Clinical Application of a Hybrid RapidArc Radiotherapy Technique for Locally Advanced Lung Cancer

Abstract

Objective: Radiation treatment planning for locally advanced lung cancer can be technically challenging, as delivery of !60 Gy to large volumes with concurrent chemotherapy is often associated with significant risk of normal tissue toxicity. We clinically implemented a novel hybrid RapidArc technique in patients with lung cancer and compared these plans with 3-dimensional conformal radiotherapy and RapidArc-only plans. Materials/Methods: Hybrid RapidArc was used to treat 11 patients with locally advanced lung cancer having bulky mediastinal adenopathy. All 11 patients received concurrent chemotherapy. All underwent a 4-dimensional computed tomography planning scan. Hybrid RapidArc plans concurrently combined static (60%) and RapidArc (40%) beams. All cases were replanned using 3-to 5-field 3-dimensional conformal radiotherapy and RapidArc technique as controls. Results: Significant reductions in dose were observed in hybrid RapidArc plans compared to 3-dimensional conformal radiotherapy plans for total lung V20 and mean (À2% and À0.6 Gy); contralateral lung mean (À2.92 Gy); and esophagus V60 and mean (À16.0% and À2.2 Gy; all P < .05). Contralateral lung doses were significantly lower for hybrid RapidArc plans compared to RapidArc-only plans (all P < .05). Compared to 3-dimensional conformal radiotherapy, heart V60 and mean dose were significantly improved with hybrid RapidArc (3% vs 5%, P ¼ .04 and 16.32 Gy vs 16.65 Gy, P ¼ .03). However, heart V40 and V45 and maximum spinal cord dose were significantly lower with RapidArc plans compared to hybrid RapidArc plans. Conformity and homogeneity were significantly better with hybrid RapidArc plans compared to 3-dimensional conformal radiotherapy plans (P < .05). Treatment was well tolerated, with no grade 3þ toxicities. Conclusion: To our knowledge, this is the first report on the clinical application of hybrid RapidArc in patients with locally advanced lung cancer. Hybrid RapidArc permitted safe delivery of 60 to 66 Gy to large lung tumors with concurrent chemotherapy and demonstrated advantages for reduction in low-dose lung volumes, esophageal dose, and mean heart dose.

Dynamic conformal arc radiotherapy for locally advanced lung cancer: a comparison with static-beam conformal radiotherapy

“…Studies have shown an increased risk of radiation pneumonitis with a lung V5 > 60%. Silva et al compared hybrid VMAT, VMAT-only, and 3DCRT plans in patients with locally advanced lung cancer [ 9 ] and reported significant reductions in the dose to normal organs, including the lungs, using hybrid VMAT compared with the other plans. After a median follow-up time of 17 months, there was no symptomatic radiation pneumonitis in patients with a median V5 value of 57–58%.…”

Hybrid Tomo‐Helical and Tomo‐Direct radiotherapy for localized prostate cancer

“…Hybrid Rapid Arc plans were created with the combination of static (60%) and Rapid Arc (40%) beams and showed advantages for reducing the OARs dose. 33 We tried different fraction combinations for the hybrid plans in this study. We conclude that 45 Gy/18 fxs for TH and 25 Gy/10 fxs for TD is the best combination.…”

“…presented the clinical application of the hybrid Rapid Arc in patients with locally advanced lung cancer. Hybrid Rapid Arc plans were created with the combination of static (60%) and Rapid Arc (40%) beams and showed advantages for reducing the OARs dose 33 . We tried different fraction combinations for the hybrid plans in this study.…”