Different functional lung-sparing strategies and radiotherapy techniques for patients with esophageal cancer.

Background: Integration of 4D-CT ventilation function images into esophageal cancer radiation treatment planning aimed to assess dosimetric differences between different functional lung (FL) protection strategies and radiotherapy techniques. Methods: A total of 15 patients with esophageal cancer who had 4D-CT scans were included. Lung ventilation function images based on Jacobian values were obtained by deformation image registration and ventilation imaging algorithm. Several different plans were designed for each patient: clinical treatment planning (non-sparing planning), the same beam distribution to FL-sparing planning, three fixed-beams FL-sparing intensity-modulated radiation therapy (IMRT) planning (5F-IMRT, 7F-IMRT, 9F-IMRT), and two FL-sparing volumetric modulated arc therapy (VMAT) planning [1F-VMAT (1-Arc), 2F-VMAT (2-Arc)]. The dosimetric parameters of the planning target volume (PTV) and organs at risk (OARs) were compared and focused on dosimetric differences in FL. Results: The FL-sparing planning compared with the non-sparing planning significantly decreased the FL-Dmean, V5-30 and Lungs-Dmean, V10-30 (Vx: volume of receiving ≥X Gy), although it slightly compromised PTV conformability and increased Heart-V40 (P< 0.05). The 5F-IMRT had the lowest PTV-conformability index (CI) but had a lower Lungs and Heart irradiation dose compared with those of the 7F-IMRT and 9F-IMRT (P< 0.05). The 2F-VMAT had higher PTV-homogeneity index (HI) and reduced irradiation dose to FL, Lungs, and Heart compared to those of the 1F-VMAT planning (P< 0.05). The 2F-VMAT had higher PTV conformability and homogeneity and decreased FL-Dmean, V5-20 and Lungs-Dmean, V5-10 but correspondingly increased spinal cord-Dmean compared with those of the 5F-IMRT planning (P< 0.05). Conclusion: In this study, 4D-CT ventilation function image-based FL-sparing planning for esophageal cancer can effectively reduce the dose of the FL. The 2F-VMAT planning is better than the 5F-IMRT planning in reducing the dose of FL.

Functional Liver Imaging in Radiotherapy for Liver Cancer: A Systematic Review and Meta-Analysis.

Backgrounds: Functional liver imaging can identify functional liver distribution heterogeneity and integrate it into radiotherapy planning. The feasibility and clinical benefit of functional liver-sparing radiotherapy planning are currently unknown. Methods: A comprehensive search of several primary databases was performed to identify studies that met the inclusion criteria. The primary objective of this study was to evaluate the dosimetric and clinical benefits of functional liver-sparing planning radiotherapy. Secondary objectives were to assess the ability of functional imaging to predict the risk of radiation-induced liver toxicity (RILT), and the dose-response relationship after radiotherapy. Results: A total of 20 publications were enrolled in descriptive tables and meta-analysis. The meta-analysis found that mean functional liver dose (f-MLD) was reduced by 1.0 Gy [95%CI: (-0.13, 2.13)], standard mean differences (SMD) of functional liver volume receiving ≥20 Gy (fV20) decreased by 0.25 [95%CI: (-0.14, 0.65)] when planning was optimized to sparing functional liver (P >0.05). Seven clinical prospective studies reported functional liver-sparing planning-guided radiotherapy leads to a low incidence of RILD, and the single rate meta-analysis showed that the RILD (defined as CTP score increase ≥2) incidence was 0.04 [95%CI: (0.00, 0.11), P <0.05]. Four studies showed that functional liver imaging had a higher value to predict RILT than conventional anatomical CT. Four studies established dose-response relationships in functional liver imaging after radiotherapy. Conclusion: Although functional imaging modalities and definitions are heterogeneous between studies, but incorporation into radiotherapy procedures for liver cancer patients may provide clinical benefits. Further validation in randomized clinical trials will be required in the future.

Efficacy and safety of different dosages of rituximab for refractory generalized AChR myasthenia gravis: A meta-analysis.

BACKGROUND: Rituximab (RTX) is a mouse-human chimeric anti-CD20 monoclonal antibody and has been increasingly used for preventing relapses in myasthenia gravis (MG). However, the appropriate dose for maximizing the beneficial effects in refractory MG with acetylcholine receptor (AChR) autoantibody is a long-standing and critical debating question. METHODS: We performed a meta-analysis to evaluate the efficacy and safety of the different doses of RTX in 260 refractory AChR-MG patients. RESULTS: The AChR-MG patients were divided into low or routine RTX dose groups. An overall proportion of 77% (p = 0.000) AChR-MG patients demonstrated improved clinical status as indicated by the Myasthenia Gravis Foundation of America post-intervention scale (MGFA-PIS). There were 77.1% patients showed improved clinical status in lower dose of RTX group (p = 0.000) and 76.8% in routine protocol group (p = 0.000). Although we found there was no significant difference in the proportion of AChR-MG patients with improved clinical status or adverse reactions between the two groups, adverse reactions might be lower in the lower dose RTX group. CONCLUSION: Most of refractory MG patients with anti-AChR autoantibody were well responsive and tolerated to RTX treatment. Repeated application of lower dose of RTX was effective and might be more appropriate for refractory AChR-MG patients with potential lower side effects.

The feasibility of mapping dose distribution of 4DCT images with deformable image registration in lung.

Calculating an accurate cumulative dose through individual phases for four-dimensional computed tomography (4DCT) images from the lung is time-consuming. Although the dose distribution of different phases is similar, copying the dose distribution of one phase directly to another phase would yield a dosimetric error of approximately 4% without further optimization. To reduce the dosimetric error, three-dimensional B-spline elastic deformable image registration (DIR) was used to quickly obtain a relatively accurate cumulative dose of 4DCT images acquired from ten lung cancer patients. The dose distribution of the end-expiration phase was mapped to the end-inspiration phase using DIR. The mapped dose in the end-inspiration phase was then compared with the directly copied dose by analysis (3cm/3%) and the t-test. The results showed that optimization using DIR was significantly better in the average pass rate (by 0.6-4.7%). Our results indicate it is feasible to map the dose distribution of 4DCT images in lung with DIR, and that the motion amplitude of individual respiratory and different DIR algorithms affect the differences between the mapped and actual dose.

Comparison of SPECT/CT, MRI and CT in diagnosis of skull base bone invasion in nasopharyngeal carcinoma.

Early detection of skull base invasion in nasopharyngeal carcinoma (NPC) is crucial for correct staging, assessing treatment response and contouring the tumor target in radiotherapy planning, as well as improving the patient's prognosis. To compare the diagnostic efficacy of single photon emission computed tomography/computed tomography (SPECT/CT) imaging, magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of skull base invasion in NPC. Sixty untreated patients with histologically proven NPC underwent SPECT/CT imaging, contrast-enhanced MRI and CT. Of the 60 patients, 30 had skull base invasion confirmed by the final results of contrast-enhanced MRI, CT and six-month follow-up imaging (MRI and CT). The diagnostic efficacy of the three imaging modalities in detecting skull base invasion was evaluated. The rates of positive findings of skull base invasion for SPECT/CT, MRI and CT were 53.3%, 48.3% and 33.3%, respectively. The sensitivity, specificity and accuracy were 93.3%, 86.7% and 90.0% for SPECT/CT fusion imaging, 96.7%, 100.0% and 98.3% for contrast-enhanced MRI, and 66.7%, 100.0% and 83.3% for contrast-enhanced CT. MRI showed the best performance for the diagnosis of skull base invasion in nasopharyngeal carcinoma, followed closely by SPECT/CT. SPECT/CT had poorer specificity than that of both MRI and CT, while CT had the lowest sensitivity.

Volume and dosimetric variations during two-phase adaptive intensity-modulated radiotherapy for locally advanced nasopharyngeal carcinoma.

The aims of this study were to evaluate the volume and dosimetric variations during IMRT for locally advanced NPC and to identify the benefits of a two-phase adaptive IMRT method. Twenty patients with locally advanced NPC having received IMRT treatment were included. Each patient had both an initial planning CT (CT-1) and a repeated CT scan (CT-2) after treatment at a dose of 40 Gy. Three IMRT planning scenarios were compared: (1) the initial plan on the CT-1 (plan-1); (2) the hybrid plan recalculated the initial plan on the CT-2 (plan-2); (3) the replan generated on the CT-2 being used to complete the course of IMRT (plan-3). The mean gross target volume and mean volumes of the positive neck lymph nodes, high-risk clinical target volume, and the left and right parotid glands significantly decreased by 30.2%, 45.1%, 21.1%, 14.7% and 18.2%, respectively on the CT-2. Comparing plan-2 with plan-1, the dose coverage of the targets remained unchanged, whereas the dose delivered to the parotid glands and spinal cord increased significantly. These patients with locally advanced NPC might benefit from replanning because of the sparing of the parotid glands and spinal cord.

Bis(2,2'-bipyridyl-κN,N')(carbonato-κO,O')cobalt(III) bromide trihydrate.

The title complex, [Co(CO(3))(C(10)H(8)N(2))(2)]Br·3H(2)O, is isostructural with the chloride analogue. The six-coordinated octahedral [Co(2,2'-bipy)(2)CO(3)](+) cation (2,2'-bipy is 2,2'-bipyrid-yl), bromide ion and water mol-ecules are linked together via O-H⋯Br and O-H⋯O hydrogen bonds, generating a one-dimensional chain.