Determination of internal target volume with Cine-MRI sequence for prostate MRI-Guided radiotherapy

BACKGROUND

In prostate radiotherapy, the intrafractional target motion negatively affects treatment accuracy. Generating internal target volume (ITV) using four-dimensional (4D) images may resolve the issue of intrafractional target motion induced by bladder filling and bowel movement. However, no 4D imaging techniques suitable for the prostate are currently available in clinical practice.

PURPOSE

This study aimed to determine the ITV based on cine magnetic resonance imaging (MRI) sequence for intrafractional target motion management in prostate MRI-guided radiotherapy.

MATERIALS AND METHODS

A reference ITV was generated in simulation process. Then, the reference ITV was adapted with cine MRI sequence before online planning in each fraction. Finally, the reference ITV was updated with the cine MRI sequence acquired during beam delivery after each fraction. Cine MRI sequences and positioning three-dimensional (3D) MRI from 35 patients were retrospectively collected. Clinical target volume (CTV) coverage was computed according to the two-dimensional contour of CTV and ITV on cine MRI images. Relative target size was calculated as the ratio of the volume of ITV and CTV. Isotropic planning target volume (PTV; 5 mm margin) and anisotropic PTV (3 mm margin in the posterior direction and 5 mm margin in other directions) were generated for comparison.

RESULTS

The CTV coverage rate of the proposed ITV had a mean value of 98.61% ± 0.51%, whereas the CTV coverage rates of the isotropic and anisotropic PTVs were 97.43% ± 0.41% and 96.58% ± 0.73%, respectively. The proposed ITV had a relative target size of 1.79 ± 0.17, whereas the anisotropic and isotropic PTVs had relative target sizes of 1.92 ± 0.12 and 2.21 ± 0.19, respectively. For both the CTV coverage rate and target relative size, significant differences were observed between the proposed ITV and the other two PTVs (p < 0.05).

CONCLUSION

The ITV achieved higher CTV coverage with smaller size than conventional isotropic and anisotropic PTVs, indicating that it can effectively deal with the intrafractional movement of the prostate.

Adaptive ultra-hypofractionated whole-pelvic radiotherapy in high-risk and very high-risk prostate cancer on 1.5-Tesla MR-Linac: Estimated delivered dose and early toxicity results

Background

Magnetic resonance (MR)-guided ultra-hypofractionated radiotherapy with whole-pelvic irradiation (UHF-WPRT) is a novel approach to radiotherapy for patients with high-risk (HR) and very high-risk (VHR) prostate cancer (PCa). However, the inherent complexity of adaptive UHF-WPRT might inevitably result in longer on-couch time. We aimed to estimate the delivered dose, study the feasibility and safety of adaptive UHF-WPRT on a 1.5-Tesla MR-Linac.

Methods

Ten patients with clinical stage T3a-4N0-1M0-1c PCa, who consecutively received UHF-WPRT, were enrolled prospectively. The contours of the target and organ-at-risks on the position verification-MR (PV-MR), beam-on 3D-MR(Bn-MR), and post-MR (after radiotherapy delivery) were derived from the pre-MR data by deformable image registration. The physician then manually adjusted them, and dose recalculation was performed accordingly. GraphPad Prism 9 (GraphPad Prism Software Inc.) was utilized for conducting statistical analyses.

Results

In total, we collected 188 MR scans (50 pre-MR, 50 PV-MR, 44 Bn-MR, and 44 post-MR scans). With median 59 min, the mean prostate clinical target volume (CTV)-V100% was 98.59% ± 2.74%, and the mean pelvic CTVp-V100% relative percentages of all scans was 99.60% ± 1.18%. The median V29 Gy change in the rectal wall was -2% (-18% to 20%). With a median follow-up of 9 months, no patient had acute Common Terminology Criteria for Adverse Events (CTCAE) grade 2 or more severe genitourinary (GU) or gastrointestinal (GI) toxicities (0%).

Conclusion

UHF-RT to the prostate and the whole pelvis with concomitant boost to positive nodes using an Adapt-To-Shape (ATS) workflow was technically feasible for patients with HR and VHR PCa, presenting only mild GU and GI toxicities. The estimated target dose during the beam-on phase was clinically acceptable based on the 3D-MR-based dosimetry analysis.

Clinical trial registration

Chinese Clinical Trial Registry ChiCTR2000033382.

Sophora tonkinensis: response and adaptation of physiological characteristics, functional traits, and secondary metabolites to drought stress

The medicinal plant Sophora tonkinensis is a characteristic Chinese shrub of karst areas. The arid climate in karst areas produces high-quality S. tonkinensis; however, the mechanisms of drought tolerance are not clear, which restricts sustainable plantings of S. tonkinensis. This study involved a 20-day drought stress experiment with potted S. tonkinensis and threee soil water regimes: control (CK), mild drought (MDT), and severe drought (SDT). Plant morphology, biomass, physiological indicators, alkaloid content, and other changes under drought stress were monitored. The content of soluble sugars and proteins, and activity of antioxidant enzymes in leaves and roots were higher under drought than CK, indicating that S. tonkinensis is tolerant to osmotic stress in early drought stages. Content of matrine and oxymatrine increased gradually with increasing drought duration in the short term. The epidermis of S. tonkinensis leaves have characteristics of desert plants, including upper epidermal waxy layer, lower epidermal villi, and relatively sunken stomata, suggesting that S. tonkinensis has strong drought tolerance. In conclusion, drought stress changed the cell structure of S. tonkinensis, induced antioxidant enzyme activity and increased its resistance to drought.

Partial Stereotactic Ablative Radiotherapy in Bulky Urinary Tract Malignancy: An Update Clinical Outcomes and Dosimetric Analysis

PURPOSE/OBJECTIVE(S)

Patients with bulky urinary tract malignancy have poor prognosis. Stereotactic ablative radiotherapy (SABR) needs careful consideration in abdominopelvic bulky tumors because of dose constraints on the OARs. We reported updated clinical outcomes to evaluate the safety and efficacy of partial stereotactic ablative radiotherapy(P-SABR) in bulky urinary tract malignancy. The study also aims to investigate the feasibility of P-SABR in dose and biologic effective dose (BED) escalation inside the tumors with equivalent toxicity.

MATERIALS/METHODS

A total of 26 patients with urinary tract malignancy underwent P-SABR radiotherapy from January 2013 to September 2018 were retrospectively analyzed in this study. All the patients were in inoperable locally advanced or metastatic stage with tumor diameter > 4.0 cm. The P-SABR plan consisted of the SABR for gross tumor volume boost (GTVb) and following conventionally fractionated radiotherapy for planning target volume (PTV). The first SABR plan to GTVb was delivered in 15-32Gy/3-5f. The second conventionally fractionated radiotherapy plan to PTV was delivered in 40.0-58.08Gy/15-26f. The total P-SABR plan met the OARs constraints. Local control and overall survival were estimated. Acute and late toxicity were evaluated according to RTOG criteria. Paired conventionally fractionated radiotherapy (CFRT) plans were re-designed for all patients, with the same OARs dose constraints and total dose of PTV margin. Dosimetric and BED parameters were compared in P-SABR and paired CFRT plans.

RESULTS

Median age of the patients was 66.5 years (range, 46-90 years). The tumor treated by P-SABR had a median diameter of 8.4 cm (4.1-19.5 cm) and a median volume of 99.2 cc (23.9-631.8 cc). Median follow-up time was 19.1 months. The local control at 1 and 2 years were 83.2%, 77.3%, respectively. The overall survival at 1 and 2 years were 72.2% ,45.5%, respectively. 6 cases have no local recurrence after 36 months. 4 cases remained alive after 60 months. Local symptoms improved in 15/16 cases after P-SABR. Multivariate analysis showed tumor diameter (≥8cm vs. <8cm) was the independent factor affecting local control and overall survival (P=0.033, P=0.016). No patient was observed radiotherapy directly induced ≥grade 3 toxicity. Compared with the paired CFRT plans, the P-SABR plans had no significant difference in most OAR dose parameters, except for the small intestine/colon V15, V45 with an increase of 14.6 cc, 3.4 cc. However, P-SABR plans increased the dose of PTV Dmean, Dmax by 8.7Gy, 14.4Gy (P < 0.001), respectively. In addition, the dose and BED of GTVb had a significant escalation of 15.8Gy and 30.2Gy (P<0.001) respectively in P-SABR plans.

CONCLUSION

We had reported P-SABR is well-tolerated in bulky urinary tract malignancy in previous study. Updated outcomes showed P-SABR may have long-term local control in these people. Compared with traditional CFRT plans, P-SABR plans escalated the dose and BED inside bulky tumors with equivalent toxicity.

Adaptive Ultra-Hypofractionated Whole-Pelvic Radiotherapy in High-Risk and Very High-Risk Prostate Cancer on 1.5-1.5 MR Linac: The Estimated Delivered Dose and Early Toxicity Results

PURPOSE/OBJECTIVE(S)

To study the feasibility and safety for patients with high-risk (HR) and very high-risk (VHR) prostate cancer treated with adaptive ultra-hypofractionated whole-pelvic radiotherapy (UHF-WPRT) on 1.5 magnetic resonance (MR)-Linac.

MATERIALS/METHODS

Sevenpatients with clinical stage T3a-4N0-1M0-1c consecutively treated with UHF-WPRT on a 1.5-T MR-Linac were recruited prospectively in a phase II trial (NCT05183074, ChiCTR2000033382). A 36.25 Gy dose in five fractions was delivered every other day with a boost of 40 Gy to the whole prostate, as well as 25 Gy to whole pelvic nodal area with a concomitant boost of 35 Gy to metastatic regional nodes. To estimate the delivered dose, we collected data by 3D-MR for the following stages: pre-MR, position verification-MR (PV-MR) in the Adapt-To-Shape (ATS) workflow, and 3D-MR during the beam-on phase (Bn-MR) and at the end of RT (post-MR). The target and organ-at-risk contours in the PV-MR, Bn-MR, and post-MR stages were projected from the pre-MR data by deformable image registration and manually adapted by the physician, followed by dose recalculation for the ATS plan. The cumulative acute genitourinary (GU) and gastrointestinal (GI) toxicities were evaluated as per NCI-CTCAE 5.0 criteria. The primary endpoints were acute ≥grade 3 genitourinary (GU) and gastrointestinal (GI) toxicities during the first 3 months.

RESULTS

Overall, 133 MR scans were collected (35 pre-MR, 35 PV-MR, 31 Bn-MR and 32 post-MR scans). With a median on-couch time of 61 minutes, the mean prostate and pelvic planning target volume (PTV)-V95% of all scans was 96.98 ± 3.06% and 96.44 ± 2.85%, respectively. The corresponding mean prostate clinical target volume (CTV)-V100% was 99.89 ± 0.32%, 98.71 ± 1.90%, 97.77 ± 2.89%, and 98.56 ± 1.72%, and the mean pelvic CTV-V100% was 97.57% ± 3.70%, 96.54 ± 3.80%, 95.43 ± 4.31%, and 94.39 ± 4.47% on pre-MR, PV-MR, Bn-MR and post-MR scans, respectively. For the 4 patients with positive nodes, the mean V100% of metastatic regional nodes was 99.89 ± 0.81%. The median V29 Gy change in the rectal wall was -1% (-18%-20%). The V29 Gy of the rectal wall increased by >15% was observed in one scan. A slight increase in the high dose of bladder wall was noted due to gradual bladder growth during the workflow. With median follow-up time of 7.3 (4.6-12.2) months, all patients were followed-up for more than 3 months. No patient was observed with acute CTCAE grade 2 or more severe GU or GI toxicities (0%).

CONCLUSION

UHF-RT to prostate and pelvic with ATS workflow is well tolerated by patients with HR and VHR prostate cancer, with only mild GU and GI toxicities. The 3D-MR-based dosimetry analysis demonstrated clinically acceptable estimated dose coverage of target volumes during the beam-on period.

Bevacizumab biosimilar candidate TAB008 compared to Avastin® in patients with locally advanced, metastatic EGFR wild-type non-squamous non-small cell lung cancer: a randomized, double-blind, multicenter study

BACKGROUND

Bevacizumab (Avastin®) is a monoclonal antibody targeting the vascular endothelial growth factor (VEGF). Used alone or in combination with chemotherapy and/or immunotherapy, Avastin® has shown promising efficacy in many cancers. This study compared the efficacy and safety of TAB008 with Avastin® sourced from the EU (bevacizumab-EU), in patients with non-squamous non-small cell lung cancer (nsNSCLC).

METHOD

In this randomized, double-blind, multicenter, phase III similarity study, treatment naïve for metastatic lung cancer., EGFR wild-type, locally advanced, metastatic, or recurrent non-squamous, non-small cell, lung cancer (nsNSCLC) patients were enrolled and randomized (1:1) into TAB008 or Avastin® groups. Patients received TAB008 or Avastin® 15 mg/kg intravenously plus paclitaxel/carboplatin for 4-6 cycles followed by TAB008 or Avastin® 7.5 mg/kg until disease progression, unacceptable toxicity or death. The primary endpoint compared the objective response rate (ORR) within 6 cycles as read by an independent radiological review committee (IRRC). Secondary endpoints compared disease control rate (DCR) Within 6 cycles, duration of response (DoR), progression-free survival (PFS), a year overall survival rate (OSR), overall survival (OS), safety, immunogenicity, and steady-state pharmacokinetics.

RESULTS

A total of 549 nsNSCLC patients were enrolled (277 in TAB008 group and 272 in Avastin® group). In the full analysis set, ORRs were 55.957% for TAB008 and 55.720% for Avastin®, and the ORR ratio was 1 (90% CI 0.89-1.14), well within the predefined equivalence margin of 0.75-1.33. No significant differences were found in DCR within 6 cycles (95.703% vs 95.367%, p = 0.8536), DoR (8.17 vs 7.3 months, p = 0.3526), PFS (9.10 vs. 7.97 months, p = 0.9457), 1 year overall survival rate (66.2% vs 68%, p = 0.6793), or OS (20.4 vs 17.6 months, p = 0.6549). Serious adverse events (SAEs) occurred in 37.55% (104/277) of patients in the TAB008 group and 34.32% (93/271) in the Avastin® group. Anti-drug antibodies were reported in 3 of 277 (1.08%) TAB008 patients, and 5 of 271 (1.85%) Avastin® patients, neutralizing antibody (Nab) was positive in 1 patient on Avastin®, which became negative upon follow-up. The steady-state trough concentrations (Cssmin) were 106.13 μg/mL in TAB008 group and 96.03 μg/mL in Avastin® groups, with the treatment group ratio of LS geometric means fully contained within the bioequivalence limits of 80.00-125.00% (90% CI was 101.74-120.05%).

CONCLUSIONS

TAB008 is similar to Avastin® in terms of efficacy, safety, and pharmacokinetic parameters, with comparable immunogenicity.

TRIAL REGISTRATION

ClinicalTrials.gov number; NCT05427305.

Improving accelerated 3D imaging in MRI-guided radiotherapy for prostate cancer using a deep learning method

PURPOSE

This study was to improve image quality for high-speed MR imaging using a deep learning method for online adaptive radiotherapy in prostate cancer. We then evaluated its benefits on image registration.

METHODS

Sixty pairs of 1.5 T MR images acquired with an MR-linac were enrolled. The data included low-speed, high-quality (LSHQ), and high-speed low-quality (HSLQ) MR images. We proposed a CycleGAN, which is based on the data augmentation technique, to learn the mapping between the HSLQ and LSHQ images and then generate synthetic LSHQ (synLSHQ) images from the HSLQ images. Five-fold cross-validation was employed to test the CycleGAN model. The normalized mean absolute error (nMAE), peak signal-to-noise ratio (PSNR), structural similarity index measurement (SSIM), and edge keeping index (EKI) were calculated to determine image quality. The Jacobian determinant value (JDV), Dice similarity coefficient (DSC), and mean distance to agreement (MDA) were used to analyze deformable registration.

RESULTS

Compared with the LSHQ, the proposed synLSHQ achieved comparable image quality and reduced imaging time by ~ 66%. Compared with the HSLQ, the synLSHQ had better image quality with improvement of 57%, 3.4%, 26.9%, and 3.6% for nMAE, SSIM, PSNR, and EKI, respectively. Furthermore, the synLSHQ enhanced registration accuracy with a superior mean JDV (6%) and preferable DSC and MDA values compared with HSLQ.

CONCLUSION

The proposed method can generate high-quality images from high-speed scanning sequences. As a result, it shows potential to shorten the scan time while ensuring the accuracy of radiotherapy.

Establishing Clinically Meaningful Change on Outcome Assessments Frequently Used in Trials of Mild Cognitive Impairment Due to Alzheimer's Disease

BACKGROUND

Consensus is lacking on what constitutes a meaningful score change for individual patients on clinical outcome assessments (COAs) that are commonly used in clinical trials of Alzheimer's disease. Such thresholds are one important approach to help contextualize trial results and demonstrate meaningful treatment benefit.

OBJECTIVES

To estimate meaningful within-patient change thresholds for the Clinical Dementia Rating Scale - Sum of Boxes (CDR-SB), Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-Cog), and the Mini-Mental State Examination (MMSE) among participants with mild cognitive impairment (MCI).

DESIGN

Retrospective anchor- and distribution-based analyses of data from the ADC-008 (NCT00000173) study were used to estimate thresholds for meaningful within-patient change on the target measures.

SETTING

Analyses were conducted using data from ADC-008 a Phase III, multicenter, randomized, double-blind, placebo-controlled, parallel-group study among participants with the amnestic subtype of MCI, which was conducted by the Alzheimer's Disease Cooperative Study (ADCS) between March 1999 and January 2004 in the United States and Canada.

PARTICIPANTS

Analyses were based on 769 eligible participants who completed the baseline assessment from 69 ADCS sites in the United States and Canada.

MEASUREMENTS

The target outcome measures for this analysis included the CDR-SB, the ADAS-Cog, and the MMSE. The anchor measures for this analysis included the Global Deterioration Scale and the MCI-Clinical Global Impression of Change.

RESULTS

Focusing on the 12-month time point, within-patient increases of 1-2.5 points in the CDR-SB and increases of 2-5 points on the 11-item ADAS-Cog and 13-item ADAS-Cog, on average, reflect minimal-to-moderate levels of deterioration, respectively.

CONCLUSIONS

These thresholds may be useful to aid the interpretation of Alzheimer's disease clinical trial data by illustrating meaningful within-patient progression over the course of a clinical trial via supplementary progressor analyses, which may in turn be informative for treatment decisions. Estimates generated via these methods are specifically intended to evaluate within-patient change and are not intended to assess the magnitude and meaningfulness of differences between group-level changes over time.

[Mid-term efficacy of China Net Childhood Lymphoma-mature B-cell lymphoma 2017 regimen in the treatment of pediatric Burkitt lymphoma]

Objective: To analyze the clinical characteristics of children with Burkitt lymphoma (BL) and to summarize the mid-term efficacy of China Net Childhood Lymphoma-mature B-cell lymphoma 2017 (CNCL-B-NHL-2017) regimen. Methods: Clinical features of 436 BL patients who were ≤18 years old and treated with the CNCL-B-NHL-2017 regimen from May 2017 to April 2021 were analyzed retrospectively. Clinical characteristics of patients at disease onset were analyzed and the therapeutic effects of patients with different clinical stages and risk groups were compared. Survival analysis was performed by Kaplan-Meier method, and Cox regression was used to identify the prognostic factors. Results: Among 436 patients, there were 368 (84.4%) males and 68 (15.6%) females, the age of disease onset was 6.0 (4.0, 9.0) years old. According to the St. Jude staging system, there were 4 patients (0.9%) with stage Ⅰ, 30 patients (6.9%) with stage Ⅱ, 217 patients (49.8%) with stage Ⅲ, and 185 patients (42.4%) with stage Ⅳ. All patients were stratified into following risk groups: group A (n=1, 0.2%), group B1 (n=46, 10.6%), group B2 (n=19, 4.4%), group C1 (n=285, 65.4%), group C2 (n=85, 19.5%). Sixty-three patients (14.4%) were treated with chemotherapy only and 373 patients (85.6%) were treated with chemotherapy combined with rituximab. Twenty-one patients (4.8%) suffered from progressive disease, 3 patients (0.7%) relapsed, and 13 patients (3.0%) died of treatment-related complications. The follow-up time of all patients was 24.0 (13.0, 35.0) months, the 2-year event free survival (EFS) rate of all patients was (90.9±1.4) %. The 2-year EFS rates of group A, B1, B2, C1 and C2 were 100.0%, 100.0%, (94.7±5.1) %, (90.7±1.7) % and (85.9±4.0) %, respectively. The 2-year EFS rates was higher in group A, B1, and B2 than those in group C1 (χ²=4.16, P=0.041) and group C2 (χ²=7.21, P=0.007). The 2-year EFS rates of the patients treated with chemotherapy alone and those treated with chemotherapy combined with rituximab were (79.3±5.1)% and (92.9±1.4)% (χ²=14.23, P<0.001) respectively. Multivariate analysis showed that stage Ⅳ (including leukemia stage), serum lactate dehydrogenase (LDH)>4-fold normal value, and with residual tumor in the mid-term evaluation were risk factors for poor prognosis (HR=1.38,1.23,8.52,95%CI 1.05-1.82,1.05-1.43,3.96-18.30). Conclusions: The CNCL-B-NHL-2017 regimen show significant effect in the treatment of pediatric BL. The combination of rituximab improve the efficacy further.

Personalized modeling to improve pseudo-CT images for magnetic resonance imaging-guided adaptive radiotherapy

PURPOSE

Magnetic resonance imaging-guided adaptive radiotherapy (MRIgART) greatly improves daily tumor localization and enables online re-planning to obtain maximum dosimetric benefits. However, accurately predicting patient-specific electron density maps for adaptive radiotherapy (ART) planning remains a challenge. Therefore, this study proposes a personalized modeling framework for generating pseudo-computed tomography (pCT) in MRIgART.

METHODS AND MATERIALS

Eighty-three patients who received MRIgART were included and CT simulations were performed on all the patients. Daily T2-weighted 1.5 T MRI was acquired using the Unity MR-linac for adaptive planning. Pairs of co-registered CT and daily MRI images of the randomly selected training set (68 patients) were inputted into a generative adversarial network (GAN) to establish a population model. The personalized model for each patient in the test set (15 patients) was acquired using model fine-tuning, which adopted the pair of the deformable-registered CT and the first daily MRI to fine-tune the population model. The pCT quality was quantitatively evaluated in the second and the last fractions with three metrics: intensity accuracy using mean absolute error (MAE); anatomical structure similarity using dice similarity coefficient (DSC); and dosimetric consistency using gamma-passing rate (GPR).

RESULTS

The image generation speed was 65 slices per second. For the last fractions, and for head-neck, thoracoabdominal, and pelvic cases, the average MAEs were 76.8 HU vs. 123.6 HU, 38.1 HU vs. 52.0 HU, and 29.5 HU vs. 39.7 HU, respectively. Furthermore, the average DSCs of bone were 0.92 vs. 0.80, 0.85 vs. 0.73, and 0.94 vs. 0.88; and the average GPRs (1%/1 mm) were 95.5% vs. 84.7%, 97.7% vs. 92.8%, and 95.5% vs. 88.7%, for personalized vs. population models, respectively. Results of the second fractions were similar.

CONCLUSIONS

The proposed personalized modeling framework remarkably improved pCT quality for multiple treatment sites and was well suited for the MRIgART clinical setting.

[Analysis of experience in diagnosis and treatment of fetal goiter in patients with Graves' disease complicated with pregnancy]

This article reported the clinical diagnosis and treatment experience of two cases of fetal goiter in Graves' disease (GD) complicated with pregnancy. Two GD patients took antithyroid drugs regularly during pregnancy and their thyroid functions were well controlled, but the levels of thyrotropin receptor antibody (TRAb) of the two cases were still above the upper limit in the second and third trimester. Two fetuses had fetal goiter in the middle and late stages of pregnancy. After continuously controlling maternal thyroid function and closely monitoring fetal ultrasound, there was no aggravation of the fetal goiter, and the delivery went smoothly. One case had neonatal hyperthyroidism. It is suggested that although the thyroid function was well controlled during pregnancy in patients with GD, the high level of serum TRAb still needs to be alert to the occurrence of fetal goiter, and fetal ultrasound is the most direct non-invasive monitoring method.

[Analysis on prevalence and epidemic risk of animal plague in different ecological plague foci in Inner Mongolia Autonomous Region]

The risk of plague epidemics and relapse of various types of plague foci persists in Inner Mongolia Autonomous Region. For Marmota sibirica plague foci, the animal plague has not been found but antibody has been detected positive. Nowadays, Marmota sibirica has been increasing in population and distribution in China. In bordering countries Mongolia and Russia, the animal plague has been continuously prevalent. For Spermophilus dauricus plague foci, the animal plague has been taken place now and then. Compared to the above foci, the animal plague is most prevalent in Meriones unguiculatus plague foci and frequently spread to humans. Due to higher strain virulence and historical disaster in Marmota sibirica plague foci and Spermophilus dauricus plague foci, plague prevention and control should be strengthened on these foci. In addition to routine surveillance, epidemic dynamics need to be further monitored in these two foci, in order to prevent their relapse and spread to humans.