Contrast Enhanced CT Radiogenomics in a Retrospective NSCLC Cohort: Models, Attempted Validation of a Published Model and the Relevance of the Clinical Context

RATIONALE AND OBJECTIVE

To develop a radiogenomic predictive model for non-small cell lung cancer (NSCLC) patients studied through contrast enhanced chest computed tomography (CE-CT) targeting the most frequent gene alterations. M&M: A retrospective study of patients with NSCLC imaged with CE-CT before treatment and had their tumor genomics sequenced at our institution was performed. Data was gathered from their imaging studies, their electronic medical records and a web-based database search (cBioPortal.ca). All of the patient data was tabulated for analysis. Two predictive models (M1 & M2) were created using different approaches and a third model was extracted from the literature to also be tested in our population.

RESULTS

Out of 157 patients, eighty were male (51%) and 124 (79%) had a history of smoking. The three most prevalent genes were KRAS, TP53 and EGFR. The M1 radiomics-only model median AUC were 0.61 (TP53), 0.53 (KRAS) and 0.64 (EGFR) and for M1 radiomics + clinical were 0.61 (TP53), 0.61 (KRAS) and 0.80 (EGFR). The M2 radiomics-only model median AUC were 0.63 (TP53), 0.60 (KRAS) and 0.65 (EGFR) and for M2 radiomics + clinical were 0.64 (TP53), 0.62 (KRAS) and 0.81 (EGFR). The external EGFR radiomic model showed an AUC of 0.69 and 0.86 for the radiomics-only and combined radiomics + clinical respectively.

CONCLUSION

Our study was able to provide robust predictive radiomics model evaluation for the detection of TP53, KRAS and EGFR. We also compared our performance with an already published model and observed how impactful clinical variables can be on models' performance.

CLINICAL RELEVANCE STATEMENT

Identifying tumor mutations in patients that can't undergo biopsy is critical for their outcomes.

KEYPOINTS

• Tumor genomic profiling is critical for treatment selection • CE-CT radiomics produce robust predictive models comparable to those already published • Clinical variables should be considered/included in predictive models.

Qualitative and quantitative performance of ¹⁸F-FDG-PET/MRI versus ¹⁸F-FDG-PET/CT in patients with head and neck cancer

BACKGROUND AND PURPOSE

MR imaging and PET/CT are integrated in the work-up of head and neck cancer patients. The hybrid imaging technology (18)F-FDG-PET/MR imaging combining morphological and functional information might be attractive in this patient population. The aim of the study was to compare whole-body (18)F-FDG-PET/MR imaging and (18)F-FDG-PET/CT in patients with head and neck cancer, both qualitatively in terms of lymph node and distant metastases detection and quantitatively in terms of standardized uptake values measured in (18)F-FDG-avid lesions.

MATERIALS AND METHODS

Fourteen patients with head and neck cancer underwent both whole-body PET/CT and PET/MR imaging after a single injection of (18)F-FDG. Two groups of readers counted the number of lesions on PET/CT and PET/MR imaging scans. A consensus reading was performed in those cases in which the groups disagreed. Quantitative standardized uptake value measurements were performed by placing spheric ROIs over the lesions in 3 different planes. Weighted and unweighted κ statistics, correlation analysis, and the Wilcoxon signed rank test were used for statistical analysis.

RESULTS

κ statistics for the number of head and neck lesion lesions counted (pooled across regions) revealed interreader agreement between groups 1 and 2 of 0.47 and 0.56, respectively. Intrareader agreement was 0.67 and 0.63. The consensus reading provided an intrareader agreement of 0.63. For the presence or absence of metastasis, interreader agreement was 0.85 and 0.70. The consensus reading provided an intrareader agreement of 0.72. The correlations between the maximum standardized uptake value in (18)F-FDG-PET/MR imaging and (18)F-FDG-PET/CT for primary tumors and lymph node and metastatic lesions were very high (Spearman r = 1.00, 0.93, and 0.92, respectively).

CONCLUSIONS

In patients with head and neck cancer, (18)F-FDG-PET/MR imaging and (18)F-FDG-PET/CT provide comparable results in the detection of lymph node and distant metastases. Standardized uptake values derived from (18)F-FDG-PET/MR imaging can be used reliably in this patient population.

Recurrent and metastatic breast cancer PET, PET/CT, PET/MRI: FDG and new biomarkers

Primary breast cancer often displays only moderately increased glucose metabolism resulting in a low sensitivity of positron emission tomography (PET) using [F-18]fluorodeoxyglucose (FDG) in detecting small breast carcinomas, locoregional micrometastases and non-enlarged tumor infiltrated lymphnodes. In contrast, distant breast cancer metastases are generally characterized by significantly increased metabolic activity compared to normal tissue. Therefore, FDG-PET provides accurate diagnostic information as a whole body imaging modality in staging of breast cancer patients. The metabolic information from FDG-PET/CT is often more sensitive than conventional imaging for the detection of distant metastases, particularly in the recurrent setting. FDG-PET is superior in detecting tumor-involved distant lymphnodes, particularly those which are normal in size, as well as in characterizing enlarged lymphnodes as positive or negative for malignancy. Of note, CT is superior in detecting small lung metastases. Although the overall sensitivity for bone scintigraphy and FDG-PET are comparable, bone scintigraphy seems to be superior in the detection of osteoblastic disease whereas FDG-PET is superior for osteolytic metastases, suggesting a complementary role for both imaging procedures. FDG-PET/MR has an evolving role in breast cancer management, for example in the detection of liver metastases and in the research setting for treatment monitoring. The utilization of PET for prediction of treatment response to primary chemotherapy is an area of active research, using FDG as well as other PET biomarkers including [F-18]Fluoroestradiol, [F-18]Fluorothymidine and integrin targeting tracer for monitoring anti-angiogenic therapy.

Erythrocytapheresis with recombinant human erythropoietin in hereditary hemochromatosis therapy: a new alternative

BACKGROUND AND OBJECTIVES

The purposes of this study were to evaluate the tolerance, efficacy and safety of isovolemic erythrocytapheresis (EA) in nonanemic patients with hereditary hemochromatosis (HH), and to assess the usefulness of recombinant human erythropoietin (rHuEPO) associated with EA to reduce treatment duration.

MATERIALS AND METHODS

In 10 asymptomatic patients with serum ferritin >400 microg/l, transferrin saturation >50%, and GPT elevation, EA with rHuEPO and folic acid was performed.

RESULTS

Red cell indices, serum ferritin, and other iron metabolism parameters (serum iron, transferrin, and transferrin saturation); GPT and other laboratory data were considerably improved.

CONCLUSION

This method offers better results in less time than traditional phlebotomy. EA with rHuEPO is an effective therapeutic alternative for patients with HH.

[Allogeneic hematopoietic transplantation with stem cells extracted from peripheral blood]

Fifty three patients (pts) received an allogeneic hematopoietic transplant using peripheral blood progenitor cells (PBPC). Diagnosis were acute myeloid leukemia (AML) in 16 pts, acute lymphoblastic leukemia (ALL) in 15, chronic myeloid leukemia (CML) in first chronic phase in 12, aplastic anemia in 4, myelodysplasia in 3 and Hodgkin's disease, major thalasemia and Hunter's syndrome in one each. Mean age was 20 years-old (2-55), 28 males and 25 females. Conditioning regimens were total body irradiation with 1200 cGy and cyclophosphamide 120 mg/kg in 38 pts, busulfan 16 mg/kg and cyclophosphamide 120 mg/kg in 10 pts, total lymphoid irradiation and cyclophosphamide in 3, 2 pts received other chemotherapy based conditionings. PBPC were infused unmanipulated through a central catheter. Graft versus host disease (GVHD) prophylaxis was cyclosporin and short course methotrexate. Donors were 6/6 HLA compatible siblings in 52 cases and 5/6 match in one case. PBPC mobilization was done with G-CSF at a dose of 10 micrograms/kg/day subcutaneously for four days, pheresis started on day 5. Bone marrow harvest was also done in the first thirty cases. Mean cellularities for CD34, CD3, CD4, CD8, CD56, CD19 (cel x 10(6)/kg) were 4.12; 4.59; 2.57; 1.9; 0.55 and 0.68, respectively. Mean recovery of neutrophils > 500/microL was obtained on day +11 and platelets > 20,000/microL on day +13. Patients were hospitalized for a mean period of 26 days (range 18-39) and days with parenteral antibiotics were 12.2 (5-45). Two pts had venoocclusive disease of the liver. Transplant related mortality was 15%. Acute graft versus host disease (GVHD) was observed in 43.4% of pts, only 5 pts had acute GVHD III or IV. Mean time for aGVHD diagnosis was +23 (8-76). Forty three pts were evaluable for chronic GVHD with a mean follow-up of 18 months (4-39). Chronic GVHD was observed in 26.4% by day +240, only 2 pts developed severe cGVHD. The present experience demonstrates an acceptable incidence for cGVHD; however, taking into account recent reports showing an increase of this complication, it seems reasonable not to perform this procedure for non-malignant diseases in which graft versus malignancy effect is not to be expected.

[Renal vascular lesion and microangiopathic hemolytic anemia in systemic lupus erythematosus]

A 22 year-old woman with a seven year history of (SLE) was readmitted because of oliguria, edema, dyspnea and arterial hypertension. She had a previous biopsy diagnosis of focal glomerulonephritis, (WHO III b), and had been treated with immunosuppressors and steroids. Laboratory data showed lupus activity, AHM with thrombocytopenia, nephrotic-range proteinuria and renal failure. A second renal biopsy was performed showing diffuse proliferative nephritis, (WHO IV), in association with noninflammatory necrotizing vasculopathy with luminal obliteration. She started with hemodialysis and was subsequently treated with methylprednisolone pulses, plasmapheresis, cyclophosphamide and oral steroids. During the inpatient period, she had generalized seizures, acute lung injury and pulmonary hemorrhage. These complications, the AHM and the thrombocytopenia receded totally. Renal function was never resumed. We emphasize that this association of diffuse proliferative nephritis with noninflammatory necrotizing vasculopathy is not infrequent and has a poor renal prognosis. The AHM with thrombocytopenia was interpreted as secondary to endothelial cell damage due to vasculopathy.

[Hepatitis B (HBV) and C (HBC) virus infections in Down's syndrome and in neuropsychiatric patients without Down's syndrome]

Hepatitis B virus (HBV) markers are found with high frequency in immunocompromised individuals. In order to find out if this is also true for the hepatitis C virus (HCV), we have analyzed a group (G.1) of 46 patients (pts.) with Down syndrome, situation known to be associated with immunodepression G. 1. We compared them with a G. of 310 mentally retarded pts. without Down syndrome G. 2 and without evidence of immunological disfunction. All of them were studied for infection with HBV. All pts. in G. 1 and G. 2 were also tested for HCV. The pts. have been hospitalized in a specialized medical institution for mentally retarded on a long term basis and were followed during 1 year. Finally G 3 was composed of 5454 voluntary blood donors.

MATERIAL AND METHODS

In all pts. search for HBV infection markers (anti-HBc, HBsAg, HBeAg by EIA test and HBV-DNA by nucleic acids hybridization) were performed. Search for HCV markers was done by a second generation EIA kit (Abbott Hepatitis C (rDNA) (Antigen).

RESULTS

HBsAg was found to be positive in 12/46 (26%) of G. I and 25/310 (8%) of G. II (p < 0.001). HBeAg was positive in 8/12 (67%) of G. I and in 2/25 (8%) of G. II (p < 0.001). All HBeAg positive pts. had elevated values of DNA-HBV. In G. I, 4/12 (33%) pts. lost HBeAg during the observation period, one of them remained HBV-DNA positive and none become HBsAg negative.(ABSTRACT TRUNCATED AT 250 WORDS)