Characteristics and treatment outcomes of co-infected tuberculosis patients with human immunodeficiency virus in Southeast China, 2012-2021.

BACKGROUND: Tuberculosis (TB) is a chronic respiratory infection. Co-infection with human immunodeficiency virus (HIV) has been a significant obstacle to TB control. Insufficient attention has been given to TB/HIV, and more information is needed to address this issue. We conducted an observational study to investigate the epidemiological characteristics, treatment outcomes and its associated factors of HIV-positive TB patients in Southeast China. METHODS: An observational study was conducted based on data collected directly from China National TB Surveillance System during 2012-2021. Epidemiological characteristics, drug resistance and outcomes were described as frequency (n) and percentage (%). Risk factors for unsuccessful outcomes were determined using univariate (chi-squared) and multivariate logistic regression analysis. RESULTS: A total of 347 TB/HIV cases were included, and the proportion of HIV-positive cases among all TB cases increased significantly from 0.06% to 2012 to 0.40% in 2021. The majority of cases were males (86.5%), non-local household registers (139, 40.1%), farmers or workers (179, 51.6%), and aged 40-59 (142, 40.9%). Of 347 cases, 290 (83.6%) had pulmonary TB (PTB), 10 (2.9%) had extra pulmonary TB (EPTB) and 47(13.5%) had both PTB and EPTB. A total A total of 258 (74.4%) were HIV positive prior to TB diagnosis. 8.0% (4/50) of cases were resistant to rifampicin (RIF) and 274 patients (83.8%) had successful outcomes. Being non-local (AOR = 2.193, 95% CI = 1.196-4.022, P = 0.011) and diagnosed HIV infection after TB (AOR = 2.365, 95% CI = 1.263-4.430, P = 0.007) were independent risk factors for unsuccessful outcomes of anti-TB treatment. CONCLUSION: During 2012-2021, the proportion of HIV-positive cases among all TB cases increased significantly in Southeast China. HIV-positive TB patients were significantly more likely to develop resistance to RIF and INH and unsuccessful anti-TB treatment. Non-local registration and becoming HIV positive after TB diagnosis were independent risk factors associated with unsuccessful outcomes.

IMRT and RapidArc commissioning of a TrueBeam linear accelerator using TG-119 protocol cases.

The purpose of this study is to evaluate the overall accuracy of intensity-modulated radiation therapy (IMRT) and RapidArc delivery using both flattening filter (FF) and flattening filter-free (FFF) modalities based on test cases developed by AAPM Task Group 119. Institutional confidence limits (CLs) were established as the baseline for patient specific treatment plan quality assurance (QA). The effects of gantry range, gantry speed, leaf speed, dose rate, as well as the capability to capture intentional errors, were evaluated by measuring a series of Picket Fence (PF) tests using the electronic portal imaging device (EPID) and EBT3 films. Both IMRT and RapidArc plans were created in a Solid Water phantom (30 × 30 × 15 cm3) for the TG-119 test cases representative of normal clinical treatment sites for all five photon energies (6X, 10X, 15X, 6X-FFF, 10X-FFF) and the Exact IGRT couch was included in the dose calculation. One high-dose point in the PTV and one low-dose point in the avoidance structure were measured with an ion chamber in each case for each energy. Similarly, two GAFCHROMIC EBT3 films were placed in the coronal planes to measure planar dose distributions in both high- and low-dose regions. The confidence limit was set to have 95% of the measured data fall within the tolerance. The mean of the absolute dose deviation for variable dose rate and gantry speed during RapidArc delivery was within 0.5% for all energies. The corresponding results for leaf speed tests were all within 0.4%. The combinations of dynamic leaf gap (DLG) and MLC transmission factor were optimized based on the ion chamber measurement results of RapidArc delivery for each energy. The average 95% CLs for the high-dose point in the PTV were 0.030 ± 0.007 (range, 0.022-0.038) for the IMRT plans and 0.029 ± 0.011 (range, 0.016-0.043) for the RapidArc plans. For low-point dose in the avoidance structures, the CLs were 0.029 ± 0.006 (range, 0.024-0.039) for the IMRT plans and 0.027 ± 0.013 (range, 0.017-0.047) for the RapidArc plans. The average 95% CLs using 3%/3 mm gamma criteria in the high-dose region were 5.9 ± 2.7 (range, 1.4-8.6) and 3.9 ± 2.9 (range, 1.5-8.8) for IMRT and RapidArc plans, respectively. The average 95% CLs in the low-dose region were 5.3 ± 2.6 (range, 1.2-7.4) and 3.7 ± 2.8 (range, 1.8-8.3) for IMRT and RapidArc plans, respectively. Based on ion chamber, as well as film measurements, we have established CLs values to ensure the high precision of IMRT and RapidArc delivery for both FF and FFF modalities.

Correlation of dose computed using different algorithms with local control following stereotactic ablative radiotherapy (SABR)-based treatment of non-small-cell lung cancer.

PURPOSE: To retrospectively compute dose distributions for lung cancer patients treated with SABR, and to correlate dose distributions with outcome using a tumor control probability (TCP) model. METHODS: Treatment plans for 133 NSCLC patients treated using 12 Gy/fxn × 4 (BED=106 Gy), and planned using a pencil-beam (1D-equivalent-path-length, EPL-1D) algorithm were retrospectively re-calculated using model-based algorithms (including convolution/superposition, Monte Carlo). 4D imaging was performed to manage motion. TCP was computed using the Marsden model and associations between dose and outcome were inferred. RESULTS: Mean D95 reductions of 20% (max.=33%) were noted with model-based algorithms (relative to EPL-1D) for the smallest tumors (PTV<20 cm(3)), corresponding to actual delivered D95 BEDs of ≈ 60-85 Gy. For larger tumors (PTV>100 cm(3)), D95 reductions were ≈ 10% (BED>100 Gy). Mean lung doses (MLDs) were 15% lower for model-based algorithms for PTVs<20 cm(3). No correlation between tumor size and 2-year local control rate was observed clinically, consistent with TCP calculations, both of which were ≈ 90% across all PTV bins. CONCLUSION: Results suggest that similar control rates might be achieved for smaller tumors using lower BEDs relative to larger tumors. However, more studies with larger patient cohorts are necessary to confirm this possible finding.