Quantitative analysis in peritumoral volumes of brain metastases treated with stereotactic radiotherapy

Distinguishment between high-grade gliomas and solitary brain metastases in peritumoural oedema: quantitative analysis using synthetic MRI at 3 T

AIM

To investigate the efficacy of synthetic magnetic resonance imaging (MRI) in distinguishing high-grade gliomas (HGGs) from solitary brain metastases (SBMs) in peritumoural oedema.

MATERIALS AND METHODS

Thirty-five patients with HGGs and 25 patients with SBMs were recruited and scanned using synthetic MRI using a 3 T scanner. Two radiologists measured synthetic MRI-derived relaxation values independently (T1, T2, proton density [PD]) in the peritumoural oedema, which was used to generate quantitative metrics before (T1native, T2native, and PDnative) and after (T1post, T2post, and PDpost) contrast agent injection. Student's t-test or the Mann-Whitney U-test was performed to detect statistically significant differences in the aforementioned metrics in peritumoural oedema between HGGs and SBMs. The receiver operating characteristic (ROC) curves were plotted to evaluate the efficacy of each metric in distinguishing the two groups, and the areas under the curves (AUCs) were compared pairwise by performing the Delong test.

RESULTS

The mean T1native, T2native, and T1post values in the peritumoural oedema of HGGs were significantly lower compared with SBMs (all p<0.05). The T1post value had a higher AUC (0.843) in differentiating HGGs and SBMs than all other individual metrics (all p<0.05). The combined T1native, T2native, and T1post model had the best distinguishing performance with an AUC, sensitivity, and specificity of 0.987, 94.3%, and 100%, respectively.

CONCLUSIONS

Synthetic MRI may be a potential supplement to the preoperative diagnosis of HGGs and SBMs in clinical practice, as the synthetic MRI-derived tri-parametric model in the peritumoural oedema showed significantly improved diagnostic performance in distinguishing HGGs from SBMs.

Neurocognitive impairment following proton therapy for paediatric brain tumour: a systematic review of post-therapy assessments

BACKGROUND

Proton therapy (PT), frequently utilised to treat paediatric brain tumour (PBT) patients, eliminates exit dose and minimises dose to healthy tissues that theoretically can mitigate treatment-related effects including cognitive deficits. As clinical outcome data are emerging, we aimed to systematically review current evidence of cognitive changes following PT of PBT.

MATERIALS AND METHODS

We searched PubMed and Scopus electronic databases to identify eligible reports on cognitive changes following PT of PBT according to PRISMA guidelines. Reports were extracted for information on demographics and cognitive outcomes. Then, they were systematically reviewed based on three themes: (1) comparison with photon therapy, (2) comparison with baseline cognitive measures, to population normative mean or radiotherapy-naïve PBT patients and (3) effects of dose distribution to cognition.

RESULTS

Thirteen reports (median size (range): 70 (12-144)) were included. Four reports compared the cognitive outcome between PBT patients treated with proton to photon therapy and nine compared with baseline/normative mean/radiotherapy naïve from which two reported the effects of dose distribution. Reports found significantly poorer cognitive outcome among patients treated with photon therapy compared with proton therapy especially in general cognition and working memory. Craniospinal irradiation (CSI) was consistently associated with poorer cognitive outcome while focal therapy was associated with minor cognitive change/difference. In limited reports available, higher doses to the hippocampus and temporal lobes were implicated to larger cognitive change.

CONCLUSION

Available evidence suggests that PT causes less cognitive deficits compared with photon therapy. Children who underwent focal therapy with proton were consistently shown to have low risk of cognitive deficit suggesting the need for future studies to separate them from CSI. Evidence on the effect of dose distribution to cognition in PT is yet to mature.

Based on arterial spin labeling helps to differentiate high-grade gliomas from brain solitary metastasis: A systematic review and meta-analysis

BACKGROUND

We first introduced this meta-analysis was to assess the accuracy of arterial spin labeling (ASL) in the differentiating high-grade gliomas (HGG) from brain solitary metastases (BSM).

METHODS

The PubMed, Web of Knowledge, and Cochrane Libraries and China National Knowledge Infrastructure databases were searched up to August 31, 2018. The pooled weighted sensitivity and specificity, summary receiver operating characteristic curve (SROC), sensitivity analysis, and threshold effect analysis were performed on Stata version 12.0 and Meta-Disc version 1.4. Deeks' funnel plot asymmetry test was performed to assess publication bias.

RESULTS

Of 5 eligible articles, of the 346 lesions from 346 patients, 274 were HGG, and 72 were BSM. The forest pooled sensitivity of 0.88 (95% confidence interval [CI]: 0.65, 0.96) and specificity of 0.85 (95% CI: 0.74, 0.92) of ASL were reported in this meta-analysis. The pooled area under the curve of SROC was 0.92 (95% CI: 0.89, 0.94). Sensitivity analysis demonstrated that the pooled estimates were reliable. No evident publication bias was obtained (P = .38).

CONCLUSION

The parameters derived from ASL with high accuracy in differentiating HGG from BSM. However, results must be interpreted with caution due to the small sample size considered. Large sample prospective studies were necessary to assess and confirm its clinical value.