[1] CNR, Inst Biostruct & Bioimaging, Naples, Italy
[2] Irccs SDN, Image Proc Dept, Naples, Italy
[3] Univ Texas MD Anderson Canc Ctr, Dept Radiat Oncol, Houston, TX 77030 USA
[4] Ist Nazl Fis Nucl, Trento Inst Fundamental Phys & Applicat, Trento, Italy
[5] GSI Helmholtz Ctr Heavy Ion Res, Dept Biophys, Darmstadt, Germany
[6] Univ Texas MD Anderson Canc Ctr, Dept Radiat Phys, Houston, TX 77030 USA