Dosimetric effect of intra-fractional and inter-fractional target motion in lung cancer radiotherapy techniques

Purpose: The purpose of present study was to experimentally evaluate the dosimetric uncertainties in 3-dimensional conformal radiotherapy (3DCRT), dynamic intensity modulated radiotherapy (D-IMRT), step-shoot (SS-IMRT), and volumetric modulated arc therapy (VMAT) treatment delivery techniques due to intra- and inter-fractional target motion. Methods: A previously treated lung patient was selected for this study and was replanned for 60 Gy in 30 fractions using four techniques (3DCRT, D-IMRT, SS-IMRT, and VMAT). These plans were delivered in a clinical linear accelerator equipped with HexaPOD™ evo RT System. The target dose of static QUASAR phantom was calculated that served as reference dose to the target. The QUASAR respiratory body phantom along with patients breathing wave form and HexaPOD™ evo RT System was used to simulate the intra-fraction and inter-fraction motions. Dose measurements were done by applying the intra-fractional and inter-fractional motions in all the four treatment delivery techniques.Results: The maximum percentage deviation in a single field was -4.3%, 10.4%, and -12.2% for 3DCRT, D-IMRT and SS-IMRT deliveries, respectively. Similarly, the deviation for a single fraction was -1.51%, -1.88%, -2.22%, and -3.03% for 3DCRT, D-IMRT, SS-IMRT and VMAT deliveries, respectively. Conclusion: The impact of inter-fractional and intra-fractional uncertainties calculated as deviation between dynamic and static condition dose was large in some fractions, however average deviation calculated for thirty fractions was well within 0.5% in all the four techniques. Therefore, inter- and intra-fractional uncertainties could be concern in fewer fraction treatments such as stereotactic body radiation therapy, and should be used in conjunction with intra- and inter-fractional motion management techniques

Pulmonary tuberculosis as differential diagnosis of lung cancer

Patients with lung cancer are often misdiagnosed as pulmonary tuberculosis leading to delay in the correct diagnosis as well as exposure to inappropriate medication. Several factors are responsible for this situation in developing countries, including lack of awareness, inadequate infrastructure and socio-economic factors. This article outlines the differences between the two diseases as well as features that would make a clinician suspect the right diagnosis early

Impact of EGFR and p53 expressions on survival and quality of life in locally advanced oral squamous cell carcinoma patients treated with chemoradiation

EGFR and p53 are molecular markers which play important role in tumor progression and development. The objective of this study was to assess the association between EGFR and p53 expression and survival, and to determine whether EGFR and p53 expression levels were associated with differences quality of life in OSCC patients undergoing chemoradiation. A total of 120 OSCC patients aged 20–67 y and stage III/IV were recruited. Treatment response was assessed according to W.H.O. (1979). EGFR and p53 expression in tumor tissue was estimated by immunohistochemical (IHC) method and quantified as percentage positive nuclei. Molecular marker expressions of both EGFR and p53 were found significantly (P < 0.01 or P < 0.001) associated with overall response, survivals and quality of life. Neither EGFR nor p53 expression was associated with hematologic or non-hematologic toxicity. EGFR and p53 molecular marker expressions may have significant association with survival and QOL in OSCC patients undergoing chemoradiation

Tumefactive demyelinating lesion: Experience with two unusual patients

Tumefactive demyelinating lesion, a variant of multiple sclerosis, is a solitary large demyelinating lesion, which mimics cerebral neoplasm. Distinguishing tumefactive lesions from other etiologies of intracranial space-occupying lesions is essential to avoid inadvertent surgical or toxic chemotherapeutic interventions. We report two unusual cases of tumefactive demyelinating lesion. The first patient presented with recurrent right focal tonic-clonic seizures with secondary generalization of three-month duration. Her neurological examination was normal. Another patient presented with right homonymous hemianopia. In this patient, the diagnosis was established after biopsy of the lesion, which revealed perivascular lymphocytic infiltrate and aggregates of foam cells in white matter with relatively uninvolved grey matter, suggestive of tumefactive demyelinating lesion. Administration of intravenous methylprednisolone resulted in rapid clinical improvement in both the patients and the brain lesion decreased in size. Both, epilepsy and homonymous hemianopia, are unusual manifestations of tumefactive demyelinating lesions. In our cases, cerebral tumors were initial diagnoses. Presence of an open ring or incomplete ring lesions and other magnetic resonance characteristics helped in differentiating demyelinating lesions from other neoplastic and infective diseases of the brain. Differential diagnosis of tumefactive demyelinating lesions, at times, may prove to be a challenging task for the treating physician

Unique mutational changes in SARS-CoV-2 genome: A case study for the largest state of India

AbstractCOVID-19 is a global pandemic causing more than 8 million deaths till mid-August, 2020. In India, more than 3 million confirmed cases have been reported although with relatively low death rate of 1.8%. In this study, we sequenced 47 genomes of SARS-CoV-2 from the patients of 13 districts of Uttar Pradesh (UP), the largest state of India using third-generation sequencing technique. The phylogenetic clustering revealed that no UP sample was aligned with the previously defined USA clade, where the mortality was high. We identified 56 distinct SNP variations in the genomes of UP resulting in a unique mutation rate of 1.19% per sequence, which is greater than the value 0.88% obtained for the rest of India. The relatively less death rate in UP indicates that the mutation in the virus is deleterious. Further investigation is required with larger sample size to determine the degree of virulence vis-a-vis SNP variation.</jats:p