en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;"><span style="font-size:10pt"><span style="text-justify:newspaper"><span style="text-kashida-space:50%"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black"><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Background</span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-US">:</span></span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">The optimal inter-fraction interval in fractionated thoracic radiosurgery remains unclear. Several institutions maintain at least a 48-hour interval between each radiosurgery fraction. However, evidence supporting such radiosurgery schedule is lacking. Since 2014, we have performed daily fractionated thoracic radiosurgery without interruption. In this study, we evaluated the safety of daily administration of fractionated thoracic radiosurgery in patients with primary or metastatic lung cancer.&nbsp;</span></span></span></span></span></span></span></span></span><span lang="en-US" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold">Materials and methods</span></span></span></span><span lang="en-US" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"><span style="color:#1f497d"><span style="font-weight:bold">:</span></span></span><span lang="en-US" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"> Patients who received radical or salvage fractionated radiosurgery for treatment of primary or metastatic lung cancer were included in this study. All patients received fractionated radiosurgery divided into 2-4 fractions administered daily without interruption. Radiosurgery-induced toxicities were evaluated.</span><span style="color: black; font-family: Calibri; font-size: 10pt; text-align: justify;"> </span><span lang="en-US" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold">Results</span></span></span></span><span lang="en-US" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"><span style="color:#1f497d"><span style="font-weight:bold">:</span></span></span><span style="color: black; font-family: Calibri; font-size: 10pt; text-align: justify;"> </span><span lang="en-US" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;">Eighty-eight patients and 94 lung masses were treated. Radiosurgery-induced leukopenia and grade 5 toxicity did not occur. One patient experienced radiosurgery-induced grade 4 pneumonitis and dyspnea. Grade 3 pneumonitis, dyspnea, and fatigue developed in 23 (24.5%), 2 (2.1%), and 2 (2.1%) patients, respectively. Four (4.3%) patients experienced rib fracture. Dyspnea, fatigue, nausea, and pneumonitis were more common and severe in patients with central lung lesions. In contrast, dermatitis and rib fracture developed only in patients with peripheral lung lesions.</span><span style="color: black; font-family: Calibri; font-size: 10pt; text-align: justify;"> </span><span lang="en-US" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold">Conclusions</span></span></span></span><span lang="en-US" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"><span style="color:#1f497d"><span style="font-weight:bold">:</span></span></span><span lang="en-US" style="color: black; font-family: Calibri; text-align: justify; font-size: 9pt;"> Daily fractionated radiosurgery is safe and well-tolerated in patients with primary or metastatic lung cancer. For patient convenience and better treatment outcomes, daily-fractionated thoracic radiosurgery can be considered.</span></div> Dose fractionation, lung neoplasm, radiosurgery, safety, toxicity. 687 692 http://ijrr.com/browse.php?a_code=A-10-1-964&slc_lang=en&sid=1 M. Kong kongmoonkyoo@khu.ac.kr 7900319475328460022161 7900319475328460022161 Yes Department of Radiation Oncology, Kyung Hee University Medical Center, Kyung Hee University College of Medicine, Seoul, Republic of Korea Y.J. Lim 7900319475328460022162 7900319475328460022162 No Department of Radiation Oncology, Kyung Hee University Medical Center, Kyung Hee University College of Medicine, Seoul, Republic of Korea