Radiomics/Radiogenomics in Lung Cancer: Basic Principles and Initial Clinical Results

Simple Summary

Radiogenomics is a promising new approach in cancer assessment, providing an evaluation of the molecular basis of imaging phenotypes after establishing associations between radiological features and molecular features at the genomic–transcriptomic–proteomic level. This review focuses on describing key aspects of radiogenomics while discussing limitations of translatability to the clinic and possible solutions to these challenges, providing the clinician with an up-to-date handbook on how to use this new tool.

Abstract

Lung cancer is the leading cause of cancer-related deaths worldwide, and elucidation of its complicated pathobiology has been traditionally targeted by studies incorporating genomic as well other high-throughput approaches. Recently, a collection of methods used for cancer imaging, supplemented by quantitative aspects leading towards imaging biomarker assessment termed “radiomics”, has introduced a novel dimension in cancer research. Integration of genomics and radiomics approaches, where identifying the biological basis of imaging phenotypes is feasible due to the establishment of associations between molecular features at the genomic–transcriptomic–proteomic level and radiological features, has recently emerged termed radiogenomics. This review article aims to briefly describe the main aspects of radiogenomics, while discussing its basic limitations related to lung cancer clinical applications for clinicians, researchers and patients.

Leiomyoma of the Retzius space in a male patient: A case report and a diagnostic approach to Retzius space diseases

Retzius space is a small anatomical compartment located directly posterior to the pubic symphysis and anterior to the urinary bladder. Diseases developing primarily in this space are rare; only 7 cases of leiomyomas of the Retzius space have been reported in the literature so far, all of them in female patients. We present a unique case of a leiomyoma of the Retzius space in a male patient. An imaging-based diagnostic approach to Retzius space disease is proposed.

Arteriovenous malformation: An unusual cause of rectus sheath hematoma, following laparoscopic cholecystectomy

Rectus sheath hematoma (RSH) is an accumulation of blood in the rectus abdominis muscle sheath, secondary to several conditions which may cause the epigastric vessel rupture or muscular tear, but mostly affecting patients undergoing anticoagulation therapy.We present a rare case of a 67-year-old woman who underwent laparoscopic cholecystectomy and developed RSH on the 12th postoperative day. The patient was under anticoagulation therapy with acenocoumarole due to mitral valve replacement. The bleeding source was an arteriovenous malformation (AVM) rupture as indicated by the angiogram images and it was embolized succefully. The patient was discharged seven days later.

Prediction of successful discectomy using MRI quantitation of dural sac and herniated disc dimensions

OBJECTIVE

To evaluate the ability of magnetic resonance imaging (MRI) quantitation of disc prolapse and dural sac to identify those who would benefit from discectomy.

METHODS

Thirty consecutive patients with disc herniation and leg pain who had MRI of lumbar spine and subsequently underwent discectomy were prospectively enrolled and compared with 30 controls. The anteroposterior (AP) diameter and the cross-sectional area of disc prolapse and of dural sac were measured. The ratios of AP diameters and cross-sectional areas were calculated. The measurements were correlated with the relief of symptoms based on a visual analogue scale assessment preoperatively and 1 week postoperatively.

RESULTS

All patients preoperatively had a pain score of seven or higher (mean +/- SD = 7.9 +/- 0.3) and postoperatively a score of < or = 2(mean +/- SD = 1.1 +/- 0.2). The AP diameter of disc prolapse and the ratio of AP diameters demonstrated the highest sensitivity and specificity: an AP diameter of 3.3 mm was 99% sensitive and specific and a ratio of the AP diameters of 0.37 was 100% sensitive and 99% specific.

CONCLUSION

Quantitative measurements of MRI can improve significantly the ability to identify the patients who would benefit from discectomy.

Hepatic primary and secondary malignancies: comparison of helical CT and helical CT during arterial portography

BACKGROUND/AIMS

To compare the sensitivity of helical CT to that of helical CT arterial portography in the detection of hepatic primary or secondary malignancies, in 20 patients who subsequently underwent surgery to confirm findings.

METHODOLOGY

Twenty patients with suspected primary hepatic or secondary malignancies who all underwent helical CT and helical CT arterial portography preoperatively were prospectively evaluated. All the images were reviewed by two radiologists. The results were subsequently correlated with surgical and pathological findings. The sensitivity and the positive predictive values for lesion detection were determined for each modality.

RESULTS

There were 39 pathologically confirmed hepatic malignant lesions. The overall sensitivity and positive predictive value of helical CT arterial portography were 87.1% and 82.5%, respectively, while of helical CT were 84.6% and 94.2%, respectively.

CONCLUSIONS

Helical CT arterial portography and helical CT of the liver were approximately equivalent for lesion detection in patients who were evaluated preoperatively for resection of liver malignancies. The lower cost and non-invasive nature of helical CT suggest that it should be the preferred modality.

Superselective microcoil embolization of a traumatic pseudoaneurysm of the cavernosal artery

According to the literature, straddle injuries of the perineum may result in arteriosinusoidal fistula and secondary high-flow priapism. We report a case of a 23-year-old man who developed a traumatic pseudoaneurysm of the cavernosal artery, secondary to straddle injury, and presented with painless priapism. It was treated successfully with superselective microcoil embolization and the priapism resolved.

Preoperative embolization of bone metastases from renal cell carcinoma

The purpose of this study was to correlate the effectiveness of preoperative embolization with the blood loss and transfusion requirement during surgery for bone metastases from renal cell carcinoma. Twenty-eight preoperative embolizations in 26 patients with renal cell carcinoma metastatic to bone were retrospectively evaluated and divided into two groups: Group A included the embolizations that resulted in complete devascularization of the lesion as defined by the post-embolization arteriograms, and group B included those with an incomplete result. The two groups were compared with regard to blood loss and transfusion requirement during surgery, by unpaired two-tailed Student's t-test. Where complete embolization was effected (group A, 10 cases), there was a mean blood loss of 535 +/- 390 ml. When a less than complete embolization was achieved (group B, 18 cases), the mean blood loss was 1.247 +/- 1.047 ml (p = 0.049). The red blood cell transfusion in group A was 1.3 +/- 1 units, whereas in group B it was 2.4 +/- 1.2 (p = 0.03). Preoperative embolization of bone metastases from renal cell carcinoma with subsequent complete devascularization leads to significant reduction of blood loss during surgery. Interventional radiologists should pursue and embolize every feeder to the metastasis, because any less than complete devascularization increases the amount of blood loss and the amount of red blood cell transfusion during surgery.

Torsion, necrosis, and inflammation of an epiploic appendix of the large bowel: a diagnostic and therapeutic dilemma

We present the case of a young patient with abdominal pain of 3 weeks' duration and a preoperative presumptive diagnosis of acute appendicitis, diverticulitis, colon perforation, or possibly neoplasm. Even after resection of a large mass involving the right colon, the diagnosis was not confirmed until surgical pathology identified torsion, partial necrosis, and inflammation of an epiploic appendix of the right colon.