Total Tumor Burden Research Articles

Whole-body tumor segmentation from FDG-PET/CT: Leveraging a segmentation prior from tissue-wise projections.

Background: Accurate tumor detection and quantification are important for optimized therapy planning and evaluation. Total tumor burden is also an appealing biomarker for clinical trials. Manual examination and annotation of oncologic PET/CT is labor-intensive and demands a high level of expertise. One significant challenge is the risk for human error, leading to potential omission of especially small tumors and tumors with low FDG uptake. Purpose: In this study, we introduced an automated framework with segmentation prior, from a tissue-wise multi-channel multi-angled based approach, to enhance tumor segmentation in whole-body FDG-PET/CT. Method: The proposed framework utilized a segmentation prior generated from tumor segmentations in tissue-wise multi-channel projections of the standardized uptake value (SUV) from PET. Projections were created from various angles and the tissues were identified based on their CT Hounsfield values. The resulting segmentation masks were subsequently backprojected into a unified 3D volume for creation of the segmentation prior. Finally, the segmentation prior was provided as an additional input channel along with the CT and SUV images to three variants of 3D segmentation networks (3D UNet, dynUNet, nnUNet) to enhance the overall tumor segmentation performance. All the methods were independently evaluated using 5-fold cross-validation on the autoPET dataset and subsequently tested on the U-CAN dataset. Results: Combining the segmentation prior with the original SUV and CT images improved overall tumor segmentation performance significantly compared to a baseline network. The increase in Dice coefficient for lymphoma, lung cancer, and melanoma across different segmentation networks were: 3D UNet ( , , ), dynUNet ( , , ), and nnUNet ( , , ), respectively; *, p-value < 0.05; ns, non-significance. Conclusion: The increased segmentation accuracy could be attributed to the segmentation prior generated from tissue-wise SUV projections, revealing information from various tissues that was useful for segmentation of tumors. The results from this study highlight the potential of the proposed method as a valuable future tool for time-efficient quantification of tumor burden in oncologic FDG-PET/CT.

Study protocol for Adaptive ChemoTherapy for Ovarian cancer (ACTOv): a multicentre phase II randomised controlled trial to evaluate the efficacy of adaptive therapy (AT) with carboplatin, based on changes in CA125, in patients with relapsed platinum-sensitive high-grade serous or high-grade endometrioid ovarian cancer

IntroductionAdaptive ChemoTherapy for Ovarian cancer (ACTOv) is a phase II, multicentre, randomised controlled trial, evaluating an adaptive therapy (AT) regimen with carboplatin in women with relapsed, platinum-sensitive high-grade serous or...

Challenges in developing response evaluation criteria for peptide receptor radionuclide therapy: A consensus report from the European Neuroendocrine Tumor Society Advisory Board Meeting 2022 and the ENETS Theranostics Task Force.

Assessing the response to systemic therapy in neuroendocrine tumors (NET) is challenging since morphological imaging response is often delayed and not necessarily reflective of clinical benefit. Peptide receptor radionuclide therapy (PRRT) has a complex mechanism of action, further complicating response assessment. In response to these challenges, the European Neuroendocrine Tumor Society (ENETS) Theranostics Task Force conducted a statement-based survey among experts to identify the current landscape and unmet needs in PRRT response assessment. The survey, presented at the 2022 ENETS Advisory Board (AB) meeting in Vienna, was completed by 70% of AB members, most of whom (81%) were from ENETS Centers of Excellence (CoE). It comprised a set of 13 questions with two substatements in three questions. Six (46%) of the statements achieved more than 75% agreement, while five (39%) additional statements reached over 60% consensus. Key points from the survey include: AB members agreed that lesions deemed equivocal on computed tomography (CT) or magnetic resonance imaging (MRI) should be characterized by somatostatin receptor (SST) positron emission tomography (PET)/CT before being designated as target lesions. It was agreed that interim response assessments should occur after the second or third PRRT cycle. Over half (54%) preferred using both conventional cross-sectional imaging (CT and/or MRI) and hybrid imaging (SST PET/CT) for this purpose. Almost all AB members supported further response assessment 3 months after the final PRRT cycle. A majority (62%) preferred using a combination of conventional cross-sectional imaging and SST PET/CT. For cases showing equivocal progression (ambiguous lesions or nontarget lesions) on CT and/or MRI, further confirmation using SST PET/CT was recommended. A significant majority (74%) preferred assessing pseudo-progression and delayed response by combining SST PET with diagnostic CT and/ or MRI. Though just below the 75% consensus threshold, there was substantial agreement on selecting target lesions based on SST PET/CT uptake intensity and homogeneity. Sixty-nine percent noted the importance of documenting and closely following heterogeneity in lesions in liver, lymph nodes, primary tumors, or other organs. As to the statement on parameters for new response criteria, AB members recommended exploring maximum standard unit value, tumor-to-background ratio, Hounsfield Unit (Choi Criteria), total tumor burden, and novel serum or molecular markers for future response evaluation criteria. Sixty-five percent supported the use of a single SST PET/CT for response assessment of NET lesions treated with PRRT. These findings highlight the importance of integrating advanced imaging techniques and recognizing the need for more nuanced criteria in assessing the efficacy of PRRT in NET patients. This approach aims to enhance the accuracy of treatment monitoring and improve patient outcomes.

Influence of brain metastases on the classification, treatment, and outcome of patients with extracranial oligometastasis: a single-center cross-sectional analysis

Background and introductionIncreasing evidence suggests that a subgroup of patients with oligometastatic cancer might achieve a prolonged disease-free survival through local therapy for all active cancer lesions. Our aims are to investigate the impact of brain metastases on the classification, treatment, and outcome in these patients.Materials and methodsWe analyzed a total of 7,000 oncological positron emission tomography scans to identify patients with extracranial oligometastatic disease (defined as ≤ 5 intra- or extra-cranial metastases). Concurrent magnetic resonance imaging brain was assessed to quantify intracranial tumor burden. We investigated the impact of brain metastases on oligometastatic disease state, therapeutic approaches, and outcome. Predictors for transitioning from oligo- to polymetastatic states were evaluated using regression analysis.ResultsA total of 106 patients with extracranial oligometastases and simultaneous brain metastases were identified, primarily originating from skin or lung/pleura cancers (90%, n = 96). Brain metastases caused a transition from an extracranial oligometastatic to a whole-body polymetastatic state in 45% (n = 48) of patients. While oligometastatic patients received systemic therapy (55% vs. 35%) more frequently and radiotherapy for brain metastases was more often prescribed to polymetastatic patients (44% vs. 26%), the therapeutic approach did not differ systematically between both sub-groups. The oligometastatic sub-group had a median overall survival of 28 months compared to 10 months in the polymetastatic sub-group (p < 0.01).ConclusionIn patients with brain metastases, a low total tumor burden with an oligometastatic disease state remained a significant prognostic factor for overall survival. Presence of brain metastases should therefore not serve as exclusion criterion for clinical trials in the field of oligometastatic disease. Moreover, it underscores the importance of considering a multimodality treatment strategy in oligometastatic cancer patients.

Chemokine Receptor 4-Targeted PET/CT with [68Ga]pentixather in Newly Diagnosed Multiple Myeloma: a Comparative Study with [68Ga]pentixafor PET/CT.

This study aimed to compare the detection rate of [68Ga]pentixather PET/CT and [68Ga]pentixafor PET/CT in newly diagnosed multiple myeloma (NDMM) patients, and to explore the value of [68Ga]pentixather PET/CT for tumor load assessment. Nineteen NDMM Patients were prospectively recruited and underwent both [68Ga]pentixather PET/CT and [68Ga]pentixafor PET/CT. A positive PET scan was defined as the presence of PET-positive focal bone lesions, paraskeletal disease, extramedullary plasmacytoma, or diffuse bone marrow uptake. Lesion numbers, SUVmax and PET-related tumor burden values were compared. The correlations between PET-related tumor burden and clinical risk stratification were analyzed. [68Ga]pentixather PET/CT showed a tendency of higher positive rate compared with [68Ga]pentixafor PET/CT [94.7% (18/19) vs. 78.9% (15/19), p > 0.05]. Among 14 patients with 151 matched focal bone lesions, [68Ga]pentixather PET detected more or equal number of lesions in 13 patients, and demonstrated higher uptake value than 68Ga-pentixafor PET [SUVmax, 16.8 (9.0, 23.8) vs. 13.4 (6.5, 20.4), p < 0.001]. For PET related-tumor burden, positive correlations of total bone marrow uptake (TBmU) (r = 0.9540, p < 0.0001) and SUVmean of total bone marrow (r = 0.9632, p < 0.0001) in two PET scans were observed. Higher TBmU [7864.9 (5549.2, 11,616.2) vs. 5383.4(4102.7, 11,041.8), p < 0.001], SUVmean of total bone marrow [1.4 (1.1, 2.2) vs. 1.1 (0.7, 2.1), p < 0.001] were demonstrated on [68Ga]pentixather PET than [68Ga]pentixafor PET. And the level of TBmU in [68Ga]pentixather PET and [68Ga]pentixafor PET were both elevated in Durie-Salmon Staging (DSS) III than DSS I (p < 0.01). [68Ga]pentixather PET/CT performed a non-inferior capability for tumor detection compared to [68Ga]pentixafor PET/CT in NDMM patients. [68Ga]pentixather PET/CT can assess tumor load in MM patients and depict a significantly higher PET-related total tumor burden than [68Ga]pentixafor PET/CT.

PD-L1 and VEGF dual blockade enhances anti-tumor effect on brain metastasis in hematogenous metastasis model

Immunotherapy improves survival outcomes in cancer patients, but there is still an unmet clinical need in the treatment of brain metastases. Here, we used a mouse model to investigate the antitumor effect of programmed death-ligand 1 (PD-L1) and vascular endothelial growth factor (VEGF) dual blockade on metastatic brain tumors and evaluated immune responses during treatment. After establishing hematogenous brain metastasis by transplanting murine bladder carcinoma MBT2 cells stably expressing secNLuc reporter via the internal carotid artery of C3H/HeNCrl mice, we observed the formation of metastases not only in the brain parenchyma but also in the ventricles. The observed pathological areas showed that metastases in the ventricle were histologically larger than that in the brain parenchyma. Regarding the total tumor burden in the whole brain as revealed by Nluc activities, the combination of anti-PD-L1 antibody and anti-VEGF antibody showed a stronger anti-tumor effect than each single agent. Anti-PD-L1 antibody alone enhanced CD8+ T cell priming in regional lymph nodes, increased the proportion of activated CD8+ T cells in whole brain, and increased the density of CD8+ cells in the brain parenchyma. Furthermore, anti-VEGF antibody alone decreased microvessel density (MVD) in ventricular metastases, and the combination treatment increased intratumoral CD8+ cell density in the brain parenchyma and ventricular metastases. These results suggest that PD-L1 blockade enhanced cancer immunity not only in brain metastases lesions but also in the regional lymph nodes of the metastases, and that the addition of VEGF blockade increased the antitumor effect by increasing the infiltration of activated CD8+ T cell and decreasing MVD.

Deep learning-based 3D quantitative total tumor burden predicts early recurrence of BCLC A and B HCC after resection

ObjectivesThis study aimed to evaluate the potential of deep learning (DL)-assisted automated three-dimensional quantitative tumor burden at MRI to predict postoperative early recurrence (ER) of hepatocellular carcinoma (HCC).Materials and methodsThis was a single-center retrospective study enrolling patients who underwent resection for BCLC A and B HCC and preoperative contrast-enhanced MRI. Quantitative total tumor volume (cm3) and total tumor burden (TTB, %) were obtained using a DL automated segmentation tool. Radiologists’ visual assessment was used to ensure the quality control of automated segmentation. The prognostic value of clinicopathological variables and tumor burden-related parameters for ER was determined by Cox regression analyses.ResultsA total of 592 patients were included, with 525 and 67 patients assigned to BCLC A and B, respectively (2-year ER rate: 30.0% vs. 45.3%; hazard ratio (HR) = 1.8; p = 0.007). TTB was the most important predictor of ER (HR = 2.2; p < 0.001). Using 6.84% as the threshold of TTB, two ER risk strata were obtained in overall (p < 0.001), BCLC A (p < 0.001), and BCLC B (p = 0.027) patients, respectively. The BCLC B low-TTB patients had a similar risk for ER to BCLC A patients and thus were reassigned to a BCLC An stage; whilst the BCLC B high-TTB patients remained in a BCLC Bn stage. The 2-year ER rate was 30.5% for BCLC An patients vs. 58.1% for BCLC Bn patients (HR = 2.8; p < 0.001).ConclusionsTTB determined by DL-based automated segmentation at MRI was a predictive biomarker for postoperative ER and facilitated refined subcategorization of patients within BCLC stages A and B.Clinical relevance statementTotal tumor burden derived by deep learning-based automated segmentation at MRI may serve as an imaging biomarker for predicting early recurrence, thereby improving subclassification of Barcelona Clinic Liver Cancer A and B hepatocellular carcinoma patients after hepatectomy.Key PointsTotal tumor burden (TTB) is important for Barcelona Clinic Liver Cancer (BCLC) staging, but is heterogenous.TTB derived by deep learning-based automated segmentation was predictive of postoperative early recurrence.Incorporating TTB into the BCLC algorithm resulted in successful subcategorization of BCLC A and B patients.

Prognostic impact of the number and total tumor burden of secondary cerebral lesions in patients with resected brain metastases of non-small cell lung cancers.

Systemic therapeutic advancements have improved the prognosis of cancer patients, leading to surgery more frequently being carried out for patients with multiple brain metastases (BM). The underlying evidence for the strategy is currently lacking. This study aimed to evaluate the prognostic significance of the number of BM and total tumor burden (TTB) on the overall survival (OS) of patients with resected BM of non-small cell lung cancer (NSCLC) in a modern series. In this monocentric retrospective series, patients who underwent resection of BM of NSCLC between 2015 and 2021 were included. Demographic, clinical, and histological parameters were collected, and formal radiological volumetric analyses were performed. Prognostic biomarkers for cerebral progression-free survival (C-PFS) and OS were analyzed with univariate and multivariate Cox proportional hazards analysis. One hundred eighty-four patients were included in the study. Among these, 108 patients (58.7%) presented with a single brain metastasis, 36 patients (19.6%) with 2 BM, 22 patients (11.9%) with 3 BM, and 18 patients (9.8%) with more than 3 BM (maximum 15 BM). The mean ± SD (range) preoperative tumor burden was 23.1 ± 25.3 (1.1-145.3) cm3. The mean residual tumor burden after surgery was 0.3 ± 0.8 (0.0-6.3) cm3. By the time of the analysis, 128 patients (69.6%) had died. The median follow-up duration was 49.0 months (95% CI 39.6-63.6). The median OS was 19.2 months (95% CI 13.2-24.0), and the survival rates at 6 months, 1 year, and 2 years were 76% (95% CI 69%-82%), 61% (95% CI 53%-67%), and 43% (95% CI 35%-50%), respectively. The median C-PFS was 8.4 months (95% CI 7.2-12.0). In the Cox multivariate regression model, younger age (< 65 years), single brain metastasis, adjuvant brain radiation therapy, adjuvant use of targeted therapy, and TTB < 7 cm3 were all independent predictors of longer OS. In this era of modern systemic treatments for cancer, the number of BM and total cerebral tumor burden remain significant prognostic factors of OS. However, resection should be considered as an option even in those patients with multiple BM in order to enhance patient clinical status, enable further local and systemic treatment delivery, and improve their survival and quality of life.

Abstract 634: Tuba-seq and CRISPR/Cas9 analysis of TBX2 subfamily genes: Exploring contextual tumor suppression in lung adenocarcinoma

Abstract Lung adenocarcinoma (LUAD) is a multifaceted and genetically diverse cancer, shaped by a myriad of oncogenic and tumor suppressive events. Through recent clinical and in vitro investigations, we have discovered that the TBX2 subfamily of genes, encompassing TBX2, TBX3, TBX4, and TBX5, are linked to LUAD progression. Specifically, we have observed marked downregulation of their expression in clinical LUAD specimens, and reduced growth in LUAD cell lines when the subfamily is re-activated- hinting at a potential tumor suppressive function. Paradoxically, the role of TBX2 subfamily genes in other cancer types remains enigmatic, with varying reports of both oncogenic and tumor suppressive effects. In this study, we harnessed the power of Tumor Barcoding with Ultradeep Barcode Sequencing technology (Tuba-seq) and CRISPR/Cas9-mediated genome editing to systematically investigate the effects of knocking-out Tbx genes and associated partners EGR1, CHD2, A20 and ATF3 in LUAD preclinical models. We investigated their effects in both normal lung epithelium and Ras-driven lung tumors via in situ gene editing and assessed tumor burden via histology and targeted DNA sequencing of tumor barcodes. TBX2 subfamily gene losses appear to have a profound effect on tumor initiation and early growth, which somewhat attenuates with progression. In Ras-driven tumors, we found that these genes are moderately tumor suppressive when measuring mean growth rate, although these effects (sans Egr1 loss) are more pronounced at 6 weeks of growth than at 20 weeks. Strikingly, however, we observed an unprecedented increase in total tumor burden when deleting these genes in genomically-normal (Kras w.t.) cells, including 4-20+ fold increase in Tbx2, Tbx3, Tbx4, and Tnfaip3-deficient cell lineages 20-week following transduction. Increases in total lineage burden of this magnitude are typically only seen for frequently-deleted hallmark tumor suppressor genes such as Tp53, Stk11, or Pten. This increased burden, however, seems to primarily affect early-stage progression, as no appreciable increases in mean lineage size relative to w.t. lineages are observed after 40 weeks of growth. Our study reveals the context-specific functions of the TBX2 subfamily while introducing the first in vivo model for TBX2-driven LUADs. This model facilitates the development of targeted therapeutic strategies and encourages accurate tumor modeling across various progression stages and diverse genetic backgrounds. Citation Format: Athar Khalil, Jaff Maltas, Mira Rahm, Zachary Faber, Madeline Bedrock, Xiangzhen Wei, Bindi Patel, Christopher McFarland. Tuba-seq and CRISPR/Cas9 analysis of TBX2 subfamily genes: Exploring contextual tumor suppression in lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 634.

Prognostic value of bone marrow and tumor 18F-FDG uptake on PET/CT in patients with oropharyngeal cancer and the interplay between inflammation and FDG uptake.

To examine the prognostic value of F-18 fluorodeoxyglucose (FDG) uptake in the bone marrow (BM) for disease recurrence and survival in patients with oropharyngeal squamous cell carcinoma (OP-SCC). The secondary aims were to evaluate the prognostic value of PET/CT parameters for the primary oropharyngeal tumor and total tumor burden, and to assess the correlation between FDG uptake variables and serum inflammatory markers. This was an observational study of 91 patients with OP-SCC who underwent pretreatment FDG-PET/CT. The patients' blood samples were collected before treatment, and treatment was administered with the intention to cure. The median follow-up time was 40 months. The PET parameters measured were SUVmeanBM for the assessment of BM FDG uptake, SUVmean, SUVmax, total lesion glycolysis (TLG), and metabolic tumor volume (MTV) for the evaluation of primary oropharyngeal tumor and total tumor burden. Blood samples were analyzed to determine each patient's white cell, red cell, and platelet cell counts, hemoglobin, and C-reactive protein level. In a subgroup of 33 patients, blood serum was analyzed to evaluate the expression of serum immune proteins using a proximity extension assay (Olink Proteomics). The univariate analysis revealed that SUVmeanBM and tumor-specific parameters (SUVmaxtumor, SUVmeantotal, SUVmaxtotal, MTVtotal, TLGtotal) were significantly associated with recurrence-free survival (RFS). After adjusting for age, sex, and stage only SUVmeanBM remained significantly associated with RFS. Spearman's correlation identified several correlations between PET parameters and inflammatory markers. Our results show that several FDG-PET/CT parameters may have a prognostic value of treatment outcome in patients with OP-SCC. However, SUVmeanBM was the only independent PET parameter that showed a prognostic value for RFS in the study cohort. Moreover, the study findings might suggest an association between systemic inflammation and the metabolic activity in the BM.

Bile acids mediate fructose-associated liver tumour growth in mice

High fructose diets are associated with an increased risk of liver cancer. Previous studies in mice suggest increased lipogenesis is a key mechanism linking high fructose diets to liver tumour growth. However, these studies administered fructose to mice at supraphysiological levels. The aim of this study was to determine whether liver tumour growth and lipogenesis were altered in mice fed fructose at physiological levels. To test this, we injected male C57BL/6 mice with the liver carcinogen diethylnitrosamine and then fed them diets without fructose or fructose ranging from 10 to 20 % total calories. Results showed mice fed diets with ≥15 % fructose had significantly increased liver tumour numbers (2–4-fold) and total tumour burden (∼7-fold) vs mice fed no-fructose diets. However, fructose-associated tumour burden was not associated with lipogenesis. Conversely, unbiased metabolomic analyses revealed bile acids were elevated in the sera of mice fed a 15 % fructose diet vs mice fed a no-fructose diet. Using a syngeneic ectopic liver tumour model, we show that ursodeoxycholic acid, which decreases systemic bile acids, significantly reduced liver tumour growth in mice fed the 15 % fructose diet but not mice fed a no-fructose diet. These results point to a novel role for systemic bile acids in mediating liver tumour growth associated with a high fructose diet. Overall, our study shows fructose intake at or above normal human consumption (≥15 %) is associated with increased liver tumour numbers and growth and that modulating systemic bile acids inhibits fructose-associated liver tumour growth in mice.

Prognostic value of artificial intelligence (AI) –driven tumor estimation of PSMA PET total tumor burden (TTB) in newly diagnosed high-volume metastatic hormone-sensitive prostate cancer (mHSPC).

47 Background: Prostate cancer represents a significant economic burden for health systems; the identification of risk factors that allows the identification of subgroups of patients that require closer follow-up or more intense therapeutic regimens has a direct impact on the prognosis and expenses for the patient, there is currently great interest in patients with high-volume mHSPC, this group is defined according to the number of lesions and their location, this could represent a challenge in decision making due to the variety of presentations regarding tumor burden, currently with the development of AI algorithms it is possible to estimate the PSMA TTB by identifying patients who are candidates for specific therapies without exposing them to comorbidities associated to aggressive regimens. Methods: Baseline PSMA PET scans of patients with histopathological corroborated diagnosis of prostate cancer and considered as high volume according to 68Ga PSMA PET/CT imaging in the period from October 2017 to June 2020 were retrospectively analyzed using an automated algorithm to estimate PSMA TTB, the median follow-up was of 44 +/- 9.7 months. These patients were divided into two groups according to the optimal cutoff values of PSMA TTB and estimate progression-free survival after initial therapy with Kaplan-Meier curves and correlation index between tumor burden and prostatic specific antigen. Results: 53 patients with a mean age of 71 years (+/- 5.1) were included, 17 with Gleason 7 (4+3/3+4), 18; G8 (4+4), 15; G9 (5+4/4+5) and 3; G10 (5+5), ISUP group 3 (n=17), group 4 (n=18) group 5 (n=18), the mean PSA value at diagnosis was 62.1 ng/dL (range 25.2- 201.5). PSMA TTB mean was 100.1cm3 (range 21cm3- 518.8 cm3). Log-rank test revealed that PSMA TTB lower than 45 cm3 (n=21) presented higher time of progression-free survival in comparison with patients with PSMA TTB higher than 45 cm3 (n=32) (31.1 mo vs 47.8 mo, p &lt;0.003). TTB and PSA demonstrated a significant correlation (Pearson r= 0.526, p&lt; 0.0001). There was no difference between groups of low and high PSMA TTB and ISUP groups or Gleason score. Sites of visceral disease were lung (n=11), (pleura=9) liver (n=9), adrenal, (n=5) brain, (n=2), and sites of extra spinal and pelvic disease were ribs (n=24) femur (n=16), skull (n=8), scapula (n=7), humerus (n=7). All patients had one or more lesions at previously described sites. Conclusions: PSMA TTB has great value in predicting progression-free survival of patients with newly diagnosed high-volume metastatic hormone-sensitive prostate cancer and has a strong correlation with PSA, strengthening the role of next-generation molecular imaging with PSMA PET as an invaluable tool in initial diagnosis and potentially in follow-up by providing information on the biological behavior of the disease in a systemic way.

Thermal ablation for local control of lung metastases and its effect on pulmonary function

Image-guided thermal ablation in the lung has consistently demonstrated preservation of lung function without permanent decline following treatment compared to other local treatment options, specifically surgical intervention or stereotactic radiation therapy. Here, we report a case of a 68-year-old female with mesonephric adenocarcinoma of the uterus metastatic to the lung, treated with primarily thermal ablation to manage her lung tumor burden. The patient underwent a hysterectomy and wedge resection of the left lower lobe in addition to first-line chemotherapy. To reduce the total lung tumor burden, in the absence of other more effective therapies and to strategically eradicate ultra-central lung tumors, the patient underwent multiple ablative therapies. In total, she underwent 45 ablation sessions, of which 42 were cryoablation with the rest conducted with microwave ablation, two stereotactic body radiation therapies, and one brachytherapy for 75 lung metastases. Pulmonary function tests were conducted before the start of serial ablation treatments and measured again after 32 ablation sessions which revealed minimal change in pulmonary function parameters while maintaining adequate functional status. We highlight the potential benefit of ablative therapies regarding pulmonary function compared to other local treatment options for metastatic lung cancer.

The role of immune cells in resistance to oncolytic viral therapy.

Resistance to treatment poses a major challenge for cancer therapy, and oncoviral treatment encounters the issue of viral resistance as well. In this investigation, we introduce deterministic differential equation models to explore the effect of resistance on oncolytic viral therapy. Specifically, we classify tumor cells into resistant, sensitive, or infected with respect to oncolytic viruses for our analysis. Immune cells can eliminate both tumor cells and viruses. Our research shows that the introduction of immune cells into the tumor-virus interaction prevents all tumor cells from becoming resistant in the absence of conversion from resistance to sensitivity, given that the proliferation rate of immune cells exceeds their death rate. The inclusion of immune cells leads to an additional virus-free equilibrium when the immune cell recruitment rate is sufficiently high. The total tumor burden at this virus-free equilibrium is smaller than that at the virus-free and immune-free equilibrium. Therefore, immune cells are capable of reducing the tumor load under the condition of sufficient immune strength. Numerical investigations reveal that the virus transmission rate and parameters related to the immune response significantly impact treatment outcomes. However, monotherapy alone is insufficient for eradicating tumor cells, necessitating the implementation of additional therapies. Further numerical simulation shows that combination therapy with chimeric antigen receptor (CAR T-cell) therapy can enhance the success of treatment.

Characteristics of multifocality/multicentricity in breast cancer and its effect on axillary lymph node metastasis

Multifocal (MF) and multicentric (MC) breast cancers are seen with increasing frequency with advances in imaging methods. However, there is no consensus on the behavior and management of these tumors. In this study, we aimed to investigate the characteristics of MF/MC breast cancers and their relationship with axillary lymph node metastasis (ALNM). Patients who underwent surgery for breast cancer between January 2015 and January 2023 were retrospectively scanned. Exclusion criteria were as follows; male breast cancer, second primary cancer diagnosis, previous breast cancer history, previous excisional/incisional breast biopsy, neoadjuvant chemotherapy, and occult breast cancer. Multiple tumors that were closer than 5 cm to each other were defined as MF, and the others were defined as MC. T stage was determined in two different ways, using the largest tumor diameter (Tmax) and the aggregate tumor diameter (Tsum), and two different multivariate analysis models were applied. A total of 156 patients were enrolled in the study, including 130 unifocal (UF), 17 MF and 9 MC. Lymphovascular invasion (LVI) (p=0.43), ALNM (p=0.23), younger age (&lt;50) (p=0.41) and invasive lobular carcinoma (ILC) (p&lt;0.001) were higher in MF/MC tumors than in UFs. When comparing MF and MC, no difference was seen except progesterone receptor positivity (p=0.017). In both multivariate analyses, LVI and ILC had an effect on ALNM, while no effect of MF/MC was seen. In addition, while T stage had a significant effect on ALNM in the model using Tsum, it did not have a significant effect in the Tmax model. Our retrospective data supports that MF/MC is not a direct risk factor for ALNM and that the main factor affecting ALNM is the total tumor burden.

Examining the Relationship and Prognostic Significance of Cell-Free DNA Levels and the PSMA-Positive Tumor Volume in Men with Prostate Cancer: A Retrospective-Prospective [68Ga]Ga-PSMA-11 PET/CT Study.

Functional imaging with prostate-specific membrane antigen (PSMA) ligands has emerged as the standard imaging method for prostate cancer (PCA). In parallel, the analysis of blood-derived, cell-free DNA (cfDNA) has been shown to be a promising quantitative biomarker of PCA aggressiveness and patient outcome. This study aimed to evaluate the relationship and prognostic value of cfDNA concentrations and the PSMA-positive tumor volume (PSMA-TV) in men with PCA undergoing [68Ga]Ga-PSMA-11 PET/CT imaging. Methods: We recruited 148 men with histologically proven PCA (mean age, 70.7 ± 7.7 y) who underwent [68Ga]Ga-PSMA-11 PET/CT (184.9 ± 18.9 MBq) and blood sampling between March 2019 and August 2021. Among these, 74 (50.0%) had hormone-sensitive PCA and 74 (50.0%) had castration-resistant PCA (CRPC). All patients provided written informed consent before blood sample collection and imaging. The cfDNA was extracted and quantified, and PSMA-expressing tumor lesions were delineated to extract the PSMA-TVs. The Spearman coefficient assessed correlations between PSMA-TV and cfDNA concentrations and cfDNA's relation with clinical parameters. The Kruskal-Wallis test examined the mean cfDNA concentration differences based on PSMA-TV quartiles for significantly correlated patient groups. Log-rank and multivariate Cox regression analyses evaluated the prognostic significance of high and low cfDNA and PSMA-TV levels for overall survival. Results: Weak positive correlations were found between cfDNA concentration and PSMA-TV in the overall group (r = 0.16, P = 0.049) and the CRPC group (r = 0.31, P = 0.007) but not in hormone-sensitive PCA patients (r = -0.024, P = 0.837). In the CRPC cohort, cfDNA concentrations significantly differed between PSMA-TV quartiles 4 and 1 (P = 0.002) and between quartiles 4 and 2 (P = 0.016). Survival outcomes were associated with PSMA-TV (P < 0.0001, P = 0.004) but not cfDNA (P = 0.174, P = 0.12), as per the log-rank and Cox regression analysis. Conclusion: These findings suggest that cfDNA might serve as a biomarker of advanced, aggressive CRPC but does not reliably reflect total tumor burden or prognosis. In comparison, [68Ga]Ga-PSMA-11 PET/CT provides a highly granular and prognostic assessment of tumor burden across the spectrum of PCA disease progression.

Lymph Node Molecular Analysis with OSNA Enables the Identification of pT1 CRC Patients at Risk of Recurrence: A Multicentre Study.

Early-stage colorectal carcinoma (CRC)-pT1-is a therapeutic challenge and presents some histological features related to lymph node metastasis (LNM). A significant proportion of pT1 CRCs are treated surgically, resulting in a non-negligible surgical-associated mortality rate of 1.5-2%. Among these cases, approximately 6-16% exhibit LNM, but the impact on survival is unclear. Therefore, there is an unmet need to establish an objective and reliable lymph node (LN) staging method to optimise the therapeutic management of pT1 CRC patients and to avoid overtreating or undertreating them. In this multicentre study, 89 patients with pT1 CRC were included. All histological features associated with LNM were evaluated. LNs were assessed using two methods, One-Step Nucleic Acid Amplification (OSNA) and the conventional FFPE plus haematoxylin and eosin (H&E) staining. OSNA is an RT-PCR-based method for amplifying CK19 mRNA. Our aim was to assess the performance of OSNA and H&E in evaluating LNs to identify patients at risk of recurrence and to optimise their clinical management. We observed an 80.9% concordance in LN assessment using the two methods. In 9% of cases, LNs were found to be positive using H&E, and in 24.7% of cases, LNs were found to be positive using OSNA. The OSNA results are provided as the total tumour load (TTL), defined as the total tumour burden present in all the LNs of a surgical specimen. In CRC, a TTL ≥ 6000 CK19 m-RNA copies/µL is associated with poor prognosis. Three patients had TTL > 6000 copies/μL, which was associated with higher tumour budding. The discrepancies observed between the OSNA and H&E results were mostly attributed to tumour allocation bias. We concluded that LN assessment with OSNA enables the identification of pT1 CRC patients at some risk of recurrence and helps to optimise their clinical management.

How Does Target Lesion Selection Affect RECIST? A Computer Simulation Study.

Response Evaluation Criteria in Solid Tumors (RECIST) is grounded on the assumption that target lesion selection is objective and representative of the change in total tumor burden (TTB) during therapy. A computer simulation model was designed to challenge this assumption, focusing on a particular aspect of subjectivity: target lesion selection. Disagreement among readers and the disagreement between individual reader measurements and TTB were analyzed as a function of the total number of lesions, affected organs, and lesion growth. Disagreement rises when the number of lesions increases, when lesions are concentrated on a few organs, and when lesion growth borders the thresholds of progressive disease and partial response. There is an intrinsic methodological error in the estimation of TTB via RECIST 1.1, which depends on the number of lesions and their distributions. For example, for a fixed number of lesions at 5 and 15, distributed over a maximum of 4 organs, the error rates are observed to be 7.8% and 17.3%, respectively. Our results demonstrate that RECIST can deliver an accurate estimate of TTB in localized disease, but fails in cases of distal metastases and multiple organ involvement. This is worsened by the "selection of the largest lesions," which introduces a bias that makes it hardly possible to perform an accurate estimate of the TTB. Including more (if not all) lesions in the quantitative analysis of tumor burden is desirable.

Change in total lesion PSMA (TLP) during [177Lu]Lu-PSMA-617 radioligand therapy predicts overall survival in patients with mCRPC: monocentric evaluation of a prospective registry

PurposeThis study investigates imaging response of [177Lu]Lu-PSMA-617 radioligand therapy (RLT) based on the whole-body parameter total lesion PSMA (TLP), derived by PSMA-PET/CT and reflecting the total tumor burden, in patients with metastatic castration-resistant prostate cancer (mCRPC) enrolled in a prospective registry (NCT 04833517).MethodsA total of n = 102 mCRPC patients received a [68Ga]Ga-PSMA-11 PET/CT at baseline and after two cycles of PSMA-RLT, in which TLP was measured by using a semi-automated tumor segmentation. TLP was defined as the summed products of volume and uptake (∑ Volume × SUVmean) of all tumor lesions. The Kaplan-Meier method was used to determine the most appropriate ∆TLP thresholds for classification into partial remission (PR), stable disease (SD), and progressive disease (PD) regarding overall survival (OS). Furthermore, we analyzed criteria that are also frequently used in established response frameworks, such as the occurrence of new metastases as independent criterion (I) or in combination with change in tumor burden (II), and the change in PSA serum value (III).ResultsFor the ∆TLP thresholds −30%/+30% (and also for higher thresholds, −40%/+40% or −50%/+50%), significant differences between all three response categories became apparent (PR/PD: p = 0.001; PR/SD: p = 0.001; SD/PD: p = 0.018). Including the development of new metastases as independent criterion of PD, there was no significant difference in OS between SD and PD (p = 0.455), neither when applied in combination with TLP (p = 0.191). Similarly, significant differentiation between SD and PD was not achieved by PSA serum value (p = 0.973).ConclusionIn the largest monocentric study to date, TLP is shown to be a qualified prognostic biomarker, applying ∆TLP thresholds of −30%/+30%. It significantly differentiated between PR, SD, and PD, whereas other response criteria did not differentiate SD vs. PD. Using TLP, the development of new metastases is not a required information for predicting OS.

Larger Tumor Volume is Associated with Visual Acuity Loss and Axonal Degeneration in Children with Optic Pathway Gliomas Secondary to Neurofibromatosis Type 1

Abstract BACKGROUND We investigated whether volumetric magnetic resonance imaging (MRI) measures of the anterior visual pathway (AVP) in optic pathway gliomas secondary to Neurofibromatosis type 1 (NF1-OPG) are associated with visual acuity (VA) loss and axonal loss, as measured using optical coherence tomography (OCT). METHODS Children with NF1-OPGs enrolled in a prospective study of VA and OCT measures of the circumpapillary retinal nerve fiber layer (cpRNFL) thickness were eligible if they had undergone 3-Tesla MRI that included a T1-weighted volumetric sequence. The linear dimension and volume of the optic nerves, chiasm and optic tracts were measured using our semi-automated algorithm. The combined volume of these components comprising the proximal AVP was used as a surrogate of total tumor burden. Regression models for VA and cpRNFL thickness were reported on a per-eye basis. RESULTS Fifty-two study eyes (26 children, mean 7.1 years) met inclusion criteria, of which 40% (N=21 eyes) had abnormal VA. In regression analysis, only total AVP volume demonstrated a significant relationship to axonal loss, such that for every 1 ml increase in AVP volume, cpRNFL declined by 5.4 microns (p = 0.01). Total AVP volume &amp;gt; 1.75 ml predicted both axonal loss and abnormal VA (positive predictive value of 83.3% and 70.8%, respectively; negative predictive value of 80.0% and 88.0%, respectively). CONCLUSIONS Volumetric measures of NF1-OPGs identified children with VA loss and axonal degeneration. Total tumor burden, as measured by AVP volume, had the strongest relationship with axonal injury. NF1-OPG volumetric measures may be helpful in making treatment decisions.