Daksha: On Alert for High Energy Transients

We present Daksha, a proposed high energy transients mission for the study of electromagnetic counterparts of gravitational wave sources, and gamma ray bursts. Daksha will comprise of two satellites in low earth equatorial orbits, on opposite sides of earth. Each satellite will carry three types of detectors to cover the entire sky in an energy range from 1 keV to >1 MeV. Any transients detected on-board will be announced publicly within minutes of discovery. All photon data will be downloaded in ground station passes to obtain source positions, spectra, and light curves. In addition, Daksha will address a wide range of science cases including monitoring X-ray pulsars, studies of magnetars, solar flares, searches for fast radio burst counterparts, routine monitoring of bright persistent high energy sources, terrestrial gamma-ray flashes, and probing primordial black hole abundances through lensing. In this paper, we discuss the technical capabilities of Daksha, while the detailed science case is discussed in a separate paper.Comment: 9 pages, 3 figures, 1 table. Additional information about the mission is available at https://www.dakshasat.in

Science with the Daksha High Energy Transients Mission

We present the science case for the proposed Daksha high energy transients mission. Daksha will comprise of two satellites covering the entire sky from 1~keV to $>1$~MeV. The primary objectives of the mission are to discover and characterize electromagnetic counterparts to gravitational wave source; and to study Gamma Ray Bursts (GRBs). Daksha is a versatile all-sky monitor that can address a wide variety of science cases. With its broadband spectral response, high sensitivity, and continuous all-sky coverage, it will discover fainter and rarer sources than any other existing or proposed mission. Daksha can make key strides in GRB research with polarization studies, prompt soft spectroscopy, and fine time-resolved spectral studies. Daksha will provide continuous monitoring of X-ray pulsars. It will detect magnetar outbursts and high energy counterparts to Fast Radio Bursts. Using Earth occultation to measure source fluxes, the two satellites together will obtain daily flux measurements of bright hard X-ray sources including active galactic nuclei, X-ray binaries, and slow transients like Novae. Correlation studies between the two satellites can be used to probe primordial black holes through lensing. Daksha will have a set of detectors continuously pointing towards the Sun, providing excellent hard X-ray monitoring data. Closer to home, the high sensitivity and time resolution of Daksha can be leveraged for the characterization of Terrestrial Gamma-ray Flashes.Comment: 19 pages, 7 figures. Submitted to ApJ. More details about the mission at https://www.dakshasat.in

Evolving Paradigm of Radiotherapy for High-Risk Prostate Cancer: Current Consensus and Continuing Controversies

High-risk prostate cancer is an aggressive form of the disease with an increased risk of distant metastasis and subsequent mortality. Multiple randomized trials have established that the combination of radiation therapy and long-term androgen deprivation therapy improves overall survival compared to either treatment alone. Standard of care for men with high-risk prostate cancer in the modern setting is dose-escalated radiotherapy along with 2-3 years of androgen deprivation therapy (ADT). There are research efforts directed towards assessing the efficacy of shorter ADT duration. Current research has been focused on assessing hypofractionated and stereotactic body radiation therapy (SBRT) techniques. Ongoing randomized trials will help assess the utility of pelvic lymph node irradiation. Research is also focused on multimodality therapy with addition of a brachytherapy boost to external beam radiation to help improve outcomes in men with high-risk prostate cancer

Evolving Paradigm of Radiotherapy for High-Risk Prostate Cancer: Current Consensus and Continuing Controversies

High-risk prostate cancer is an aggressive form of the disease with an increased risk of distant metastasis and subsequent mortality. Multiple randomized trials have established that the combination of radiation therapy and long-term androgen deprivation therapy improves overall survival compared to either treatment alone. Standard of care for men with high-risk prostate cancer in the modern setting is dose-escalated radiotherapy along with 2-3 years of androgen deprivation therapy (ADT). There are research efforts directed towards assessing the efficacy of shorter ADT duration. Current research has been focused on assessing hypofractionated and stereotactic body radiation therapy (SBRT) techniques. Ongoing randomized trials will help assess the utility of pelvic lymph node irradiation. Research is also focused on multimodality therapy with addition of a brachytherapy boost to external beam radiation to help improve outcomes in men with high-risk prostate cancer

Multidisciplinary management of patients with localized bladder cancer.

Multidisciplinary approach to muscle-invasive bladder cancer is imperative to achieve optimal long-term cancer control. Radical cystectomy, pelvic lymph node dissection, and urinary diversion have been the mainstay of therapy for decades. Laparoscopic and robotic-assisted surgical techniques are becoming increasingly prevalent, and have shown short-term benefits in terms of blood loss, less pain, and smaller incisions. Neoadjuvant chemotherapy plus surgery results in absolute survival advantage and this approach is encouraged in appropriate patients. A similar survival advantage with the use of adjuvant chemotherapy has yet to be convincingly demonstrated. Bladder-preservation protocols involving a visibly complete transurethral resection followed by chemoradiation may be a feasible option for select patients

Are Patients Traveling for Intraoperative Radiation Therapy?

Purpose. One benefit of intraoperative radiation therapy (IORT) is that it usually requires a single treatment, thus potentially eliminating distance as a barrier to receipt of whole breast irradiation. The aim of this study was to evaluate the distance traveled by IORT patients at our institution. Methods. Our institutional prospective registry was used to identify IORT patients from 10/2011 to 2/2017. Patient’s home zip code was compared to institution zip code to determine travel distance. Characteristics of local (100 miles) patients were compared. Results. 150 were patients included with a median travel distance of 27 miles and mean travel distance of 121 miles. Most were local (68.7%), with the second largest group living faraway (20.0%). Subset analysis of local patients demonstrated 20.4% traveled 1000 miles. The local, regional, and faraway patients did not differ with respect to age, race, tumor characteristics, or whole breast irradiation. Conclusions. Breast cancer patients are traveling for IORT, with 63% traveling >20 miles for care. IORT is an excellent strategy to promote breast conservation in selected patients, particularly those who live remote from a radiation facility