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The Bohai Sea is one of the southernmost areas for sea ice formation in the northern hemisphere. Sea ice disasters in this body of water severely affect marine activities and the safety of coastal residents. In this study, we analyze the variation characteristics of the sea ice in the Bohai Sea and establish an annual regression model based on predictable mode analysis method. The results show the following: 1) From 1970 to 2018, the average ice grade is (2.6±0.8), with a maximum of 4.5 and a minimum of 1.0. Liaodong Bay (LDB) has the heaviest ice conditions in the Bohai Sea, followed by Bohai Bay (BHB) and Laizhou Bay (LZB). In-terannual variation is obvious in all three bays, but the linear decreasing trend is significant only in BHB. 2) Three modes are obtained from empirical orthogonal function analysis, namely, single polarity mode with the same sign of anomaly in all of the three bays and strong interannual variability (82.0%), the north-south dipole mode with BHB and LZB showing an opposite sign of anomalies to that in LDB and strong decadal variations (14.5%), and a linear trend mode (3.5%). Critical factors are analyzed and regression equations are established for all the principal components, and then an annual hindcast model is established by synthesizing the results of the three modes. This model provides an annual spatial prediction of the sea ice in the Bohai Sea for the first time, and meets the demand of operational sea ice forecasting.

To explore the relationship between metabolic uptake of the 18F-ALF-NOTA-PRGD2 (18F-RGD) tracer on positron emission tomography/computerized tomography (PET/CT) and the antiangiogenic effect of apatinib in patients with solid malignancies. Patients with measurable lesions scheduled for second- or third-line single-agent therapy with apatinib were eligible for this prospective clinical trial. All patients underwent 18F-RGD PET/CT examination before the start of treatment. Standardized uptake values (SUVs) of contoured tumor lesions were computed and compared using independent sample t-tests or the Mann–Whitney U test. Receiver-operating characteristic (ROC) curve analysis was used to determine accuracy in predicting response. Survival curves were compared using the Kaplan–Meier method. Of 38 patients who consented to study participation, 25 patients with 42 measurable lesions met the criteria for inclusion in this response assessment analysis. The median follow-up time was 3 months (range, 1–10 months), and the median progression-free survival (PFS) was 3 months (95% confidence interval, 1.04–4.96). The SUVpeak and SUVmean were significantly higher in responding tumors than in non-responding tumors (4.98 ± 2.34 vs 3.59 ± 1.44, p = 0.048; 3.71 ± 1.15 vs 2.95 ± 0.49, P = 0.036). SUVmax did not differ between responding tumors and non-responding tumors (6.58 ± 3.33 vs 4.74 ± 1.83, P = 0.078). An exploratory ROC curve analysis indicated that SUVmean [area under the ROC curve (AUC) = 0.700] was a better parameter than SUVpeak (AUC = 0.689) for predicting response. Using a threshold value of 3.82, high SUVmean at baseline was associated with improved PFS (5.0 vs. 3.4 months, log-rank P = 0.036). 18F-RGD uptake on PET/CT imaging pretreatment may predict the response to antiangiogenic therapy, with higher 18F-RGD uptake in tumors predicting a better response to apatinib therapy.

To explore a representative hypoxic parameter to predict the treatment response and prognosis for [18F]fluoromisonidazole ([18F]FMISO) positron emission tomography (PET)/X-ray computed tomography (CT) in patients with non-small cell lung cancer (NSCLC). Twenty-nine patients with NSCLC underwent FMISO-PET scans before chemoradiotherapy (CRT). The maximum standard uptake values (SUVmax) in the tumor, normal lung, aortic arch, and vertical ridge muscle were measured, and the tumor-to-lung (T/L) ratios, tumor-to-blood (T/B) ratios, ands tumor-to-muscle (T/M) ratios were calculated and analyzed. Fractional hypoxic volume (FHV) was expressed as percentage of hypoxic volume. SUVmax, T/L ratio, T/B ratio, and FHV were all significantly different between the responders and the non-responders (SUVmax, 2.07 ± 0.53 vs. 2.61 ± 0.69, P = 0.026; T/L ratio, 3.16 ± 0.85 vs. 4.09 ± 1.46, P = 0.047; T/B ratio, 1.27 ± 0.20 vs. 1.48 ± 0.32, P = 0.042; 38.92 ± 18.47 vs. 52.91 ± 11.29 %, P = 0.020). However, the T/M ratio was not significantly different between the two populations (1.46 ± 0.31 vs. 1.67 ± 0.33, P = 0.098). The correlation ratio between hypoxic parameters and treatment responses ranged from high to low as FHV (r = 0.412); SUVmax (r = 0.400); T/L ratio (r = 0.379), P

Aims To perform a dosimetric evaluation of four different simultaneous integrated boost whole brain radiotherapy modalities with hippocampus and inner ear avoidance in the treatment of limited brain metastases. Methods Computed tomography/magnetic resonance imaging data of 10 patients with limited (1–5) brain metastases were used to replan step-and-shoot intensity-modulated radiotherapy (sIMRT), dynamic intensity-modulated radiation therapy (dIMRT), volumetric-modulated arc therapy (VMAT), and helical tomotherapy (Tomo). The prescribed doses of 40–50 Gy in 10 fractions and 30 Gy in 10 fractions were simultaneously delivered to the metastatic lesions and the whole-brain volume, respectively. The hippocampal dose met the RTOG 0933 criteria for hippocampal avoidance (Dmax ≤17 Gy, D100% ≤10 Gy). The inner ear dose was restrained to Dmean ≤15 Gy. Target coverage (TC), homogeneity index (HI), conformity index (CI), maximum dose (Dmax), minimum dose (Dmin) and dose to organs at risk (OARs) were compared. Results All plans met the indicated dose restrictions. The mean percentage of planning target volume of metastases (PTVmets) coverage ranged from 97.1 to 99.4%. For planning target volume of brain (PTVbrain), Tomo provided the lowest average D2% (37.5 ± 2.8 Gy), the highest average D98% (25.2 ± 2.0 Gy), and the best TC (92.6% ± 2.1%) and CI (0.79 ± 0.06). The two fixed gantry IMRT modalities (step and shot, dynamic) provided similar PTVbrain dose homogeneity (both 0.76). Significant differences across the four approaches were observed for the maximum and minimum doses to the hippocampus and the maximum doses to the eyes, lens and optic nerves. Conclusion All four radiotherapy modalities produced acceptable treatment plans with good avoidance of the hippocampus and inner ear. Tomo obtained satisfactory PTVbrain coverage and the best homogeneity index. Trial registration Clinicaltrials.gov, NCT03414944. Registered 29 January 2018