Medical Imaging Biomarker Discovery and Integration Towards AI-Based Personalized Radiotherapy

Intensity-modulated radiation therapy (IMRT) has been used for high-accurate physical dose distribution sculpture and employed to modulate different dose levels into Gross Tumor Volume (GTV), Clinical Target Volume (CTV) and Planning Target Volume (PTV). GTV, CTV and PTV can be prescribed at different dose levels, however, there is an emphasis that their dose distributions need to be uniform, despite the fact that most types of tumour are heterogeneous. With traditional radiomics and artificial intelligence (AI) techniques, we can identify biological target volume from functional images against conventional GTV derived from anatomical imaging. Functional imaging, such as multi parameter MRI and PET can be used to implement dose painting, which allows us to achieve dose escalation by increasing doses in certain areas that are therapy-resistant in the GTV and reducing doses in less aggressive areas. In this review, we firstly discuss several quantitative functional imaging techniques including PET-CT and multi-parameter MRI. Furthermore, theoretical and experimental comparisons for dose painting by contours (DPBC) and dose painting by numbers (DPBN), along with outcome analysis after dose painting are provided. The state-of-the-art AI-based biomarker diagnosis techniques is reviewed. Finally, we conclude major challenges and future directions in AI-based biomarkers to improve cancer diagnosis and radiotherapy treatment.

Limited Adenocarcinoma of the Prostate on Needle Core Biopsy

Context.— Grading small foci of prostate cancer on a needle biopsy is often difficult, yet the clinical significance of accurate grading remains uncertain. Objective.— To assess if grading of limited adenocarcinoma on prostate biopsy specimen is critical. Design.— We studied 295 consecutive patients undergoing extended-sextant biopsy with only 1-core involvement of adenocarcinoma, followed by radical prostatectomy. Results.— The linear tumor lengths on these biopsy specimens were: less than 1 mm (n = 114); 1 mm or more or less than 2 mm (n = 82); 2 mm or more or less than 3 mm (n = 35); and 3 mm or more (n = 64). Longer length was strongly associated with higher Grade Group (GG) on biopsy or prostatectomy specimen, higher risk of extraprostatic extension/seminal vesicle invasion and positive surgical margin, and larger estimated tumor volume. When cases were compared based on biopsy specimen GG, higher grade was strongly associated with higher prostatectomy specimen GG, higher incidence of pT3/pT3b disease, and larger tumor volume. Outcome analysis further showed significantly higher risks for biochemical recurrence after radical prostatectomy in patients with 1 mm or more, 2 mm or more, 3 mm or more, GG2-4, GG3-4, GG4, less than 1 mm/GG2-4, less than 1 mm/GG3-4, less than 2 mm/GG3-4, 3 mm or more/GG2-4, or 3 mm or more/GG3-4 tumor on biopsy specimens, compared with respective control subgroups. In particular, 3 mm or more, GG3, and GG4 on biopsy specimens showed significance as independent prognosticators by multivariate analysis. Meanwhile, there were no significant differences in the rate of upgrading or downgrading after radical prostatectomy among those subgrouped by biopsy specimen tumor length (eg, <1 mm [44.7%] versus ≥1/<2 mm [41.5%] versus ≥2/<3 mm [45.7%] versus ≥3 mm [46.9%]). Conclusions.— These results indicate that pathologists still need to make maximum efforts to grade relatively small prostate cancer on biopsy specimens.

The Clinical Significance of Perineural Invasion by Prostate Cancer on Needle Core Biopsy

Context.— Perineural invasion (PNI) by prostate cancer has been associated with adverse pathology, including extraprostatic extension. However, the significance of PNI quantification on prostate biopsy (PBx) remains unclear. Objective.— To compare radical prostatectomy (RP) findings and long-term outcomes in patients whose PBx had exhibited PNI. Design.— We assessed 497 consecutive patients undergoing sextant (6-site/≥12-core) PBx showing conventional adenocarcinoma followed by RP. Results.— PNI was found in 1 (n = 290)/2 (n = 132)/3 (n = 47)/4 (n = 19)/5 (n = 5)/6 (n = 4) of the sites/regions of PBx. Compared with a single PNI site, multiple PNIs were significantly associated with higher preoperative prostate-specific antigen, higher Grade Group (GG) on PBx or RP, higher pT or pN category, positive surgical margin, and larger estimated tumor volume. When compared in subgroups of patients based on PBx GG, significant differences in RP GG (GG1–3), pT (GG1–2/GG1–3/GG2/GG3), surgical margin status (GG1–3/GG3/GG5), or tumor volume (GG1–2/GG1–3/GG2/GG3) between 1 versus multiple PNIs were observed. Moreover, there were significant differences in prostate-specific antigen (PNI sites: 1–2 versus 3–6/1–3 versus 4–6/1–4 versus 5–6), RP GG (1–3 versus 4–6/1–4 versus 5–6), pT (1–2 versus 3–6/1–3 versus 4–6), pN (1–3 versus 4–6), or tumor volume (1–2 versus 3–6/1–4 versus 5–6). Outcome analysis revealed significantly higher risks of disease progression in the entire cohort or PBx GG1–2/GG1–3/GG2/GG3/GG5 cases showing 2 to 6 PNIs, compared with respective controls with 1-site PNI. In multivariate analysis, multisite PNI was an independent predictor for progression (hazard ratio = 1.556, P = .03). Conclusions.— Multiple sites of PNI on PBx were associated with worse histopathologic features in RP specimens and poorer prognosis. PNI may thus need to be specified, if present, in every sextant site on PBx, especially those showing GG1–3 cancer.

Longitudinal symptom and clinical outcome analysis of hospitalized COVID-19 patients

COVID-19 pandemics increased patient hospitalization impacting the hospital operations and patient care beyond COVID-19 patients. Although longitudinal symptom analysis may provide prognostic utility about clinical outcomes and critical hospitalization events of COVID-19 patients, such analysis is still missing. Here, we have analyzed over 10,000 hospitalized COVID-19 patients in the Houston Methodist Hospital at the Texas Medical Center from the beginning of pandemics till April of 2020. Our study used statistical and regression analysis over symptoms grouped into symptom groups based on their anatomical locations. Symptom intensity analysis indicated that symptoms peaked at the time of admission and subsided within the first week of hospitalization for most of the patients. Patients surviving the infection (n=9,263), had faster remission rates, usually within the first days of hospitalization compared to sustained symptom for the deceased patient group (n=1,042). The latter had also a longer hospitalization stay and more comorbidities including diabetes, cardiovascular, and kidney disease. Inflammation-associated systemic symptoms (Systemic) such as fever and chills, and lower respiratory system specific symptoms (Lower Respiratory System) such as shortness of breath and pneumonia, were the most informative for the analysis of longitudinal symptom dynamics. Our results suggest that the symptom remission rate could possess prognostic utility in evaluating patient hospitalization stay and clinical outcomes early in hospitalization. We believe knowledge and information about symptom remission rates can be used to improve hospital operations and patient care by using common and relatively easy to process source of information.

Aspirin with Low-Dose Ticagrelor or with Low-Dose Rivaroxaban for Secondary Prevention: A Cost Per Outcome Analysis

Introduction: Secondary prevention of cardiovascular events among patients with diagnosed cardiovascular disease and high ischemic risk poses a significant challenge in clinical practice. The combinations of aspirin with low dose (LD) Ticagrelor or LD-Rivaroxaban have shown superiority in preventing major adverse cardiovascular events (MACE) than aspirin treatment alone. The comparative value for money of these two regimens remains unexplored.Methods: We analyzed each regimen's annual cost needed to treat (CNT) by multiplying the annualized number needed to treat (aNNT) by the annual cost of each drug. The aNNTs were based on outcome data from PEGASUS TIMI-54 and COMPASS trials. Scenario analyses were performed to overcome variances in terms of population risk. Costs were based on 2021 US prices. The primary outcome was defined as CNT to prevent one MACE across the two regimens. Secondary value analysis was performed for myocardial infarction (MI), stroke, and CV death as separate outcomes. Results: The aNNTs to prevent MACE with LD-Ticagrelor and with LD-Rivaroxaban were 229 [95% confidence interval (CI):141-734] and 147 (95%CI:104-252), respectively. At an annual cost of 3,618$ versus 4,308$, the corresponding CNTs were 828,478$ (95%CI:510,111$-2,655,471$) with LD-Ticagrelor and 633,270$ (95%CI:448,028$-1,085,607$) with LD-Rivaroxaban. LD-Rivaroxaban.Conclusion: Combining aspirin with LD-Rivaroxaban provides better value for money than with LD-Ticagrelor for secondary prevention of MACE.

The Efficacy of the WRF-ARW Model in the Genesis and Intensity Forecast of Tropical Cyclone Fani over the Bay of Bengal

An attempt has been carried out to assess the efficacy of the Weather Research and Forecasting (WRF) model in predicting the genesis and intensification events of Very Severe Cyclonic Storm (VSCS) Fani (26 April – 04 May 2019) over the Bay of Bengal (BoB). WRF model has been conducted on a single domain of 10 km horizontal resolution using the Global Data Assimilation System (GDAS) FNL (final) data (0.250 × 0.250). According to the model simulated outcome analysis, the model is capable of predicting the Minimum Sea Level Pressure (MSLP) and Maximum Sustainable Wind Speed (MSWS) pattern reasonably well, despite some deviations. The model has forecasted the Lowest Central Pressure (LCP) of 919 hPa and the MSWS of 70 ms-1 based on 0000 UTC of 26 April. Except for the model run based on 0000 UTC of 26 April, the simulated values of LCP are relatively higher than the observations. According to the statistical analysis, MSLP and MSWS at 850 hPa level demonstrate a significantly greater influence on Tropical Cyclone (TC) formation and intensification process than any other parameters. The model can predict the intensity features well enough, despite some uncertainty regarding the proper lead time of the model run. Reduced lead time model run, particularly 24 to 48 hr, can be chosen to forecast the genesis and intensification events of TC with minimum uncertainty. Journal of Engineering Science 12(3), 2021, 85-100

Venous outflow profiles are associated with early edema progression in ischemic stroke

Background: In patients with acute ischemic stroke due to large vessel occlusion (AIS–LVO), development of extensive early ischemic brain edema is associated with poor functional outcomes, despite timely treatment. Robust cortical venous outflow (VO) profiles correlate with favorable tissue perfusion. We hypothesized that favorable VO profiles (VO+) correlate with a reduced early edema progression rate (EPR) and good functional outcomes. Methods: Multicenter, retrospective analysis to investigate AIS–LVO patients treated by mechanical thrombectomy between May 2013 and December 2020. Baseline computed tomography angiography (CTA) was used to determine VO using the cortical vein opacification score (COVES); VO+ was defined as COVES ⩾ 3 and unfavorable as COVES ⩽ 2. EPR was determined as the ratio of net water uptake (NWU) on baseline non-contrast CT and time from symptom onset to admission imaging. Multivariable regression analysis was performed to assess primary (EPR) and secondary outcome (good functional outcomes defined as 0–2 points on the modified Rankin scale). Results: A total of 728 patients were included. Primary outcome analysis showed VO+ (β: –0.03, SE: 0.009, p = 0.002), lower presentation National Institutes of Health Stroke Scale (NIHSS; β: 0.002, SE: 0.001, p = 0.002), and decreased time from onset to admission imaging (β: –0.00002, SE: 0.00004, p < 0.001) were independently associated with reduced EPR. VO+ also predicted good functional outcomes (odds ratio (OR): 5.07, 95% CI: 2.839–9.039, p < 0.001), while controlling for presentation NIHSS, time from onset to imaging, general vessel reperfusion, baseline Alberta Stroke Program Early CT Score, infarct core volume, EPR, and favorable arterial collaterals. Conclusions: Favorable VO profiles were associated with slower infarct edema progression and good long-term functional outcomes as well as better neurological status and ischemic brain alterations at admission.