78 research outputs found
Selection of head and neck cancer patients for adaptive radiotherapy to decrease xerostomia
AbstractBackground and purposeThe aim of this study was to develop and validate a method to select head and neck cancer patients for adaptive radiotherapy (ART) pre-treatment. Potential pre-treatment selection criteria presented in recent literature were included in the analysis.Materials and methodsDeviations from the planned parotid gland mean dose (PG ΔDmean) were estimated for 113 head and neck cancer patients by re-calculating plans on repeat CT scans. Uni- and multivariable linear regression analyses were performed to select pre-treatment parameters, and ROC curve analysis was used to determine cut off values, for selecting patients with a PG dose deviation larger than 3Gy. The patient selection method was validated in a second patient cohort of 43 patients.ResultsAfter multivariable analysis, the planned PG Dmean remained the only significant parameter for PG ΔDmean. A sensitivity of 91% and 80% could be obtained using a threshold of PG Dmean of 22.2Gy, for the development and validation cohorts, respectively. This would spare 38% (development cohort) and 24% (validation cohort) of patients from the labour-intensive ART procedure.ConclusionsThe presented method to select patients for ART pre-treatment reduces the labour of ART, contributing to a more effective allocation of the department resources
Differences in delineation guidelines for head and neck cancer result in inconsistent reported dose and corresponding NTCP
AbstractPurposeTo test the hypothesis that delineation of swallowing organs at risk (SWOARs) based on different guidelines results in differences in dose–volume parameters and subsequent normal tissue complication probability (NTCP) values for dysphagia-related endpoints.Materials and methodsNine different SWOARs were delineated according to five different delineation guidelines in 29 patients. Reference delineation was performed according to the guidelines and NTCP-models of Christianen et al. Concordance Index (CI), dosimetric consequences, as well as differences in the subsequent NTCPs were calculated.ResultsThe median CI of the different delineation guidelines with the reference guidelines was 0.54 for the pharyngeal constrictor muscles, 0.56 for the laryngeal structures and 0.07 for the cricopharyngeal muscle and esophageal inlet muscle. The average difference in mean dose to the SWOARs between the guidelines with the largest difference (maxΔD) was 3.5±3.2Gy. A mean ΔNTCP of 2.3±2.7% was found. For two patients, ΔNTCP exceeded 10%.ConclusionsThe majority of the patients showed little differences in NTCPs between the different delineation guidelines. However, large NTCP differences >10% were found in 7% of the patients. For correct use of NTCP models in individual patients, uniform delineation guidelines are of great importance
Changes in anti-viral effectiveness of interferon after dose reduction in chronic hepatitis c patients: a case control study
BACKGROUND: High dose interferon induction treatment of hepatitis C viral infection blocks viral production over 95%. Since dose reduction is often performed due to clinical considerations, the effect of dose reduction on hepatitis C virus kinetics was studied. METHODS: A new model that allowed longitudinal changes in the parameters of viral dynamics was used in a group of genotype-1 patients (N = 15) with dose reduction from 10 to 3 million units of interferon daily in combination with ribavirin, in comparison to a control group (N = 9) with no dose reduction. RESULTS: Dose reduction gave rise to a complex viral kinetic pattern, which could be only explained by a decrease in interferon effectiveness in blocking virion production. The benefit of the rapid initial viral decline following the high induction dose is lost after dose reduction. In addition, in some patients also the second phase viral decline slope, which is highly predictive of success of treatment, was impaired by the dose reduction resulting in smaller percentage of viral clearance in the dose reduction group. CONCLUSIONS: These findings, while explaining the failure of many induction schedules, suggest that for genotype-1 patients induction therapy should be continued till HCVRNA negativity in serum in order to increase the sustained response rate for chronic hepatitis C
Driving pressure during general anesthesia for open abdominal surgery (DESIGNATION) : study protocol of a randomized clinical trial
Background
Intraoperative driving pressure (Delta P) is associated with development of postoperative pulmonary complications (PPC). When tidal volume (V-T) is kept constant, Delta P may change according to positive end-expiratory pressure (PEEP)-induced changes in lung aeration. Delta P may decrease if PEEP leads to a recruitment of collapsed lung tissue but will increase if PEEP mainly causes pulmonary overdistension. This study tests the hypothesis that individualized high PEEP, when compared to fixed low PEEP, protects against PPC in patients undergoing open abdominal surgery.
Methods
The "Driving prESsure durIng GeNeral AnesThesIa for Open abdomiNal surgery trial" (DESIGNATION) is an international, multicenter, two-group, double-blind randomized clinical superiority trial. A total of 1468 patients will be randomly assigned to one of the two intraoperative ventilation strategies. Investigators screen patients aged >= 18 years and with a body mass index <= 40 kg/m(2), scheduled for open abdominal surgery and at risk for PPC. Patients either receive an intraoperative ventilation strategy with individualized high PEEP with recruitment maneuvers (RM) ("individualized high PEEP") or one in which PEEP of 5 cm H2O without RM is used ("low PEEP"). In the "individualized high PEEP" group, PEEP is set at the level at which Delta P is lowest. In both groups of the trial, V-T is kept at 8 mL/kg predicted body weight. The primary endpoint is the occurrence of PPC, recorded as a collapsed composite of adverse pulmonary events. Discussion DESIGNATION will be the first randomized clinical trial that is adequately powered to compare the effects of individualized high PEEP with RM versus fixed low PEEP without RM on the occurrence of PPC after open abdominal surgery. The results of DESIGNATION will support anesthesiologists in their decisions regarding PEEP settings during open abdominal surgery
Addition of PEG-interferon to long-term nucleos(t)ide analogue therapy enhances HBsAg decline and clearance in HBeAg-negative chronic hepatitis B:Multicentre Randomized Trial (PAS Study)
We studied whether 48 weeks of PEG-IFN alfa-2a add-on increases HBsAg-decline and clearance in HBeAg-negative patients on long-term nucleo(s)tide analogue (NA) therapy. In this investigator-initiated, randomized, controlled trial conducted in Europe and Canada, HBeAg-negative patients treated with NA > 12 months, with HBVDNA < 200 IU/mL, were enrolled. Patients were randomized 2:1 to 48 weeks of PEG-IFN alfa-2a add-on (180 μg per week) or continued NA-monotherapy with subsequent follow-up to Week 72. Endpoints were HBsAg decline (≥1 log10 IU/mL) and HBsAg clearance at Week 48. Of the 86 patients in the modified-intention-to-treat analysis, 58 patients received PEG-IFN add-on, and 28 continued NA monotherapy. At Week 48, 16(28%) patients achieved HBsAg decline ≥1 log10 in the add-on arm versus none on NA-monotherapy (p <.001), and HBsAg clearance was observed in 6 (10%) PEG-IFN add-on patients versus 0% NA-monotherapy (p =.01). HBVRNA was only detected in 2% after PEG-IFN treatment versus 19% in NA-monotherapy (p =.002) at Week 48. PEG-IFN add-on therapy was well tolerated in majority of patients. Low baseline HBsAg levels (<10 IU/mL) identified patients most likely to achieve HBsAg loss with PEG-IFN add-on, whereas an HBsAg level > 200 IU/mL at on-treatment Week 12 was highly predictive of non-response (NPV = 100%). Addition of PEG-IFN to long-term NA enhanced HBsAg decline and increased the chance of HBsAg clearance in HBeAg-negative patients on long-term NA. On-treatment HBsAg levels >200 IU/mL identify patients unlikely to benefit from PEG-IFN add-on and could be used as a potential stopping-rule for PEG-IFN therapy. Our findings support further exploration of immune modulation add-on to antiviral therapy, preferably using response-guided strategies, to increase functional cure rates in patients with CHB.</p
Diagnostic criteria and long-term outcomes in AIH-PBC variant syndrome under combination therapy
Background & Aims: Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) can co-exist in AIH-PBC, requiring combined treatment with immunosuppression and ursodeoxycholic acid (UDCA). The Paris criteria are commonly used to identify these patients; however, the optimal diagnostic criteria are unknown. We aimed to evaluate the use and clinical relevance of both Paris and Zhang criteria. Methods: Eighty-three patients with a clinical suspicion of AIH-PBC who were treated with combination therapy were included. Histology was re-evaluated. Characteristics and long-term outcomes were retrospectively compared to patients with AIH and PBC. Results: Seventeen (24%) patients treated with combination therapy fulfilled the Paris criteria. Fifty-two patients (70%) fulfilled the Zhang criteria. Patients who met Paris and Zhang criteria more often had inflammation and fibrosis on histology compared to patients only meeting the Zhang criteria. Ten-year liver transplant (LT)-free survival was 87.3% (95% CI 78.9–95.7%) in patients with AIH-PBC. This did not differ in patients in or outside the Paris or Zhang criteria (p = 0.46 and p = 0.40, respectively) or from AIH (p = 0.086). LT-free survival was significantly lower in patients with PBC and severe hepatic inflammation – not receiving immunosuppression – compared to those with AIH-PBC (65%; 95% CI 52.2–77.8% vs. 87%; 95% CI 83.2–90.8%; hazard ratio 0.52; p = 0.043). Conclusions: In this study, patients with AIH-PBC outside Paris or Zhang criteria were frequently labeled as having AIH-PBC and were successfully treated with combination therapy with similar outcomes. LT-free survival was worse in patients with PBC and hepatic inflammation than in those treated as having AIH-PBC. More patients may benefit from combination therapy. Impact and implications: This study demonstrated that patients with AIH-PBC variant syndrome treated with combined therapy consisting of immunosuppressants and ursodeoxycholic acid often do not fulfill the Paris criteria. They do however have comparable response to therapy and long-term outcomes as patients who do fulfill the diagnostic criteria. Additionally, patients with PBC and additional signs of hepatic inflammation have poorer long-term outcomes compared to patients treated as having AIH-PBC. These results implicate that a larger group of patients with features of both AIH and PBC may benefit from combined treatment. With our results, we call for improved consensus among experts in the field on the diagnosis and management of AIH-PBC variant syndrome.</p
Diagnostic criteria and long-term outcomes in AIH-PBC variant syndrome under combination therapy
Background & Aims: Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) can co-exist in AIH-PBC, requiring combined treatment with immunosuppression and ursodeoxycholic acid (UDCA). The Paris criteria are commonly used to identify these patients; however, the optimal diagnostic criteria are unknown. We aimed to evaluate the use and clinical relevance of both Paris and Zhang criteria. Methods: Eighty-three patients with a clinical suspicion of AIH-PBC who were treated with combination therapy were included. Histology was re-evaluated. Characteristics and long-term outcomes were retrospectively compared to patients with AIH and PBC. Results: Seventeen (24%) patients treated with combination therapy fulfilled the Paris criteria. Fifty-two patients (70%) fulfilled the Zhang criteria. Patients who met Paris and Zhang criteria more often had inflammation and fibrosis on histology compared to patients only meeting the Zhang criteria. Ten-year liver transplant (LT)-free survival was 87.3% (95% CI 78.9–95.7%) in patients with AIH-PBC. This did not differ in patients in or outside the Paris or Zhang criteria (p = 0.46 and p = 0.40, respectively) or from AIH (p = 0.086). LT-free survival was significantly lower in patients with PBC and severe hepatic inflammation – not receiving immunosuppression – compared to those with AIH-PBC (65%; 95% CI 52.2–77.8% vs. 87%; 95% CI 83.2–90.8%; hazard ratio 0.52; p = 0.043). Conclusions: In this study, patients with AIH-PBC outside Paris or Zhang criteria were frequently labeled as having AIH-PBC and were successfully treated with combination therapy with similar outcomes. LT-free survival was worse in patients with PBC and hepatic inflammation than in those treated as having AIH-PBC. More patients may benefit from combination therapy. Impact and implications: This study demonstrated that patients with AIH-PBC variant syndrome treated with combined therapy consisting of immunosuppressants and ursodeoxycholic acid often do not fulfill the Paris criteria. They do however have comparable response to therapy and long-term outcomes as patients who do fulfill the diagnostic criteria. Additionally, patients with PBC and additional signs of hepatic inflammation have poorer long-term outcomes compared to patients treated as having AIH-PBC. These results implicate that a larger group of patients with features of both AIH and PBC may benefit from combined treatment. With our results, we call for improved consensus among experts in the field on the diagnosis and management of AIH-PBC variant syndrome.</p
3D Variation in delineation of head and neck organs at risk
<p>Abstract</p> <p>Background</p> <p>Consistent delineation of patient anatomy becomes increasingly important with the growing use of highly conformal and adaptive radiotherapy techniques. This study investigates the magnitude and 3D localization of interobserver variability of organs at risk (OARs) in the head and neck area with application of delineation guidelines, to establish measures to reduce current redundant variability in delineation practice.</p> <p>Methods</p> <p>Interobserver variability among five experienced radiation oncologists was studied in a set of 12 head and neck patient CT scans for the spinal cord, parotid and submandibular glands, thyroid cartilage, and glottic larynx. For all OARs, three endpoints were calculated: the Intraclass Correlation Coefficient (ICC), the Concordance Index (CI) and a 3D measure of variation (3D SD).</p> <p>Results</p> <p>All endpoints showed largest interobserver variability for the glottic larynx (ICC = 0.27, mean CI = 0.37 and 3D SD = 3.9 mm). Better agreement in delineations was observed for the other OARs (range, ICC = 0.32-0.83, mean CI = 0.64-0.71 and 3D SD = 0.9-2.6 mm). Cranial, caudal, and medial regions of the OARs showed largest variations. All endpoints provided support for improvement of delineation practice.</p> <p>Conclusions</p> <p>Variation in delineation is traced to several regional causes. Measures to reduce this variation can be: (1) guideline development, (2) joint delineation review sessions and (3) application of multimodality imaging. Improvement of delineation practice is needed to standardize patient treatments.</p
Aspirin with or without Clopidogrel after Transcatheter Aortic-Valve Implantation
BACKGROUND The effect of single as compared with dual antiplatelet treatment on bleeding and thromboembolic events after transcatheter aortic-valve implantation (TAVI) in patients who do not have an indication for long-term anticoagulation has not been well studied. METHODS In a randomized, controlled trial, we assigned a subgroup of patients who were undergoing TAVI and did not have an indication for long-term anticoagulation, in a 1:1 ratio, to receive aspirin alone or aspirin plus clopidogrel for 3 months. The two primary outcomes were all bleeding (including minor, major, and life-threatening or disabling bleeding) and non-procedure-related bleeding over a period of 12 months. Most bleeding at the TAVI puncture site was counted as non-procedure-related. The two secondary outcomes were a composite of death from cardiovascular causes, non-procedure-related bleeding, stroke, or myocardial infarction (secondary composite 1) and a composite of death from cardiovascular causes, ischemic stroke, or myocardial infarction (secondary composite 2) at 1 year, with both outcomes tested sequentially for noninferiority (noninferiority margin, 7.5 percentage points) and superiority. RESULTS A total of 331 patients were assigned to receive aspirin alone and 334 were assigned to receive aspirin plus clopidogrel. A bleeding event occurred in 50 patients (15.1%) receiving aspirin alone and in 89 (26.6%) receiving aspirin plus clopidogrel (risk ratio, 0.57; 95% confidence interval [CI], 0.42 to 0.77; P=0.001). Non-procedure-related bleeding occurred in 50 patients (15.1%) and 83 patients (24.9%), respectively (risk ratio, 0.61; 95% CI, 0.44 to 0.83; P=0.005). A secondary composite 1 event occurred in 76 patients (23.0%) receiving aspirin alone and in 104 (31.1%) receiving aspirin plus clopidogrel (difference, −8.2 percentage points; 95% CI for noninferiority, −14.9 to −1.5; P<0.001; risk ratio, 0.74; 95% CI for superiority, 0.57 to 0.95; P=0.04). A secondary composite 2 event occurred in 32 patients (9.7%) and 33 patients (9.9%), respectively (difference, −0.2 percentage points; 95% CI for noninferiority, −4.7 to 4.3; P=0.004; risk ratio, 0.98; 95% CI for superiority, 0.62 to 1.55; P=0.93). A total of 44 patients (13.3%) and 32 (9.6%), respectively, received oral anticoagulation during the trial. CONCLUSIONS Among patients undergoing TAVI who did not have an indication for oral anticoagulation, the incidence of bleeding and the composite of bleeding or thromboembolic events at 1 year were significantly less frequent with aspirin than with aspirin plus clopidogrel administered for 3 months
Tolerance and cross-tolerance to neurocognitive effects of THC and alcohol in heavy cannabis users
and cross-tolerance to neurocognitive effects of THC and alcohol in heavy cannabis user
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