; P = .005) and OS (HR 13.799, 95% CI 3.378-56.361; P < 0.001). MRI and [18F]FDG-PET/CT findings were incorporated with clinical evidences into the FIGO classification. With respect to the combination of clinical, MRI and ceCT data, the use of next-generation imaging (NGI) determined a stage migration in 10/36 (27.7%) of patients. Different NGI-based FIGO classes showed remarkably different median RFS (stage IIB: not reached; stage IIIC1: 44 months; stage IIIC2: 3 months; P < 0.001) and OS (stage IIB: not reached; stage IIIC1: not reached; stage IIIC2: 14 months; P < 0.001). A FIGO classification based on the combination of MRI and [18F]FDG-PET/CT might predict RFS and OS of LACC patients treated with concurrent chemoradiotherapy.

PET/CT in assessment of colorectal liver metastases: a comprehensive review with emphasis on 18F-FDG

Approximately 25% of those who are diagnosed with colorectal cancer will develop colorectal liver metastases (CRLM) as their illness advances. Despite major improvements in both diagnostic and treatment methods, the prognosis for patients with CRLM is still poor, with low survival rates. Accurate employment of imaging methods is critical in identifying the most effective treatment approach for CRLM. Different imaging modalities are used to evaluate CRLM, including positron emission tomography (PET)/computed tomography (CT). Among the PET radiotracers, fluoro-18-deoxyglucose (18F-FDG), a glucose analog, is commonly used as the primary radiotracer in assessment of CRLM. As the importance of 18F-FDG-PET/CT continues to grow in assessment of CRLM, developing a comprehensive understanding of this subject becomes imperative for healthcare professionals from diverse disciplines. The primary aim of this article is to offer a simplified and comprehensive explanation of PET/CT in the evaluation of CRLM, with a deliberate effort to minimize the use of technical nuclear medicine terminology. This approach intends to provide various healthcare professionals and researchers with a thorough understanding of the subject matter.

Quality and consistency of clinical practice guideline recommendations for PET/CT and PET: a systematic appraisal

OBJECTIVES

To systematically appraise the methodologies used for guidelines for positron emission tomography (PET) imaging and to compare the consistency of these recommendations.

METHODS

We searched PubMed, EMBASE, four guideline databases, and Google Scholar to identify evidence-based clinical practice guidelines pertaining to the use of PET, PET/computed tomography (CT), or PET/magnetic resonance in routine practice. We assessed the quality of each guideline using the Appraisal of Guidelines for Research and Evaluation II instrument and compared recommendations regarding indications for 18F-fluorodeoxyglucose (FDG) PET/CT.

RESULTS

Thirty-five guidelines for PET imaging, published between 2008 and 2021, were included. These guidelines performed well in the domains of scope and purpose (median 80.6%, inter-quartile range [IQR] 77.8-83.3%) and clarity of presentation (median 75%, IQR 69.4-83.3%), but poorly in applicability (median 27.1%, IQR 22.9-37.5%). Recommendations for 48 indications in 13 cancers were compared. Considerable inconsistencies in the direction of whether to support the use of FDG PET/CT were observed in 10 (20.1%) indications pertaining to 8 cancer types: head and neck cancer (treatment response assessment), colorectal cancer (staging in patients with stages I-III disease), esophageal cancer (staging), breast cancer (restaging and treatment response assessment), cervical cancer (staging in patients with stage < IB2 disease and treatment response assessment), ovarian cancer (restaging), pancreatic cancer (diagnosis), and sarcoma (treatment response assessment).

CONCLUSIONS

Current guidelines for PET imaging vary in methodological quality and provided considerably inconsistent recommendations. Efforts are needed to improve adherence to guideline development methodologies, to synthesis high-quality evidence, and to adopt standard terminologies.

PROTOCOL REGISTRATION NUMBER

PROSPERO CRD42020184965.

CLINICAL RELEVANCE STATEMENT

Guidelines for PET imaging provide considerably inconsistent recommendations and vary in methodological quality. It is suggested that clinicians be critical of these recommendations when applying them in practice, that guideline developers adopt more rigorous development methodologies, and that researchers prioritize research gaps identified by current guidelines.

KEY POINTS

• PET guidelines vary in methodological quality and provided inconsistent recommendations. Efforts are needed to improve methodologies, synthesize high-quality evidence, and standardize terminologies. • Among six domains of methodological quality assessed by the AGREE II tool, guidelines for PET imaging performed well in scope and purpose (median 80.6%, inter-quartile range 77.8-83.3%) and clarity of presentation (75%, 69.4-83.3%), but poorly in applicability (27.1%, 22.9-37.5%). • Among the 48 recommendations (for 13 cancer types) compared, conflicts in the direction of whether to support FDG PET/CT use were observed in 10 (20.1%), for 8 cancer types (i.e., head and neck, colorectal, esophageal, breast, cervical, ovarian, pancreatic, and sarcoma).

Comparison of pathological findings and accumulation of fluorin-18 fluorodeoxyglucose on positron emission tomography/computed tomography: A case of relapsing polychondritis

A 70-year-old woman with a hoarse voice and dry cough was referred to our hospital. Positron emission tomography/computed tomography showed abnormal accumulation of fluorine-18 fluorodeoxyglucose (FDG) at the nasal septum, larynx, trachea, bronchus, and costal cartilages. The maximum standard uptake values of FDG accumulation in the nasal septum and costal cartilage were similar. Biopsies of the nasal septum and costal cartilage were performed. The patient was diagnosed with relapsing polychondritis (RP) based on the clinical features and pathological findings. Histopathological examination revealed progressive initial RP findings. The disease progression was different, even with the same FDG accumulation.

Value of 18F-FDG-PET/CT radiomics combined with clinical variables in the differential diagnosis of malignant and benign vertebral compression fractures

BACKGROUND

Vertebral compression fractures (VCFs) are common clinical problems that arise from various reasons. The differential diagnosis of benign and malignant VCFs is challenging. This study was designed to develop and validate a radiomics model to predict benign and malignant VCFs with 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT).

RESULTS

Twenty-six features (9 PET features and 17 CT features) and eight clinical variables (age, SUVmax, SUVpeak, SULmax, SULpeak, osteolytic destruction, fracture line, and appendices/posterior vertebrae involvement) were ultimately selected. The area under the curve (AUCs) of the radiomics and clinical-radiomics models were significantly different from that of the clinical model in both the training group (0.986, 0.987 vs. 0.884, p < 0.05) and test group (0.962, 0.948 vs. 0.858, p < 0.05), while there was no significant difference between the radiomics model and clinical-radiomics model (p > 0.05). The accuracies of the radiomics and clinical-radiomics models were 94.0% and 95.0% in the training group and 93.2% and 93.2% in the test group, respectively. The three models all showed good calibration (Hosmer-Lemeshow test, p > 0.05). According to the decision curve analysis (DCA), the radiomics model and clinical-radiomics model exhibited higher overall net benefit than the clinical model.

CONCLUSIONS

The PET/CT-based radiomics and clinical-radiomics models showed good performance in distinguishing between malignant and benign VCFs. The radiomics method may be valuable for treatment decision-making.

An Optimal Radiomics Nomogram Based on 18F-FDG PET/CT for Identifying Event-Free Survival in Pediatric Neuroblastoma

RATIONALE AND OBJECTIVES

To investigate whether the 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) radiomics features that combine tumor and bone marrow can more accurately identify event-free survival (EFS) in pediatric neuroblastoma.

MATERIALS AND METHODS

A total of 126 patients with neuroblastoma were retrospectively included and randomly divided into the training and validation cohorts (7:3 ratio). Radiomics features were extracted to develop a tumor- and bone marrow-based radiomics risk score (RRS). The Kaplan-Meier method was used to evaluate the effectiveness of RRS in EFS risk stratification. Univariate and multivariate Cox regression analyses were used to determine independent clinical risk factors and construct the clinical models. The conventional PET model was constructed based on conventional PET parameters, and the noninvasive combined model integrated the RRS and the noninvasive independent clinical risk factors. The performance of the models was evaluated using C-index, calibration curves, and decision curve analysis (DCA).

RESULTS

A total of 15 radiomics features were selected to build the RRS. According to Kaplan-Meier analysis, there was a significant difference in EFS between the low-risk and high-risk groups as defined by the value of RRS (P < .05). The noninvasive combined model combining RRS and the International Neuroblastoma Risk Group stage achieved the best prognostic prediction of EFS, with a C-index of 0.810 and 0.783 in the training and validation cohorts, respectively. The calibration curves and DCA indicated that the noninvasive combined model had good consistency and clinical utility.

CONCLUSION

The 18F-FDG PET/CT-based radiomics of neuroblastoma allows a reliable evaluation of EFS. The performance of the noninvasive combined model was superior to the clinical and conventional PET models.

Predictive value of radiomic signature based on 2-[18F]FDG PET/CT in HER2 status determination for primary breast cancer with equivocal IHC results

PURPOSE

To evaluate the predictive power of 2-[18F]FDG PET/CT-derived radiomic signature in human epidermal growth factor receptor 2 (HER2) status determination for primary breast cancer (BC) with equivocal immunohistochemistry (IHC) results for HER2.

METHODS

A total of 154 primary BC with equivocal IHC results for HER2 were retrospectively enrolled in the study. First, the following five conventional PET parameters (SUVmax, SUVmean, SUVpeak, MTV, TLG) were measured and compared between HER2-positive and HER2-negative cohorts. After quantitative radiomic features extraction and reduction, the least absolute shrinkage and selection operator (LASSO) algorithm was used to establish a radiomic signature model. Then, the area under the curve (AUCs) after a receiver operator characteristic (ROC) analysis, accuracy, sensitivity and specificity were calculated and used as the main outcomes. Finally, a total of 37 BC patients from an external institution were included to perform an external validation.

RESULTS

All the five conventional PET parameters were unable to discriminate between HER2-positive and HER2-negative cohorts for BC (P = 0.104-0.544). Whereas, the developed radiomic signature model was potentially predictive of HER2 status with an of AUC 0.887 (95% confidence interval [CI], 0.824-0.950) in the training cohort and 0.766 (95% CI, 0.616-0.916) in the validation cohort, respectively. For external validation, the AUC for the external test cohort was 0.788 (95% CI, 0.633-0.944).

CONCLUSIONS

Radiomic signature based on 2-[18F]FDG PET/CT images was capable of non-invasively predicting the HER2 status with a comparable ability to FISH assay, especially for those with equivocal IHC results for HER2.

Post-treatment PET/CT for p16-positive oropharynx cancer treated with definitive proton therapy

Objectives

Given emerging data suggesting that uncertainty in the relative biologic effectiveness at the distal end of the Bragg peak results in increased mucosal injury in patients with oropharynx cancer receiving adjuvant proton therapy, we evaluated the results of post-treatment positron emission tomography-computed tomography (PET/CT) in patients with p16-positive oropharynx cancer (p16+OPC) treated with definitive intensity-modulated proton therapy (IMPT).

Material and Methods

A retrospective cohort study of patients with p16+OPC treated with definitive IMPT between 2016 and 2022 was performed at a single institution. Patients with PET/CT scans within 6 months following completion of IMPT were included in the study. Positive post-treatment scans were defined by a maximum standard uptake values (SUVmax) >4.0 or a <65% reduction in SUVmax in either the primary tumor or lymph node. The Fisher's exact test was used to evaluate factors associated with positive post-treatment PET/ CT values.

Results

Sixty-two patients were included for analysis. Median follow-up was 21 months (range: 3-71 months) with a median time to post-treatment PET/CT of 3 months (range: 2-6 months). Median post-treatment SUVmax of the primary disease and nodal disease was 0 (mean: 0.8, range: 0-7.7) and 0 (mean: 0.7, range: 0-9.5), respectively. Median post-treatment percent reduction in SUVmax for the primary site and lymph node was 100% (mean: 94%, range: 31.3-100%) and 100% (mean: 89%, range: 23-100%), respectively. Eleven patients had a positive post-treatment PET/CT with one biopsy-proven recurrence. Negative and positive predictive values (NPV and PPV) were 98% and 9.1%, respectively. There were no factors associated with positive post-treatment PET/CT.

Conclusion

Similar to patients treated with photon-based radiation therapy, post-treatment PET/CT has a high NPV for patients with p16+OPC treated with definitive proton therapy and should be used to guide patient management. Additional patients and more events are needed to confirm the PPV of a post-treatment PET/CT in this favorable patient cohort.

Cancer of unknown primary eventually diagnosed as poorly differentiated prostate cancer: a case report

BACKGROUND

Prostate cancer has been well known to have a high prevalence among middle-aged and older men, with high incidence of metastases to the bone-the main metastatic site. However, prostate cancer among those less than 50 years of age is extremely rare, and neck swelling is seldom the initial symptom.

CASE PRESENTATION

We herein report case of a 47-year-old Japanese male with poorly differentiated prostate cancer that had been initially diagnosed as a cancer of unknown primary with multiple lymph node and bone metastases before reaching a definitive diagnosis. The patient has been started on endocrine therapy and is currently alive without progression.

DISCUSSION AND CONCLUSION

When locating the primary lesion in men with cancer of unknown primary, it is important to consider the possibility of prostate cancer, confirm serum prostate-specific antigen levels, and perform local prostate evaluation.

Diagnostic Performance of 68Ga-PSMA-11 Positron Emission Tomography/Computed Tomography to Monitor Treatment Response in Patients with Metastatic Prostate Cancer: The Concordance Between Biochemical Response and Prostate-specific Membrane Antigen Results

BACKGROUND

Treatment response is traditionally monitored using prostate-specific antigen (PSA) and conventional imaging in patients with metastatic prostate cancer (mPCa).

OBJECTIVE

To assess the diagnostic performance of prostate-specific membrane antigen (PSMA) positron emission tomography (PET)/computed tomography (CT) when monitoring mPCa patients receiving systemic treatment and also to investigate the concordance between PSMA PET response according to the PSMA PET progression (PPP) criteria and biochemical response.

DESIGN, SETTING, AND PARTICIPANTS

A total of 96 patients with 68Ga-PSMA-11 PET/CT-detected mPCa at baseline PSMA PET/CT (bPSMA) who underwent at least one follow-up scan after receiving systemic treatment were included in the study. PSA levels at bPSMA and follow-up PSMA PET (fPSMA) scans were recorded. The PPP criteria were used to define PSMA progression. Biochemical progression was defined as ≥25% increase in PSA. PSMA PET and PSA responses were dichotomized into progressive disease (PD) versus non-PD, and the concordance between PSA and PSMA responses was evaluated.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The concordance between PSA and PSMA PET responses was presented using frequencies, percentages, and Cohen's kappa test.

RESULTS AND LIMITATIONS

A total of 345 serial PSMA PET/CT (96 bPSMA and 249 fPSMA) scans were evaluated. The positivity rates of PSMA PET scans for PSA levels of <0.01, 0.01-0.2, 0.2-4, and >4 ng/ml were 55.6%, 75.0%, 100%, and 98.8%, respectively. PSA and PSMA responses showed moderate-to-high concordance (Cohen's κ = 0.623, p < 0.001). PSA-PSMA discordance was detected in 39 scans (17%). The most common cause of discordance was the discordant results between different metastatic lesions (16/28, 57.1%) in patients with PPP without PSA progression and local progression in prostate (n = 7/11, 63.6%) in patients with PSA progression without PPP.

CONCLUSIONS

PSMA PET/CT showed very high detection rates of malignant lesions even at very low PSA values and showed significant concordance with PSA response when monitoring treatment response in patients receiving systemic treatment for mPCa.

PATIENT SUMMARY

This study describes that prostate-specific membrane antigen positron emission tomography (PSMA PET), a new sensitive imaging tool, can detect malignant lesions even at very low prostate-specific antigen values when monitoring metastatic prostate cancer. The PSMA PET response and biochemical response showed significant concordance, and the reason for discordant results seems to be the different responses of metastatic lesions and prostatic lesions to systemic treatment.

Imaging of Anal Squamous Cell Carcinoma: Survey Results and Expert Opinion from the Rectal and Anal Cancer Disease-Focused Panel of the Society of Abdominal Radiology

The role and method of image-based staging of anal cancer has evolved with the rapid development of newer imaging modalities and the need to address the rising incidence of this rare cancer. In 2014, the European Society of Medical Oncology mandated pelvic magnetic resonance imaging (MRI) for anal cancer and subsequently other societies such as the National Comprehensive Cancer Network followed suit with similar recommendations. Nevertheless, great variability exists from center to center and even within individual centers. Notably, this is in stark contrast to the imaging of the anatomically nearby rectal cancer. As participating team members for this malignancy, we embarked on a comprehensive literature review of anal cancer imaging to understand the relative merits of these new technologies which developed after computed tomography (CT), e.g., MRI and positron emission tomography/computed tomography (PET/CT). The results of this literature review helped to inform our next stage: questionnaire development regarding the imaging of anal cancer. Next, we distributed the questionnaire to members of the Society of Abdominal Radiology (SAR) Rectal and Anal Disease-Focused Panel, a group of abdominal radiologists with special interest, experience, and expertise in rectal and anal cancer, to provide expert radiologist opinion on the appropriate anal cancer imaging strategy. In our expert opinion survey, experts advocated the use of MRI in general (65% overall and 91-100% for primary staging clinical scenarios) and acknowledged the superiority of PET/CT for nodal assessment (52-56% agreement for using PET/CT in primary staging clinical scenarios compared to 30% for using MRI). We therefore support the use of MRI and PET and suggest further exploration of PET/MRI as an optimal combined evaluation. Our questionnaire responses emphasized the heterogeneity in imaging practice as performed at numerous academic cancer centers across the United States and underscore the need for further reconciliation and establishment of best imaging practice guidelines for optimized patient care in anal cancer.

Head-to-head comparison of [68Ga]Ga-PSMA-11 and [18F]FDG PET/CT in multiple myeloma

PURPOSE

The aim of this study was to compare [18F]FDG and [68Ga]Ga-PSMA-11 PET/CT image findings in patients with multiple myeloma (MM).

METHODS

Twenty consecutive patients with symptomatic biopsy-proven MM were submitted to whole body [18F]FDG and [68Ga]Ga-PSMA-11 PET/CT with a time interval of 1-8 days between procedures. All lesions were counted and had their maximum SUV (SUVmax) measured. Intra-class correlation (ICC) was used to assess the agreement between [18F]FDG and [68Ga]Ga-PSMA-11 PET/CT findings.

RESULTS

A total of 266 lesions were detected in 19/20 patients. [18F]FDG detected 223/266 (84%) lesions in 17 patients and [68Ga]Ga-PSMA-11 190/266 (71%) lesions in 19 patients. Both procedures did not identify any active lesion in 1 patient. Forty-three (16%) lesions were detected only by [68Ga]Ga-PSMA-11 and 76 (29%) only by [18F]FDG. Both tracers identified 147 (55%) lesions. Intralesional mismatch of FDG-PSMA uptake was identified in 25 of these 147 lesions, found in 8 different patients. Different lesions with uptake of only [18F]FDG or [68Ga]Ga-PSMA-11 in the same patient were found in 4 patients. The highest SUVmax of [18F]FDG and [68Ga]Ga-PSMA-11 had a median (min-max) SUVmax of 6.5 (2.0-37.8) and 5.5 (1.7-51.3), respectively. [18F]FDG and [68Ga]Ga-PSMA-11 respectively identified 18 and 19 soft tissue lesions. False-positive [18F]FDG findings had minimal or no uptake of [68Ga]Ga-PSMA-11. Good reliability (ICC ≥ 0.75) was found for number of lesions, number of soft tissue lesions and highest SUVmax in each patient.

CONCLUSION

[18F]FDG or [68Ga]Ga-PSMA-11 alone can detect most MM lesions. Almost half of the lesions take up only one of the tracers, reflecting increased glycolysis or angiogenesis in specific lesions, and suggesting their possible complementary role in MM. The marked [68Ga]Ga-PSMA-11 uptake in some cases raises the possibility of a theranostic approach in selected patients.

Preoperative evaluation of prostate cancer by 68Ga-PMSA positron emission tomography/computed tomography: comparison with magnetic resonance imaging and with histopathological findings

Objective

To evaluate the accuracy of preoperative positron emission tomography/computed tomography with 68Ga-labeled prostate-specific membrane antigen (68Ga-PSMA PET/CT) for staging prostate cancer and compare it with magnetic resonance imaging (MRI) using histopathology of surgical specimens as the gold standard.

Materials and Methods

In this retrospective study, 65 patients with prostate cancer were analyzed.

Results

The accuracy of 68Ga-PSMA PET/CT for tumor detection was 95%, and that of MRI was 91%. There was no difference between 68Ga-PSMA PET/CT and MRI regarding localization of the lesion. The sensitivity of 68Ga-PSMA PET/CT for detecting extraprostatic extension was quite low (14%). For detection of seminal vesicle invasion, 68Ga-PSMA PET/CT showed a sensitivity of 57% and accuracy of 91%. There was a moderate correlation between the maximum standardized uptake value (SUVmax) and the serum level of prostate-specific antigen (p < 0.01; ρ = 0.368) and between the SUVmax and the International Society of Urological Pathology (ISUP) grade (p < 0.01; ρ = 0.513).

Conclusion

68Ga-PSMA PET/CT is a promising tool for detecting and evaluating the primary tumor, which can alter the staging and management of the disease.

18F-FDG PET/CT radiomics predicts brain metastasis in I-IIIA resected Non-Small cell lung cancer

OBJECTIVE

To establish ¹⁸F-FDG PET/CT radiomics model for predicting brain metastasis in non-small cell lung cancer (NSCLC) patients.

METHODS

This research comprised 203 NSCLC patients who had received surgical therapy at two institutions. To identify independent predictive factors of brain metastasis, metabolic indicators, CT features, and clinical features were investigated. A prediction model was established by incorporating radiomics signature and clinicopathological risk variables. The suggested model's performance was assessed from the perspective of discrimination, calibration, and clinical application.

RESULTS

The C-indices of the PET/CT radiomics model in the training, internal validation, and external validation cohorts were 0.911, 0.825 and 0.800, respectively. According to the multivariate analysis, neuron-specific enolase (NSE) and air bronchogram were independent risk factors for brain metastasis (BM). Furthermore, the combined model integrating radiomics and clinicopathological characteristics related to brain metastasis performed better in terms of prediction, with C-indices of 0.927, 0.861, and 0.860 in the training, internal validation, and external validation cohorts, respectively. The decision curve analysis (DCA) suggested that the PET/CT nomogram was clinically beneficial.

CONCLUSIONS

A predictive algorithm based on PET/CT imaging information and clinicopathological features may accurately predict the probability of brain metastasis in NSCLC patients following surgery. This presented doctors with a unique technique for screening NSCLC patients at high risk of brain metastasis.

Radiomics in colorectal cancer patients

The main therapeutic options for colorectal cancer are surgical resection and adjuvant chemotherapy in non-metastatic disease. However, the evaluation of the overall adjuvant chemotherapy benefit in patients with a high risk of recurrence is challenging. Radiological images can represent a source of data that can be analyzed by using automated computer-based techniques, working on numerical information coded within Digital Imaging and Communications in Medicine files: This image numerical analysis has been named "radiomics". Radiomics allows the extraction of quantitative features from radiological images, mainly invisible to the naked eye, that can be further analyzed by artificial intelligence algorithms. Radiomics is expanding in oncology to either understand tumor biology or for the development of imaging biomarkers for diagnosis, staging, and prognosis, prediction of treatment response and diseases monitoring and surveillance. Several efforts have been made to develop radiomics signatures for colorectal cancer patient using computed tomography (CT) images with different aims: The preoperative prediction of lymph node metastasis, detecting BRAF and RAS gene mutations. Moreover, the use of delta-radiomics allows the analysis of variations of the radiomics parameters extracted from CT scans performed at different timepoints. Most published studies concerning radiomics and magnetic resonance imaging (MRI) mainly focused on the response of advanced tumors that underwent neoadjuvant therapy. Nodes status is the main determinant of adjuvant chemotherapy. Therefore, several radiomics model based on MRI, especially on T2-weighted images and ADC maps, for the preoperative prediction of nodes metastasis in rectal cancer has been developed. Current studies mostly focused on the applications of radiomics in positron emission tomography/CT for the prediction of survival after curative surgical resection and assessment of response following neoadjuvant chemoradiotherapy. Since colorectal liver metastases develop in about 25% of patients with colorectal carcinoma, the main diagnostic tasks of radiomics should be the detection of synchronous and metachronous lesions. Radiomics could be an additional tool in clinical setting, especially in identifying patients with high-risk disease. Nevertheless, radiomics has numerous shortcomings that make daily use extremely difficult. Further studies are needed to assess performance of radiomics in stratifying patients with high-risk disease.

Diagnostic performance of diffusion-weighted imaging versus 18F-FDG PET/CT in differentiating pulmonary lesions: an updated meta-analysis of comparative studies

OBJECTIVE

To compare the diagnostic accuracy of diffusion-weighted imaging (DWI) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for differentiating pulmonary nodules and masses.

METHODS

We systematically searched six databases, including PubMed, EMBASE, the Cochrane Library, and three Chinese databases, to identify studies that used both DWI and PET/CT to differentiate pulmonary nodules. The diagnostic performance of DWI and PET/CT was compared and pooled sensitivity and specificity were calculated along with 95% confidence intervals (CIs). The Quality Assessment of Diagnostic Accuracy Studies 2 was used to assess the quality of the included studies, and STATA 16.0 software was utilized to perform statistical analysis.

RESULTS

Overall, 10 studies that enrolled a total of 871 patients with 948 pulmonary nodules were included in this meta-analysis. DWI had greater pooled sensitivity (0.85 [95% CI 0.77-0.90]) and specificity (0.91 [95% CI 0.82-0.96]) than PET/CT (sensitivity, 0.82 [95% CI 0.70-0.90]); specificity, (0.81, [95% CI 0.72-0.87]). The area under the curve of DWI and PET/CT were 0.94 (95% CI 0.91-0.96) and 0.87 (95% CI 0.84-0.90) (Z = 1.58, P > 0.05), respectively. The diagnostic odds ratio of DWI (54.46, [95% CI 17.98-164.99]) was superior to that of PET/CT (15.77, [95% CI 8.19-30.37]). The Deeks' funnel plot asymmetry test showed no publication bias. The Spearman correlation coefficient test revealed no significant threshold effect. Lesion diameter and reference standard could be potential causes for the heterogeneity of both DWI and PET/CT studies, and quantitative or semi-quantitative parameters used would be a potential source of bias for PET/CT studies.

CONCLUSION

As a radiation-free technique, DWI may have similar performance compare with PET/CT in differentiating malignant pulmonary nodules or masses from benign ones.

Dynamic PET/CT scan of (68)Ga-FAPI-04 for the optimal acquisition time in suspected malignant hepatic cancer patients

PURPOSE

Dynamic PET/CT scan of ⁶⁸Ga-FAPI-04 in patients with suspected malignant hepatic lesions were retrospectively analyzed to find the optimal acquisition time with better lesion detection rate.

METHODS

Twenty-two patients with lesions confirmed by CT or MRI were performed with dynamic ⁶⁸Ga-FAPI-04 PET/CT scan. Tracer uptake of lesions and normal organs at different time points were analyzed. Standardized uptake value (SUV) and tumor-to-background (TBR) were calculated based on the quantification of images.

RESULTS

SUV of normal organs decreased rapidly from 10 to 30 min and decreased gradually from 30 to 60 min. Besides, the uterus showed a particularly high uptake in all patients (12.62 ± 4.58 at 10 min p.i., 12.04 ± 3.99 at 30 min p.i., 10.92 ± 2.38 at 60 min p.i.). SUV of lesions decreased gradually, while TBR increased from 10- to 60-min post-injection. Visual analysis verified a comparable lesion detectability of 30 min and 60 min with images of 10 min showing a decreased lesion detection number.

CONCLUSION

This study revealed that similar detection rates were achieved at both 30 and 60 min, suggesting a static scan at 30 min to be appropriate in the clinic. Besides, although with high lesion uptake, early ⁶⁸Ga-FAPI-04 PET imaging at 10 min after tracer injection could cause missed lesion detection.

Respiratory muscle metabolic activity on PET/CT correlates with obstructive ventilatory defect severity and prognosis in patients undergoing lung cancer surgery

BACKGROUND AND OBJECTIVE

Respiratory muscle activity is increased in patients with chronic respiratory disease. ¹⁸ F-FDG-PET/CT can assess respiratory muscle activity. We hypothesized that respiratory muscles metabolism was correlated to lung function impairment and was associated to prognosis in patients undergoing lung cancer surgery based on the research question whether respiratory muscle metabolism quantitatively correlates with the severity of lung function impairment in patients? Does respiratory muscle hypermetabolism have prognostic value?

METHODS

Patients undergoing ¹⁸ F-FDG-PET/CT and pulmonary function tests prior to lung cancer surgery were identified. Maximum Standardized Uptake Value (SUVm) were measured in each respiratory muscle group (sternocleidomastoid, scalene, intercostal, diaphragm), normalized against deltoid SUVm. Respiratory muscle hypermetabolism was defined as SUVm >90th centile in any respiratory muscle group. Clinical outcomes were collected from a prospective cohort.

RESULTS

One hundred fifty-six patients were included, mostly male [110 (71%)], 53 (34%) with previous diagnosis of COPD. Respiratory muscle SUVm were: scalene: 1.84 [1.51-2.25], sternocleidomastoid 1.64 [1.34-1.95], intercostal 1.01 [0.84-1.16], diaphragm 1.79 [1.41-2.27]. Tracer uptake was inversely correlated to FEV1 for the scalene (r = -0.29, p < 0.001) and SCM (r = -0.17, p = 0.03) respiratory muscle groups and positively correlated to TLC for the scalene (r = 0.17, p = 0.04). Respiratory muscle hypermetabolism was found in 45 patients (28.8%), who had a lower VO₂ max (15.4 [14.2-17.5] vs. 17.2 mL/kg/min [15.2-21.1], p = 0.07) and poorer overall survival when adjusting to FEV1% (p < 0.01).

CONCLUSION

Our findings show respiratory muscle hypermetabolism is associated with lung function impairment and has prognostic significance. ¹⁸ F-FDG/PET-CT should be considered as a tool for assessing respiratory muscle activity and to identify high-risk patients.

The Impact of Metabolic 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Parameters on the Prognosis of Resectable Pancreatic Adenocarcinoma

Objectives

¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) is a useful staging method in pancreatic cancer. The prognosis of pancreatic adenocarcinoma is affected by the tumor stage and resectable state. Maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of primary tumors are related to prognostic parameters in pancreatic cancer. This study compared ¹⁸F-FDG PET/CT findings with prognostic factors and overall survival of patients with pancreatic cancer.

Methods

Patients with pancreatic adenocarcinoma, referred to our department between 2015 and 2022 for staging, were retrospectively evaluated. Head-to mid-thigh PET/CT images were obtained 1 h after ¹⁸F-FDG injection. Demographic data, survival, and clinical and pathological findings of 39 patients, who underwent surgery after PET/CT imaging, were collected. All primary tumor MTV, SUV_max, background SUV_max, and TLG data have were measured.

Results

The images of 39 patients (24 women and 15 men) with a mean age of 66.62±9.60 years were evaluated. The mean SUV_max, MTV 40%, and TLG of the primary tumors in the pancreatic tissue were 6.28±2.33, 19.33±9.77, and 66.56±45.99, respectively. The average survival after disease diagnosis was 18.97±11.47 (2-55) months. MTV and TLG were significantly higher in patients who died during our study. SUV_max has a significant effect on mortality.

Conclusion

¹⁸F-FDG PET/CT metabolic parameters of SUV_max, MTV, and TLG could help predicting the prognosis of pancreatic cancer preoperatively and follow-up in patients with resectable tumors. Additionally, in our study group tumor grade and perineural invasion significantly affected overall survival.

Comparison of whole-body 18F-FDG PET/CT and PET/MRI for distant metastases in patients with malignant tumors: a meta-analysis

BACKGROUND

As a first-line imaging modality, whole-body fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) and 18F-FDG PET/magnetic resonance imaging (MRI) had been widely applied in clinical practice. However, 18F-FDG PET/MRI may be superior to PET/CT for the diagnosis of distant metastases in patients with advanced-stage. Therefore, it is timely and important to systematically determine the diagnostic accuracy of 18F-FDG PET/MRI compared with that of 18F-FDG PET/CT for the diagnosis of distant metastases.

METHODS

This study aimed to compare the diagnostic accuracy of 18F-FDG PET/CT and PET/MRI for the diagnosis of distant metastases in patients with malignant tumors. Relevant studies using both 18F-FDG PET/CT and PET/MRI for assessment of distant metastases in patients with malignant tumors were searched in PubMed, Embase, The Cochrane Library, and Scopus from January 2010 to November 2023. Two reviewers independently selected studies according to the inclusion and exclusion criteria. A reviewer extracted relevant data and assessed the quality of the eligible studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and area under the summary receiver operating characteristic curve (AUC) for 18F-FDG PET/CT and PET/MRI were analyzed. Subgroup analysis was performed.

RESULTS

Across 14 studies (1042 patients), 18F-FDG PET/MRI had a higher sensitivity (0.87 versus 0.81), AUC value (0.98 versus 0.95), and similar specificity (0.97 versus 0.97), than PET/CT for detecting distant metastases. In 3 studies of breast cancer (182 patients), 18F-FDG PET/MRI had a higher sensitivity (0.95 versus 0.87) and specificity (0.96 versus 0.94) than PET/CT. In 5 studies of lung cancer (429 patients), 18F-FDG PET/CT had a higher sensitivity (0.87 versus 0.84) and a lower specificity (0.95 versus 0.96) to PET/MRI.

CONCLUSIONS

18F-FDG PET/MRI and PET/CT both performed well as detectors of distant metastases in patients with malignant tumors, and the former has higher sensitivity. The subgroup analysis highlights that 18F-FDG PET/MRI and PET/CT hold different advantages for distant metastases staging in different tumors, PET/MRI has a higher accuracy in patients with breast cancer patients, while PET/CT has a higher accuracy in patients with lung cancer.

Differentiation of lower limb vasculitis from physiological uptake on FDG PET/CT imaging

PURPOSES

To analyze the difference of 2-deoxy-2-[¹⁸F]fluoro-D-glucose (¹⁸F-FDG) uptake between vasculitis and non-vasculitic patients in PET/CT imaging and the factors related to vascular uptake in non-vasculitic patients. To investigate the feasibility of identifying vasculitis of the lower limb and physiological uptake with delayed imaging.

PROCEDURES

Among 244 patients who underwent PET/CT examination, imaging features of patients with or without vasculitis were retrospectively analyzed. The factors related to FDG uptake in the lower limb vessels of non-vasculitic patients were analyzed. Another 44 patients with suspected systemic vasculitis in PET/CT were prospectively studied to analyze the efficacy of delayed imaging on differentiating vascular uptake in lower limbs.

RESULTS

In PET/CT imaging of patients with vasculitis, involvement of trunk vessels showed segmental or diffuse FDG distribution. Lower limb vascular involvement showed reticular uptake accompanied by nodular or patchy changes. In non-vasculitic patients, vascular uptake mainly showed linear uptake in lower limb vessels and there was no significant difference in uptake degree compared with vasculitis patients. Body weight and interval time were the independent influence factors of vascular uptake in lower limbs of non-vasculitic patients. In delayed imaging, lower limb vasculitis all showed reticular uptake and physiological uptake all showed a linear pattern. ROC analysis showed the change rate of SUV_max (≥ 20%) between early and delayed imaging could delineate physiological vascular uptake with a sensitivity of 100% and specificity of 81.0%.

CONCLUSIONS

When PET/CT is used for the diagnosis and classification of vasculitis, the physiological uptake of lower limb vessels may mislead the diagnosis. PET/CT imaging features or delayed imaging improved diagnostic efficacy.

Predicting pathological highly invasive lung cancer from preoperative [18F]FDG PET/CT with multiple machine learning models

PURPOSE

The efficacy of sublobar resection of primary lung cancer have been proven in recent years. However, sublobar resection for highly invasive lung cancer increases local recurrence. We developed and validated multiple machine learning models predicting pathological invasiveness of lung cancer based on preoperative [¹⁸F]fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT) radiomic features.

METHODS

Overall, 873 patients who underwent lobectomy or segmentectomy for primary lung cancer were enrolled. Radiomics features were extracted from preoperative PET/CT images with the PyRadiomics package. Seven machine learning models and an ensemble of all models (ENS) were evaluated after 100 iterations. In addition, the probability of highly invasive lung cancer was calculated in a nested cross-validation to assess the calibration plot and clinical usefulness and to compare to consolidation tumour ratio (CTR) on CT images, one of the generally used diagnostic criteria.

RESULTS

In the training set, when PET and CT features were combined, all models achieved an area under the curve (AUC) of ≥ 0.880. In the test set, ENS showed the highest mean AUC of 0.880 and smallest standard deviation of 0.0165, and when the cutoff was 0.5, accuracy of 0.804, F1 of 0.851, precision of 0.821, and recall of 0.885. In the nested cross-validation, the AUC of 0.882 (95% CI: 0.860-0.905) showed a high discriminative ability, and the calibration plot indicated consistency with a Brier score of 0.131. A decision curve analysis showed that the ENS was valid with a threshold probability ranging from 3 to 98%. Accuracy showed an improvement of more than 8% over the CTR.

CONCLUSION

The machine learning model based on preoperative [¹⁸F]FDG PET/CT images was able to predict pathological highly invasive lung cancer with high discriminative ability and stability. The calibration plot showed good consistency, suggesting its usefulness in quantitative risk assessment.

Value of preoperative 18F-FDG PET/CT and HRCT in predicting the differentiation degree of lung adenocarcinoma dominated by solid density

Purpose

To evaluate the value of positron emission tomography/computed tomography (PET/CT) combined with high-resolution CT (HRCT) in determining the degree of differentiation of lung adenocarcinoma.

Methods

From January 2018 to January 2022, 88 patients with solid density nodules that are lung adenocarcinoma were surgically treated. All patients were examined using HRCT and PET/CT before surgery. During HRCT, two independent observers assessed the presence of lobulation, spiculation, pleural indentation, vascular convergence, and air bronchial signs (bronchial distortion and bronchial disruption). The diameter and CT value of the nodules were measured simultaneously. During PET/CT, the maximum standard uptake value (SUVmax), mean standard uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the nodules were measured. The risk factors of pathological classification were predicted by logistic regression analysis.

Results

All 88 patients (mean age 60 ± 8 years; 44 males and 44 females) were evaluated. The average nodule size was 2.6 ± 1.1 cm. The univariate analysis showed that carcinoembryonic antigen (CEA), pleural indentation, vascular convergence, bronchial distortion, and higher SUVmax were more common in poor differentiated lung adenocarcinoma, and in the multivariate analysis, pleural indentation, vascular convergence, and SUVmax were predictive factors. The combined diagnosis using these three factors showed that the area under the curve (AUC) was 0.735.

Conclusion

SUVmax >6.99 combined with HRCT (pleural indentation sign and vascular convergence sign) is helpful to predict the differentiation degree of lung adenocarcinoma dominated by solid density.

Solitary hyoid plasmacytoma with unicentric Castleman disease: A case report and review of literature

BACKGROUND

Solitary plasmacytoma and unicentric Castleman disease (UCD) are rare lymphoproliferative disorders characterized by monoclonal plasma cells and a single set of locally enlarged lymph nodes, respectively.

CASE SUMMARY

A 48-year-old Han Chinese man presented to our department with a neck mass and progressive foreign body sensation in his throat. ¹⁸F-FDG positron emission tomography revealed focally increased radioactivity centered around the hyoid, and computed tomography (CT) revealed osteolytic lesions. Histopathology revealed Castleman-like features and CD138/CD38-positive mature plasma cells. Systemic work-up ruled out the possibility of POEMS syndrome, lymphoma, and multiple myeloma, leading to a final diagnosis of solitary hyoid plasmacytoma with UCD. The patient underwent partial hyoid resection and selective neck dissection, followed by intensity-modulated radiotherapy. 99mTc-MDP single-photon emission computed tomography/CT reevaluation showed neither local recurrence nor distant bone metastasis at the 40-mo follow-up.

CONCLUSION

The diagnostic process and differential diagnosis of this rare case provided valuable educational information to clinicians.

Focal Nasopharyngeal Activity Detected on [18F]FDG PET/CT: Clinical Implications and Comparison of Metabolic Parameters for Prediction of Malignancy

Purpose

We aimed to investigate the incidence and clinical significance of incidental focal nasopharyngeal uptake on [18F]FDG PET/CT and to evaluate the diagnostic performance of various metabolic parameters to differentiate between benign and malignant nasopharyngeal lesions.

Methods

A total of 63 consecutive patients with incidental focal nasopharyngeal uptake on [18F]FDG PET/CT and subsequent nasopharyngeal biopsy were retrospectively enrolled. In addition, baseline pretherapeutic [18F]FDG PET/CT images of 59 patients with newly diagnosed pathologically proven nasopharyngeal carcinoma (NPC) were reviewed. Maximum standardized uptake value (SUVmax), mean SUV (SUVmean), nasopharynx-to-palatine tonsil ratio (NPR), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the nasopharyngeal lesions were determined. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance of the metabolic parameters.

Results

Incidental focal nasopharyngeal uptake in two patients (3.2%, 2/63) was pathologically confirmed to be NPC. All the metabolic parameters (SUVmax, SUVmean, NPR, MTV, and TLG) demonstrated significantly greater values in patients with NPC compared with patients with benign or physiological nasopharyngeal uptake (p < 0.001). Among the metabolic parameters, NPR demonstrated the greatest area under the curve of 0.992 (p < 0.05), with a sensitivity of 96.7% and a specificity of 93.4% when a cut-off of 1.1 was used. Similar results were seen in nasopharyngeal lesions without morphological abnormality.

Conclusion

NPC is an infrequent but important cause of incidental focal nasopharyngeal uptake on [18F]FDG PET/CT. Metabolic parameters were shown to be useful to differentiate between benign and malignant nasopharyngeal lesions, and NPR showed the best diagnostic performance.

Factors predicting upstaging from clinical N0 to pN2a/N3a in breast cancer patients

BACKGROUND

With sentinel node metastasis in breast cancer (BC) patients, axillary lymph node (ALN) dissection is often omitted from cases with breast-conserving surgery. Omission of lymph node dissection reduces the invasiveness of surgery to the patient, but it also obscures the number of metastases to non-sentinel nodes. The possibility of finding ≥ 4 lymph nodes (pN2a/pN3a) preoperatively is important given the ramifications for postoperative treatment.

AIM

To search for clinicopathological factors that predicts upstaging from N0 to pN2a/pN3a.

METHODS

Patients who were sentinel lymph node (SLN)-positive and underwent ALN dissection between September 2007 and August 2018 were selected by retrospective chart review. All patients had BC diagnosed preoperatively as N0 with axillary evaluation by fluorodeoxyglucose (FDG) positron emission tomography/computed tomography and ultrasound (US) examination. When suspicious FDG accumulation was found in ALN, the presence of metastasis was reevaluated by second US. We examined predictors of upstaging from N0 to pN2a/pN3a.

RESULTS

Among 135 patients, we identified 1-3 ALNs (pN1) in 113 patients and ³4 ALNs (pN2a/pN3a) in 22 patients. Multivariate analysis identified the total number of SLN metastasis, the maximal diameter of metastasis in the SLN (SLNDmax), and FDG accumulation of ALN as predictors of upstaging to pN2a/pN3a.

CONCLUSION

We identified factors involved in upstaging from N0 to pN2a/pN3a. The SLNDmax and number of SLN metastasis are predictors of ≥ 4 ALNs (pN2a/pN3a) and predictors of metastasis to non-sentinel nodes, which have been reported in the past. Attention should be given to axillary accumulations of FDG, even when faint.

Diagnostic Value of 18F-FDG PET/CT-Based Radiomics Nomogram in Bone Marrow Involvement of Pediatric Neuroblastoma

OBJECTIVES

To develop and validate an ¹⁸F-FDG PET/CT-based radiomics nomogram and evaluate the value of the ¹⁸F-FDG PET/CT-based radiomics nomogram for the diagnosis of bone marrow involvement (BMI) in pediatric neuroblastoma.

MATERIALS AND METHODS

A total of 144 patients with neuroblastoma (100 in the training cohort and 44 in the validation cohort) were retrospectively included. The PET/CT images of patients were visually assessed. The results of bone marrow aspirates or biopsies were used as the gold standard for BMI. Radiomics features and conventional PET parameters were extracted using the 3D slicer. Features were selected by the least absolute shrinkage and selection operator regression, and radiomics signature was constructed. Univariate and multivariate logistic regression analyses were applied to identify the independent clinical risk factors and construct the clinical model. Other different models, including the conventional PET model, combined PET-clinical model and combined radiomics model, were built using logistic regression. The combined radiomics model was based on clinical factors, conventional PET parameters and radiomics signature, which was presented as a radiomics nomogram. The diagnostic performance of the different models was evaluated by receiver operating characteristic (ROC) curves and decision curve analysis (DCA).

RESULTS

By visual assessment, BMI was observed in 80 patients. Four conventional PET parameters (SUVmax, SUVmean, metabolic tumor volume, and total lesion glycolysis) were extracted. And 15 radiomics features were selected to build the radiomics signature. The 11q aberration, neuron-specific enolase and vanillylmandelic acid were identified as the independent clinical risk factors to establish the clinical model. The radiomics nomogram incorporating the radiomics signature, the independent clinical risk factors and SUVmean demonstrated the best diagnostic value for identifying BMI, with an area under the curve (AUC) of 0.963 and 0.931 in the training and validation cohorts, respectively. And the DCA demonstrated that the radiomics nomogram was clinically useful.

CONCLUSION

The ¹⁸F-FDG PET/CT-based radiomics nomogram which incorporates radiomics signature, independent clinical risk factors and conventional PET parameters could improve the diagnostic performance for BMI of pediatric neuroblastoma without additional medical costs and radiation exposure.

18F-FDG PET/CT-based radiomics nomogram could predict bone marrow involvement in pediatric neuroblastoma

Objective

To develop and validate an ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT)-based radiomics nomogram for non-invasively prediction of bone marrow involvement (BMI) in pediatric neuroblastoma.

Methods

A total of 133 patients with neuroblastoma were retrospectively included and randomized into the training set (n = 93) and test set (n = 40). Radiomics features were extracted from both CT and PET images. The radiomics signature was developed. Independent clinical risk factors were identified using the univariate and multivariate logistic regression analyses to construct the clinical model. The clinical-radiomics model, which integrated the radiomics signature and the independent clinical risk factors, was constructed using multivariate logistic regression analysis and finally presented as a radiomics nomogram. The predictive performance of the clinical-radiomics model was evaluated by receiver operating characteristic curves, calibration curves and decision curve analysis (DCA).

Results

Twenty-five radiomics features were selected to construct the radiomics signature. Age at diagnosis, neuron-specific enolase and vanillylmandelic acid were identified as independent predictors to establish the clinical model. In the training set, the clinical-radiomics model outperformed the radiomics model or clinical model (AUC: 0.924 vs. 0.900, 0.875) in predicting the BMI, which was then confirmed in the test set (AUC: 0.925 vs. 0.893, 0.910). The calibration curve and DCA demonstrated that the radiomics nomogram had a good consistency and clinical utility.

Conclusion

The ¹⁸F-FDG PET/CT-based radiomics nomogram which incorporates radiomics signature and independent clinical risk factors could non-invasively predict BMI in pediatric neuroblastoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13244-022-01283-8.

Multimodal deep learning model on interim [18F]FDG PET/CT for predicting primary treatment failure in diffuse large B-cell lymphoma

OBJECTIVES

The prediction of primary treatment failure (PTF) is necessary for patients with diffuse large B-cell lymphoma (DLBCL) since it serves as a prominent means for improving front-line outcomes. Using interim ¹⁸F-fluoro-2-deoxyglucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) imaging data, we aimed to construct multimodal deep learning (MDL) models to predict possible PTF in low-risk DLBCL.

METHODS

Initially, 205 DLBCL patients undergoing interim [¹⁸F]FDG PET/CT scans and the front-line standard of care were included in the primary dataset for model development. Then, 44 other patients were included in the external dataset for generalization evaluation. Based on the powerful backbone of the Conv-LSTM network, we incorporated five different multimodal fusion strategies (pixel intermixing, separate channel, separate branch, quantitative weighting, and hybrid learning) to make full use of PET/CT features and built five corresponding MDL models. Moreover, we found the best model, that is, the hybrid learning model, and optimized it by integrating the contrastive training objective to further improve its prediction performance.

RESULTS

The final model with contrastive objective optimization, named the contrastive hybrid learning model, performed best, with an accuracy of 91.22% and an area under the receiver operating characteristic curve (AUC) of 0.926, in the primary dataset. In the external dataset, its accuracy and AUC remained at 88.64% and 0.925, respectively, indicating its good generalization ability.

CONCLUSIONS

The proposed model achieved good performance, validated the predictive value of interim PET/CT, and holds promise for directing individualized clinical treatment.

KEY POINTS

• The proposed multimodal models achieved accurate prediction of primary treatment failure in DLBCL patients. • Using an appropriate feature-level fusion strategy can make the same class close to each other regardless of the modal heterogeneity of the data source domain and positively impact the prediction performance. • Deep learning validated the predictive value of interim PET/CT in a way that exceeded human capabilities.

Radiologic Imaging Modalities for Colorectal Cancer

BACKGROUND

Studies reported various diagnostic value of radiologic imaging modalities for diagnosis and management of colorectal cancer (CRC).

AIMS

To summary the diagnosis and management of CRC using computed tomography colonography (CTC), magnetic resonance colonography (MRC), and positron emission tomography (PET)/computed tomography (CT).

METHODS

Comprehensive literature searches were conducted in PubMed, EmBase, and the Cochrane library for studies published before April 2021. The diagnostic performance of CTC, MRC, and PET/CT for CRC was summarized.

RESULTS

A total of 54 studies (17 studies for CTC, 8 studies for MRC, and 29 studies for PET/CT) were selected for final analysis. The sensitivity and specificity for CTC ranged from 27 to 100%, 88 to 100%, respectively, and the pooled sensitivity and specificity for CTC were 0.97 (95% CI 0.88-0.99) and 0.99 (95% CI 0.99-1.00). The sensitivity and specificity for MRC ranged from 48 to 100%, 60 to 100%, respectively, and the pooled sensitivity and specificity for MRC were 0.98 (95% C: 0.77-1.00) and 0.94 (95% CI 0.84-0.98). The sensitivity and specificity for PET/CT ranged from 84 to 100%, 33 to 100%, respectively, and the pooled sensitivity and specificity for PET/CT were 0.94 (95% CI 0.92-0.96) and 0.94 (95% CI 0.90-0.97). The area under the receiver operating characteristic curve for CTC, MRC, and PET/CT was 1.00 (95% CI 0.99-1.00), 0.99 (95% CI 0.98-1.00), and 0.97 (0.95% CI 0.95-0.98), respectively.

CONCLUSIONS

This study suggested both CTC and MRC with relative higher diagnostic value for diagnosing CRC, while PET/CT with higher diagnostic value in detecting local recurrence for patients with CRC.

[The correlation between metabolic parameters in (18)F-FDG PET-CT and solid and micropapillary histological subtypes in lung adenocarcinoma]

Objective: Solid and micropapillary pattern are highly invasive histologic subtypes in lung adenocarcinoma and are associated with poor prognosis while the biopsy sample is not enough for the accurate histological diagnosis. This study aims to assess the correlation and predictive efficacy between metabolic parameters in (18)F-fluorodeoxy glucose positron emission tomography/computed tomography ((18)F-FDG PET-CT), including the maximum SUV (SUV(max)), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and solid and micropapillary histological subtypes in lung adenocarcinoma. Methods: A total of 145 resected lung adenocarcinomas were included. The clinical data and preoperative (18)F-FDG PET-CT data were retrospectively analyzed. Mann-Whitney U test was used for the comparison of the metabolic parameters between solid and micropapillary subtype group and other subtypes group. Receiver operating characteristic (ROC) curve and areas under curve (AUC) were used for evaluating the prediction efficacy of metabolic parameters for solid or micropapillary patterns. Univariate and multivariate analyses were conducted to determine the prediction factors of the presence of solid or micropapillary subtypes. Results: Median SUV(max) and TLG in solid and papillary predominant subtypes group (15.07 and 34.98, respectively) were significantly higher than those in other subtypes predominant group (6.03 and 10.16, respectively, P<0.05). ROC curve revealed that SUV(max) and TLG had good efficacy for prediction of solid and micropapillary predominant subtypes [AUC=0.811(95% CI: 0.715~0.907) and 0.725(95% CI: 0.610~0.840), P<0.05]. Median SUV(max) and TLG in lung adenocarcinoma with the solid or micropapillary patterns (11.58 and 22.81, respectively) were significantly higher than those in tumors without solid and micropapillary patterns (4.27 and 6.33, respectively, P<0.05). ROC curve revealed that SUV(max) and TLG had good efficacy for predicting the presence of solid or micropapillary patterns [AUC=0.757(95% CI: 0.679~0.834) and 0.681(95% CI: 0.595~0.768), P<0.005]. Multivariate logistic analysis showed that the clinical stage (Stage Ⅲ-Ⅳ), SUV(max) ≥10.27 and TLG≥7.12 were the independent predictive factors of the presence of solid or micropapillary patterns (P<0.05). Conclusions: Preoperative SUV(max) and TLG of lung adenocarcinoma have good prediction efficacy for the presence of solid or micropapillary patterns, especially for the solid and micropapillary predominant subtypes and are independent factors of the presence of solid or micropapillary patterns.