The evaluation of lung doses for radiation pneumoniarisk in stereotactic body radiotherapy: A comparisonof intensity modulated radiotherapy, intensitymodulated arc therapy, cyberknife and helicaltomotherapy

Background: radiation pneumonia (rp) is one of the most extensive sideeffects in stereotactic body radiotherapy (sbrt) of lung cancer. sbrt areperformed by means of intensity modulated radiotherapy (imrt), intensitymodulated arc therapy (imat), cyberknife (ck) or helical tomotherapy (ht)treatment methods. in this study, we performed a plan study to determinethe plan parameter such as the mean lung dose (mld), v20gy lung volumeand v5gy lung volume in the evaluation of rp risk in the treatment of lungwith sbrt. materials and methods: fifteen patients with lung cancer whohad a tumor diameter of less than 5 cm and peripheral located were includedto this study. intensity modulated radiotherapy, intensity modulated arctherapy, cyberknife and helical tomotherapy plans were separately createdfor each patients. for each plan, a total of 54 gy dose were given to planningtarget volume (ptv) in 3 fractions using a dose of 18 gy per fraction. results:in each technique for all parameters of ptv and critical organ doses (oar)meet the required criteria. total lung mld were found as 3.21 gy and totallung v20gy volume were found as 4.05 cc, total lung v5gy volume were foundas 14.06 cc as the lowest value in imrt-sbrt plan. conclusion: whentreatment plans are evaluated in terms of rp risk, total lung mld, total lungv20gy volume and contralateral lung v5gy volume are found the lower in imrt- sbrt plan than other sbrt techniques. we suggest that imrt-sbrtirradiation should be preferred in lung radiotherapy in case of high rp risk.