IMRT Head and Neck Cancer Treatment Plans with a Novel Fast Ring-Gantry Radiotherapy System

Purpose/Objective(s) A novel fast ring-gantry radiotherapy system delivers radiation beamlets using a high-speed binary multi-leaf collimator (100 transitions /sec). This study investigated plan quality and delivery efficiency of IMRT Head and Neck (H&N) cancer cases using the novel radiotherapy system. Materials/Methods Three IMRT H&N cases were planned on the novel radiotherapy treatment planning system using the ICRU 83 guidelines to deliver 54 Gy to the planning target volume (PTV) in 30 fractions. Each H&N case was planned with 1 and 2 cm field width (FW). The treatment time-PTV correlation coefficient (C2TT-PTV), homogeneity index (HI), conformity index (CI), mean dose (Dmean), Dnear-max (D2%), Dnear-min (D98%) of the PTVs and the mean dose to the 19 organs-at-risk (OARs) were investigated. Results All the H&N plans met the ICRU 83 guidelines. The C2TT-PTV for 1 cm FW and 2 cm FW were 0.95 and 0.99, respectively. In addition, the average HI and CI for 1 cm FW were 1.20±0.00 and 1.23±0.15, while the average HI and CI for 2 cm FW were 1.23±0.06 and 1.30±0.17. The average Dmean, D98% and D2% were 57.65±0.36, 50.56±4.07 and 62.63±1.17 Gy for 1 cm FW. Also, the average Dmean, D98% and D2% for 2 cm FW were 57.68±0.69, 50.77±3.53 and 63.2±1.95 Gy, respectively. Conclusion The novel radiotherapy system can be used to deliver H&N cancer radiotherapy treatment efficiently while meeting dosimetric constraints and achieving homogenous dose distribution to the PTV structures. A novel fast ring-gantry radiotherapy system delivers radiation beamlets using a high-speed binary multi-leaf collimator (100 transitions /sec). This study investigated plan quality and delivery efficiency of IMRT Head and Neck (H&N) cancer cases using the novel radiotherapy system. Three IMRT H&N cases were planned on the novel radiotherapy treatment planning system using the ICRU 83 guidelines to deliver 54 Gy to the planning target volume (PTV) in 30 fractions. Each H&N case was planned with 1 and 2 cm field width (FW). The treatment time-PTV correlation coefficient (C2TT-PTV), homogeneity index (HI), conformity index (CI), mean dose (Dmean), Dnear-max (D2%), Dnear-min (D98%) of the PTVs and the mean dose to the 19 organs-at-risk (OARs) were investigated. All the H&N plans met the ICRU 83 guidelines. The C2TT-PTV for 1 cm FW and 2 cm FW were 0.95 and 0.99, respectively. In addition, the average HI and CI for 1 cm FW were 1.20±0.00 and 1.23±0.15, while the average HI and CI for 2 cm FW were 1.23±0.06 and 1.30±0.17. The average Dmean, D98% and D2% were 57.65±0.36, 50.56±4.07 and 62.63±1.17 Gy for 1 cm FW. Also, the average Dmean, D98% and D2% for 2 cm FW were 57.68±0.69, 50.77±3.53 and 63.2±1.95 Gy, respectively. The novel radiotherapy system can be used to deliver H&N cancer radiotherapy treatment efficiently while meeting dosimetric constraints and achieving homogenous dose distribution to the PTV structures.