Early Tumor Response Research Articles

The value of predicting neoadjuvant chemotherapy early efficacy in nasopharyngeal carcinoma based on amide proton transfer imaging and diffusion weighted imaging.

Early detection of nasopharyngeal carcinoma (NPC) patients who are not sensitive to neoadjuvant chemotherapy (NAC) can guard against overtreatment. This study aimed to evaluate the effectiveness of amide proton transfer (APT) imaging and diffusion-weighted imaging (DWI) in predicting the early response to NAC in patients with NPC. This prospective study enrolled fifty patients with biopsy-confirmed NPC from September 2021 to May 2023. Magnetic resonance imaging (MRI) including APT and DWI, was performed before NAC. After NAC, patients were divided into complete response (CR), partial response (PR), and stable disease (SD) and progressive disease (PD) groups based on the Response Evaluation Criteria in Solid Tumours Version 1.1. The Kruskal-Wallis H test was used for statistical analysis. The differences in APT and apparent diffusion coefficient (ADC) values among the different efficacy groups were compared, the receiver operating characteristic (ROC) curve was drawn for statistically significant parameters, and the area under the curve (AUC) was calculated. Fifty patients (mean age: 47±14 years; 42 males and 8 females) were included in the final analysis (11 were in the CR group, 30 in the PR group, 9 in the SD group, and 0 in the PD group). The ADC values showed no significant differences among the different treatment response groups. The SD group showed significantly lower APTmax (P=0.025), APTskewness (P=0.025) and APT90% (P=0.001) values than the CR and PR groups. Setting APT90% =3.10% as the cut-off value, optimal diagnostic performance (AUC: 0.831; sensitivity: 0.778; specificity: 0.878) was obtained in predicting the SD group. APT imaging can predict the early tumour response to NAC in patients with NPC. APT imaging may be superior to DWI in predicting tumour response.

Prediction of early recurrence of adult-type diffuse gliomas following radiotherapy using multi-modal magnetic resonance images.

Adult-type diffuse gliomas are among the central nervous system's most aggressive malignant primary neoplasms. Despite advancements in systemic therapies and technological improvements in radiation oncology treatment delivery, the survival outcome for these patients remains poor. Fast and accurate assessment of tumor response to oncologic treatments is crucial, as it can enable the early detection of recurrent or refractory gliomas, thereby allowing timely intervention with life-prolonging salvage therapies. Radiomics is a developing field with great potential to improve medical image interpretation. This study aims to apply a radiomics-based predictive model for classifying response to radiotherapy within the first 3 months post-treatment. Ninety-five patients were selected from the Burdenko Glioblastoma Progression Dataset. Tumor regions were delineated in the axial plane on contrast-enhanced T1(CE T1W) and T2 fluid-attenuated inversion recovery (T2_FLAIR) magnetic resonance imaging (MRI). Hand-crafted radiomic (HCR) features, including first- and second-order features, were extracted using PyRadiomics (3.7.6) in Python (3.10). Then, recursive feature elimination with a random forest (RF) classifier was applied for feature dimensionality reduction. RF and support vector machine (SVM) classifiers were built to predict treatment outcomes using the selected features. Leave-one-out cross-validation was employed to tune hyperparameters and evaluate the models. For each segmented target, 186 HCR features were extracted from the MRI sequence. Using the top-ranked radiomic features from a combination of CE T1W and T2_FLAIR, an optimized classifier achieved the highest averaged area under the curve (AUC) of 0.829±0.075 using the RF classifier. The HCR features of CE T1W produced the worst outcomes among all models (0.603±0.024 and 0.615±0.075 for RF and SVM classifiers, respectively). We developed and evaluated a radiomics-based predictive model for early tumor response to radiotherapy, demonstrating excellent performance supported by high AUC values. This model, harnessing radiomic features from multi-modal MRI, showed superior predictive performance compared to single-modal MRI approaches. These results underscore the potential of radiomics in clinical decision support for this disease process.

243 Early complete tumor response as a survival predictor in HCC patients receiving SBRT

243 Early complete tumor response as a survival predictor in HCC patients receiving SBRT

Development of Granzyme B-targeted Smart Positron Emission Tomography Probes for Monitoring Tumor Early Response to Immunotherapy.

Granzyme B is an immune-related biomarker that closely correlates with cytotoxic T lymphocytes (CTLs), and hence detecting the expression level of granzyme B can provide a dependable scheme for clinical immune response assessment. In this study, two positron emission tomography (PET) probes [18F]SF-M-14 and [18F]SF-H-14 targeting granzyme B are designed based on the intramolecular cyclization scaffold SF. [18F]SF-M-14 and [18F]SF-H-14 can respond to granzyme B and glutathione (GSH) to conduct intramolecular cyclization and self-assemble into nanoaggregates to enhance the retention of probe at the target site. Both probes are prepared with high radiochemical purity (>98%) and high stability in PBS and mouse serum. In 4T1 cells cocultured with T lymphocytes, [18F]SF-M-14 and [18F]SF-H-14 reach the maximum uptake of 6.71 ± 0.29 and 3.47 ± 0.09% ID/mg at 0.5 h, respectively, but they remain below 1.95 ± 0.22 and 1.47 ± 0.21% ID/mg in 4T1 cells without coculture of T lymphocytes. In vivo PET imaging shows that the tumor uptake in 4T1-tumor-bearing mice after immunotherapy is significantly higher (3.5 times) than that in the untreated group. The maximum tumor uptake of [18F]SF-M-14 and [18F]SF-H-14 in the mice treated with BEC was 4.08 ± 0.16 and 3.43 ± 0.12% ID/g, respectively, while that in the untreated mice was 1.04 ± 0.79 and 1.41 ± 0.11% ID/g, respectively. These results indicate that both probes have great potential in the early evaluation of clinical immunotherapy efficacy.

The contrast-free diffusion MRI multiple index for the early prediction of pathological response to neoadjuvant chemotherapy in breast cancer.

Early tumor response prediction can help avoid overtreatment with unnecessary chemotherapy sessions. It is important to determine whether multiple apparent diffusion coefficient indices (S index, ADC-diff) are effective in the early prediction of pathological response to neoadjuvant chemotherapy (NAC) in breast cancer (BC). Patients with stage II and III BCs who underwent T1WI, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced MRI using a 3 T system were included. They were divided into two groups: major histological responders (MHRs, Miller-Payne G4/5) and nonmajor histological responders (nMHRs, Miller-Payne G1-3). Three b values were used for DWI to derive the S index; ADC-diff values were obtained using b = 0 and 1000 s/mm2. The different interquartile ranges of percentile S-index and ADC-diff values after treatment were calculated and compared. The assessment was performed at baseline and after two and four NAC cycles. A total of 59 patients were evaluated. There are some correlations of interquartile ranges of S-index parameters and ADC-diff values with histopathological prognostic factors (such as estrogen receptor and human epidermal growth factor receptor 2 expression, all p < 0.05), but no significant differences were found in some other interquartile ranges of S-index parameters or ADC-diff values between progesterone receptor positive and negative or for Ki-67 tumors (all P > 0.05). No differences were found in the dynamic contrast-enhanced MRI characteristics between the two groups. HER-2 expression and kurtosis of the S-index distribution were screened out as independent risk factors for predicting MHR group (p < 0.05, area under the curve (AUC) = 0.811) before NAC. After early NAC (two cycles), only the 10th percentile S index was statistically significant between the two groups (p < 0.05, AUC = 0.714). No significant differences were found in ADC-diff value at any time point of NAC between the two groups (P > 0.1). These findings demonstrate that the S-index value may be used as an early predictor of pathological response to NAC in BC; the value of ADC-diff as an imaging biomarker of NAC needs to be further confirmed by ongoing multicenter prospective trials.

Early tumor response in first‐line palbociclib plus AI in Chinese women with HR+/HER2- advanced breast cancer: Primary analysis of a multicenter, prospective real-world study.

e13078 Background: The CDK4/6 inhibitors (CDK4/6i) and aromatase inhibitors (AIs) regimen is the first-line standard for HR+/HER2- advanced breast cancer. Despite this, high-risk patients often receive combination chemotherapy for quicker disease control, a practice supported by anecdotal evidence of the efficacy of the CDK4/6i and AI combination but lacking rigorous research validation. Early tumor shrinkage (ETS), a prognostic marker in colorectal cancer, remains undefined in HR+ breast cancer. This study (NCT04858997) aims to investigate the early effectiveness of the CDK4/6i and AI combination through ETS, addressing a significant gap in the literature. Methods: This study enrolled HR+/HER2- advanced breast cancer patients diagnosed between April 2021 and October 2023, who were treatment-naïve for their advanced disease and consented to palbociclib and AI therapy. Participants underwent CT scans to evaluate treatment response at baseline, week 4, week 12, and every 12 weeks thereafter. The study primarily investigated ETS, defined herein as a ≥10% reduction in the sum of diameters of target lesions by week 4. Secondary endpoints encompassed TTR, ORR, and PFS. Results: The study enrolled 30 patients with a median age of 55 years (range 29-76); 30% were premenopausal, and 40% presented with ≥3 metastatic sites. Visceral metastases were observed in 53.3% of the cohort (N=16). ETS was achieved in 73.3% of patients at the first assessment 4 weeks post-treatment initiation, with 68.8% in patients with visceral metastases and 78.8% in those without. The mTTR=3 months, differing between patients with visceral metastases (6 months) and those without (3 months). The overall response rate (ORR) was 63.3%. The ETS outcomes predict the best response in patients, with 77.3% reaching ETS eventually achieving partial or complete response (PR/CR), compared to only 25% of those not reaching ETS. Conclusions: This study validates the CDK4/6i and AI combination's early effectiveness in HR+/HER2- advanced breast cancer, showing that 4-week treatment responses predict best of response outcomes. Achieving ETS is closely linked to a higher likelihood of therapeutic success, underscoring its value as a prognostic marker for informed therapy choices.

CD4 effector T cell expansion to identify objective responses to the CD40 agonist mitazalimab in combination with modified FOLFIRINOX (mFFX) as first-line therapy for metastatic pancreatic ductal adenocarcinoma (mPDAC) in the OPTIMIZE-1 study.

2569 Background: CD40 agonists have the potential to enhance the efficacy of standard of care chemotherapy and to trigger antitumor immunity. Preclinical models indicate that the success of this approach depends on appropriate sequencing of chemotherapy with a CD40 agonist. Preliminary efficacy results from the OPTIMIZE-1 Phase II study (NCT04888312) combining mitazalimab (anti-CD40) with mFFX chemotherapy in patients with mPDAC have been previously reported. Here, we investigated immunological determinants associated with favorable outcomes with this combination therapy. Methods: Newly diagnosed, chemotherapy-naive patients with mPDAC received mitazalimab (900 µg/kg) on day 1 prior to beginning an every 2-week mFFX regimen on day 8, followed by mitazalimab 48 hours later. Tumor response was determined using RECIST v1.1 criteria. Peripheral blood was analyzed for selected cytokines and chemokines and by flow cytometry to assess changes in leukocyte subsets including B cells, monocytes, T cells, and NK cells. Flow cytometric data from evaluable patients were subjected to unsupervised hierarchical clustering to identify immune subsets. A classifier was generated from an interim dataset (n=21) using a random forest model to predict cell populations and their association with tumor response, which were then applied to the full dataset (n=47). Results: Mitazalimab triggered an expected immune response characterized by transient cytokine (IFNg and MCP-1) release and B cell depletion. Chemotherapy caused a reduction in classical monocytes and proliferating CD4+ T cells. Both mitazalimab and chemotherapy caused a transient reduction in circulating dendritic cells and NK cells. Tumor response was associated with an expansion in the frequency of effector CD4 T cells (p &lt; 0.0001) at day 8 after receiving mitazalimab. In a blinded analysis based on the classifier, CD4 T cell expansion was linked to an early tumor response to treatment (accuracy 70%, sensitivity 68%, specificity 72%). Conclusions: Mitazalimab and mFFX differentially modulate immune responses in patients with mPDAC. Pharmacological analyses identify mitazalimab-induced expansion of CD4 effector T cells one week after first administration as a correlate of treatment outcomes. These data suggest the contribution of mitazalimab to tumor responses, and further substantiate a priming dose of mitazalimab, prior to administering chemotherapy.

The Immunomodulatory Potential of Concurrent High-Dose Radiotherapy and Immune Checkpoint Inhibitor Cemiplimab in Advanced Cutaneous Squamous Cell Carcinoma: Initial Results.

In this retrospective case series, we investigate the synergistic effect and the immunomodulatory potential of combination radiotherapy and immunotherapy on 11 patients affected by locally advanced or metastatic cutaneous squamous cell carcinoma (CSCC), treated at our institution between 2020 and 2023. The primary endpoints of this study are objective tumor response, assessed by Immunotherapy Response Evaluation Criteria in Solid Tumors (iRECIST), and time to treatment failure (disease progression). In all patients, surgery was deemed not amenable, due to its potential functional and aesthetic impact. Therefore, upon multidisciplinary agreement, radiotherapy and immunotherapy with cemiplimab were alternatively administered. After 6 months, an early objective tumor response was observed in 9/11 patients, with 17/20 cutaneous lesions (85%) presenting either a complete or partial response. Only 2/11 patients, with a total of 3/20 cutaneous lesions (15%), had stable disease. These benefits persisted at a longer follow-up (21.4 ± 9.7 months), with no patients presenting disease progression. Despite the retrospective nature of this study and small sample size, our experience highlights the ability of concomitant radiotherapy and cemiplimab to promote an early objective response in patients with advanced CSCC. Moreover, in our population, the clinical benefits were also related to a longer progression-free survival, without any safety alert reported.

A COMPARATIVE STUDY OF TWO HYPOFRACTIONATED EXTERNAL BEAM RADIATION THERAPY SCHEDULES IN SYMPTOM PALLIATION IN UNRESECTABLE CARCINOMA GALLBLADDER

Introduction: Gallbladder cancer is a highly aggressive cancer, with majority of the patients presenting in advanced stage having a dismal prognosis. Objective: The aim of the study, is to compare the symptom relief, loco-regional tumour response and tolerance between the two different external beam radiation therapy schedules. Methods: A randomized study was conducted for two years including 60 patients. The patients were divided into two arms, with Arm-A receiving a total dose of 33Gy/15# and theArm-B receiving 30Gy/10#. Results: Early tumour response was slightly better in Arm-B than in Arm-A, with 50% patients showing partial response in Arm-B in comparison to 40% in Arm-A. Symptom relief was better and statistically significant in Arm-B with respect to Arm-A. At 3 and 6 month follow up, the symptomatic relief was comparable between the two arms, with 72% patients having relief of nausea/ vomiting in Arm-B with respect to 39.1% patients in Arm-A. The weekly toxicities were almost comparable between the arms, with haematological toxicities being slightly higher in Arm-A as compared to Arm-B. Late treatment related toxicities were also higher in Arm-A as compared to Arm-B. Conclusion: Palliative radiation therapy given to patients, over a short period of time is better in comparison to similarequivalent dose given over longer period of time in symptom palliationfor patients with unresectable gallbladder cancer.

Early radiologic and metabolic tumour response assessment during combined chemo-radiotherapy for locally advanced NSCLC

BackgroundThe role of early treatment response for patients with locally advanced non-small cell lung cancer (LA-NSCLC) treated with concurrent chemo-radiotherapy (cCRT) is unclear. The study aims to investigate the predictive value of response to induction chemotherapy (iCX) and the correlation with pattern of failure (PoF). Materials and methodsPatients with LA-NSCLC treated with cCRT were included for analyses (n = 276). Target delineations were registered from radiotherapy planning PET/CT to diagnostic PET/CT, in between which patients received iCX. Volume, sphericity, and SUVpeak were extracted from each scan. First site of failure was categorised as loco-regional (LR), distant (DM), or simultaneous LR+M (LR+M). Fine and Gray models for PoF were performed: a baseline model (including performance status (PS), stage, and histology), an image model for squamous cell carcinoma (SCC), and an image model for non-SCC. Parameters included PS, volume (VOL) of tumour, VOL of lymph nodes, ΔVOL, sphericity, SUVpeak, ΔSUVpeak, and oligometastatic disease. ResultsMedian follow-up was 7.6 years. SCC had higher sub-distribution hazard ratio (sHR) for LRF (sHR = 2.771 [1.577:4.87], p < 0.01) and decreased sHR for DM (sHR = 0.247 [0.125:0.485], p < 0.01). For both image models, high diagnostic SUVpeak increased risk of LRF (sHR = 1.059 [1.05:1.106], p < 0.01 for SCC, sHR = 1.12 [1.03:1.21], p < 0.01 for non-SCC). Patients with SCC and less decrease in VOL had higher sHR for DM (sHR = 1.025[1.001:1.048] pr. % increase, p = 0.038). ConclusionPoor response in disease volume was correlated with higher sHR of DM for SCC, no other clear correlation of response and PoF was observed. Histology significantly correlated with PoF with SCC prone to LRF and non-SCC prone to DM as first site of failure. High SUVpeak at diagnosis increased the risk of LRF for both histologies.

Preclinical Application of CEST MRI to Detect Early and Regional Tumor Response to Local Brain Tumor Treatment.

Treating glioblastoma and monitoring treatment response non-invasively remain challenging. Here, we developed a robust approach using a drug-loaded liposomal hydrogel that is mechanically compatible with the brain, and, simultaneously, we successfully monitored early tumor response using Chemical Exchange Saturation Transfer (CEST) MRI. This CEST-detectable liposomal hydrogel was optimized based on a sustainable drug release and a soft hydrogel for the brain tumor, which is unfavorable for tumor cell proliferation. After injecting the hydrogel next to the tumor, three distinctive CEST contrasts enabled the monitoring of tumor response and drug release longitudinally at 3T. As a result, a continuous tumor volume decrease was observed in the treatment group along with a significant decrease in CEST contrasts relating to the tumor response at 3.5 ppm (Amide Proton Transfer; APT) and at -3.5 ppm (relayed Nuclear Overhauser Effect; rNOE) when compared to the control group (p < 0.05). Interestingly, the molecular change at 3.5 ppm on day 3 (p < 0.05) was found to be prior to the significant decrease in tumor volume on day 5. An APT signal also showed a strong correlation with the number of proliferating cells in the tumors. This demonstrated that APT detected a distinctive decrease in mobile proteins and peptides in tumors before the change in tumor morphology. Moreover, the APT signal showed a regional response to the treatment, associated with proliferating and apoptotic cells, which allowed an in-depth evaluation and prediction of the tumor treatment response. This newly developed liposomal hydrogel allows image-guided brain tumor treatment to address clinical needs using CEST MRI.

Pattern recognition of microcirculation with super-resolution ultrasound imaging provides markers for early tumor response to anti-angiogenic therapy.

Rationale: Cancer treatment outcome is traditionally evaluated by tumor volume change in clinics, while tumor microvascular heterogeneity reflecting tumor response has not been fully explored due to technical limitations. Methods: We introduce a new paradigm in super-resolution ultrasound imaging, termed pattern recognition of microcirculation (PARM), which identifies both hemodynamic and morphological patterns of tumor microcirculation hidden in spatio-temporal space trajectories of microbubbles. Results: PARM demonstrates the ability to distinguish different local blood flow velocities separated by a distance of 24 μm. Compared with traditional vascular parameters, PARM-derived heterogeneity parameters prove to be more sensitive to microvascular changes following anti-angiogenic therapy. Particularly, PARM-identified "sentinel" microvasculature, exhibiting evident structural changes as early as 24 hours after treatment initiation, correlates significantly with subsequent tumor volume changes (|r| > 0.9, P < 0.05). This provides prognostic insight into tumor response much earlier than clinical criteria. Conclusions: The ability of PARM to noninvasively quantify tumor vascular heterogeneity at the microvascular level may shed new light on early-stage assessment of cancer therapy.

High-tailored Anal Canal Radiotherapy (HIT-ART): Outcomes of a 10-Year Single Center Clinical Experience.

The current standard for anal cancer treatment is essentially a 'one size fits all' approach where the dose of radiotherapy is similar whether the tumor is very small or very large. Trials are ongoing to evaluate dose de-escalation or escalation in localized disease depending on tumor size. The aim of the study was to assess results of a personalized approach involving dose stratification by stage and boost dose adjusted according to tumor early response. We retrospectively reviewed squamous cell anal cancer (SCAC) patients treated between 2011 and 2021 by long-course intensity-modulated radiotherapy (IMRT) and concomitant chemotherapy (CT); a sequential boost could be administered by IMRT or interventional radiotherapy (IRT) to obtain a total equivalent dose in 2 Gy (EQD2) of 54-60 Gy. We analyzed 110 patients (61% T3-4 stage, 71% node-positive). A total of 68.2% of patients received a sequential boost, mainly by IRT; median total EQD2 to primary site was 59.3 Gy. Acute ≥G3 toxicity rate was 36.4%. Median follow-up (FUP) was 35.4 months. A total of 83% of patients achieved clinical complete response (cCR); locoregional recurrence (LRR) occurred in 20.9% and distant metastases in 6.4% of cases. A total of 12.7% patients underwent salvage surgery. A total of 25.5% of patients reported ≥G2 and 4.5% ≥G3 late toxicity. The estimated 3-year overall survival, disease-free survival and colostomy-free survival were 92%, 72% and 84% respectively; 3-year-LRR was 22%. Nodal stage was associated with poorer cCR probability and higher LRR (p<0.05). Our results on a large cohort of patients with locally advanced SCAC and long FUP time confirmed the efficacy of IMRT; high local control and manageable toxicity also suggest IRT as a promising method in treatment personalization.

A Novel Method for Evaluating Early Tumor Response Based on Daily CBCT Images for Lung SBRT.

We aimed to develop a new tumor response assessment method for lung SBRT. In total, 132 lung cancer patients with 134 tumors who received SBRT treatment with daily CBCT were included in this study. The information about tumor size (area), contrast (contrast-to-noise ratio (CNR)), and density/attenuation (μ) was derived from the CBCT images for the first and the last fractions. The ratios of tumor area, CNR, and μ (RA, RCNR, Rμ) between the last and first fractions were calculated for comparison. The product of the three rations was defined as a new parameter (R) for assessment. Tumor response was independently assessed by a radiologist based on a comprehensive analysis of the CBCT images. R ranged from 0.27 to 1.67 with a mean value of 0.95. Based on the radiologic assessment results, a receiver operation characteristic (ROC) curve with the area under the curve (AUC) of 95% was obtained and the optimal cutoff value (RC) was determined as 1.1. The results based on RC achieved a 94% accuracy, 94% specificity, and 90% sensitivity. The results show that R was correlated with early tumor response to lung SBRT and that using R for evaluating tumor response to SBRT would be viable and efficient.

A comparative study on ctDNA and tumor DNA mutations in lung cancer and benign cases with a high number of CTCs and CTECs

BackgroundLiquid biopsy provides a non-invasive approach that enables detecting circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) using blood specimens and theoretically benefits early finding primary tumor or monitoring treatment response as well as tumor recurrence. Despite many studies on these novel biomarkers, their clinical relevance remains controversial. This study aims to investigate the correlation between ctDNA, CTCs, and circulating tumor-derived endothelial cells (CTECs) while also evaluating whether mutation profiling in ctDNA is consistent with that in tumor tissue from lung cancer patients. These findings will help the evaluation and utilization of these approaches in clinical practice.Methods104 participants (49 with lung cancer and 31 with benign lesions) underwent CTCs and CTECs detection using integrating subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH) strategy. The circulating cell-free DNA (cfDNA) concentration was measured and the mutational profiles of ctDNA were examined by Roche AVENIO ctDNA Expanded Kit (targeted total of 77 genes) by next generation sequencing (NGS) in 28 patients (20 with lung cancer and 8 with benign lesions) with highest numbers of CTCs and CTECs. Mutation validation in matched tumor tissue DNA was then performed in 9 patients with ctDNA mutations using a customized xGen pan-solid tumor kit (targeted total of 474 genes) by NGS.ResultsThe sensitivity and specificity of total number of CTCs and CTECs for the diagnosis of NSCLC were 67.3% and 77.6% [AUC (95%CI): 0.815 (0.722–0.907)], 83.9% and 77.4% [AUC (95%CI): 0.739 (0.618–0.860)]. The concentration of cfDNA in plasma was statistically correlated with the size of the primary tumor (r = 0.430, P = 0.022) and CYFRA 21–1 (r = 0.411, P = 0.041), but not with the numbers of CTCs and CTECs. In this study, mutations were found to be poorly consistent between ctDNA and tumor DNA (tDNA) in patients, even when numerous CTCs and CTECs were present.ConclusionDetection of CTCs and CTECs could be the potential adjunct tool for the early finding of lung cancer. The cfDNA levels are associated with the tumor burden, rather than the CTCs or CTECs counts. Moreover, the poorly consistent mutations between ctDNA and tDNA require further exploration.

Early response monitoring during [177Lu]Lu-PSMA I&T therapy with quantitated SPECT/CT predicts overall survival of mCRPC patients: subgroup analysis of a Swiss-wide prospective registry study

PurposeTo assess early tumor response with quantitated SPECT/CT and to correlate it with clinical outcome in metastatic castration–resistant prostate cancer (mCRPC) patients treated with 177Lutetium-PSMA I&T therapy.MethodsSingle-center, observational study, part of the prospective Swiss national cancer registry study investigating the safety and efficacy of [177Lu]Lu-PSMA I&T (EKNZ: 2021–01271) in mCRPC patients treated with at least two cycles of [177Lu]Lu-PSMA I&T 6-weekly. After the first and second cycle quantitated SPECT/CT (Symbia Intevo, Siemens) was acquired 48 h after injection (three fields of view from head to thigh, 5 s/frame) and reconstructed using xQuant® (48i, 1 s, 10-mm Gauss). Image analysis: The PSMA-positive total tumor volumes (TTV) were semi-automatically delineated using a SUV threshold of 3 with MIMencore® (version 7.1.3, Medical Image Merge Software Inc.). Changes in TTV, highest tumor SUVmax, and total tumor SUVmean between cycles 1 and 2 were calculated and grouped into a) stable or decrease and b) increase. Serum PSA levels were assessed at each therapy cycle and at follow-up until progression or death. Changes in TTV, PSA, SUVmax, and SUVmean were correlated with PSA-progression-free survival (PSA-PFS) and the overall survival (OS) using the Kaplan–Meier methodology (log-rank test).ResultsBetween 07/2020 and 04/2022, 111 patients were screened and 73 finally included in the data analysis. The median follow-up was 8.9 months (range 1.4–26.6 months). Stable or decreased TTV at cycle 2 was associated with longer OS (hazard ratio (HR) 0.28, 95% confidence interval (CI) 0.09–0.86, p < 0.01). Similar, stable, or decreased PSA was associated with longer OS (HR 0.21; CI 0.07–0.62, p < 0.01) and PSA-PFS (HR 0.34; 95% CI 0.16–0.72, p < 0.01). Combining TTV and PSA will result in an augmented prognostic value for OS (HR 0.09; CI 0.01–0.63; p < 0.01) and for PSA-PFS (HR 0.11; CI 0.02–0.68; p < 0.01). A reduction of SUVmax or SUVmean was not prognostically relevant, neither for OS (p 0.88 and 0.7) nor for PSA-PFS (p 0.73 and 0.62, respectively).ConclusionSix weeks after initiating [177Lu]Lu-PSMA I&T, TTV and serum PSA appear to be good prognosticators for OS. Combined together, TTV + PSA change demonstrates augmented prognostic value and can better predict PSA-PFS. Larger studies using TTV change prospectively as an early-response biomarker are warranted for implementing management change towards a more personalized clinical practice.

GRECCAR 14 - a multicentric, randomized, phase II-III study evaluating the tailored management of locally advanced rectal carcinoma after a favourable response to induction chemotherapy: Study protocol.

Total neoadjuvant treatment (TNT) is becoming standard in patients with locally advanced rectal carcinoma (LARC). Preoperative chemoradiotherapy (CRT) has proven side effects on bowel and genitourinary function. An early tumoral response to induction chemotherapy demonstrates its high prognostic value. Tailored management could be used as an alternative to systematic CRT. The GRECCAR 14 trial will attempt to personalize treatment strategy according to the patient's early tumour response to intensive chemotherapy with the aim of achieving the best toxicity-efficiency ratio. GRECCAR 14 is a multicentric, randomized, two-arm, phase II-III noninferiority trial. Patients with mid or low LARC with a predictive circumferential resection margin ≤2 mm or T3c-d stage with extramural venous invasion will be included. Evaluation of the tumoral response will be performed after six courses of high-dose FOLFIRINOX chemotherapy. Good responders (GRs) will be defined by a 60% decrease in tumoral volume on magnetic resonance imaging. Patients will be randomized to CRT before surgery. The primary endpoints will be R0 resection for phase II and the 3-year disease-free survival (DFS) for phase III. Tailored management of LARC is becoming an exciting challenge for the modality of neoadjuvant treatment and for the type of surgery or its omission. Neoadjuvant FOLFIRINOX has established efficacy, with a significant increase in the 3-year DFS. Better control of systemic disease must be accompanied by the same locoregional control, with the lowest morbidity. Our previous GRECCAR 4 trial demonstrated the high value of the early tumoral response after induction chemotherapy and the long-term safety of tailored management for GRs. If GRECCAR 14 demonstrates the ability to tailor TNT for LARC, this could lead to changes in clinical practice.

Predicting pathological complete response based on weakly and semi-supervised joint learning from breast cancer MRI.

Neoadjuvant chemotherapy (NAC) is the standard treatment for breast cancer patients. Patients achieving complete pathological response (pCR) after NAC usually have a good prognosis. However, automatic pCR prediction has been a challenging problem due to lacking well annotations in 3D MRI. Thus far, unifying different annotation information to predict the tumor's early response to NAC has not been systematically addressed. This paper proposes a weakly and semi-supervised joint learning method that integrates attentional features from multi-parametric MRI with radiomic features for predicting pCR to NAC in breast cancer patients. The attention-based multi-instance learning (MIL) is first developed to generate informative MRI bag-level features and mine key instances. The mean-teacher framework is then employed to segment tumor regions in a semi-supervised setting for extracting radiomic features. We perform experiments on 442 patients' data and show that our method achieves an AUC value of 0.85 in pCR prediction, which is superior to comparative methods. It is also shown that learning from multi-parametric MRI outperforms that of single-parameter MRI in pCR prediction.

The emergence of RAS mutations in patients with RAS wild-type mCRC receiving cetuximab as first-line treatment: a noninterventional, uncontrolled multicenter study

AbsrtactBackgroundPatients treated with anti-epidermal growth factor receptor (anti-EGFR) will ultimately develop acquired resistance promoted by clonal selection, mainly the emergence of mutations in the MAPK pathway (mostly RAS mutations). Baseline assessment of RAS mutations in the blood of patients correlates well with RAS tumour tissue testing and is currently an alternative option in routine clinical practice to guide first-line therapy. The aim of this study was the prevalence of acquired genomic alterations detected in the auxiliary tool of ctDNA testing and investigated the role of RAS ctDNA status for detecting tumour response and predicting benefit to anti-EGFR therapy.MethodsOnly patients with concordant wild-type formalin-fixed, paraffin-embedded (FFPE) tumour tissue and baseline ctDNA RAS wild-type were included. RAS mutations in plasma were evaluated using MassARRAY platform. Blood samples were collected at baseline, every 3 months during first-line treatment, and at disease progression. The primary endpoint was the detection rate of RAS mutations during cetuximab treatment. The correlation between response and survival outcomes and the emergence of circulating RAS mutations was also analysed.ResultsThe detection rate of RAS mutations during treatment was 9.3% (10/108). RAS mutations detection occurred a median of 3 months prior to radiologic documentation. The subgroup of patients with RAS mutations exhibited significantly inferior progression-free survival and overall survival (P = 0.002 and 0.027, respectively) but the baseline characteristics, response rates, disease control rates, and metastatectomy were not significant (all P > 0.05).ConclusionsWe demonstrated that RAS ctDNA status might be a valuable biomarker for detecting early tumour response and predicting benefit to anti-EGFR therapy.Clinical Trial Registration: NCT03401957 (January 17, 2018).

Robot-Assisted Transarterial Chemoembolization of Hepatocellular Carcinoma Using a Coaxial Microcatheter Driving Controller-Responder Robot System: Clinical Pilot Study

PurposeTo evaluate the feasibility and safety of robot-assisted transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) using a new coaxial microcatheter driving controller-responder robot (CRR) system. Materials and MethodsA single-center prospective pilot study approved by the institutional review board was conducted using this CRR developed after analyzing 20 cases of conventional TACE procedures from May to October 2021. The study included 10 patients with HCCs: 5 (median age, 72 years; range, 64–73 years) underwent robot-assisted TACE, and 5 (median age, 57 years; range, 44–76 years) underwent conventional TACE for comparison. The feasibility and safety of robot-assisted TACE were evaluated by assessing the technical success, procedure time, adverse event rate, radiation dose, and early tumor response. ResultsThe entire TACE procedure was divided into 30 steps, of which 8 could be robotized. In robot-assisted TACE, technical success was achieved in 4 (80%) of 5 patients. No procedure-related adverse event was observed. The median procedure time was 56 minutes. At the 1-month follow-up, 3 of the 4 patients showed a complete or partial response after robot-assisted TACE. The median radiation doses for the operator and patients were 0.4 and 2,167.5 μSv in robot-assisted TACE and 53.2 and 2,989.7 μSv in conventional TACE, respectively. ConclusionsRobot-assisted TACE using a new CRR system was feasible and safe for the treatment of HCC and could remarkably decrease radiation exposure for the operators.