Integrative radiomics expression predicts molecular subtypes of primary clear cell renal cell carcinoma

AIM

To identify combined positron-emission tomography (PET)/magnetic resonance imaging (MRI)-based radiomics as a surrogate biomarker of intratumour disease risk for molecular subtype ccA and ccB in patients with primary clear cell renal cell carcinoma (ccRCC).

MATERIALS AND METHODS

PET/MRI data were analysed retrospectively from eight patients. One hundred and sixty-eight radiomics features for each tumour sampling based on the regionally sampled tumours with 23 specimens were extracted. Sparse partial least squares discriminant analysis (SPLS-DA) was applied to feature screening on high-throughput radiomics features and project the selected features to low-dimensional intrinsic latent components as radiomics signatures. In addition, multilevel omics datasets were leveraged to explore the complementing information and elevate the discriminative ability.

RESULTS

The correct classification rate (CCR) for molecular subtype classification by SPLS-DA using only radiomics features was 86.96% with permutation test p=7×10^-4. When multi-omics datasets including mRNA, microvascular density, and clinical parameters from each specimen were combined with radiomics features to refine the model of SPLS-DA, the best CCR was 95.65% with permutation test, p<10^-4; however, even in the case of generating the classification based on transcription features, which is the reference standard, there is roughly 10% classification ambiguity. Thus, this classification level (86.96-95.65%) of the proposed method represents the discriminating level that is consistent with reality.

CONCLUSION

Featured with high accuracy, an integrated multi-omics model of PET/MRI-based radiomics could be the first non-invasive investigation for disease risk stratification and guidance of treatment in patients with primary ccRCC.

Comparison of mid-lobe versus lateral systematic sextant biopsies in the detection of prostate cancer

OBJECTIVE

Systematic sextant biopsies are a powerful tool in the diagnosis of prostate cancer. Interpretation of the histopathologic results of these biopsies plays a central role in treatment decisions. This biopsy approach was originally described as sampling the prostate in the mid-lobe, parasagittal plane at the apex, mid-gland, and base, bilaterally. Morphometric analysis of prostate specimens has revealed that most clinically significant cancers are mainly located in the posterolateral aspect of the gland, not the mid-lobe. We sought to determine if cancer detection could be improved by obtaining more laterally placed biopsies.

MATERIALS AND METHODS

Forty-one patients underwent transrectal ultrasound with mid-lobe sextant as well as lateral sextant biopsies. Biopsy specimens were evaluated for Gleason grade and length of cancer present in each core. The mid-lobe and lateral biopsy results were then compared.

RESULTS

Thirteen of 41 patients (31.7%) were found to have no cancer on either biopsy set. Cancer was detected by both the mid-lobe and the lateral biopsies in 19 patients (46.3%). In 6 patients (14.6%), only the lateral biopsies revealed cancer, and in 3 patients (7.3%), only the mid-lobe biopsies revealed cancer.

CONCLUSIONS

Laterally-placed systematic sextant biopsies may yield an improved diagnosis rate in patients with palpable nodularity in the lateral aspect of the prostate, patients without any palpable abnormalities but with elevated PSA levels, and in those patients undergoing repeat biopsies.