12 research outputs found
Agreement between diagnoses of childhood lymphoma assigned in Uganda and by an international reference laboratory
BACKGROUND: Correct diagnosis is key to appropriate treatment of cancer in children. However, diagnostic challenges are common in low-income and middle-income countries. The objective of the present study was to assess the agreement between a clinical diagnosis of childhood non- Hodgkin lymphoma (NHL) assigned in Uganda, a pathological diagnosis assigned in Uganda, and a pathological diagnosis assigned in The Netherlands. METHODS: The study included children with suspected NHL referred to the Mulago National Referral Hospital, Kampala, Uganda, between 2004 and 2008. A clinical diagnosis was assigned at the Mulago National Referral Hospital, where tissue samples were also obtained. Hematoxylin and eosin-stained slides were used for histological diagnosis in Uganda, and were re-examined in a pathology laboratory in The Netherlands, where additional pathological, virological and serological testing was also carried out. Agreement between diagnostic sites was compared using kappa statistics. RESULTS: Clinical and pathological diagnoses from Uganda and pathological diagnosis from The Netherlands was available for 118 children. The agreement between clinical and pathological diagnoses of NHL assigned in Uganda was 91% (95% confidence interval [CI] 84–95; kappa 0.84; P < 0.001) and in The Netherlands was 49% (95% CI 40–59; kappa 0.04; P = 0.612). When Burkitt’s lymphoma was considered separately from other NHL, the agreement between clinical diagnoses in Uganda and pathological diagnoses in Uganda was 69% (95% CI 59–77; kappa 0.56; P < 0.0001), and the corresponding agreement between pathological diagnoses assigned in The Netherlands was 32% (95% CI 24–41; kappa 0.05; P = 0.326). The agreement between all pathological diagnoses assigned in Uganda and The Netherlands was 36% (95% CI 28–46; kappa 0.11; P = 0.046). CONCLUSION: Clinical diagnosis of NHL in Uganda has a high probability of error compared with pathological diagnosis in Uganda and in The Netherlands. In addition, agreement on the pathological diagnosis of NHL between Uganda and The Netherlands is very low
Test beam performance measurements for the Phase I upgrade of the CMS pixel detector
A new pixel detector for the CMS experiment was built in order to cope with the instantaneous luminosities anticipated for the Phase I Upgrade of the LHC. The new CMS pixel detector provides four-hit tracking with a reduced material budget as well as new cooling and powering schemes. A new front-end readout chip mitigates buffering and bandwidth limitations, and allows operation at low comparator thresholds. In this paper, comprehensive test beam studies are presented, which have been conducted to verify the design and to quantify the performance of the new detector assemblies in terms of tracking efficiency and spatial resolution. Under optimal conditions, the tracking efficiency is (99.95 ± 0.05) %, while the intrinsic spatial resolutions are (4.80 ± 0.25) μm and (7.99 ± 0.21) μm along the 100 μm and 150 μm pixel pitch, respectively. The findings are compared to a detailed Monte Carlo simulation of the pixel detector and good agreement is found.Peer reviewe