Search

Diffuse large B-cell lymphoma (DLBCL) is a common and aggressive subtype of lymphoma, and accurate survival prediction is crucial for treatment decisions. This study aims to develop a robust survival prediction strategy to integrate various risk factors effectively, including clinical risk factors and Deauville scores in positron-emission tomography/computed tomography at different treatment stages using a deep-learning-based approach. We conduct a multi-institutional study on 604 DLBCL patients’ clinical data and validate the model on 220 patients from an independent institution. We propose a survival prediction model using transformer architecture and a categorical-feature-embedding technique that can handle high-dimensional and categorical data. Comparison with deep-learning survival models such as DeepSurv, CoxTime, and CoxCC based on the concordance index (C-index) and the mean absolute error (MAE) demonstrates that the categorical features obtained using transformers improved the MAE and the C-index. The proposed model outperforms the best-performing existing method by approximately 185 days in terms of the MAE for survival time estimation on the testing set. Using the Deauville score obtained during treatment resulted in a 0.02 improvement in the C-index and a 53.71-day improvement in the MAE, highlighting its prognostic importance. Our deep-learning model could improve survival prediction accuracy and treatment personalization for DLBCL patients.

Lymphovascular invasion (LVI) is one of the most important prognostic factors in gastric cancer as it indicates a higher likelihood of lymph node metastasis and poorer overall outcome for the patient. Despite its importance, the detection of LVI(+) in histopathology specimens of gastric cancer can be a challenging task for pathologists as invasion can be subtle and difficult to discern. Herein, we propose a deep learning-based LVI(+) detection method using H&E‐stained whole‐slide images. The ConViT model showed the best performance in terms of both AUROC and AURPC among the classification models (AUROC: 0.9796; AUPRC: 0.9648). The AUROC and AUPRC of YOLOX computed based on the augmented patch-level confidence score were slightly lower (AUROC: -0.0094; AUPRC: -0.0225) than those of the ConViT classification model. With simple averaging of the patch-level confidence scores, the ensemble model exhibited the best AUROC, AUPRC, and F1 scores of 0.9880, 0.9769, and 0.9280, respectively. The proposed model is expected to contribute to precision medicine by potentially saving examination-related time and labor and reducing disagreements among pathologists.

OBJECTIVES We compared the diagnostic performance of C-11 acetate and F-18 fluorodeoxyglucose (FDG) PET/computed tomography (CT) for the detection of extrahepatic metastasis in patients with hepatocellular carcinoma (HCC) and evaluated whether the improvement in the diagnostic performance of dual tracer PET/CT differs by the metastatic site. METHODS Fifty-eight patients who had extrahepatic metastasis on either C-11 acetate or F-18 FDG PET/CT were enrolled, and 193 metastatic lesions were analyzed in this retrospective study. The metastatic lesions were categorized based on six sites of involvement. According to each involved site, the tracer avidity of the metastatic lesions was compared using the maximum standardized uptake value (SUVmax). RESULTS Bone was the most frequent categorized metastatic site (44.8%), followed by lymph node (39.7%), lung (34.5%), soft tissue (27.6%), adrenal gland (6.9%), and vascular category (3.4%). C-11 acetate PET/CT showed a higher SUVmax than F-18 FDG PET/CT in metastatic bone lesions (P = 0.003). F-18 FDG uptake was significantly higher than C-11 acetate uptake in metastatic lymph node lesions (P

Renal insufficiency (RI) is a frequent manifestation of multiple myeloma (MM) at time of diagnosis but there is no reliable prognostic factor for patients with MM presenting with RI. This study investigated the prognostic impact of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with MM with RI at diagnosis. The records of 209 patients with MM between June 2011 and November 2018 were retrospectively analyzed. PET/CT positivity was defined as the presence of more than three focal lesions or the presence of extramedullary disease. Of 209 patients, 90 (43.1%) had RI and showed similar survival outcomes to patients who had normal renal function. In total, 113 patients (54.0%) were PET/CT-positive, and 46.6% of patients with RI were PET/CT-positive at baseline. In patients with RI, those who were PET/CT-positive showed significantly inferior survival outcomes to those who were PET/CT-negative [progression-free survival (PFS), 12.7 vs. 34.0 months, P

PURPOSE: We investigated the clinical role of F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) in the identification of the primary site and the selection of the optimal biopsy site in patients with suspected bone metastasis of unknown primary site. METHODS: The patients with suspected bone metastasis who underwent PET-CT for evaluation of primary site were enrolled in this study. The primary sites were identified by the histopathologic or imaging studies and were classified according to the FDG uptake positivity of the primary site. To evaluate the guiding capability of PET-CT in biopsy site selection, we statistically analyzed whether the biopsy site could be affected according to the presence of extra-skeletal FDG uptake. RESULTS: Among 74 enrolled patients, 51 patients had a metastatic bone disease. The primary site was identified in 48 of 51 patients (94.1%). Forty-six patients were eligible to test the association of clinical choice of biopsy site with PET positivity of extra-skeletal lesion. The extra-skeletal biopsies were done in 42 out of 43 patients with positive extra-skeletal uptake lesions. Bone biopsies were inevitably performed in the other three patients without extra-skeletal uptake lesions. The association came out to be significant (Fisher’s exact test, P

Significance With the emergence of new therapeutic modalities, the diagnosis of melanoma at the earliest practicable stage has become more important for improving the survival of patients. We developed a positron emission tomography (PET) imaging probe, N-(2-(dimethylamino)ethyl)-5-[18F]fluoropicolinamide ([18F]DMPY2) and evaluated diagnostic performance in animal models. [18F]DMPY2 PET exhibited excellent performance in detecting primary and metastatic melanomas, demonstrating strong/prolonged tumoral uptake and rapid background clearance. This suggests that this radiotracer could be used as a novel PET imaging agent to obtain outstanding image quality in the diagnosis of melanoma. This is the pioneering report of pyridine-based benzamide derivative with reduced alkyl chains in the amine residue and ultrasensitive detection of melanoma lesions in living subjects compared to conventional PET imaging agents., Malignant melanoma has one of the highest mortality rates of any cancer because of its aggressive nature and high metastatic potential. Clinical staging of the disease at the time of diagnosis is very important for the prognosis and outcome of melanoma treatment. In this study, we designed and synthesized the 18F-labeled pyridine-based benzamide derivatives N-(2-(dimethylamino)ethyl)-5-[18F]fluoropicolinamide ([18F]DMPY2) and N-(2-(dimethylamino)ethyl)-6-[18F]fluoronicotinamide ([18F]DMPY3) to detect primary and metastatic melanoma at an early stage and evaluated their performance in this task. [18F]DMPY2 and [18F]DMPY3 were synthesized by direct radiofluorination of the bromo precursor, and radiochemical yields were ∼15–20%. Cell uptakes of [18F]DMPY2 and [18F]DMPY3 were >103-fold and 18-fold higher, respectively, in B16F10 (mouse melanoma) cells than in negative control cells. Biodistribution studies revealed strong tumor uptake and retention of [18F]DMPY2 (24.8% injected dose per gram of tissue [ID/g] at 60 min) and [18F]DMPY3 (11.7%ID/g at 60 min) in B16F10 xenografts. MicroPET imaging of both agents demonstrated strong tumoral uptake/retention and rapid washout, resulting in excellent tumor-to-background contrast in B16F10 xenografts. In particular, [18F]DMPY2 clearly visualized almost all metastatic lesions in lung and lymph nodes, with excellent image quality. [18F]DMPY2 demonstrated a significantly higher tumor-to-liver ratio than [18F]fluorodeoxyglucose ([18F]FDG) and the previously reported benzamide tracers N-[2-(diethylamino)-ethyl]-5-[18F]fluoropicolinamide ([18F]P3BZA) and N-[2-(diethylamino)-ethyl]-4-[18F]fluorobenzamide ([18F]FBZA) in B16F10-bearing or SK-MEL-3 (human melanoma)-bearing mice. In conclusion, [18F]DMPY2 might have strong potential for the diagnosis of early stage primary and metastatic melanoma using positron emission tomography (PET).

OBJECTIVES The aim of this study was to evaluate a prognostic value of the extent of metastatic lymph node combined with TSH-stimulated serum thyroglobulin (sTg) measured just before radioactive iodine (RAI) therapy in patients with papillary thyroid cancer (PTC). METHODS The retrospective study included 468 patients with PTC who underwent total thyroidectomy with neck dissection and postoperative RAI therapy. The extent of metastatic lymph node was evaluated with the lymph node ratio (LNR) which was defined as the number of metastatic lymph nodes out of the number of total removed lymph nodes. We investigated which factors could significantly predict persistent or recurrent disease (PRD). RESULTS LNR ≥0.4 (P = 0.002) and sTg ≥6.0 ng/mL (P

Bacteria-mediated cancer therapy is a potential therapeutic strategy for cancer that has unique properties, including broad tumor-targeting ability, various administration routes, the flexibility of delivery, and facilitating the host's immune responses. The molecular imaging of bacteria-mediated cancer therapy allows the therapeutically injected bacteria to be visualized and confirms the accurate delivery of the therapeutic bacteria to the target lesion. Several hurdles make bacteria-specific imaging challenging, including the need to discriminate therapeutic bacterial infection from inflammation or other pathologic lesions. To realize the full potential of bacteria-specific imaging, it is necessary to develop bacteria-specific targets that can be associated with an imaging assay. This review describes the current status of bacterial imaging techniques together with the advantages and disadvantages of several imaging modalities. Also, we describe potential targets for bacterial-specific imaging and related applications.

Tumor-targeting bacteria have been actively investigated as a new therapeutic tool for solid tumors. However, in vivo imaging of tumor-targeting bacteria has not been fully established. 18F-fluorodeoxysorbitol (FDS) positron emission tomography (PET) is known to be capable of imaging Gram-negative Enterobacteriaceae infection. In the present study, we aimed to validate the use of 18F-FDS PET for visualization of the colonization and proliferation of tumor-targeting Escherichia coli (E. coli) MG1655 in mouse tumor models. Methods: E. coli (5 × 107 colony forming unit) were injected intravenously into BALB/c mice bearing mouse colon cancer (CT26). Before and 1, 3, and 5 days after the bacterial injection, PET imaging was performed following i.v. injection of approximately 7.4 MBq of 18F-FDS. Regions of interest were drawn in the engrafted tumor and normal organs including the heart, liver, lung, brain, muscle, and intestine. Semiquantitative analysis was performed using maximum standardized uptake value (SUVmax). Results: 18F-FDS uptake was significantly higher in tumors colonized by live E. coli MG1655 than in uncolonized tumors (p < 0.001). The PET signals in the colonized tumors at 3 days after bacterial injection were 3.1-fold higher than those in the uncolonized tumors. Tumoral 18F-FDS uptake correlated very strongly with the number of E. coli in tumors (r = 0.823, p < 0.0001). Cross sectional analysis of autoradiography, bioluminescence, and pathology revealed that the 18F-FDS uptake sites in tumors matched the locations of E. coli MG1655. Conclusion: In conclusion, 18F-FDS PET is expected to be useful for the semiquantitative visualization of tumor-targeting bacteria when bacterial cancer therapy is performed using Gram-negative Enterobacteriaceae such as E. coli.

Background Epstein-Barr virus (EBV)–positive diffuse large B-cell lymphoma (DLBCL) in an immunocompromised patient with organ transplantation demonstrated unusual brain magnetic resonance imaging (MRI) findings. Recognition of EBV-positive DLBCL by radiologists on MRI may prevent unnecessary neurosurgical resection, and it could be important to obtain viable cells for accurate diagnosis on stereotactic biopsy because of extensive necrosis. Case Description A 62-year-old woman presented to the emergency department with left hemiparesis grade III and dysarthria lasting for 3 weeks. She underwent kidney transplantation in 2007 and was taking immunosuppressants and had hypothyroidism. Brain MRI showed a 3.8-cm peripheral enhancing lesion with extensive central necrosis in association with marked perilesional edema. The irregular ringlike enhancing lesion showed diffusion restriction and mildly increased regional cerebral blood volume in the rim portion of the mass. 11C-Methionine positron emission tomography revealed slightly increased uptake in the peripheral lesion. The provisional diagnosis was a high-grade glioma. Stereotactic multiple biopsies were performed for the central necrotic area and peripheral enhancing lesion. The nonenhancing areas showed only necrotic material, without viable cells, and the enhancing portion showed viable cells for an accurate diagnosis in a frozen biopsy specimen. The pathologic diagnosis was EBV-positive DLBCL with extensive necrosis. Positron emission tomography of the chest, abdomen, pelvis, and neck soft tissues ruled out systemic diseases. She underwent whole-brain radiotherapy at a dose of 30.6 Gy. Eight months later, her neurologic symptoms had improved, with a stable brain lesion and improved perilesional edema. Conclusions We report an immunocompromised patient with EBV-positive DLBCL, which showed atypical MRI findings, including extensive necrosis. Multiple biopsies were required for final diagnosis.

Purpose: The clinical role of 18F-fluorodeoxyglucose (FDG)-positron emission tomography-computed tomography (PET/CT) in performing upfront high-dose chemotherapy followed by autologous stem cell transplantation (ASCT) remains unclear in peripheral T cell lymphomas (PTCLs). This study investigated the prognostic relevance of interim and final FDG-PET/CT in predicting the outcome of upfront ASCT for the treatment of PTCLs. Method: The study conducted newly diagnosed 96 patients with PTCLs who aged under 65 years between January 2005 and December 2016 from two independent institutions. For making a comparison of clinical outcome between transplant and non-transplant patients according to interim or final FDG- PET/CT, 37 transplanted and 59 non-transplanted patients with the same populations were evaluated as a comparative group (non-ASCT). The enrolled patients were treated with mainly anthracycline-based chemotherapy except patients with NK/T cell lymphoma who were treated with non-anthracycline-based. If achieved complete or partial remission after primary treatment, patients proceeded to upfront ASCT. FDG-PET/CT was performed at the time of diagnosis, interim, and after primary treatment. The response of interim or final FDG-PET/CT was analyzed by visual assessment using Deauville five-point scale (5-PS). Results: The characteristics of transplant patients were similar to non-transplant patients except two features (IPI score, CT response). Final FDG-PET/CT response (P Conclusion: Final FDG-PET/CT response based on Deauville 5-PS had prognostic significance on the treatment outcome of PTCLs regardless of upfront ASCT. However, patients with ≥ 3 of Deauville score assessed by interim or final FDG-PET/CT had poor prognosis even though performing upfront ASCT. Disclosures No relevant conflicts of interest to declare.

There is growing interest in the role of microorganisms in human health and disease, with evidence showing that new types of biotherapy using engineered bacterial therapeutics, including bacterial derivatives, can address specific mechanisms of disease. The complex interactions between microorganisms and metabolic/immunologic pathways underlie many diseases with unmet medical needs, suggesting that targeting these interactions may improve patient treatment. Using tools from synthetic biology and chemical engineering, non-pathogenic bacteria or bacterial products can be programmed and designed to sense and respond to environmental signals to deliver therapeutic effectors. This review describes current progress in biotherapy using live bacteria and their derivatives to achieve therapeutic benefits against various diseases.

We aimed to characterize solitary pulmonary nodule (SPN) using imaging parameters for F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) or enhanced CT corrected by tumor shadow disappearance rate (TDR) to reflect the tissue density.We enrolled 51 patients with an SPN who underwent PET/CT and chest CT with enhancement. The FDG uptake of SPN was evaluated using maximum standardized uptake value (SUVmax) on PET/CT. The mean Hounsfield unit (HU) for each SPN was evaluated over the region of interest on nonenhanced and enhanced CT images. The change in mean HU (HUpeak-pre) was quantified by subtracting the mean HU of the preenhanced CT from that of the post-enhanced CT. TDR was defined as the ratio of the tumor area, which disappears at a mediastinal window, to the tumor area of the lung window. We investigated which parameters (SUVmax or HUpeak-pre) could contribute to the characterization of SPN classified by TDR value and whether diagnostic performance could be improved using TDR-corrected imaging parameters.For SPN with higher tissue density (TDR42%, n = 22), high value of SUVmax (≥3.1) was a significant factor to predict malignancy (P = .006). High value of HUpeak-pre (≥38) was a significant factor to characterize SPN (P = .002) with lower tissue density (TDR ≥42%, n = 29). The combined approach using TDR-corrected parameters had better predictive performance to characterize SPN than SUVmax only (P = .031).Applying imaging parameters such as SUVmax or HUpeak-pre in consideration of tissue density calculated with TDR could contribute to accurate characterization of SPN.

Segmentation of liver tumors from Computerized Tomography (CT) images remains a challenge due to the natural variation in tumor shape and structure as well as the noise in CT images. A key assumption is that the performance of liver tumor segmentation depends on the characteristics of multiple features extracted from multiple filters. In this paper, we design an enhanced approach based on a two-class (liver, tumor) convolutional neural network that discriminates tumor as well as liver from CT images. First, the contrast and intensity values in CT images are adjusted and high frequencies are removed using Hounsfield units (HU) filtering and standardization. Then, the liver tumor is segmented from entire images with multiple filter U-net (MFU-net). Finally, a quantitative analysis is carried out to evaluate the segmentation results using three different methods: boundary-distance-based metrics, size-based metrics, and overlap-based metrics. The proposed method is validated on CT images from the 3Dircadb and LiTS dataset. The results demonstrate that the multiple filters are useful for extracting local and global feature simultaneously, minimizing the boundary distance errors, and our approach demonstrates better performance in heterogeneous tumor regions of CT images.

Invasive aspergillosis is a critical complication in immunocompromised patients with hematologic malignancies or with viral pneumonia caused by influenza virus or SARS‑CoV‑2. Although early and accurate diagnosis of invasive aspergillosis can maximize clinical outcomes, current diagnostic methods are time-consuming and poorly sensitive. Here, we assess the ability of 2-deoxy-2

Bacterial cancer therapy (BCT) approaches have been extensively investigated because bacteria can show unique features of strong tropism for cancer, proliferation inside tumors, and antitumor immunity, while bacteria are also possible agents for drug delivery. Despite the rapidly increasing number of preclinical studies using BCT to overcome the limitations of conventional cancer treatments, very few BCT studies have advanced to clinical trials. In patients undergoing BCT, the precise localization and quantification of bacterial density in different body locations is important; however, most clinical trials have used subjective clinical signs and invasive sampling to confirm bacterial colonization. There is therefore a need to improve the visualization of bacterial densities using noninvasive and repetitive in vivo imaging techniques that can facilitate the clinical translation of BCT. In vivo optical imaging techniques using bioluminescence and fluorescence, which are extensively employed to image the therapeutic process of BCT in small animal research, are hard to apply to the human body because of their low penetrative power. Thus, new imaging techniques need to be developed for clinical trials. In this review, we provide an overview of the various in vivo bacteria-specific imaging techniques available for visualizing tumor-treating bacteria in BCT studies.

BACKGROUND: IBM Watson for Oncology (WFO) is a cognitive computing system helping physicians quickly identify key information in a patient’s medical record, surface relevant evidence, and explore treatment options. This study assessed the possibility of using WFO for clinical treatment in lung cancer patients. METHODS: We evaluated the level of agreement between WFO and multidisciplinary team (MDT) for lung cancer. From January to December 2018, newly diagnosed lung cancer cases in Chonnam National University Hwasun Hospital were retrospectively examined using WFO version 18.4 according to four treatment categories (surgery, radiotherapy, chemoradiotherapy, and palliative care). Treatment recommendations were considered concordant if the MDT recommendations were designated ‘recommended’ by WFO. Concordance between MDT and WFO was analyzed by Cohen’s kappa value. RESULTS: In total, 405 (male 340, female 65) cases with different histology (adenocarcinoma 157, squamous cell carcinoma 132, small cell carcinoma 94, others 22 cases) were enrolled. Concordance between MDT and WFO occurred in 92.4% (k=0.881, P

Renal insufficiency (RI) is a frequent manifestation of multiple myeloma (MM) at time of diagnosis but there is no reliable prognostic factor for patients with MM presenting with RI. This study investigated the prognostic impact of

Background: Although 11C-methionine positron emission tomography (MET-PET) images can be fused with magnetic resonance (MR) images using planning software for gamma knife radiosurgery (GKR), the stereotactic information has limited value in patients with recurrent malignant brain tumor due to the difference in imaging protocols between MET-PET and MR images. The aim of this study was to evaluate the clinical application of MR imaging (MRI)-deformed MET-PET images in GKR using a deformable registration tool. Methods: We examined the enhanced MR stereotactic images, MET-PET and MRI-deformed MET-PET images without stereotactic information for 12 newly developed metastatic brain tumors. MET-PET and MRI-deformed MET-PET images were co-registered with the MR stereotactic images using radiosurgery planning software. Visual analysis was performed to determine whether the MET-PET and MR images matched better after using the deformable registration tool. In addition, the matching volume between MR and MET-PET images was compared before and after applying this tool. The matching volume was calculated as the metabolic tumor volume on the MET-PET images, including the MR-enhanced volume. The matching percentage was calculated as the matching volume divided by the MR-enhanced volume, multiplied by 100. Results: Visual analysis revealed that the MRI-deformed MET-PET images provided the same axial plane as that of the MR images, with the same window level, enabling easy identification of the tumor with the radiosurgery planning software. The mean matching percentage of the MET-PET/MR fusion images was 61.1% (range 24.7–94.7) and that of the MRI-deformed MET-PET/MR fusion images was 63.4% (range 20.8–94.3). No significant difference was found in the matching percentage between the two types of fusion images (p = 0.754). Conclusions: The MRI-deformed MET-PET images enable utilization of the functional information when planning a treatment in GKR without significant volume change.

The aim of this study was to establish a risk-stratification model integrating posttreatment metabolic response using the Deauville score and the pretreatment National Comprehensive Cancer Network-International Prognostic Index (NCCN-IPI) in nodal PTCLs. We retrospectively analysed 326 patients with newly diagnosed nodal PTCLs between January 2005 and June 2016 and both baseline and posttreatment PET/CT data. The final model was validated using an independent prospective cohort of 79 patients. Posttreatment Deauville score (1/2, 3, and 4/5) and the NCCN-IPI (low, low-intermediate, high-intermediate, and high) were independently associated with progression-free survival: for the Deauville score, the hazard ratios (HRs) were 1.00 vs. 2.16 (95% CI 1.47–3.18) vs. 7.86 (5.66–10.92), P

PURPOSE: Thyroglobulin (Tg) may be released from damaged residual thyroid tissues after radioactive iodine (RAI) therapy in patients with differentiated thyroid carcinoma (DTC). We investigated whether altered levels of serum Tg after recombinant human thyrotropin (rhTSH)-aided RAI therapy could be a prognostic marker in patients with DTC. METHODS: We evaluated 68 patients who underwent RAI therapy after total thyroidectomy. Serum Tg levels were measured just before RAI administration (D0Tg) and 7 days after RAI therapy (D7Tg). Patients with a D0Tg level greater than 2.0 ng/mL were excluded to more precisely evaluate the injury effect of RAI in small remnant tissues. The ratioTg was defined as the D7Tg level divided by that on D0Tg. The therapeutic responses were classified as acceptable or non-acceptable. Finally, we investigated which clinicopathologic parameters were associated with therapeutic response. RESULTS: At the follow-up examination, an acceptable response was observed in 50 patients (73.5%). Univariate analysis revealed significant differences in N stage (P = 0.003) and ratioTg (acceptable vs. non-acceptable responses, 21.9 ± 33.6 vs. 3.8 ± 6.5; P = 0.006). In multivariate analysis, only ratioTg significantly predicted an acceptable response (odds ratio 1.104; 95% confidence interval 1.005–1.213; P = 0.040). A ratioTg above 3.5 predicted an acceptable response with a sensitivity of 66.0%, specificity of 83.3%, and accuracy of 70.6% (area under the curve = 0.718; P = 0.006). CONCLUSIONS: Altered levels of serum Tg after RAI therapy, calculated as the ratioTg (D7Tg/D0Tg), significantly predicted an acceptable response in patients with DTC.

Purpose Induction chemotherapy (ICT) with docetaxel, cisplatin, and 5-fluorouracil (TPF) followed by concurrent chemoradiotherapy (CCRT) has the advantages of organ preservation and systemic control in head and neck cancer (HNC). Early prediction of CCRT efficacy may help identify patients who will benefit more from surgery than from CCRT. We investigated the role of interim 18-fluoro-2-deoxy-glucose positron emission tomography computed tomography (FDG PET-CT) after ICT to predict the efficacy of CCRT and clinical outcomes. Methods Tumor responses were retrospectively reviewed after CCRT based on the Response Evaluation Criteria in Solid Tumors. FDG PET-CT imaging was performed before and after three cycles of TPF. We examined the associations between the metabolic response (percentage decrease in the maximum standardized uptake value [SUVmax] and total metabolic tumor volume [MTV]) after ICT and complete response (CR) to CCRT, progression-free survival (PFS), and overall survival (OS). Results We studied 43 HNC patients with a median follow-up of 32.7 months. Lymph node (LN) SUVmax and total MTV decreases from baseline after ICT were greater in patients with a CR to CCRT than in non-CR patients (LN SUVmax, 88.8% vs. 62.5%, respectively; total MTV, 99.7% vs. 89.9%, respectively). Decreases in total MTV ≥ 78% and LN SUVmax ≥73% after ICT predicted CR to CCRT and longer OS and PFS. Conclusions Using interim FDG PET-CT to measure SUVmax and total MTV after three cycles of ICT may be a useful technique for identifying HNC patients who will benefit from CCRT and predicting survival outcomes. Electronic supplementary material The online version of this article (10.1007/s00259-017-3836-8) contains supplementary material, which is available to authorized users.

We investigated whether the performance of serum thyroglobulin (Tg) for response prediction could be improved based on the iodine uptake pattern on the post-therapeutic I-131 whole body scan (RxWBS) and the degree of thyroid tissue damage with radioactive iodine (RAI) therapy. A total of 319 patients with differentiated thyroid carcinoma who underwent total thyroidectomy and RAI therapy were included. Based on the presence/absence of focal uptake at the anterior midline of the neck above the thyroidectomy bed on RxWBS, patients were classified into positive and negative uptake groups. Serum Tg was measured immediately before (D0Tg) and 7 days after RAI therapy (D7Tg). Patients were further categorized into favorable and unfavorable Tg groups based on the prediction of excellent response (ER) using scan-corrected Tg developed through the stepwise combination of D0Tg with ratio Tg (D7Tg/D0Tg). We investigated whether the predictive performance for ER improved with the application of scan-corrected Tg compared to the single Tg cutoff. The combined approach using scan-corrected Tg showed better predictive performance for ER than the single cutoff of D0Tg alone (p &lt, 0.001). Therefore, scan-corrected Tg can be a promising biomarker to predict the therapeutic responses after RAI therapy.

Tumor-targeting bacteria have been actively investigated as a new therapeutic tool for solid tumors. However, in vivo imaging of tumor-targeting bacteria has not been fully established. 18F-fluorodeoxysorbitol (FDS) positron emission tomography (PET) is known to be capable of imaging Gram-negative Enterobacteriaceae infection. In the present study, we aimed to validate the use of 18F-FDS PET for visualization of the colonization and proliferation of tumor-targeting Escherichia coli (E. coli) MG1655 in mouse tumor models. Methods: E. coli (5 × 107 colony forming unit) were injected intravenously into BALB/c mice bearing mouse colon cancer (CT26). Before and 1, 3, and 5 days after the bacterial injection, PET imaging was performed following i.v. injection of approximately 7.4 MBq of 18F-FDS. Regions of interest were drawn in the engrafted tumor and normal organs including the heart, liver, lung, brain, muscle, and intestine. Semiquantitative analysis was performed using maximum standardized uptake value (SUVmax). Results: 18F-FDS uptake was significantly higher in tumors colonized by live E. coli MG1655 than in uncolonized tumors (p < 0.001). The PET signals in the colonized tumors at 3 days after bacterial injection were 3.1-fold higher than those in the uncolonized tumors. Tumoral 18F-FDS uptake correlated very strongly with the number of E. coli in tumors (r = 0.823, p < 0.0001). Cross sectional analysis of autoradiography, bioluminescence, and pathology revealed that the 18F-FDS uptake sites in tumors matched the locations of E. coli MG1655. Conclusion: In conclusion, 18F-FDS PET is expected to be useful for the semiquantitative visualization of tumor-targeting bacteria when bacterial cancer therapy is performed using Gram-negative Enterobacteriaceae such as E. coli.

Although 11C-methionine positron emission tomography (MET-PET) images can be fused with magnetic resonance (MR) images using planning software for gamma knife radiosurgery (GKR), the stereotactic information has limited value in patients with recurrent malignant brain tumor due to the difference in imaging protocols between MET-PET and MR images. The aim of this study was to evaluate the clinical application of MR imaging (MRI)-deformed MET-PET images in GKR using a deformable registration tool.We examined the enhanced MR stereotactic images, MET-PET and MRI-deformed MET-PET images without stereotactic information for 12 newly developed metastatic brain tumors. MET-PET and MRI-deformed MET-PET images were co-registered with the MR stereotactic images using radiosurgery planning software. Visual analysis was performed to determine whether the MET-PET and MR images matched better after using the deformable registration tool. In addition, the matching volume between MR and MET-PET images was compared before and after applying this tool. The matching volume was calculated as the metabolic tumor volume on the MET-PET images, including the MR-enhanced volume. The matching percentage was calculated as the matching volume divided by the MR-enhanced volume, multiplied by 100.Visual analysis revealed that the MRI-deformed MET-PET images provided the same axial plane as that of the MR images, with the same window level, enabling easy identification of the tumor with the radiosurgery planning software. The mean matching percentage of the MET-PET/MR fusion images was 61.1% (range 24.7-94.7) and that of the MRI-deformed MET-PET/MR fusion images was 63.4% (range 20.8-94.3). No significant difference was found in the matching percentage between the two types of fusion images (p = 0.754).The MRI-deformed MET-PET images enable utilization of the functional information when planning a treatment in GKR without significant volume change.

F-18 fluorodeoxyglucose (FDG)-avid metastatic lesions are associated with a poor response to radioiodine ablation therapy (RIT) in papillary thyroid cancer (PTC). This study evaluated the significance of preablative FDG positron emission tomography (PET) for the assessment of risk factors and frequency of malignant FDG-avid lymph nodes in patients with PTC undergoing RIT. The study included 339 consecutive patients (mean age 46.3 ± 12.5 y; 260 females) with PTC referred for the first RIT and who underwent routine preablative FDG PET between April 2011 and February 2013. FDG-avid lymph nodes (FALNs) were identified using retrospective image reviews. The frequency of malignant FALN (mFALN), its contribution to persistent or recurrent PTC, and its risk factors were analyzed. Among the patients, 112 had FALNs (33.0%): 11 mFALNs (3.2%) and 101 benign FALNs (bFALNs, 29.8%). mFALN contributed to 55% of persistent or recurrent PTC after RIT, which was observed in 20 of 339 patients (5.9%) during the post-RIT follow-up. Among preoperative risk factors, suspicious extrathyroidal extension and lateral neck lymph node metastasis on imaging studies were associated with mFALN. Among postoperative risk factors, T3/T4 and N1b stages, higher stimulated thyroglobulin, and higher numbers of metastatic lymph nodes and dissected lymph nodes, were associated with mFALN. mFALNs were observed in a small number of patients with PTC undergoing RIT, but it contributed 55% of total recurrent or persistent disease. Increased frequency of mFALNs is associated with more advanced PTC. Preablative FDG PET has value in evaluation of patients with RIT-resistant lesions and may help determine further treatment strategies.

Due to the increase of lung cancer globally, and particularly in Korea, survival analysis for this type of cancer has gained prominence in recent years. For this task, mathematical and traditional machine learning approaches are commonly used by medical doctors. While the deep learning approach has had proven success in computer vision tasks, natural language processing and other AI techniques are also adopted for this task. Due to the privacy issues and management process, data in medicine are difficult to collect, which leads to a paucity of samples. The small number of samples makes it difficult to use deep learning and renders this approach unusable. In this investigation, we propose a network architecture that combines a variational autoencoder (VAE) with the typical DNN architecture to solve the survival analysis task. With a training size of n = 4107, MVAESA achieves a C-index of 0.722 while CoxCC, CoxPH, and CoxTime achieved scores of 0.713, 0.703, and 0.710, respectively. With a small training size of n = 379, MVAESA achieves a C-index of 0.707, compared with 0.689, 0.688 and 0.690 for CoxCC, CoxPH, and CoxTime, respectively. The results show that the combination of a VAE with a target task makes the network more stable and that the network could be trained using a small-sized sample.

Bacterial cancer therapy (BCT) approaches have been extensively investigated because bacteria can show unique features of strong tropism for cancer, proliferation inside tumors, and antitumor immunity, while bacteria are also possible agents for drug delivery. Despite the rapidly increasing number of preclinical studies using BCT to overcome the limitations of conventional cancer treatments, very few BCT studies have advanced to clinical trials. In patients undergoing BCT, the precise localization and quantification of bacterial density in different body locations is important; however, most clinical trials have used subjective clinical signs and invasive sampling to confirm bacterial colonization. There is therefore a need to improve the visualization of bacterial densities using noninvasive and repetitive in vivo imaging techniques that can facilitate the clinical translation of BCT. In vivo optical imaging techniques using bioluminescence and fluorescence, which are extensively employed to image the therapeutic process of BCT in small animal research, are hard to apply to the human body because of their low penetrative power. Thus, new imaging techniques need to be developed for clinical trials. In this review, we provide an overview of the various in vivo bacteria-specific imaging techniques available for visualizing tumor-treating bacteria in BCT studies.

We evaluated the relationships between coronary flow reserve (CFR) and relative flow reserve (RFR) measured by N-13 ammonia positron emission tomography (PET) for characterization of epicardial coronary artery disease (CAD). Sixty-nine consecutive stable angina patients underwent N-13 ammonia PET, coronary computed tomography angiography (CCTA), and if necessary, invasive coronary angiography (CAG) within 2 weeks. Myocardial blood flow (MBF), CFR, RFR, and coronary vascular resistance of the reference arterial territory (CVRref) were measured by N-13 ammonia PET. The presence of significant stenosis (SS) and diffuse atherosclerosis (DA) was evaluated on CCTA and CAG. Functional parameters measured by PET were compared among arteries with and without SS and DA. Arteries with SS and those with DA showed significantly lower stress MBF, as compared to those without. RFR was significantly lower in arteries with SS as compared to those without, while CFR was not. CFR was significantly lower in arteries with DA as compared to those without, while RFR was not. Among arteries without SS, CFR was significantly lower in those with DA as compared to those without. However, among arteries with SS, CFR was similar between those with and without DA. In contrast, RFR was significantly lower in arteries with SS, regardless of the presence of DA. CFR and RFR showed a weak positive correlation (r = 0.269) with discordance in 24 cases (35%). Among the arteries with CFR-RFR discordance, the prevalence of DA was significantly higher in those with low CFR but preserved RFR, as compared to those with preserved CFR but low RFR (75 vs 25%, p = 0.028). CVRref was significantly higher in arteries with DA, implicating a correlation of DA with underlying microvascular disease. CFR and RFR measured by myocardial perfusion PET could provide a comprehensive information for characterization of epicardial CAD.

The aim of this study was to evaluate the prognostic value of additional evaluation of left ventricular mechanical dyssynchrony (LVMD) by gated myocardial perfusion single-photon emission computed tomography (GMPS) in patients with acute myocardial infarction (MI) and multivessel disease. One hundred and nine acute MI patients with >50 % stenosis in at least one non-culprit artery who underwent GMPS within 2 weeks were enrolled. All patients underwent successful revascularization of the culprit arteries. Those with previous MI, atrial fibrillation, or frequent ventricular premature complexes, cardiac devices, significant patient motion, or procedure-related events were excluded. Phase standard deviation (PSD) and phase histogram bandwidth (PBW) were measured for assessment of LVMD. Patients were followed up for a median of 26 months after index MI, for composite major adverse cardiac events (MACE), which consisted with all-cause death, unplanned hospitalization due to heart failure and severe ventricular arrhythmias (sustained ventricular tachycardia or ventricular fibrillation). Independent predictors of MACE were evaluated. MACE occurred in 22 patients (20 %). Stress PSD (53.3 ± 17.3° vs. 35.3 ± 18.9°; p