A review article on the dosimetry in intraluminal HDR brachytherapy of lung carcinoma.

Lung cancer is one of the most common cancers in the world. Intraluminal brachytherapy (BT) is one of the most adopted treatment modalities for lung malignancies with Ir-192 source in radiotherapy. In intraluminal BT, treatment delivery is required to be very accurate and precise with respect to the plan created in the treatment planning system (TPS). The BT dosimetry is necessary for better treatment outcomes. Therefore in this review article, some relevant studies were identified and analyzed for dosimetric outcomes in intraluminal BT in lung malignancies. The dosimetry in BT for plan verification is not presently in practice, which needs to be performed to check the variation between the planned and measured doses. The necessary dosimetric work done by the various researchers in intraluminal BT such as the Monte Carlo CYLTRAN code was used to calculate and measure the dose rate in any medium. Anthropomorphic phantom was used to measure doses at some distance from the source with Thermo luminescence dosimeters (TLDs). The dosimetric influence of air passage in the bronchus was evaluated with the GEANT4 Monte Carlo method. A pinpoint chamber was used to measure and quantify the impact of inhomogeneity in wax phantom for the Ir-192 source. The Gafchromic films and Monte Carlo methods were used to find the phantom and heterogeneities, which were found to underestimate the dose for the lungs and overestimated for the bones in TPS. The exact tool to quantify the variation in planned and delivered doses should be cost-effective and easy to use possibly with tissue equivalent phantoms and Gafchromic films in lung malignancies treatment.

A method to detect immunoreactions on the basis of current vs. concentration slope - an electrochemical approach.

The emergence of novel infectious diseases is rising with time and is a major threat to the society. The recent outbreak of infectious coronavirus disease has made a huge impact in our lives. The massive outbreak of the disease revealed that there is room for development of new diagnostics tools and methods to screen huge numbers of samples in the shortest possible time. Our current work relates to an electronic diagnostic system and method that rapidly detects the presence of an antigen in solution. Our designed system is capable of separating the immunocomplex formation on the basis of the slope it produces in contrast to the controls, when oxidation peak current is plotted against the concentration of the reactant after electrochemistry measurement. In this system, antibody conjugated copper nanoparticles synthesized by the electroexplosion method has played the key role. The values of the slopes of copper nanoparticles (CuNPs) was found to be -3.7637, whereas those for CuNP conjugated Antibody and CuNPAntibodyAntigen were -2.3044 and -0.8332, respectively. Hence, the current method could become one of the easiest and fastest method for the electronic detection of an immune reaction and a good replacement for the time-consuming, label-based assays in multistep reaction.

A dosimetric comparison between three-dimensional conformal radiation therapy and intensity-modulated radiation therapy in the treatment of posterior fossa boost in medulloblastoma.

AIMS: To compare three-dimensional conformal radiation therapy (3DCRT) and intensity-modulated radiation therapy (IMRT) in posterior fossa (PF) boost in children with medulloblastoma (MB); dosimetrically evaluating and comparing both techniques with regard to target coverage and doses to organs at risk. SETTINGS AND DESIGN: Structured. SUBJECTS AND METHODS: Seven previously irradiated patients of MB were retrieved and re-planned with both 3DCRT and IMRT techniques. Dosimetric comparison was done by performing two plans for the PF boost for the same patient. Prescription dose and normal tissue constraints were identical for both plans. STATISTICAL ANALYSIS USED: SPSS, version 19, statistical software package was used. For quantitative data, paired t-test was applied to calculate the difference between two means. RESULTS: Mean values of planning target volume (PTV); PTV95% and PTV5% in IMRT were 97.19% and 106.07% and for 3DCRT were 96.57% and 106.33%, respectively. The dose homogeneity was better in IMRT (1.091) as compared to 3DCRT (1.100), but was not statistically significant (P = 0.341). Conformity index was comparable in both the plans, i.e., 3DCRT (0.979) and IMRT (0.976) with P = 0.819. IMRT plan provided reduced mean dose to cochlea relative to the 3DCRT plans with P = 0.032 for the right cochlea and 0.020 for the left cochlea. IMRT showed no advantage over 3DCRT in sparing the anterior cranial structures where mean doses to the right and left lens were 0.61 Gy and 0.56 Gy for IMRT and 0.16 Gy and 0.09 Gy for 3DCRT, respectively. CONCLUSIONS: IMRT technique was able to improve homogeneity index, spare the cochleae, but 3DCRT plans were superior in sparing anterior cranial structures without compromising the dose to PF.