Predictive value of magnetic resonance imaging diffusion parameters using artificial intelligence in low-and intermediate-risk prostate cancer patients treated with stereotactic ablative radiotherapy: A pilot study

INTRODUCTION

To investigate the predictive value of the pre-treatment diffusion parameters of diffusion-weighted magnetic resonance imaging (DW-MRI) using artificial intelligence (AI) for prostate-specific antigen (PSA) response in patients with low- and intermediate-risk prostate cancer (PCa) treated with stereotactic ablative radiotherapy (SABR).

METHODS

Retrospective evaluation was performed for 30 patients using pre-treatment multi-parametric MR image datasets between 2017 and 2021. MR-based mean- and minimum apparent diffusion coefficients (ADCmean, ADCmin) were calculated for the intraprostatic dominant lesion. Therapeutic response was assessed using PSA levels. Predictive performance was assessed by the receiver operating characteristic (ROC) analysis. Statistics performed with a significance level of p ≤ 0.05.

RESULTS

No biochemical relapse was detected after a median follow-up of twenty-three months (range: 3-50), with a median PSA of 0.01 ng/ml (range: 0.006-2.8) at the last examination. Significant differences were observed between the pre-treatment ADCmean, ADCmin parameters, and the group averages of patients with low and high 1-year-PSA measurements (p < 0.0001, p < 0.0001). In prediction, the random forest (RF) model outperformed the decision tree (DT) and support vector machine (SVM) models by yielding area under the curves (AUC), with 0.722, 0.685, and 0.5, respectively.

CONCLUSION

Our findings suggest that pre-treatment MR diffusion data may predict therapeutic response using the novel approach of machine learning in PCa patients treated with SABR.

IMPLICATIONS FOR PRACTICE

Clinicians shall measure and implement the evaluation of the suggested parameters (ADCmin, ADCmean) to provide the most accurate therapy for the patient.

Burnout among oncologists, nurses, and radiographers working in oncology patient care during the COVID-19 pandemic

INTRODUCTION

Oncology care professionals are exposed to high levels of stress that can lead to burnout. The aim of this study was to investigate the prevalence of burnout among nurses, oncologists and radiographers working in oncology patient care during the COVID -19 pandemic.

METHODS

Our electronic questionnaire was sent to e-mail contacts registered in the system of the Hungarian Society of Oncologists and to all oncology staff via an internal information system in each cancer center. Burnout was measured using the Maslach Burnout Inventory, which measures depersonalization (DP), emotional exhaustion (EE), and personal accomplishment (PA). Demographic and work-related characteristics were collected in our self-designed questionnaire. Descriptive statistics, chi-square tests, two-sample t-tests, analyzes of variance, Mann-Whitney and Kruskal-Wallis tests were performed.

RESULTS

A total of 205 oncology care workers' responses were analyzed. Oncologists (n = 75) were found to be significantly more committed to DP and EE (p = 0.001; p = 0.001). Working more than 50 h per week and being on-call had a negative effect on the EE dimension (p = 0.001; p = 0.003). Coming up with the idea of working abroad had a negative effect on all three dimensions of burnout (p ≤ 0.05). Respondents who did not leave their job due to their current life situation had significantly higher DE, EE, and lower PA (p ≤ 0.05). Intention to leave current profession was specific in (n = 24/78; 30.8%) of nurses (p = 0.012).

CONCLUSION

Our results suggest that male gender, being an oncologist, working more than 50 h per week and taking on call duties have a negative impact on individual burnout. Future measures to prevent burnout should be integrated into the professionals' work environment, regardless of the impact of the current pandemic.

IMPLICATIONS FOR PRACTICE

Prevention and oncopsychological training should be developed gradually at the organisational or personal level to avoid early burnout of professionals.

Molecular characterization of Sphaerospora molnari (Myxozoa), the agent of gill sphaerosporosis in common carp Cyprinus carpio carpio

Sphaerospora molnari Lom, Dyková, Pavlásková and Grupcheva, 1983 often causes severe infections in the gills and skin of common carp fingerlings Cyprinus carpio carpio in Central Europe. Although most Sphaerospora spp. are coelozoic and affect the excretory system of fish, S. molnari develops mature spores in the epithelia of gill filaments, making it a rare representative of histozoic freshwater species within the genus. On the basis of a partial 18S rDNA sequence assigned as belonging to S. molnari, previous phylogenetic studies located the species within the Myxobolus clade. In the present study, S. molnari isolates from Hungary and the Czech Republic were characterized based on morphology, DNA sequence analysis and phylogenetic comparison. The obtained 3714 bp final consensus 18S rDNA sequence of the parasite showed several, sometimes extremely long inserts in the variable regions of the gene and differed considerably from the one published in GenBank in 2002. In situ hybridization confirmed the validity of the obtained DNA sequence and detected pre-sporogonic blood stages in the interstitium and blood vessels of the kidney. Phylogenetic analysis showed that S. molnari clusters within the Sphaerospora sensu stricto clade with a high support, revealing it as the first known histozoic member of the Sphaerospora subclade comprising parasites of freshwater fish.

The structure of the mammalian antibacterial peptide cecropin P1 in solution, determined by proton-NMR

Cecropins are peptides with antibacterial activity originally found in insects. Recently a cecropin-type peptide was isolated from pig intestine. This peptide, porcine cecropin P1, which has 31 amino acid residues and is not amidated in the C-terminus, has been synthesized, purified, and investigated by CD and two-dimensional 1H-NMR at pH 5.0 in aqueous solution with 30% (by vol.) 1,1,1,3,3,3-hexafluoro-2-propanol. All proton resonances have been assigned except for the N-terminal serine. Using constraints derived from NOE connectivities and 3JNH alpha-coupling constants, three-dimensional structures have been calculated by means of a distance-geometry program. Some of these structures have been refined by energy minimization and restrained molecular dynamics. The structures reveal an alpha-helix of approximately seven turns along nearly the full length of the peptide. The central part of the helix is very well defined by the NMR constraints. Also the chemical shifts of the alpha protons and the results of CD measurements are in accord with this structure, which is different from the helix-hinge-helix structure earlier found in cecropin A and related peptides. In the alpha-helix of cecropin P1 there is a long amphipathic section, of 4-5 turns, and a short hydrophobic section of one to two turns, with an intervening Glu-Gly sequence, which is a potential bend-forming section. The helix can easily span a lipid membrane.

Two-dimensional proton-NMR studies on a hybrid peptide between cecropin A and melittin. Resonance assignments and secondary structure

A hybrid peptide of cecropin A and melittin was investigated by two-dimensional 1H-NMR at pH 5.8 in aqueous solution with 30% (by vol.) hexafluoroisopropanol. The peptide contains 26 amino acids, is a combination of the first 13 residues of each of the two parent peptides, CA(1-13)M(1-13) identical to CAM(1-26) and has an amidated C terminal. This peptide was recently synthesized [Boman, H.G., Wade, D., Boman, I.A., Wåhlin, B. & Merrifield, R.B. (1989) FEBS Lett. 259, 103-106] and shown to have strong antibacterial activity but to be harmless towards erythrocytes. All resonances of the main chain and side chain beta-protons are assigned except for those of the N-terminal lysine. Several medium range NOE connectivities were observed showing two separated alpha-helices, involving residues 4-12 and 16-26. The JNH alpha-coupling constants in these sections support the conclusion. From the exchange rates of the NH protons it is concluded that the alpha-helix of residues 16-26 is much more stable than the other helix. The circular dichroism data indicates about 30% less alpha-helix character than the NMR data. A reduced contribution to the ellipticity from the unstable helix is suggested. The chemical-shift differences between the two parts of the hybrid and the respective parent peptides are larger for the cecropin part than for the melittin part. For the latter, residues 17-26 of the hybrid are proposed to have a secondary structure very similar to that of residues 4-13 of melittin.(ABSTRACT TRUNCATED AT 250 WORDS)