Overcoming Radio-Immunotherapy Treatment Resistance through ILT4 Blockade and Reversal of HFRT Induced CXCL1-CXCR2 Axis Activation and Tumor-Associated Macrophage Immunosuppression

PURPOSE/OBJECTIVE(S)

Immunotherapy combined with radiotherapy (iRT) has unlimited potential, but up to 60% of cancer patients do not benefit from it. Enhancing the anti-tumor immune stimulatory effect triggered by radiotherapy is the key to overcome iRT resistance. Immunoglobulin-like transcript (ILT) 4 is a potential immune checkpoint molecule, highly expressed in various tumor cells, but its role in radiotherapy is still unknown. This study confirmed the role and molecular mechanism of ILT4 in suppressing radiotherapy immunosuppressive microenvironment formation and promoting tumor radiotherapy resistance. We propose a new therapeutic strategy that block ILT4 to enhance the efficacy of radiotherapy, and cooperate with radiotherapy to reverse immunotherapy resistance.

MATERIALS/METHODS

Using multiplex immunohistochemistry, we analyzed ILT4 expression, tumor-associated macrophage (TAM) /T cell phenotype and quantity in tumor patient treated with SBRT. Using mice subcutaneous tumor models, Single-cell RNA sequencing and multiplex flowcytometry, we assessed the role of ILT4 inhibition and hyper-fractionated radiotherapy (HFRT) on preventing tumor growth and immune escape. The molecular signaling and cytokines regulated by ILT4 under HFRT were analyzed by transcriptome sequencing and further verified by molecular experiments. By establishing cancer cell/TAM co-culture system in vitro, using CXCL1 protein or CXCR2 inhibitor and macrophage/CD8+ T cell deletion antibody in vivo, we identified the downstream pathway and cytokine of ILT4 to enhancing HFRT -induced TAM immune response.

RESULTS

In the tumor specimens of NSCLC patients treated with SBRT, we found that high ILT4 expression predicted poor progression-free survival and more M2-TAM recruitment. Among the C57BL/6 mice model, ILT4 inhibition in cancer cells reduced HFRT mediated M2-TAMs accumulation, and to sustain activation and proliferation of CD8+ T cells, and eventually suppressed tumor progression. Mechanistically, RT promoted ILT4 expression, which subsequently induced NF-κB pathway activation and CXCL1 secretion to enhance M2-TAMs migration in vitro. Using CXCL1 protein or CXCR2 inhibitor administration, inferring that ILT4 promotes TAMs migration via NF-κB-CXCL1-CXCR2 axis. Consistently, depletion of TAMs blocked the T cell function impairment and radiotherapy resistance induced by ILT4 in vivo. Importantly, targeting ILT4 potentiated the effect of radiotherapy, overcomes radio-immunotherapy treatment resistance.

CONCLUSION

ILT4 mediates HFRT-induced M2-like TAMs recruitment and subsequently T cell response impairment by regulating NF-κB-CXCL1-CXCR2 axis. ILT4 is an attractive drug target for enhancing radiotherapy and overcomes radio-immunotherapy treatment resistance.

Endoscopic Ultrasonography-Derived Maximum Tumor Thickness and Tumor Shrinkage Rate as Independent Prognostic Factors in Locally Advanced Esophageal Squamous Cell Carcinoma after Neoadjuvant Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

Neoadjuvant chemoradiotherapy (NCRT) is increasingly used in patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC). Endoscopic ultrasonography (EUS)-derived maximum tumor thickness (MTT) before and after standard NCRT for LA-ESCC indicates treatment response. However, the accuracy of predicting long-term survival remains uncertain. This study aimed to investigate the association between EUS-derived MTT pre- and post-NCRT and tumor shrinkage rate as well as long-term survival in patients with LA-ESCC receiving NCRT.

MATERIALS/METHODS

We retrospectively enrolled patients with LA-ESCC who underwent EUS examination pre- and post-NCRT from 2017 to 2021. MTT was measured using EUS. Tumor shrinkage rate was the ratio of the difference between pre- and post-MTT to pre-MTT. The most fitted cut-off value defining the EUS response was determined by the receiver operating characteristic curve. Univariate and multivariate Cox regression analyses and Kaplan-Meier (KM) curves were used to calculate overall survival (OS) and progression-free survival (PFS). Data from another center were also used for external validation testing.

RESULTS

The median follow-up period was 30.6 months.230 patients with LA-ESCC who underwent EUS pre- or post-NCRT were enrolled. Of the patients, 178 completed the first EUS pre-NCRT and obtained pre-MTT, 200 completed the re-examined EUS post-NCRT and obtained post-MTT, and 148 completed both EUS and achieved tumor shrinkage. In the whole group the 1-year and 3-year OS rates were 93.9% and 67.9%, and PFS rates were 77.7% and 54.1%, respectively. Thinner post-MTT (≤8.8 mm) and EUS-responders (tumor shrinkage rate≥52%) were independently associated with better OS. The result of EUS-respond was an independent prognostic factor could be confirmed in the external validation group. Among LA-ESCC patients with initial ultrasonic T2-3 staging and T4 staging, no statistically differences were observed between the responder and non-responder groups (P = 0.082; P = 0.190).

CONCLUSION

EUS-derived MTT and tumor shrinkage post-NCRT are independent prognostic factors for long-term survival and may be an alternative method for evaluating tumor response in patients with LA-ESCC after NCRT. Initial tumor infiltration beyond esophageal adventitial layer on ultrasound effect could not, however, predict the long-term prognosis.

The Effect of Three Different Positioning Approaches for Prone Rectum Radiotherapy on Positioning Accuracy and Treatment Margins

PURPOSE/OBJECTIVE(S)

The positioning accuracy of rectal radiotherapy patients was greatly affected by the immobilization gadget, breathing motion, bladder volume etc. Prone is one of the common treatment positions for rectum radiotherapy patients as it can displace the small bowels to reduce side effects. Our team would like to further enhance positioning accuracy by evaluating different positioning approaches.

MATERIALS/METHODS

A total of 16 patients from each group were selected retrospectively. All patients fulfilled the bladder (±20% of CT-sim bladder volume) and bowel (empty bowel before the treatment) protocol before entering the treatment unit. Group A patients were positioned using commercial prone pelvic board (Orfit, Belgium) combined with thermoplastic membrane and skin markings; Group B patients were fixed with innovative prone pelvic board and vac-bag which positioned using skin markings. First three fractions and once weekly CBCT images were retrieved for data analysis. Group C patients were fixed the same as Group B and positioned using skin markings during the first fraction. New reference surface for the SGRT system (Vision RT Ltd, UK) was captured after CBCT shifts applied. The subsequent treatment, patient was aligned to ±0.1 cm and ±1.5° according to the new reference surface. CBCT shifts that were taken at fraction 2, 3, 4 and once weekly were recorded in 6 degrees of freedom.

RESULTS

A total of 112 sets of data were retrieved from each groups respectively. The results were compared using nonparametric tests based on the normal distribution of the data. PTV margins (M) were calculated using the formula M = 2.5Σ+0.7σ. Positioning errors were shown in Table 1. The median positioning errors was statistically significant in lateral, vertical, roll and yaw for Group A and B. Whereas, Group C positioning errors was superior to Group B in all axes (p<0.05) except roll and yaw directions. The margins of Group A, B and C were 0.68cm, 1.17cm and 0.62cm; 0.56cm, 0.99cm and 0.75cm; 0.39cm, 0.36cm and 0.34cm in lateral, longitudinal and vertical directions. The results shown that Group B margins was smaller than Group A in lateral and longitudinal directions. Group C required the least margins.

CONCLUSION

Positioning prone rectum patients using innovative pelvic board with the aid of surface guidance resulted in higher accuracy and smaller margins especially in longitudinal direction. Accurate positioning and good reproducibility could potentially reduce the margins from 6mm to 4mm for our prone rectum radiotherapy patients.

RUNX1 as a Potential Target for Combined Radioimmunotherapy of Lung Adenocarcinoma

PURPOSE/OBJECTIVE(S)

Radioimmunotherapy for non-small cell lung cancer has good clinical application prospects. The role and mechanism of RUNX1 in DNA damage repair were explored for its potential role in lung adenocarcinoma radioimmunotherapy.

MATERIALS/METHODS

To study the effect of RUNX1 expression level on the expression of DNA damage repair system related factors and radiation sensitivity of lung adenocarcinoma cells. As an important nuclear transcription factor, RUNX1 was explored whether directly regulating the expression of Nrf2, Rad51, BRCA1, and verifying their respective DNA binding sites in the promoter region through relevant databases. To observe the effect of RUNX1 knockout and overexpression on the expression level of PD-L1 in tumor cells at the cell level; The effect of RUNX1 expression level on the sorting and presentation of PD-L1 cells was investigated by the method of nucleocytoplasmic separation. According to literature reports, CMTM6 and ALIX play a key role in the process of PD-L1 cell sorting and presentation, and explore whether RUNX1 plays a role through this factor. The effect of phosphorylation level of different splicing bodies of RUNX1 (RUNX1a/b/c) on the expression level and DNA damage repair system related factors on tumor radiosensitivity were also explored.

RESULTS

According to TCGA database, RUNX1 is highly expressed and phosphorylated in lung adenocarcinoma. Through gene comparison with the database, it was found that RUNX1 binding sites existed in the promoter region of several factors related to this study, including ALIX, Nrf2, BRCA1, RAD51, ATM, H2AX, etc. After being activated by MAPKp38 phosphorylation, RUNX1a can positively regulate Nrf2 signal pathway. The expression of RUNX1 and p-RUNX1 is time-dependent on ionizing radiation. At the same time, it was found that the expression of RUNX1 and p-RUNX1 was dose-dependent on ionizing radiation, and the expression trend of Nrf2 signal pathway related factors was consistent with RUNX1. RUNX1 regulates the expression of PD-L1, BRCA1, ALIX and Nrf2. Bioinformatics analysis and flow cytometry data show that RUNX1 has inhibitory effect on tumor microenvironment of lung adenocarcinoma.

CONCLUSION

RUNX1 regulates DNA damage repair system and has inhibitory effect on tumor immunity. Inhibiting the expression of RUNX1 in lung adenocarcinoma cells can enhance the effect of radioimmunotherapy.

Comparison of Standard vs. Relative Risk Models to Define Candidates for Deintensification in Locoregionally Advanced P16+ Oropharyngeal Cancer

PURPOSE/OBJECTIVE(S)

Various methods to identify candidates for treatment deintensification with p16+ oropharyngeal squamous cell carcinoma (OPSCC) have been used, but the optimal approach is unknown.

MATERIALS/METHODS

Multi-institutional cohort study of 385 patients with previously untreated p16+ OPSCC undergoing definitive radiotherapy (RT) with or without systemic therapy between 2009-2020. Chemotherapy intensity was categorized as high (bolus cisplatin and/or induction chemotherapy), medium (weekly cisplatin), or low (non-cisplatin or RT alone). Standard favorable vs. unfavorable risk was defined using NRG HN005 eligibility criteria. High vs. low relative risk (RR) group was defined using the HNCIG omega score (≥ 0.80 vs. < 0.80), which quantifies the proportion of a patient's overall event risk due to cancer. We used multivariable ordinal logistic regression to estimate effects of age (yrs), sex, performance status (PS), Charlson comorbidity index (CCI), T/N (AJCC 8th), current smoking, and pack-years (> 10 vs. ≤ 10) on treatment allocation. Effects on relative event hazards were estimated using generalized competing event regression.

RESULTS

Median follow-up time was 44.2 months. Chemotherapy intensity was high in 206 (54%), medium in 108 (28%), and low in 71 (18%). 280 patients (73%) were unfavorable risk and 197 (51%) were high RR. 178 patients (46%) had discordant risk classification. On univariable analysis, significant predictors of higher intensity chemotherapy (normalized odds ratio (OR)) were CCI 0-1 (OR 1.49, 95% CI: 1.23-1.79), high omega score (OR 1.46; 1.20-1.77), decreased age (OR 1.43; 1.18-1.74), and PS 0 (OR 1.22; 1.01-1.48). Controlling for CCI, higher omega score was associated with significantly higher odds of intensive chemotherapy (OR 1.35; 1.10-1.65, but unfavorable risk (HN005 ineligibility) was not (OR 1.19; 0.98-1.44). Higher omega score was also associated with significantly higher RR for cancer recurrence (Rec) vs. competing mortality (CM) events (relative HR (rHR) 1.76; 1.12-2.75), but unfavorable risk was not (rHR 1.05; 0.63-1.75). Among patients receiving cisplatin, 50 favorable risk patients (58%) had high RR; all of their event risk was due to cancer recurrence (Table). The 110 unfavorable risk patients (48%) with low omega score had significantly lower RR for cancer events compared to the high omega score group (rHR 0.49; 0.29-0.84).

CONCLUSION

Many patients with favorable risk p16+ OPSCC have high relative risk for cancer events, which correlates with a benefit of intensive treatment. The HNCIG omega score is a strong predictor of allocation to intensive chemotherapy and may help identify candidates for deintensification.

More Efficient Auto-Segmentation Framework Using Patient-Specific Information for CBCT-Guided Adaptive Radiotherapy

PURPOSE/OBJECTIVE(S)

Accurate and fast delineation of regions of interest (ROIs) is critical for online adaptive radiotherapy (ART). Due to the noise, artifacts and low contrast of soft tissue on cone-beam computed tomography (CBCT), the CBCT-guided ART (CBCTgART) needs an effective tool to assist the segmentation of ROIs. This study aims to develop an efficient auto-segmentation workflow with personalized modeling for CBCTgART based on deep learning (DL) model.

MATERIALS/METHODS

Five hundred fifty-two patients with nasopharyngeal carcinoma were enrolled in this study. At the beginning, a cycle consistent adversarial network (CycleGAN) model was trained on 172 patients' CBCT/CT paired images to improve the image quality of CBCT to CT level. A generalized segmentation model was trained using the planning CT (pCT) and contour data from 530 patients. For personalized modeling, the generalized segmentation model was fine-tuned on the specific patient's pCT and contour to get the personalized model. When CBCT images were available, the trained CycleGAN model transformed the CBCT to synthetic pCT. Then the personalized auto-segmentation model generated the contour of ROIs on the synthetic pCT. We randomly selected 22 patients for model test. The proposed method (DL-personalized) was compared with other DL methods based on the same architecture of network: regular deep learning method (DL-regular), which was trained on the CBCT and corresponding contours, and generalized model in our framework (DL-generalized). So, 22 personalized, 1 generalized and 1 regular DL models were tested. The paired t-test was performed to test the significance for mean dice similarity coefficient (DSC), mean distance to agreement (MDA), and Hausdorff distance (HD) between the alternative and proposed methods.

RESULTS

Two ROIs were included: the clinical target volume (CTV) and nasopharynx gross tumor volume (GTVnx). The proposed DL-personalized model achieved better results compared with others as shown in the table. The accuracy and robustness of our proposed framework was reliable. All of p values were under 0.01, which indicated the statistically significant difference.

CONCLUSION

The proposed framework utilizing patient-specific information can improve the segmentation accuracy of ART. This method has potential to be integrated into the ART workflow to improve efficiency.

IKBKE Promotes Radioresistance of Glioblastoma through AKT/FOXO3a Pathway

PURPOSE/OBJECTIVE(S)

Glioblastoma is an intracranial highly malignant primary tumor, and postoperative radiotherapy is a common treatment of glioblastoma. While radiotherapy resistance of glioblastoma is an important reason for treatment failure. IKBKE is overexpressed in gliomas, but its role in radiotherapy is unknown. This study confirmed that IKBKE can directly phosphorylate AKT protein to regulate FOXO3a, thus promoting the radioresistance of glioblastoma, and proposed a new therapeutic strategy to enhance the efficacy of radiotherapy.

MATERIALS/METHODS

We used flow cytometry, tunel staining, plate cloning, a cell counting kit and WB to confirm the effects of IKBKE and FOXO3a on radioresistance of glioblastoma, and immunofluorescence and WB were used to detect the expression of γ-H2AX. Subcutaneous tumor formation in mice and immunohistochemical staining was performed. IP combined with mass spectrometry, immunofluorescence, endogenous and exogenous IP were used to confirm the interaction between IKBKE and AKT. Point mutation, IP and WB were used to confirm the phosphorylation site of AKT. IP and some small molecule inhibitors were used to confirm the relationship between IKBKE, AKT and PI3K. The effect of IKBKE on FOXO3a was confirmed by WB and qPCR. The protein relationship among IKBKE, FOXO3a and 14-3-3 was confirmed by CHX, MG132, ubiquitin test, immunofluorescence and IP. The above experiments were carried out to verify the effect of Amlexanox, an IKBKE inhibitor, on glioblastoma. And its pharmacokinetics in the brain was determined by LC-MS to provide a theoretical basis for further clinical use.

RESULTS

It was found that IKBKE could increase the radioresistance of glioblastoma in vitro and in vivo. IKBKE could directly phosphorylate AKT, and its phosphorylation sites were Ser473 and Thr308. We also certified that IKBKE activated AKT independent of PI3K. IKBKE inhibited the expression of FOXO3a on protein level, promoted its ubiquitin degradation, enhanced its interaction with 14-3-3, and inhibited its transportation into the nucleus. FOXO3a can increase the radiosensitivity of glioblastoma. Amlexanox, an IKBKE inhibitor, can inhibit the radiosensitivity of glioblastoma and partially pass through the blood-brain barrier to enhance the radiosensitivity of intracranial tumors.

CONCLUSION

IKBKE can activate AKT independent of PI3K by directly phosphorylating AKT Ser473 and Thr308, thus increasing the phosphorylation of FOXO3a. Phosphorylated FOXO3a promoted its ubiquitin degradation, and inhibited its transportation into the nucleus, causing radioresistance in glioblastoma. IKBKE inhibitor Amlexanox can pass through the blood-brain barrier and increase the radiosensitivity of intracranial tumor cells.

Chemoradiotherapy Combined with Nab-Paclitaxel plus Cisplatin in Patients with Locally Advanced Borderline Resectable or Unresectable Esophageal Squamous Cell Carcinoma: A Phase I/II Study

PURPOSE/OBJECTIVE(S)

To evaluate the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-PTX) plus cisplatin as the regimen of conversional chemoradiotherapy (cCRT) in locally advanced borderline resectable or unresectable esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

Patients with locally advanced ESCC (cT3-4, Nany, M0-1, M1 was limited to lymph node metastasis in the supraclavicular area) were enrolled. All the patients received the cCRT of nab-PTX plus cisplatin. After the cCRT, those resectable patients received esophagectomy; those unresectable patients continued to receive the definitive chemoradiotherapy (dCRT). The locoregional control (LRC), overall survival (OS), progression-free survival (PFS), distant metastasis free survival (DMFS), pathological complete response (pCR), R0 resection rate and adverse events (AEs) were calculated.

RESULTS

A total of 45 patients with ESCC treated from October 2019 to May 2021 were finally included. The median follow-up time was 30.3 months. The LRC, OS, EFS, DMFS at 1and 2 years were 81.5%, 86.6%, 64.3%, 73.2% and 72.4%, 68.8%, 44.8%, 52.7% respectively. 21 patients (46.7%) received conversional chemoradiotherapy plus surgery (cCRT+S). The pCR rate and R0 resection rate were 47.6% and 84.0%. The LRC rate at 1 and 2 years were 95.0%, 87.1% in cCRT+S patients and 69.3%, 58.7% in dCRT patients respectively (HR, 5.14; 95% CI, 1.10-23.94; P = 0.021). The OS rate at 1 and 2 years were 95.2% and 84.2% in resectable patients compared to 78.8% and 54.4% in unresectable patients (HR, 3.41; 95% CI, 1.10-10.61; P = 0.024). The toxicities during chemoradiotherapy were tolerated, the most common grade 3-4 toxicities were radiation esophagitis (15.6%).

CONCLUSION

Nab-PTX plus cisplatin were effective and safe as the regimen of conversional chemoradiotherapy of ESCC. The patients receiving conversional chemoradiotherapy plus surgery (cCRT+S) were prone to have a better survival.

Grade 4 Lymphopenia Might Associate with Pericardial Irradiation Dose and Worse Prognosis in Patients with Locally Advanced Esophageal Cancer Receiving Concurrent Chemo-Radiotherapy

PURPOSE/OBJECTIVE(S)

The immune system may influence prognosis, and lymphopenia is a frequent side effect of concurrent chemo-radiotherapy (CCRT). Radical irradiation for locally advanced esophageal cancer (LA-EC) exposes significant vascular and heart volumes, and we hypothesized that lymphopenia is linked to cardiac and pericardial doses and affects patient prognosis.

MATERIALS/METHODS

We identified 190 LA-EC patients who received radical CCRT between 2011 and 2019. Cardiac, pericardial, and lung dosimetric parameters were obtained and multivariate analysis (MVA) was performed to correlate clinical factors and dosimetric parameters with overall survival (OS). Absolute lymphocyte count (ALC), absolute platelet count (PLT), absolute white blood cell count (WBC), absolute neutrophil count (ANC), neutrophil-lymphocyte ratio (NLR = ANC/ALC), and platelet-lymphocyte ratio (PLR = PLT/ALC) were collected before and during CRT. Grade 4 (G4) lymphopenia was defined as Lymphocyte count nadir <0.2 103/mL during CRT and it was used to dichotomize the lymphocyte count nadir. MVA was performed to correlate hematologic toxicity with OS. Logistic stepwise regression was performed to determine the relationship between dosimetric parameters and G4 lymphopenia. Finally, a nomogram of G4 lymphopenia was developed and validated externally.

RESULTS

Median follow-up time for all patients was 27.5 months (range 12-118 months). On MVA for OS (n = 190), higher pericardial V30 (PV30) was linked to worse survival (HR = 1.013, 95% CI 1.001-1.026, p = 0.039). The median OS stratified by PV30>55.3% and PV30≤55.3% was 24 months and 54 months, respectively (p = 0.004). G4 lymphopenia was shown to be linked with worse OS in the MVA of hematological toxicity (n = 161) with OS (HR = 2.042, 95% CI 1.335-3.126, p = 0.001). 24 (24%) of the 100 patients in the training set had G4 lymphopenia. Our final model comprised Stage-IVA (p = 0.017), PLR during CRT (p = 0.008), Heart V50 (p = 0.046), and PV30 (p = 0.048). External validation 26 of 90 patients (29%) had grade 4 lymphocytopenia. The ROC curve displays an AUC for internal validation of 0.775 and external validation of 0.843.

CONCLUSION

Higher doses of pericardial radiation might affect LA-EC patients' prognosis by inducing G4 lymphopenia in CCRT process. Further prospective studies are warranted to confirm these findings, especially in the era of immune-checkpoint inhibitor treatment.

Feasibility of Omitting Contralateral Neck Irradiation in Patients with Node-Negative Sinonasal Squamous Cell Carcinoma Crossing the Midline

PURPOSE/OBJECTIVE(S)

This study aims to analyze the nodal target volume in patients with node-negative SNSCC crossing the midline.

MATERIALS/METHODS

One hundred and four patients with node-negative advanced sinonasal squamous cell carcinoma (SNSCC) crossing the midline were included. Survival rates were estimated and compared between treatment groups.

RESULTS

Sixty-four patients received contralateral ENI (contralateral ENI group), while forty patients did not (non-contralateral ENI group). The median follow-up time was 89.99 and 95.01 months in the contralateral and non-contralateral ENI groups, respectively. At 5 years, the regional relapse-free survival and contralateral regional relapse-free survival were 57.68% vs. 55.83% (p = 0.372), and 57.68% vs. 61.62% (p = 0.541), in contralateral ENI group vs. non-contralateral ENI group, respectively. Five-year overall survival, local relapse-free survival, and distant metastasis-free survival were similar in the two groups (all p > 0.05).

CONCLUSION

In patients with node-negative SNSCC crossing the midline, omission of contralateral ENI did not affect regional control and survival outcomes on the premise of receiving ipsilateral ENI covering at least levels Ib and II.

Hippocampal-Sparing Radiotherapy in Primary Sinonasal and Cutaneous Head and Neck Malignancies: A Feasibility Study

PURPOSE/OBJECTIVE(S)

Patients with primary sinonasal and cutaneous head and neck (H&N) malignancies often receive meaningful hippocampal doses, but the hippocampus is not a classic avoidance structure in radiation planning of these primary sites. This series characterizes the feasibility and tradeoffs of hippocampal-sparing radiotherapy (HSRT) for patients with primary sinonasal and cutaneous H&N malignancies.

MATERIALS/METHODS

We retrospectively identified patients at a single institution treated definitively for primary sinonasal or cutaneous malignancies of the H&N. Each patient received (chemo)radiation and all received clinically-significant radiation dose to one or both hippocampi. We created new HSRT plans for each patient with intensity-modulated radiotherapy using original target and organ-at-risk (OAR) volumes. Hippocampi were contoured based on Radiation Therapy Oncology Group guidelines. Absolute and relative differences in radiation dose to the hippocampi, planning target volumes (PTV), and OARs were recorded. We used paired-samples t-tests to compare hippocampal and PTV dosimetric measures with and without HSRT.

RESULTS

Thirty-seven patients were included (22 sinonasal, 11 cutaneous H&N, and 4 parotid primary tumors). Median prescription dose was 6600cGy (range: 5000-7440cGy). The most common fractionation regimens were 200cGy/fraction daily (51%, 19/37 patients) and 120cGy/fraction twice daily (41%, 15/37 patients). There were significant decreases in hippocampal Dmax and D100% using HSRT without compromising PTV coverage (Table 1). HSRT resulted in a relative increase of mean lacrimal gland dose by an average of 3.8%, optic chiasm Dmax by 1.3%, and whole brain Dmax of 1.2%. However, other OAR doses were lower with HSRT, including parotid gland mean dose, lens Dmax, optic nerve Dmax, cochlea mean dose, brainstem Dmax, and whole brain mean dose.

CONCLUSION

HSRT is feasible and results in meaningful radiation dose reduction to the hippocampi without reducing PTV coverage or increasing dose to other OARs. The hippocampi should be regularly included as avoidance structures when treating primary sinonasal and cutaneous H&N tumors with radiation. We suggest target hippocampal constraints of Dmax < 1600cGy and D100% < 500cGy when feasible (without compromising PTV coverage). The clinical significance of HSRT in patients with primary H&N tumors should be investigated prospectively.

Definitive Chemoradiation Treatment Response Evaluation Using NI-RADS and ctHPVDNA for HPV-Associated Oropharyngeal Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

To compare the evaluation of treatment response among patients with human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) treated with definitive (chemo)radiotherapy (CRT).

MATERIALS/METHODS

Patients with locally advanced HPV-associated OPSCC treated with definitive radiotherapy (RT) or CRT from 2019 to 2022 at a single institution were reviewed. Patients underwent standard 3-month post-CRT positron emission tomography/computed tomography (PET/CT) scan with or without contrast enhanced CT (CECT) of the head and neck. Plasma circulating tumor HPV DNA (ctHPVDNA) was collected from 2-8 months post-CRT. Equivocal findings on post-CRT imaging prompted repeat evaluation. Imaging response was assessed via NI-RADS (Neck Imaging Reporting and Data System) risk classification and independently reviewed by two board certified radiologists, both blinded to outcomes and ctHPVDNA values.

RESULTS

Our cohort of 52 patients included: 87% males; median age 61.5; 63% never smokers, 31% former smokers, 6% current smokers; 44% tonsil primary, 46% base of tongue; 4% T0, 25% T1, 40% T2, 12% T3, 17% T4; 6% N0, 15% N1, 2% N2a, 44% N2b, 25% N2c, 8% N3 (AJCC 7th edition). Concurrent systemic therapy was received in 90%. During this period 71 PET/CTs and 15 CECTs were reviewed for treatment response evaluation; 44% (23/52) patients required additional imaging for equivocal findings; 62 ctHPVDNA blood samples were co-analyzed for treatment evaluation. The highest risk classification score between mucosa, primary, and/or neck site was: 42% NI-RADS 1, 48% NI-RADS 2, and 10% NI-RADS 3. Only patients with locoregional disease recurrence/progression were included for evaluation comparison between imaging and circulating biomarkers. No cancer events occurred without imaging and/or ctHPVDNA detection. Patients with NI-RADS score ≥2 during first post-CRT imaging evaluation more frequently underwent additional imaging (70% vs 30%, p<0.001). NI-RADS risk classification suggested 5 locoregional events (2 true positives, 3 false positives) resulting in 100% sensitivity, 94% specificity, 40% positive predictive value (PPV), and 100% negative predictive value (NPV). Circulating tumor HPV-DNA identified 2 locoregional events (2 true positives, 0 false positives) resulting in 100% sensitivity, 100% specificity, 100% PPV, and 100% NPV. Salvage operations were performed in 2 of 3 patients with false positive disease by NI-RADS classification without any evidence of cancer on final pathology.

CONCLUSION

While limited by the small number of recurrence events in this cohort, ctHPVDNA for HPV-associated OPSCC in conjunction with post-treatment imaging evaluation may limit the need for repeat imaging and unwarranted salvage operations that increase patient worry, morbidity, and financial toxicity. Additional prospective study is warranted.

Stereotactic Radiotherapy or Whole Brain Radiotherapy Combined with Pyrotinib and Capecitabine in HER2-Positive Advanced Breast Cancer Patients with Brain Metastases (BROPTIMA): A Prospective, Phase Ib/II Single-Arm Clinical Study

PURPOSE/OBJECTIVE(S)

Approximately half of patients with advanced HER2-positive breast cancer (BC) will develop brain metastases (BM) over time. Local therapy including stereotactic radiotherapy (SRT) and whole brain radiotherapy (WBRT) is the main initial treatment in malignant tumor patients with BM. However, more than 50% patients after radiotherapy in one year suffered intracranial recurrence. Pyrotinib, a small molecule, irreversible, pan-ErbB receptor tyrosine kinase inhibitor (TKI), has a high potency for controlling BM and reducing the occurrence of brain metastases in advanced HER2-positive BC patients. We hypothesized that SRT or WBRT combined with pyrotinib and capecitabine could decrease intracranial progression in HER2 positive BC with newly diagnosed BM.

MATERIALS/METHODS

In this prospective single-arm phase Ib/II trial (NCT04582968), eligible patients were assigned to either fractionated stereotactic radiotherapy (FSRT) or whole-brain radiation therapy (WBRT), combined with pyrotinib and capecitabine. The primary endpoint was one-year CNS progression-free survival (PFS) rate. Secondary endpoints included intracranial objective response rate (IC-ORR) according to RANO-BM criteria, progression-free survival (PFS), overall survival (OS) and evaluation of safety and neurocognitive function.

RESULTS

From January 2020 to August 2022, 40 patients were enrolled. Twenty-nine patients were treated with FSRT in 8 Gy per fraction with 3 to 5 fractions and 11 were treated with WBRT in 3 Gy per fraction with 10 fractions, and then received chemotherapy in a time frame starting from 0 to 7 days after radiotherapy. At a median follow-up of 17.3 months, 1-year CNS-PFS rate was 74.9% (95% CI 61.9-90.7%) and median CNS-PFS was 18 months (95% CI, 15.5 to NA months). One-year PFS rate was 66.9% (53.1-84.2%) and median PFS time was 17.6 months (95% CI 12.8-34.1 months). The best intracranial response rate (IC-ORR: complete response and partial response) was 92.5% (37/40). The most common grade 3 or worse toxicity was diarrhea (7.5%) and asymptomatic radiation necrosis was detected in 4 of 67(6.0%) lesions treated with FSRT. No differences of neurocognitive function evaluated by MMSE (Mini-Mental State Exam) were observed between different groups at any time point.

CONCLUSION

Radiotherapy combined with pyrotinib and capecitabine resulted in a promising efficacy that crossed the pre-specified boundary in patients with HER2-positive advanced breast cancer with brain metastases. This is the first prospective study showing the efficacy and safety of CNS radiotherapy concurrent with pyrotinib and capecitabine in patients with BM from HER2-positive breast cancer. Further investigation in a randomized controlled study is warranted.

The Safety and Efficacy of SCART for Bulky Metastatic or Recurrent Cancer, a Phase I Study

PURPOSE/OBJECTIVE(S)

We are proposing a new treatment methodology, (called Stereotactic Centralized Ablative Radiation Therapy, (SCART), for bulky or metastatic tumors, which is based on the principles of SFRT, by using SBRT methods to deliver an ablative radiation dose to the central portion of the target while keeping the dose to surrounding normal tissue to a relatively low level. We performed a prospective dose escalation study of SCART for bulky metastatic or recurrent cancer. The purpose of the study was to determine dose-limiting toxicities (DLTs) and the Maximum Tolerated Dose (MTD) of SCART.

MATERIALS/METHODS

This study was registered at ClinicalTrials.gov Identifier: NCT0488198, and approved at Foshan Chancheng Hospital. Patients with unresectable solid "bulky" nonhematological malignancies with limited treatment options were enrolled and received SCART with a prescription to the central spot in the tumor with a peripheral dose to the tumor edge at around 20% isodose line of the prescription dose. Five dose levels were proposed. The primary endpoint was the maximum tolerated dose (MTD), defined as the highest dose where zero of three or one of six patients experienced grade 3 dose-limiting toxicity (DLT), scored according to the Common Toxicity Criteria for Adverse Events v. 4.03, up to 6 months after SCART.

RESULTS

A total of 21 patients received SCART and have eligible data for study follow-up. The dose was escalated for two patients to 24 GyX3. No grade 3 toxicity was observed in any of the enrolled patients. The median SCART dose was 18 Gy (range: 15 - 24). Six out of the 18 patients with data for overall survival (OS) died, and the median time to death was 16.29 months (range: 0.99 - 25.58). Three patients out of the 15 patients with available data for local recurrence (LR) were found to have an LR and the median time to LR was 16.01 months (range: 0.99 - 25.58). There appears to be a trend of tumors decreasing from the patient's first visit date, or pre-SCART, to their final volume post-SCART. The mean percent change for tumor shrinkage between first visit volumes and post-SCART volumes was 49.49% (SD: 40.89, p-value:0.009). Of 15 patients with available data for progression free survival, 9 had a local recurrence or were deceased. Estimated median survival (i.e., when survival is 50%) was equal to16.80 months (95% CI = 13.90, NA). The survival rate at 12 months and 24 months were72.22% and 24.07%, respectively. Of 15 patients with available data for time to local recurrence, 3 people had a local recurrence. The percent of patients that were free from local recurrence at one and two years after the beginning of SCART treatment was 85.56% for both.

CONCLUSION

Despite the high dose delivered and the excellent local control achieved; the incidence of Any toxicity was unexpectedly low. Multiple courses of SCART are possible. The optimal dose, volume and timing of SCART still need more study.

Patient-Specific Deep Learning Auto-Segmentation for MR-Guided Adaptive Radiotherapy of Prostate Cancer

PURPOSE/OBJECTIVE(S)

MR guided conventional prostate radiotherapy requires agreement of bladder and rectum position, size, and shape with reference plan anatomy. In many instances, treatments may be delayed to allow optimal filling of these organs at risk (OARs). To account for such changes, we propose a patient specific deep learning based auto-segmentation (PS-DLAS) solution to implement pseudo (adapt-to-shape) ATS planning as a replacement for (adapt-to-position) ATP for conventionally fractionated treatments, and to generate auto-segmented contours for ATS SBRT treatments.

MATERIALS/METHODS

A commercially available DLAS tool that allows to customize/re-train DLAS models to an individual patient was implemented and automated in 3 iterative steps: 1) training of initial PS-DLAS model based on the first daily MRI with manual contours for the patient, 2) using the trained model to auto-segment the next daily MRI (acquired at next fraction), and 3) re-training/updating the model with newly available daily MRI sets and the verified contours. Steps 1) and 3) were performed offline while the step 2 was online. The solution was tested using daily MRI sets collected for 6 prostate cancer patients treated with MR guided adaptive radiotherapy (MRgART) either in 5-fraction SBRT or conventionally fractionated with adapt-to-shape (ATS) or adapt-to-position (ATP) workflows on a 1.5T MR-Linac. The quality of the auto-segmented OAR contours, including bladder, penile bulb, prostate, rectum, and seminal vesicles, obtained in step 2) were assessed, where the acceptable contour slices (no editing required) were identified. Additionally, ATP was simulated using a pseudo ATS workflow on patient 6, allowing the PS-DLAS to be used on daily MRI sets and the obtained contours to be used in the daily plan optimization. The time saving and the plan quality of using the PS-DLAS were compared to those from the current standard clinical workflow.

RESULTS

The times for the offline model training in steps 1) or 3) were < 50 minutes and the times of applying the updated PS-DLAS to auto-segment a daily MRI set in step 2) were within 1 minute using a hardware of Intel(R) Xeon(R) Gold 5222 CPU. Among the auto-segmented contour slices, 87%, 92%, 88%, 86% and 84% were found to be acceptable for bladder, penile bulb, prostate, rectum, and seminal vesicles, respectively. The time savings of using the PS-DLAS were about 7 minutes, compared to the manual contouring in the current ATS workflow. Manual editing was almost always required in 1-3 most superior slices for each organ. For the patient tested with the pseudo ATS, time saving was 10 minutes with comparable plan quality to the standard ATP workflow.

CONCLUSION

In this study, we demonstrated use of a PS-DLAS approach to reduce contouring time in MR-guided ATS prostate radiotherapy. In addition, these results suggest a PS-DLAS approach combined with pseudo-ATS may reduce overall treatment times in conventionally fractionated MRgRT by eliminating time required for matching of OAR filling.

The Feasibility of Level Ib Sparing Intensity Modulated Radiation Therapy in Nasopharyngeal Carcinoma Patients with High-Risk Factors: Based on International Guideline

PURPOSE/OBJECTIVE(S)

In spite of the rarity of level Ib recurrence after intensity-modulated radiation therapy, the International Guideline (IG) provides the risk factors for prophylactic coverage. In practice, however, there are significant differences between institutions. The purpose of this study is to examine the feasibility of sparing level Ib IMRT in NPC patients with high-risk factors based on IG.

MATERIALS/METHODS

From January 2014 to October 2017, newly-diagnostic, non-metastatic NPC patients in our center were retrospectively reviewed. According to the risk factors of prophylactic level Ib coverage in patients with negative level Ib recommended by IG, the characteristics of pre-treatment MRI were analyzed. Four high-risk factors were identified: a. involvement of the structures that drain to level Ib as first echelon (FES), including anterior half of nasal cavity, oral cavity, b. involvement of submandibular gland (SMG), c. with radiologic extranodal extension (rENE) in level II LNs, or d. maximal axial diameter (MAD)≧2 cm in level II LNs. Patients with risk factors were divided into Cohort A (with risk factors a), Cohort B (with risk factor b, but without a), and Cohort C (only with risk factors c and/or d). Recurrence rates of level Ib and regional relapse-free survival (RRFS) rates were evaluated in different cohorts.

RESULTS

A total of 961 patients were finally included. Thirty-six cases (3.7%) presented with radiologically positive level Ib metastasis. For the other patients with negative Ib LNs, there were 18, 65, 421, and 444 cases classified as FES involvement, SMG involvement, level II LNs with rENE, and level II nodal with MAD ≧2 cm. Excluding overlap, a total of 571 patients with risk factors were divided into three groups: Cohort A (n = 18), Cohort B (n = 49) and Cohort C (n = 504). Nine patients (9/961, 0.94%) developed level Ib recurrence. Except for 1 patient with positive Ib LNs at diagnosis, 2 did not meet any of the risk factors, while the other six (6/9, 66.7%) met at least one risk factor. The rate of recurrence at neck level Ib was highest in Cohort A (11.1%, 2/18; Ib-sparing group: 0/10, 0.0% vs Ib-covering group: 2/8, 25.0%; P = 0.183). In Cohort B, no cases were found with level Ib recurrence (0.0%, 0/49). In Cohort C, the rates were rare (0.8%, 4/504) in both groups (0.7%, 2/276 vs 0.9%, 2/228; P > 0.999). Among the three Cohorts, there were no significant differences in 5-year RRFS between two groups, which were 90.0% vs 62.5% (p = 0.248), 90.9% vs 92.0% (p = 0.905), and 92.6% vs 90.1% (p = 0.445), respectively. Among patients with high-risk factors, the incidence of grade 3-4 late dry mouth symptom was higher in the level Ib-covering group (3.1% vs 7.5%, P = 0.033).

CONCLUSION

Level Ib sparing appears safe and feasible for NPC patients with negative level Ib LNs, even if combined with risk factors: SMG involvement, and/or level II with rENE, and/or level II MAD ≧2 cm. Level Ib-sparing irradiation reduces dry mouth symptoms compared with level Ib-irradiation.

Detection of nasopharyngeal cancer cells using the laser tweezer Raman spectroscopy technology

Nasopharyngeal cancer (NPC), which arises from the nasopharyngeal epithelial lining, is one of the common malignant otorhinolaryngological tumors in China. Due to its insidious anatomical location and highly invasive and metastatic features, it is challenging to detect NPC at early stages. In this work, a rapid laser tweezer Raman spectroscopic (LTRS) system was built and used to trap and characterize single NPC cells. Using LTRS, high-quality Raman signals of the normal nasopharyngeal cell line (NP69) and NPC cells could be successfully obtained. By analysing the Raman peaks, some unique changes were found in components, such as DNA, amide I and amide III, in NPC cells compared with normal cells. In addition, we also used a multivariate statistical algorithm to establish a diagnostic model for identifying NPC cells with an accuracy of 90.0%. These results demonstrate that LTRS in combination with the multivariate statistical analysis is a convenient and high-efficiency cell identification technology, providing a novel and rapid methodology for NPC detection at the single cell level.

Measurement of the Dependence of the Hadron Production Fraction Ratios f_{s}/f_{u} and f_{d}/f_{u} on B Meson Kinematic Variables in Proton-Proton Collisions at sqrt[s]=13 TeV

The dependence of the ratio between the B_{s}^{0} and B^{+} hadron production fractions, f_{s}/f_{u}, on the transverse momentum (p_{T}) and rapidity of the B mesons is studied using the decay channels B_{s}^{0}→J/ψϕ and B^{+}→J/ψK^{+}. The analysis uses a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of 61.6  fb^{-1}. The f_{s}/f_{u} ratio is observed to depend on the B p_{T} and to be consistent with becoming asymptotically constant at large p_{T}. No rapidity dependence is observed. The ratio of the B^{0} to B^{+} meson production fractions, f_{d}/f_{u}, is also measured, for the first time in proton-proton collisions, using the B^{0}→J/ψK^{*0} decay channel. The result is found to be within 1 standard deviation of unity and independent of p_{T} and rapidity, as expected from isospin invariance.

A nomogram predicts early neurological deterioration after mechanical thrombectomy in patients with ischemic stroke

Introduction

Early neurological deterioration (END) is common in acute ischemic stroke and is directly associated with poor outcome after stroke. Our aim is to develop and validate a nomogram to predict the risk of END after mechanical thrombectomy (MT) in acute ischemic stroke patients with anterior circulation large-vessel occlusion.

Methods

We conducted a real-world, multi-center study in patients with stroke treated with mechanical thrombectomy. END was defined as a worsening by 2 or more NIHSS points within 72-hour after stroke onset compared to admission. Multivariable logistic regression was used to determine the independent predictors of END, and the discrimination of the scale was assessed using the C-index. Calibration curves were constructed to evaluate the calibration of the nomogram, and decision curves were used to describe the benefits of using the nomogram.

Results

A total of 1007 patients were included in our study. Multivariate logistic regression analysis found age, admission systolic blood pressure, initial NIHSS scores, history of hyperlipemia, and location of occlusion were independent predictors of END. We developed a nomogram that included these 6 factors, and it revealed a prognostic accuracy with a C-index of 0.678 in the derivation group and 0.650 in the validation group. The calibration curves showed that the nomogram provided a good fit to the data, and the decision curves demonstrated a large net benefit.

Discussion

Our study established and validated a nomogram to stratify the risk of END before mechanical embolectomy and identify high-risk patients, who should be more cautious when making clinical decisions.

[Investigation on cognition, diagnosis and treatment status of chest tightness variant asthma among Chinese pediatricians]

Objective: To evaluate the awareness, diagnosis and treatment of chest tightness variant asthma (CTVA) among pediatricians in China. Methods: The survey was conducted by convenient sampling method. Pediatricians with professional title of attending physician and above from different grades hospitals in 30 provinces were invited to conduct online questionnaire surveys through WeChat, pediatricians scan QR codes to complete electronic questionnaires in the mini program from January 16th to February 4th, 2021. The contents of questionnaire included the awareness, diagnosis and treatment of CTVA, and comparing the differences between pediatricians in secondary hospitals and tertiary hospitals. Results: A total of 1 529 pediatricians participated in the survey, and 1 484 (97.06%) pediatricians completed the questionnaire and included in the analysis, including 420 males (28.30%). The awareness rate of CTVA among pediatricians was 77.83 % (1 155/1 484). Pediatricians in tertiary hospitals had higher rates of awareness of CTVA than pediatricians in secondary hospitals [81.86% (898/1 097) vs 66.41% (257/387), P<0.001] and had better execution of the guidelines [89.15% (978/1 097) vs 79.59% (308/387), P<0.001]. A total of 93.06 % (1 381/1 484) of pediatricians' first-line treatment included inhaled corticosteroids (ICS) for CTVA. Among them, a higher proportion of pediatricians in tertiary hospitals used ICS included regimens for first-line treatment of CTVA compared with pediatricians in secondary hospitals [94.90% (1 041/1 097) vs 87.86% (340/387), P<0.001]. The reported well control rate of CTVA was 32.08% (476/1 484), which was significantly lower in secondary hospitals than that in tertiary hospitals [17.31% (67/387) vs 37.28% (409/1 097), P<0.001]. Conclusion: Most pediatricians are well aware of CTVA, among which there is a certain gap in clinical practice between pediatricians in secondary hospitals and tertiary hospitals in terms of understanding, diagnosis, and treatment of CTVA.

Search for Exotic Higgs Boson Decays H→AA→4γ with Events Containing Two Merged Diphotons in Proton-Proton Collisions at sqrt[s]=13 TeV

We present the first direct search for exotic Higgs boson decays H→AA, A→γγ in events with two photonlike objects. The hypothetical particle A is a low-mass spin-0 particle decaying promptly to a merged diphoton reconstructed as a single photonlike object. We analyze the data collected by the CMS experiment at sqrt[s]=13  TeV corresponding to an integrated luminosity of 136  fb^{-1}. No excess above the estimated background is found. We set upper limits on the branching fraction B(H→AA→4γ) of (0.9-3.3)×10^{-3} at 95% confidence level for masses of A in the range 0.1-1.2 GeV.

[Application of the Chinese Expert Consensus on Diabetes Classification in clinical practice]

Objective: To evaluate the diagnostic for classification of newly diagnosed diabetes patients and assess the application of the screening tests recommended by the 2022 Chinese Expert Consensus on Diabetes Classification. Methods: Retrospective case series study. The data from the electronic medical record system of patients with new-onset diabetes mellitus (within 1 year of disease onset) who attending the Diabetes Specialist Outpatient Clinic at the Second Xiangya Hospital of Central South University from January 1, 2018 to December 31, 2021 were collected for the analysis. Based on the consensus, patients were categorized according their age of onset, body mass index (BMI), and suspicion of type 1 diabetes mellitus (T1DM). The chi-square statistic was used to compare key classifier indicators, including C-peptide, islet autoantibodies, and genetic markers, in the subgroups. The diagnosis in suspected T1DM patients was also evaluated. The screening strategy recommended in the consensus was further assessed using a logistic regression model and the area under the receiver-operating curve (AUC). Results: A total of 3 384 patients with new-onset diabetes were included. The average age of disease onset was (46.3±13.9) years, and 61.0% (2 065/3 384) of the patients were male. The proportions of patients who completed C-peptide and glutamic acid decarboxylase antibody (GADA) tests were 36.6% (1 238/3 384) and 37.5% (1 269/3 384), respectively. There were no significant differences in C-peptide test results among the subgroups (all P>0.05). In contrast, the GADA detection rate was higher in patients with young age of onset (<30 years old), in those who were non-obese (BMI<24 kg/m2), and in those clinically suspected of T1DM (all P<0.05). According to the diagnostic pathway proposed by the consensus, only 57.4% (1 941/3 384) of patients could be subtyped. For a definitive diagnosis, the remaining patients needed completion of C-peptide, islet autoantibody, genetic testing, or follow-up. Furthermore, among patients with clinical features of suspected T1DM, the antibody positivity rate was higher than in non-suspected T1DM patients [24.5% (154/628) vs. 7.1% (46/646), P<0.001]. When the clinical features of suspected T1DM defined in the consensus were taken as independent variables and antibody positivity was considered the outcome variable in the logistic regression model, young onset, non-obese onset, and ketosis onset could enter the model. Based on AUC analysis, the accuracy of the diagnostic model was 0.77 (95%CI 0.73-0.81), suggesting that the clinical features of suspected T1DM in the consensus have good clinical diagnostic value for this patient subgroup. Conclusions: There was a significant discrepancy between the clinical practice of diabetes classification and the process recommended by the consensus, which was specifically reflected in the low proportions of both subtyping indicator testing and definitively subtyped diabetes patients. Attention should be pay to the classification diagnosis process proposed in the consensus and the clinical detection rate of key diabetes subtyping indicators such as C-peptide and islet autoantibodies for diabetes classification should be improved. Noteworthy, the screening strategy for T1DM proposed by the consensus showed good clinical application value.