Perspective on the Role of Antibodies and Potential Therapeutic Drugs to Combat COVID-19.

The sudden emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing the coronavirus disease of 2019 (COVID-19) has brought the world to a standstill. Thousands of people across the globe are biting the dust with every passing day and yet more are being tested positive for the SARS-CoV-2 infection. In order to dispense this current crisis, numerous treatment options have been tried and tested and many more are still under scrutiny. The development of vaccines may help in the prevention of the global pandemic, however, there is still a need for the development of alternate approaches to combat the disease. In this review we highlight the new discoveries and furtherance in the antibody based therapeutic options and the potent drugs, with special emphasis on the development of the monoclonal and polyclonal antibodies and the repurposed drugs, which may prove to be of significant importance for the treatment of COVID-19, in the days to come. It is an attempt to evaluate the currently presented challenges so as to provide a scope for the ongoing research and assistance in the development of the effective therapeutic options against SARS-CoV-2.

A comparison between four immobilization systems for pelvic radiation therapy using CBCT and paired kilovoltage portals based image-guided radiotherapy.

INTRODUCTION: We commonly use 6- and 4-clamped thermoplastic molds (TMs) for rigid immobilization during pelvic radiotherapy (RT), sometimes a vacuum cushion (VC) is also used as leg support with TM. Our objective was to report the setup margins (SMs) associated with the different systems, to analyze whether any of these systems is superior, and to analyze whether any of them showed better reproducibility in any particular direction. MATERIALS AND METHODS: Retrospective analysis was done by dividing the patients into four groups: 6-clamp with VC (6CVC), 6-clamp without VC (6CNC), 4-clamp with VC (4CVC), and 4-clamp without VC (4CNC). A repeat offline review was done for all patients and errors were tabulated. Statistical methods were then applied. RESULTS: Total 24 patients had 413 image-guided RT (IGRT) sessions, 312 were cone beam computed tomography scan (CBCT) scans and 101 were paired kilovoltage portals (kVp). There was no statistically significant difference between 6CVC and 6CNC. However, while comparing 4CVC and 4CNC, a statistically significant difference was seen in all directions. VC improved precision in vertical and lateral direction mainly, while the 6-clamped TM improved reproducibility in longitudinal direction. CONCLUSIONS: SM was low for all the four immobilization systems studied. There is no added benefit of using a VC with 6-clamped TM for pelvic RT. Use of a VC is recommended with 4-clamped TM to improve overall reproducibility. 6-clamped TM helps keep the errors low.

Image-Guided Radiation Therapy for Muscle-Invasive Carcinoma of the Urinary Bladder with Cone Beam CT Scan: Use of Individualized Internal Target Volumes for a Single Patient.

INTRODUCTION: While planning radiation therapy (RT) for a carcinoma of the urinary bladder (CaUB), the intra-fractional variation of the urinary bladder (UB) volume due to filling-up needs to be accounted for. This internal target volume (ITV) is obtained by adding internal margins (IM) to the contoured bladder. This study was planned to propose a method of acquiring individualized ITVs for each patient and to verify their reproducibility. METHODS: One patient with CaUB underwent simulation with the proposed 'bladder protocol'. After immobilization, a planning CT scan on empty bladder was done. He was then given 300 ml of water to drink and the time (T) was noted. Planning CT scans were performed after 20 min (T+20), 30 min (T+30) and 40 min (T+40). The CT scan at T+20 was co-registered with the T+30 and T+40 scans. The bladder volumes at 20, 30 and 40 min were then contoured as CTV20, CTV30 and CTV40 to obtain an individualized ITV for our patient. For daily treatment, he was instructed to drink water as above, and the time was noted; treatment was started after 20 min. Daily pre- and post-treatment cone beam CT (CBCT) scans were done. The bladder visualized on the pre-treatment CBCT scan was compared with CTV20 and on the post-treatment CBCT scan with CTV30. RESULTS: In total, there were 65 CBCT scans (36 pre- and 29 post-treatment). Individualized ITVs were found to be reproducible in 93.85% of all instances and fell outside in 4 instances. CONCLUSIONS: The proposed bladder protocol can yield a reproducible estimation of the ITV during treatment; this can obviate the need for taking standard IMs.