Impact of deep learning image reconstruction on volumetric accuracy and image quality of pulmonary nodules with different morphologies in low-dose CT.

BACKGROUND: This study systematically compares the impact of innovative deep learning image reconstruction (DLIR, TrueFidelity) to conventionally used iterative reconstruction (IR) on nodule volumetry and subjective image quality (IQ) at highly reduced radiation doses. This is essential in the context of low-dose CT lung cancer screening where accurate volumetry and characterization of pulmonary nodules in repeated CT scanning are indispensable. MATERIALS AND METHODS: A standardized CT dataset was established using an anthropomorphic chest phantom (Lungman, Kyoto Kaguku Inc., Kyoto, Japan) containing a set of 3D-printed lung nodules including six diameters (4 to 9 mm) and three morphology classes (lobular, spiculated, smooth), with an established ground truth. Images were acquired at varying radiation doses (6.04, 3.03, 1.54, 0.77, 0.41 and 0.20 mGy) and reconstructed with combinations of reconstruction kernels (soft and hard kernel) and reconstruction algorithms (ASIR-V and DLIR at low, medium and high strength). Semi-automatic volumetry measurements and subjective image quality scores recorded by five radiologists were analyzed with multiple linear regression and mixed-effect ordinal logistic regression models. RESULTS: Volumetric errors of nodules imaged with DLIR are up to 50% lower compared to ASIR-V, especially at radiation doses below 1 mGy and when reconstructed with a hard kernel. Also, across all nodule diameters and morphologies, volumetric errors are commonly lower with DLIR. Furthermore, DLIR renders higher subjective IQ, especially at the sub-mGy doses. Radiologists were up to nine times more likely to score the highest IQ-score to these images compared to those reconstructed with ASIR-V. Lung nodules with irregular margins and small diameters also had an increased likelihood (up to five times more likely) to be ascribed the best IQ scores when reconstructed with DLIR. CONCLUSION: We observed that DLIR performs as good as or even outperforms conventionally used reconstruction algorithms in terms of volumetric accuracy and subjective IQ of nodules in an anthropomorphic chest phantom. As such, DLIR potentially allows to lower the radiation dose to participants of lung cancer screening without compromising accurate measurement and characterization of lung nodules.

Assisting walking balance using a bio-inspired exoskeleton controller.

BACKGROUND: Balance control is important for mobility, yet exoskeleton research has mainly focused on improving metabolic energy efficiency. Here we present a biomimetic exoskeleton controller that supports walking balance and reduces muscle activity. METHODS: Humans restore balance after a perturbation by adjusting activity of the muscles actuating the ankle in proportion to deviations from steady-state center of mass kinematics. We designed a controller that mimics the neural control of steady-state walking and the balance recovery responses to perturbations. This controller uses both feedback from ankle kinematics in accordance with an existing model and feedback from the center of mass velocity. Control parameters were estimated by fitting the experimental relation between kinematics and ankle moments observed in humans that were walking while being perturbed by push and pull perturbations. This identified model was implemented on a bilateral ankle exoskeleton. RESULTS: Across twelve subjects, exoskeleton support reduced calf muscle activity in steady-state walking by 19% with respect to a minimal impedance controller (p < 0.001). Proportional feedback of the center of mass velocity improved balance support after perturbation. Muscle activity is reduced in response to push and pull perturbations by 10% (p = 0.006) and 16% (p < 0.001) and center of mass deviations by 9% (p = 0.026) and 18% (p = 0.002) with respect to the same controller without center of mass feedback. CONCLUSION: Our control approach implemented on bilateral ankle exoskeletons can thus effectively support steady-state walking and balance control and therefore has the potential to improve mobility in balance-impaired individuals.

Treatment options for metastatic colorectal cancer in patients with liver dysfunction due to malignancy.

BACKGROUND: The survival of colorectal cancer patients is frequently determined by the extent of metastatic invasion to the liver; in cases of major involvement, therapeutic strategies are limited because the liver is necessary for drug metabolism. MATERIAL AND METHODS: We have reviewed articles about the pharmacokinetic profiles of each drug used in colorectal cancer patients with hepatic dysfunction to determine which of these treatments are most feasible. RESULTS: Some drugs appear to be feasible options for patients with hepatic insufficiency. Agents such as 5-fluorouracil and oxaliplatin, as well as monoclonal antibodies such as bevacizumab, cetuximab, and panitumumab, can potentially be used in these cases. On the other hand, irinotecan and regorafenib cannot be recommended because of the risk of increased toxicity. CONCLUSION: Treatment of patients with colorectal cancer and liver dysfunction represents a major challenge because the prognosis is usually very poor and alteration of liver function is normally an exclusion criterion in clinical trials. In this review, we present evidence regarding the use of each drug in patients with colorectal cancer and hepatic impairment.

A systematic review of the predictive value of 18F-fluoro-2-deoxyglucose positron emission tomography on survival in locally advanced rectal cancer after neoadjuvant chemoradiation.

AIM: Treatment of locally advanced rectal cancer (LARC) includes preoperative radiation therapy with or without chemotherapy followed by radical surgery, but the clinical outcome is uncertain. A systemic review was carried out to determine the predictive value of (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)FDG-PET) for assessing disease-free (DFS) and overall survival (OS) in LARC. METHOD: A literature search (PubMed/MEDLINE, EMBASE, Cochrane) up to January 2012 to identify full papers with sequential (18)FDG-PET and survival data, using indexing terms and free text words. The inclusion criteria were: a study of at least 10 patients, having sequential (18)FDG-PET imaging before and after adjuvant chemoradiation and a minimal follow-up of 24 months. Studies were selected by two of the authors. A meta-analysis was performed for DFS and OS using the hazard ratio (HR) as the primary outcome. RESULTS: Five eligible studies were identified including 330 patients (mean age 63 years, 64% men), in which PET-CT or PET imaging was used. The American Joint Committee on Cancer stage distribution was as follows: Stage I, 2%; Stage II, 44%; Stage III, 52%; Stage IV, 1%. The pooled HRs for complete metabolic response versus partial or no response were 0.39 (95% CI 0.18-0.86; P = 0.02) for OS and 0.70 (95% CI 0.16-3.14; P = 0.64) for DFS. The lack of significance for DFS might be explained by different follow-up characteristics. There was also clinical heterogeneity among the different studies. CONCLUSION: This systematic review indicates that complete metabolic response on sequential (18)FDG-PET data after preoperative chemoradiation of LARC is predictive of OS, but not of DFS.

Potential interactions with anticancer agents: a cross-sectional study.

BACKGROUND: Patients with cancer are particularly susceptible to drug interactions (DIs), but the extent of the problem has received limited attention. We aimed to evaluate the frequency of interactions with anticancer agents in a group of cancer patients. METHODS: The study was performed in a Belgian teaching hospital. One hundred and twenty-two patients with solid malignancies were included. A comprehensive drug history was performed by a clinical pharmacist. Three renowned DI compendia were used to identify DIs. RESULTS: Forty-one potential interactions involving an anticancer agent and considered to be clinically significant were identified among 25% of patients. The anticancer drugs mostly involved were cisplatin and methotrexate, and the most frequent co-medications involved were vitamin K antagonists, proton pump inhibitors and diuretics. In the majority of cases, the potential adverse consequence was increased toxicity of the anticancer agent and/or of the co-medication. Less than 10% of DIs were identified by the three compendia. CONCLUSIONS: Preventive measures should be taken to avoid increased toxicity or decreased efficacy of the drugs. Most of the time, this simply involves surveillance of biological or clinical parameters. Collaboration with a clinical pharmacist may be useful for the prescribing physician.

Docetaxel combined with irinotecan or 5-fluorouracil in patients with advanced oesophago-gastric cancer: a randomised phase II study.

BACKGROUND: Docetaxel and irinotecan chemotherapy have shown good efficacy in the treatment of advanced oesophago-gastric cancer. This randomised phase II study evaluated the efficacy and toxicity profile of two non-platinum docetaxel-based doublet regimens in advanced oesophago-gastric cancer. METHODS: Chemotherapy-naïve patients with advanced oesophago-gastric cancer were randomised to receive either 3-weekly DI (docetaxel 60 mg m(-2) plus irinotecan 250 mg m(-2) (Day 1)) or 3-weekly DF (docetaxel 85 mg m(-2) (Day 1) followed by 5-fluorouracil 750 mg m(-2) per day as a continuous infusion (Days 1-5)). RESULTS: A total of 85 patients received DI (n=42) or DF (n=43). The primary endpoint was overall response rate (ORR). The ORR and time to progression (TTP) in the evaluable population (n=65) were 37.5% (DI) vs 33.3% (DF), and 4.2 months vs 4.4 months, respectively. In the intent-to-treat population, the observed ORR, TTP and median overall survival were similar between the two groups. Grade 3-4 neutropenia, febrile neutropenia and diarrhoea were more frequent in the DI arm as compared with the DF arm (83.3% vs 69.8%, 40.5% vs 18.6%, and 42.9% vs 16.3%, respectively). CONCLUSION: Both docetaxel-based doublet regimens show comparable efficacy; however, the DF regimen was associated with a better toxicity profile and is an alternative treatment option for patients in whom platinum-based regimens are unsuitable.

Phase II study of everolimus in patients with locally advanced or metastatic transitional cell carcinoma of the urothelial tract: clinical activity, molecular response, and biomarkers.

BACKGROUND: This phase II study assessed the safety and efficacy of everolimus, an oral mammalian target of rapamycin inhibitor in advanced transitional carcinoma cell (TCC) after failure of platinum-based therapy. PATIENTS AND METHODS: Thirty-seven patients with advanced TCC received everolimus 10 mg/day until progressive disease (PD) or unacceptable toxicity. The primary end point was the disease control rate (DCR), defined as either stable disease (SD), partial response (PR), or complete response at 8 weeks. Angiogenesis-related proteins were detected in plasma and changes during everolimus treatment were analyzed. PTEN expression and PIK3CA mutations were correlated to disease control. RESULTS: Two confirmed PR and eight SD were observed, resulting in a DCR of 27% at 8 weeks. Everolimus was well tolerated. Compared with patients with noncontrolled disease, we observed in patients with controlled disease a significant higher baseline level of angiopoietin-1 and a significant early plasma decrease in angiopoietin-1, endoglin, and platelet-derived growth factor-AB. PTEN loss was observed only in patients with PD. CONCLUSIONS: Everolimus showed clinical activity in advanced TCC. The profile of the plasma angiogenesis-related proteins suggested a role of the everolimus antiangiogenic properties in disease control. PTEN loss might be associated with everolimus resistance.

Stratified phase II trial of cetuximab in patients with recurrent high-grade glioma.

BACKGROUND: To evaluate the antitumor activity and toxicity of single-agent cetuximab in patients with recurrent high-grade glioma (HGG) after failure of surgery, radiation therapy, and chemotherapy. PATIENTS AND METHODS: In this two-arm, open-label, phase II study patients were stratified according to their epidermal growth factor receptor (EGFR) gene amplification status. Cetuximab was administered intravenously at a dose of 400 mg/m(2) on week 1 followed by weekly dose of 250 mg/m(2). The primary end point for this study was the response rate in both study arms separately. RESULTS: Fifty-five eligible patients (28 with and 27 without EGFR amplification) tolerated cetuximab well. Three patients (5.5%) had a partial response and 16 patients (29.6%) had stable disease. The median time to progression was 1.9 months [95% confidence interval (CI) 1.6-2.2 months]. Whereas the progression-free survival (PFS) was <6 months in the majority (n = 50/55) of patients, five patients (9.2%) had a PFS on cetuximab of >9 months. Median overall survival was 5.0 months (95% CI 4.2-5.9 months). No significant correlation was found between response, survival and EGFR amplification. CONCLUSIONS: Cetuximab was well tolerated but had limited activity in this patient population with progressive HGG. A minority of patients may derive a more durable benefit but were not prospectively identified by EGFR gene copy number.

MGMT promoter hypermethylation correlates with a survival benefit from temozolomide in patients with recurrent anaplastic astrocytoma but not glioblastoma.

AIMS: To investigate the correlation between O(6)-methylguanine-DNA-methyltransferase (MGMT) promoter methylation and benefit from temozolomide in patients with recurrent high-grade glioma. PATIENTS AND METHODS: A real-time, quantitative, methylation-specific PCR assay was performed on archival tissue blocks from patients treated with temozolomide at the first recurrence. RESULTS: A subgroup of 38 patients who were chemotherapy-naive at recurrence was analysed (22 glioblastoma, 12 anaplastic astrocytoma [AA] and 4 anaplastic oligoastrocytoma [AOA]); none had 1p/19q loss. Among 10 (26%) patients with a hypermethylated MGMT promoter, none experienced disease progression within the first two treatment cycles compared with 12 of 28 (43%) patients with an unmethylated promoter (p=0.016). By Cox multivariate analysis, tumour grade and MGMT promoter methylation correlated with time to progression (p<0.05); MGMT promoter methylation correlated with superior overall survival in AA/AOA but not in glioblastoma. CONCLUSIONS: MGMT promoter methylation predicted a survival benefit in patients with 1p/19q intact AA/AOA treated with temozolomide at recurrence.

Agrobacterium radiobacter bacteremia in oncologic and geriatric patients: presentation of two cases and review of the literature.

INTRODUCTION: We report here two cases of Agrobacterium radiobacter bacteremia. These cases were observed at the same institution over a short time period (3 months). CASE REPORTS: The first patient was a female cancer patient receiving third-line chemotherapy for ovarian carcinoma. When she developed bacteremia, she was neutropenic and had an indwelling catheter that was removed as part of the treatment. The second case was a geriatric patient admitted from home with bacteremia, clinical signs of septic shock, and concomitant acute cholecystitis. OUTCOME: Both patients responded promptly and completely to antibiotherapy. No recurrence was observed.

Ovarian cancer associated with carcinomatous meningitis: a case report and review of the literature.

We report the case of a 62-year-old patient who developed a carcinomatous meningitis while on second-line chemotherapy for ovarian cancer. Cytologic analyses confirmed that carcinomatous cells of ovarian origin were present in cerebrospinal fluid. Carcinomatous meningitis is a very rare event in the natural history of ovarian carcinoma. We discuss the specificity of our case in the light of the literature. In addition, we present some relevant radiologic and pathologic documents illustrating this rare entity.

Saccharomyces cerevisiae fungemia in a head and neck cancer patient: a case report and review of the literature.

We report the case of a 65-year old male who developed Saccharomyces cerevisiae fungemia after completing a course of concomitant chemotherapy and radiation therapy for head and neck carcinoma. He had grade IV oral mucositis, and received Saccharomyces boulardii (Perenterol) orally as treatment for aseptic diarrhoea just before the onset of fungemia. We discuss the epidemiology and pathology of Saccharomyces cerevisiae in the cancer patient population.

Influence of timing of administration of 5-fluorouracil to donors on bone marrow engraftment in nonmyeloablated hosts.

We evaluated the engraftment and the cell cycle status of marrow cells at various times after 5-fluorouracil (5-FU) administration. 5-FU (150 mg/kg) was given to donor male BALB/c mice at 1, 2, 6, or 12 days prior to marrow harvest. The donor cells were then assessed in host nonmyeloablated female mice. Bone marrow engraftment of marrow treated with 5-FU was evaluated and compared to marrow treated with diluent (phosphate-buffered saline) at 3 and 10 weeks after marrow infusion. Our data show a rapid induction of an engraftment defect 1 day after 5-FU, persistence of this defect through day 6, and a recovery by day 12. Experiments using hydroxyurea (which selectively kills cells in the S phase) to determine the cell cycle status indicated that cells that engrafted in post-5-FU marrow were noncycling at days 1, 2, and 12 but cycling at day 6. Post-5-FU bone marrow was also analyzed in vitro by colony assays and its cycling status determined by 3H-thymidine suicide assay. High-proliferative-potential colony-forming cells (HPP-CFCs) and low-proliferative-potential colony-forming cells (LPP-CFCs) decreased rapidly 1 day after 5-FU, with a nadir observed at day 6 for HPP-CFCs and day 2 for LPP-CFCs. By day 12, LPP-CFCs showed a total recovery, but HPP-CFCs were still defective. Significant numbers of HPP-CFCs were cycling, mostly at days 6 and 8 after 5-FU, whereas LPP-CFCs appeared quiescent except at day 2. These results emphasize the importance of timing if post-5-FU marrow is used for gene therapy or marrow transplantation.

Stem cell engraftment strategies.

The donor stem cell phenotype and host microenvironment determine the outcome of a stem cell transplant. In a series of transplant studies in syngeneic male to female or congenic Ly5.1/Ly5.2 models in which hosts have received no or minimal irradiation (100 cGy), evidence overwhelmingly supports the concept that syngeneic engraftment is determined by stem cell competition. These approaches can be extended to H-2 mismatched allogeneic mouse combination when antigen pre-exposure and CD40-CD40 ligand antibody blockage are employed. A human trial in patients with resistant neoplasia infusing pheresed blood with 10(8) CD3 cells/kg showed that tumor responses and complete chimerism occur with very low levels of CD34+ cells/kg and that the extent of previous treatment is a critical factor in determining chimerism. A major feature of transplants is the phenotype of the donor stem cell. This phenotype shows dramatic reversible plasticity involving differentiation, adhesion protein expression, and engraftment with cytokine-induced cell-cycle transit. Homing is probably also plastic. Marked fluctuations in engraftment capacity are also seen at different points in marrow circadian rhythm.

Clearance kinetics of CD34+ cells from peripheral blood: an independent predictor of hematologic recovery after high-dose chemotherapy and hematopoietic stem cell transplantation.

We measured the concentration of CD34+ cells in peripheral blood (PB) (1/2) h prior to and (1/2), 1, 3, 6, and 12 h following hematopoietic stem cell (HSC) infusion in 34 breast cancer patients treated with high-dose chemotherapy (HDC). The decrease in these concentrations over time enabled us to determine the clearance kinetics of CD34+ cells from PB. The absolute number of CD34+ cells in PB generally peaked at (1/2) h after infusion, then rapidly declined from 1 to 3 h post infusion and continued to fall until 12 h post transplant, but more slowly. In univariate analysis, CD34+cells/kg infused, CFU-GM/kg infused, the CD34+ count at (1/2) h, and the 12-h clearance of CD34+ cells from PB were predictors of hematologic recovery, as were each of the two phases of clearance when the slope was divided into rapid and slow phases (from (1/2) to 3 and from 3 to 12 h post transplant, respectively). We then stratified our population by the number of CD34+ cells/kg infused. In group 1, patients received 7.5 x 10(6) CD34+ cells/kg. After adjusting for CD34+ cells injected, age, and purged or unpurged graft in multivariate analysis, the 12 h clearance remained a predictor of hematologic recovery in group 1. In addition, the second phase of clearance (from 3 to 12 h after infusion) was an even better predictor than the 12 h clearance. In group 2, however, no statistically significant correlation was observed, even with the number of HSC injected. Results suggest that rapidity of clearance of CD34+cells from PB is an independent indicator of hematologic recovery in patients receiving lower doses of CD34+ cells. When the cell dose injected is over a threshold, PB clearance correlations with hematologic recovery are masked.

The administration of 10 microg/kg granulocyte colony-stimulating factor (G-CSF) alone results in a successful peripheral blood stem cell collection when previous mobilization with chemotherapy and hematopoietic growth factor failed.

Some heavily pretreated cancer patients fail to mobilize enough peripheral blood stem cells (PBSC) after stimulation with chemotherapy and hematopoietic growth factors. For these patients the best way to obtain an adequate PBSC collection is unknown. Here we report 6 heavily pretreated cancer patients who failed to mobilize sufficient PBSC after stimulation with chemotherapy and G-CSF 5 microg/kg/day. In these cases, we used G-CSF 10 microg/kg/day alone for six days at least 3 weeks after the last chemotherapy. After three consecutive leukaphereses starting on day 5, five patients had adequate PBSC collections. With 6 days of G-CSF 10 microg/kg/day alone, 2.8 x 10(6) (+/- 1) CD34+ cells/kg were collected. This was significantly higher than the number of CD34+ cells/kg collected after chemotherapy and G-CSF 5 microg/kg 0.3 x 10(6) (+/- 0.1) [P = 0.05]. Four patients received high-dose chemotherapy with PBSC support. Hematologic recovery observed in these patients was as expected. In conclusion, G-CSF 10 microg/kg alone can mobilize progenitor cells into peripheral blood when previous mobilization with chemotherapy and G-CSF 5 microg/kg fails.

[Efficiency of high-dose FEC chemotherapy for the mobilization of hematopoietic stem cells into peripheral blood]. / Efficacité d'une chimiothérapie FEC à forte dose pour la mobilisation des cellules souches hématopoïétiques dans le sang périphérique.

The best regimen for mobilizing hematopoietic stem cells (HSC) into peripheral blood is not yet defined. The efficiency of FEC chemotherapy in the treatment of breast cancer is well established and the effects of FEC on HSC mobilization have been characterized. We tested the feasibility and the toxicity of a high-dose FEC regimen which may improve the mobilizing capacity of conventional FEC. Twenty patients with poor prognosis breast cancer received high-dose FEC and filgrastim 5 micrograms/kg. Three leukaphereses were performed on each patient for 3 consecutive days. Total numbers of CFU-GM and CD34+ cells were assessed, and a retrospective analysis was made. The numbers of CFU-GM/kg and CD34+ cells/kg collected (mean +/- standard error) were respectively 12.2 x 10(5) (+/- 2.4) and 14.6 x 10(6) (+/- 2.5). Extra-hematologic toxicity was negligible. Hematologic recovery after CTCb high-dose chemotherapy and HSC infusion was rapid. High-dose FEC is efficient for collecting HSC in peripheral blood. Extra-hematologic toxicity is weak and hematologic recovery after autograft is normal. Increased dosage of epirubicin and cyclophosphamide could allow a single leukapheresis collection of sufficient HSC from peripheral blood.

Quantification of CD34+ cells mobilized into the peripheral blood predicts the yield of the leukapheresis product and can replace progenitor assays.

We reviewed 333 concomitant blood and cytapheresis samples from 101 patients with solid malignancies of various histological cell types. All samples were analyzed for CFU-GM, BFU-E and CD34+ determination. We found a good correlation between progenitor assays CFU-GM and CD34+ determination in the blood and cytapheresis (r = 0.77, p < 0.0001 and r = 0.79, p < 0.0001 respectively). The number of CD34+ cells in the peripheral blood was predictive of the CD34+ yield in the cytapheresis (r = 0.86, p < 0.0001), and we determined that a threshold of 26 CD34+/microliter of blood was sufficient to harvest 10(6) CD34+/kg in a single apheresis. Thirty breast cancer patients received injections of peripheral blood stem cells after the same high-dose chemotherapy. For these patients, we found a significant correlation between the quantity of CD34+ cells or CFU-GM collected and both granulocyte and platelet recovery. In conclusion, there is a very good correlation between CFU-GM assays and CD34+ determination and a good correlation between circulating CD34+ cells and the yield obtained by the cytapheresis. The number of CD34+ cells collected is also significantly correlated with hematological recovery. Because CD34+ quantification is an accurate, fast and inexpensive technique, this can lead to the progressive forsaking of progenitor assays in a clinical setting.