Valutazione precoce della risposta a Sorafenib nel Carcinoma Epatocellulare mediante quantificazione dell'Ecografia con contrasto con software Sonotumor

Scopo dello studio: Stabilire se cambiamenti della perfusione di una lesione target di epatocarcinoma (HCC), valutati quantitativamente mediante ecografia con contrasto (CE-US) alla settimana 2 e 4 di terapia con sorafenib, possono predire la progressione di malattia alla settimana 8, valutata con la tomografia computerizzata o la risonanza magnetica con mezzo di contrasto (TC-RM) usando i criteri RECIST/RECIST modificati (response evaluation criteria in solid tumors). Pazienti e metodi: Il comitato etico ha approvato lo studio ed i pazienti hanno fornito un consenso informato scritto prima dell’arruolamento. Lo studio è stato effettuato su un campione di soggetti con epatocarcinoma avanzato o non suscettibile di trattamento curativo, in monoterapia con sorafenib. La valutazione della risposta tumorale è stata effettuata con TC o RM a 2 mesi usando i criteri RECIST/RECIST modificati. La CE-US è stata effettuata entro 1 settimana prima dell’inizio del trattamento con sorafenib e durante la terapia alla settimana 2, 4, 8, 16 e 32. I parametri quantitativi funzionali sono stati ottenuti impiegando un software dedicato. I cambiamenti dei valori dei parametri suddetti tra il tempo zero ed i punti temporali successivi sono stati confrontati con la risposta tumorale basata sui criteri RECIST/RECIST modificati. Risultati: La riduzione dei valori dei parametri relativi alla perfusione tumorale, in particolare di WiAUC e PE (parametri correlati con il volume ematico), al T2/T4 (settimana 2, 4), predice la risposta tumorale a 2 mesi, valutata secondo i criteri RECIST e RECIST modificati, risultata indicativa di malattia stabile (responders). Conclusione: L’ecografia con contrasto può essere impiegata per quantificare i cambiamenti della vascolarizzazione tumorale già alla settimana 2, 4 dopo la somministrazione di sorafenib nei pazienti con HCC. Questi precoci cambiamenti della perfusione tumorale possono essere predittivi della risposta tumorale a 2 mesi e possono avere un potenziale nella valutazione precoce dell'efficacia della terapia antiangiogenica nell’epatocarcinoma.

Outcome analysis of predictors in locally advanced pancreatic cancer

Guidelines report a wide range of options in locally advanced pancreatic cancer (LAPC): definitive chemotherapy or chemoradiotherapy or the emerging stereotactic body radiotherapy (SBRT) (+/- chemotherapy). On behalf of the AIRO (Italian Association of Radiation Oncology and Clinical Oncology) Gastrointestinal Study Group, we collected retrospective clinical data on 419 LAPC from 15 Italian centers. The study protocol (PAULA-1: Pooled Analysis in Unresectable Locally Advanced pancreatic cancer) was approved by institutional review board of S. Orsola-Malpighi Hospital (201/2015/O/OssN). From this large database we performed tree different studies. The first was a retrospective study about 56 LAPC treated with SBRT at a median biologically equivalent dose of 48 Gy +/- chemotherapy. We demonstrated a statistically significant impact of biologically equivalent dose based on an α/β ratio of 10Gy ≥ 48Gy for local control (LC) (p: 0.045) and overall survival (p: 0.042) in LAPC. The second was a retrospective matched-cohort case-control study comparing SBRT (40 patients) and chemoradiation (40 patients) in LAPC in terms of different endpoints. Our findings suggested an equivalence in terms of most outcomes among the two treatments and an advantage of SBRT in terms of LC (p: 0.017). The third study was a retrospective comparison of definitive chemotherapy, chemoradiotherapy and SBRT (+/- chemotherapy) in terms of different outcomes in LAPC. A predictive model for LC in LAPC was also developed reaching an AUC of 68% (CI 58,7%-77,4%). SBRT treatment emerged as a positive predictive factor for improved LC. Findings deriving from our three studies suggest that SBRT is comparable to standard of care (definitive chemotherapy and chemoradiotherapy) in terms of outcomes. SBRT seems to be an emerging therapeutic option in LAPC significantly improving local control. Furthermore, we have shown the potential of a predictive model for LC. Randomized trials are needed to compare these different therapeutic options in LAPC.

Innovative architecture of on-board and on-ground radio systems for space communication

The radio communication system is one of the most critical system of the overall satellite platform: it often represents the only way of communication, between a spacecraft and the Ground Segment or among a constellation of satellites. This thesis focuses on specific innovative architectures for on-board and on-ground radio systems. In particular, this work is an integral part of a space program started in 2004 at the University of Bologna, Forlì campus, which led to the completion of the microsatellite ALMASat-1, successfully launched on-board the VEGA maiden flight. The success of this program led to the development of a second microsatellite, named ALMASat-EO, a three-axis stabilized microsatellite able to capture images of the Earth surface. Therefore, the first objective of this study was focused on the investigation of an innovative, efficient and low cost architecture for on-board radio communication systems. The TT&C system and the high data rate transmitter for images downlink design and realization are thoroughly described in this work, together with the development of the embedded hardware and the adopted antenna systems. Moreover, considering the increasing interest in the development of constellations of microsatellite, in particular those flying in close formations, a careful analysis has been carried out for the development of innovative communication protocols for inter-satellite links. Furthermore, in order to investigate the system aspects of space communications, a study has been carried out at ESOC having as objective the design, implementation and test of two experimental devices for the enhancement of the ESA GS. Thus, a significant portion of this thesis is dedicated to the description of the results of a method for improving the phase stability of GS radio frequency equipments by means of real-time phase compensation and a new way to perform two antennas arraying tracking using already existing ESA tracking stations facilities.

Essays On CEO Compensation: New Evidence On The Managerial-Power Vs. Optimal Contracting Debate

This dissertation analyzes the effect of market analysts’ expectations of share prices (price targets) on executive compensation. It examines how well the estimated effects of price targets on compensation fit with two competing views on determining executive compensation: the arm’s length bargaining model, which assumes that a board seeks to maximize shareholders’ interests, and the managerial power model, which assumes that a board seeks to maximize managers’ compensation (Bebchuk et al. 2005). The first chapter documents the pattern of CEO pay from fiscal year 1996 to 2010. The second chapter analyzes the Institutional Broker Estimate System Detail History Price Target data file, which that reports analysts’ price targets for firms. I show that the number of price target announcements is positively associated with company share price’s volatility, that price targets are predictive of changes in the value of stocks, and that when analysts announce positive (negative) expectations of future stock price, share prices change in the same direction in the short run. The third chapter analyzes the effect of price targets on executive compensation. I find that analysts' price targets alter the composition of executive pay between cash-based compensation and stock-based compensation. When analysts forecast a rise (fall) in the share price for a firm, the compensation package tilts toward stock-based (cash-based) compensation. The substitution effect is stronger in companies that have weaker corporate governance. The fourth chapter explores the effect of the introduction of the Sarbanes-Oxley Act (SOX) in 2002 and its reinforcement in 2006 on the options granting process. I show that the introduction of SOX and its reinforcement eliminated the practice of backdating options but increased “spring-loading” of option grants around price targets announcements. Overall, the dissertation shows that price targets provide insights into the determinants of executive pay in favor of the managerial power model.