Plasma micoRNA-122 as a predictive marker for treatment response following transarterial chemoembolization in patients with hepatocellular carcinoma.

BACKGROUND AND AIM: Circulating microRNA (miR)-122 has recently been investigated as a potential biomarker of various hepatic diseases, such as chronic hepatitis and hepatocellular carcinoma (HCC). We investigated the association between plasma miR-122 levels and the treatment outcomes following transarterial chemoembolization (TACE) in HCC patients. METHODS: We included 177 HCC patients treated with TACE in the study; TACE refractoriness and liver transplantation-free survival were evaluated during follow up. Pretreatment plasma miR-122 levels were assessed using quantitative real-time polymerase chain reaction. Relative quantification of miR-122 expression (fold change) was determined using the 2(-ΔΔCt) method. MiR-16 was used as an internal control for the normalization of miRNA data. RESULTS: During the mean follow up of 22.4 (range, 1-79) months, 112 (69.5%) patients exhibited TACE refractoriness. Multivariate analyses showed that tumor number (hazard ratio [HR], 2.51; 95% confidence interval [CI], 1.43-4.41; P = 0.001) and tumor size (HR, 2.65; 95% CI, 1.62-4.32; P = 0.000) can independently predict overall TACE refractoriness. High miR-122 expression (> 100) was associated with early TACE refractoriness (within 1 year; HR, 2.77; 95% CI, 1.12-6.86; P = 0.028), together with tumor number (HR, 22.73; 95% CI, 2.74-188.66; P = 0.004) and tumor size (HR, 4.90; 95% CI, 1.99-12.06; P = 0.001). Univariate analyses showed that high miR-122 expression tends to be associated with poor liver transplantation-free survival (HR, 1.42; 95% CI, 0.95-2.11; P = 0.085). However, it was statistically insignificant in multivariate analysis. CONCLUSION: High expression levels of plasma miR-122 are associated with early TACE refractoriness in HCC patients treated with TACE.

Effect of beam profile measurement on arc therapy plan quality assurance: a case study.

We present an example when profile measurement and modeling of an Elekta Agility multileaf collimator (MLC) had a large effect specifically on arc therapy plan quality assurance (QA) results using ArcCheck. ArcCheck absolute dose measurements of these plans were systematically lower than planned by 3-10%. Failing QA results were seen even with unmodulated static and conformal arcs. Furthermore, the effect was found to be dependent on collimator angle, with worse results associated with near-zero collimator angles. In contrast, step-and-shoot QA results were not affected. Changing the beam model to match steeper profile measurements obtained using a different measurement device resolved the problem. This case study demonstrates that conventional gamma index analysis can be sensitive to small profile modeling changes.

Clinical course of partial virological responders under prolonged entecavir monotherapy in patients with chronic hepatitis B.

Studies about long-term entecavir (ETV) therapy for partial virological response (PVR) are lacking. This study aimed to assess the clinical course of PVR patients receiving ETV therapy and analyze the efficacy of tenofovir (TDF). We retrospectively evaluated 130 patients who showed a PVR to ETV. Among these patients, 102 were nucleot(s)ide analogue (NUC)-naïve and 28 were lamivudine (LAM)-experienced. The cumulative rates of VR were 54.1%, 70.8%, and 83.7% for the NUC-naïve group and 37.0%, 42.8%, and 42.8% for the LAM-experienced group after 24, 36, and 48 months of ETV therapy, respectively (P = 0.008). Low HBV DNA level at 12 months (P < 0.001) and absence of a LAM treatment history (P = 0.031) were significant associated factors for VR. In VR prediction at 36 months of ETV therapy in NUC-naïve patients, HBV DNA level <95 IU/ml at 12 months showed a 92.9% sensitivity and a 78.3% specificity (AUROC, 0.909; P < 0.001). ETV resistance did not develop in NUC-naïve patients with HBV DNA levels <95 IU/ml at 12 months. The cumulative probability of VR in patients who switched to or additionally received TDF was 91.3% at 15 months. Prolonged ETV therapy induced a VR without the risk of ETV resistance in NUC-naïve patients with HBV DNA levels <95 IU/ml at 12 months. All patients with LAM-experienced or NUC-naïve with HBV DNA levels ≥95 IU/ml at 12 months should be switched to TDF rescue therapy.

Low serum interleukin-6 levels as a predictive marker of recurrence in patients with hepatitis B virus related hepatocellular carcinoma who underwent curative treatment.

BACKGROUND: We aimed to investigate the use of novel serum biomarkers for predicting the recurrence and survival of patients with hepatitis B virus (HBV)-related early hepatocellular carcinoma (HCC) after hepatic resection or radiofrequency ablation (RFA). METHODS: One hundred and five patients with HBV-related HCC, who fulfilled the Milan criteria without vascular invasion and underwent hepatic resection or RFA, were followed-up for a median duration of 52months. Pretreatment serum concentrations of 16 cytokines including interleukin-6 (IL-6) were measured by using a Luminex 200 system. The measured serum cytokines and several clinical factors were analyzed retrospectively. RESULTS: Univariate analysis showed that patients with lower pretreatment serum levels of IL-10, IL-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α had significantly shorter disease-free survival (DFS) than those with higher levels. Multivariate analysis revealed that a low serum IL-6 level (⩽33.00pg/mL; hazard ratio [HR]=5.39; 95% confidence interval [CI]=1.27-22.93; P=0.022), low platelet count (<100×10(9)/L; HR=2.23; 95% CI=1.28-3.89; P=0.005), and low serum albumin level (⩽3.5g/L; HR=2.26; 95% CI=1.28-3.97; P=0.005) had a negative prognostic impact on DFS. In the analysis for overall survival, a low serum platelet level (<100×10(9)/L; HR=2.80; 95% CI=1.31-5.99; P=0.008) and multiple tumor (⩾2; HR=4.05; 95% CI=1.56-10.48; P=0.004) showed a negative prognostic impact on the overall survival. CONCLUSION: A low serum IL-6 level is, in addition to low platelet count and low serum albumin level, an independent prognostic factor for DFS in patients with HBV-related early HCC who underwent hepatic resection or RFA with curative intention.

Can we predict when to start renal replacement therapy in patients with chronic kidney disease using 6 months of clinical data?

PURPOSE: We aimed to develop a model of chronic kidney disease (CKD) progression for predicting the probability and time to progression from various CKD stages to renal replacement therapy (RRT), using 6 months of clinical data variables routinely measured at healthcare centers. METHODS: Data were derived from the electronic medical records of Ajou University Hospital, Suwon, South Korea from October 1997 to September 2012. We included patients who were diagnosed with CKD (estimated glomerular filtration rate [eGFR] < 60 mL·min-1·1.73 m-2 for ≥ 3 months) and followed up for at least 6 months. The study population was randomly divided into training and test sets. RESULTS: We identified 4,509 patients who met reasonable diagnostic criteria. Patients were randomly divided into 2 groups, and after excluding patients with missing data, the training and test sets included 1,625 and 1,618 patients, respectively. The integral mean was the most powerful explanatory (R2 = 0.404) variable among the 8 modified values. Ten variables (age, sex, diabetes mellitus[DM], polycystic kidney disease[PKD], serum albumin, serum hemoglobin, serum phosphorus, serum potassium, eGFR (calculated by Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]), and urinary protein) were included in the final risk prediction model for CKD stage 3 (R2 = 0.330). Ten variables (age, sex, DM, GN, PKD, serum hemoglobin, serum blood urea nitrogen[BUN], serum calcium, eGFR(calculated by Modification of Diet in Renal Disease[MDRD]), and urinary protein) were included in the final risk prediction model for CKD stage 4 (R2 = 0.386). Four variables (serum hemoglobin, serum BUN, eGFR(calculated by MDRD) and urinary protein) were included in the final risk prediction model for CKD stage 5 (R2 = 0.321). CONCLUSION: We created a prediction model according to CKD stages by using integral means. Based on the results of the Brier score (BS) and Harrel's C statistics, we consider that our model has significant explanatory power to predict the probability and interval time to the initiation of RRT.

The dosimetric impact of the prescription isodose line (IDL) on the quality of robotic stereotactic radiosurgery (SRS) plans.

PURPOSE: There is no consensus on the optimal prescription isodose line (IDL) in CyberKnife (CK) SRS. We designed a strategy to search for optimal CK plans at different levels of IDLs and investigated the dosimetric impact on the quality of CK plans. METHODS AND MATERIALS: The retrospective study consisted of 13 CK patients with 16 brain tumors. The mean volume and size of the tumors was 9.7 ± 10.4 cc and 30.3 ± 10.9 mm, respectively. Four shells were created at distances of 2-3 mm to 60 mm from the target. The constraint dose of the innermost shell (D1) was the primary optimization parameter. For isolated brain tumors, D1 started from the prescription dose and gradually reduced after optimization started over. The optimal plans were reached when the coverage started to degrade and the desired IDL was achieved. For eight tumors abutting an OAR, both the D1 and constraint dose to the OAR were gradually pushed until an optimal plan was reached for the desired IDL. RESULTS: For the isolated tumors, the V5 Gy, V10 Gy, V15 Gy, V20 Gy, and V25 Gy of low IDL (49.6 ± 2.1%) plans were on average 23.6%, 28.6%, 33.8%, 26.2%, and 10.6% lower, respectively, comparing to the high IDL (88.6 ± 1.3%) plans. The Conformality Index (CI) of the low IDL plans outperformed the high IDL plans (mean: 1.15 vs. 1.24), except for a lesion under 0.5 cc. The quality of the middle IDL plans (69.6 ± 1.5%) was close to the low IDL plans. Similar results were observed for tumors abutting an OAR. CONCLUSIONS: Low IDL plans outperformed high IDL plans for all metrics in tumors > 0.5 cc. The lower dose exposure of normal brain tissue and better CI could potentially reduce radiation necrosis while the higher maximum dose could improve local control.

Real patient data based cross verification of kilovoltage and megavoltage CT calibration for proton therapy.

PURPOSE: We propose a methodology to evaluate the stoichiometric calibration method on MVCT against the corresponding kVCT calibration using patient data. METHODS: Stoichiometric calibrations were conducted for a MVCT and a kVCT scanner, respectively. We retrospectively analyzed kVCT and MVCT images of 21 patients by picking small tissue volumes in kVCT images and performing image registration to locate the tissue volumes in corresponding MVCT images. We computed the difference between the mean proton stopping power derived through kVCT and MVCT calibration, taking into account the uncertainties in calibration, imaging, and image registration. RESULTS: kVCT and MVCT calibration curves were in good agreement for soft tissues such as muscle and brain, but showed statistically significant difference (p < 0.05) in stopping power of adipose (2.4 ± 1.7%) and bony structures such as spongiosa, and cranium (-3.2 ± 1.4 and -3.1 ± 2.1%, respectively). CONCLUSION: The MVCT calibration might not agree with the corresponding kVCT calibration for some tissues.

Serum transferrin as a liver fibrosis biomarker in patients with chronic hepatitis B.

BACKGROUND/AIMS: Transferrin and alpha-1 antitrypsin are reportedly associated with liver fibrosis. We evaluated the usefulness of serum transferrin and alpha-1 antitrypsin as new liver fibrosis markers in patients with chronic hepatitis B. METHODS: The study included 293 patients with chronic hepatitis B who underwent a liver biopsy between October 2005 and June 2009, and who had no history of hepatocellular carcinoma. Serum markers and liver fibrosis stages were compared. RESULTS: Univariate analysis revealed that age (P<0.001), serum platelet count (P<0.001), and serum alkaline phosphatase level (P=0.003) differed significantly between the patients with and without liver cirrhosis. Serum transferrin levels were significantly lower in advanced fibrosis than in mild fibrosis in both univariate analysis (P=0.002) and multivariate analysis (P=0.009). In addition, the serum transferrin level was significantly lower in cirrhotic patients than in noncirrhotic patients (P=0.020). However, the serum level of alpha-1 antitrypsin was not significantly associated with liver cirrhosis in patients with chronic hepatitis B. CONCLUSIONS: Serum transferrin could be promising serum marker for predicting advanced liver fibrosis in patients with chronic hepatitis B.

Optimization of heart block in the left-sided whole breast radiation treatments.

PURPOSE: Blocks have been used to protect heart from potential radiation damage in left-sided breast treatments. Since cardiac motion pattern may not be fully captured on conventional 3DCT or 4DCT simulation scans, this study was intended to investigate the optimization of the heart block design taking the cardiac motion into consideration. MATERIALS AND METHODS: Whole breast treatment plans using two opposed tangential fields were designed based on 4DCT simulation images for 10 left-sided breast cancer patients. Using an OBI system equipped to a Varian Linac, beam-eye viewed fluoroscopy images were acquired for each of the treatment beams after patient treatment setup, and the MLC heart blocks were overlaid onto the fluoroscopy images with an in-house software package. A non-rigid image registration and tracking algorithm was utilized to track the cardiac motion on the fluoroscopy images with minimal manual delineation for initialization, and the tracked cardiac motion information was used to optimize the heart block design to minimize the radiation damage to heart while avoiding the over-shielding that may lead to underdosing certain breast tissues. RESULTS: Twenty-three sets of fluoroscopy images were acquired on 23 different days of treatment for the 10 patients. As expected, heart moved under the influences of both respiratory and cardiac motion. It was observed that for 16 out of the 23 treatments, heart moved beyond the planed heart block into treatment fields and MLC had to be adjusted to fully block heart. The adjustment was made for all but one patient. The number of the adjusted MLC leaves ranged from 1 to 16 (mean = 10), and the MLC leaf position adjustment ranged from 2 to 10 mm (mean = 6 mm). The added heart block areas ranged from 3 to 1230 mm(2) (mean = 331 mm(2)). CONCLUSION: In left-sided whole breast radiation treatments, simulation CT (and 4DCT) based heart block design may not provide adequate heart protection for all the treatments. A fluoroscopy-based method has been developed to adaptively optimize the heart MLC block to achieve optimal heart protection.

Etanercept for steroid-refractory acute graft versus host disease following allogeneic hematopoietic stem cell transplantation.

BACKGROUND/AIMS: The treatment for steroid-refractory acute graft versus host disease (GVHD) after allogeneic stem cell transplantation (allo-SCT) needs to be standardized. We report our clinical experience with etanercept for steroid-refractory acute GVHD. METHODS: Eighteen patients who underwent allo-SCT and presented with steroid-refractory acute GVHD at Ajou University Hospital were studied retrospectively. They were given 25 mg of etanercept subcutaneously twice weekly for 4 weeks. The clinical responses were evaluated with regard to the severity of acute GVHD. RESULTS: The median patient age was 43.5 years. Using nonparametric tests, etanercept had a down-grading effect on acute GVHD (p = 0.005), although no patient experienced complete remission. Partial responses were seen in 80%, 17%, and 57% of grade II to IV patients, respectively. Skin and gut GVHD were well controlled with etanercept, whereas hepatic GVHD was not. Four patients died of fatal infections. No factors affecting the clinical outcome of etanercept were identified. CONCLUSIONS: Etanercept has a modest effect on steroid-refractory acute GVHD after allo-SCT, with tolerable side effects.

Dose-painted intensity modulated radiation therapy improves local control for locally advanced pancreas cancer.

Background. To evaluate the outcomes, adverse events, and therapeutic role of Dose-Painted Intensity-Modulated Radiation Therapy (DP-IMRT) for locally advanced pancreas cancer (LAPC). Methods. Patients with LAPC were treated with induction chemotherapy (n = 25) and those without metastasis (n = 20) received DP-IMRT consisting of 45 Gy to Planning Treatment Volume 1 (PTV1) including regional lymph nodes with a concomitant boost to the PTV2 (gross tumor volume + 0.5 cm) to either 50.4 Gy (n = 9) or 54 Gy (n = 11) in 25 fractions. DP-IMRT cases were compared to three-dimensional conformal radiation therapy (3D-CRT) plans to assess the potential relationship of radiation dose to adverse events. Kaplan-Meier and Cox regression analyses were used to calculate survival probabilities. The Fisher exact test and t-test were utilized to investigate potential prognostic factors of toxicity and survival. Results. Median overall and progression-free survivals were 11.6 and 5.9 months, respectively. Local control was 90%. Post-RT CA-19-9 levels following RT were predictive of survival (P = 0.02). Grade 2 and ≥grade 3 GI toxicity were 60% and 20%, respectively. In comparison to 3D-CRT, DP-IMRT plans demonstrated significantly lower V45 values of small bowel (P = 0.0002), stomach (P = 0.007), and mean liver doses (P = 0.001). Conclusions. Dose-escalated DP-IMRT offers improved local control in patients treated with induction chemotherapy for LAPC. Radiation-related morbidity appears reduced with DP-IMRT compared to 3D-CRT techniques, likely due to reduction in RT doses to organs at risk.

Effects of radiation quality and oxygen on clustered DNA lesions and cell death.

Radiation quality and cellular oxygen concentration have a substantial impact on DNA damage, reproductive cell death and, ultimately, the potential efficacy of radiation therapy for the treatment of cancer. To better understand and quantify the effects of radiation quality and oxygen on the induction of clustered DNA lesions, we have now extended the Monte Carlo Damage Simulation (MCDS) to account for reductions in the initial lesion yield arising from enhanced chemical repair of DNA radicals under hypoxic conditions. The kinetic energy range and types of particles considered in the MCDS have also been expanded to include charged particles up to and including (56)Fe ions. The induction of individual and clustered DNA lesions for arbitrary mixtures of different types of radiation can now be directly simulated. For low-linear energy transfer (LET) radiations, cells irradiated under normoxic conditions sustain about 2.9 times as many double-strand breaks (DSBs) as cells irradiated under anoxic conditions. New experiments performed by us demonstrate similar trends in the yields of non-DSB (Fpg and Endo III) clusters in HeLa cells irradiated by γ rays under aerobic and hypoxic conditions. The good agreement among measured and predicted DSBs, Fpg and Endo III cluster yields suggests that, for the first time, it may be possible to determine nucleotide-level maps of the multitude of different types of clustered DNA lesions formed in cells under reduced oxygen conditions. As particle LET increases, the MCDS predicts that the ratio of DSBs formed under normoxic to hypoxic conditions by the same type of radiation decreases monotonically toward unity. However, the relative biological effectiveness (RBE) of higher-LET radiations compared to (60)Co γ rays (0.24 keV/µm) tends to increase with decreasing oxygen concentration. The predicted RBE of a 1 MeV proton (26.9 keV/µm) relative to (60)Co γ rays for DSB induction increases from 1.9 to 2.3 as oxygen concentration decreases from 100% to 0%. For a 12 MeV (12)C ion (681 keV/µm), the 'predicted RBE for DSB induction increases from 3.4 (100% O(2)) to 9.8 (0% O(2)). Estimates of linear-quadratic (LQ) cell survival model parameters (α and ß) are closely correlated to the Monte Carlo-predicted trends in DSB induction for a wide range of particle types, energies and oxygen concentrations. The analysis suggests α is, as a first approximation, proportional to the initial number of DSBs per cell, and ß is proportional to the square of the initial number of DSBs per cell. Although the reported studies provide some evidence supporting the hypothesis that DSBs are a biologically critical form of clustered DNA lesion, the induction of Fpg and Endo III clusters in HeLa cells irradiated by γ rays exhibits similar trends with oxygen concentration. Other types of non-DSB cluster may still play an important role in reproductive cell death. The MCDS captures many of the essential trends in the formation of clustered DNA lesions by ionizing radiation and provides useful information to probe the multiscale effects and interactions of ionizing radiation in cells and tissues. Information from Monte Carlo simulations of cluster induction may also prove useful for efforts to better exploit radiation quality and reduce the impact of tumor hypoxia in proton and carbon-ion radiation therapy.