<p>Outcomes Following Stereotactic Body Radiotherapy with Intensity-Modulated Therapy versus Three-Dimensional Conformal Radiotherapy in Early Stage Non-Small Cell Lung Cancer</p>

Abstract

IntroductionThe treatment techniques used for stereotactic body radiation therapy (SBRT) for early-stage lung cancer continue to evolve. In this study, clinical outcomes following SBRT were evaluated according to the use of either 3D conformal radiotherapy (3DCRT) or intensity-modulated radiation therapy (IMRT).Patients and methodsPatients with stage I NSCLC who received SBRT from 2007 to 2015 were retrospectively reviewed. Disease control and survival were assessed using Kaplan-Meier estimates. Dosimetric analyses for target dose heterogeneity and coverage were performed.ResultsA total of 297 patients with 351 lesions were included. 3DCRT was used in 52% and IMRT in 48%. IMRT was utilized at a higher rate in more recent years. The most common regimens were 48 Gy in 4 fractions and 54–60 Gy in 3 fractions. With a median follow up of 22.7 months, there were 17 local failures for a crude relapse rate of 5.7%. Local failure did not differ in patients treated with 3DCRT and IMRT (4.9% vs 6.5%, p=0.573). Mean dose to gross tumor volume (GTV) as a percent of prescription dose was higher with 3DCRT compared with IMRT (107.7% vs 103.6%, p < 0.0001). Tumor stage, histology, and SBRT regimen did not correlate with local tumor control. Overall survival for the entire population approximated 72% at 2 years. Treatment was well tolerated with 6 documented grade 3+ events.ConclusionIn this single-institution cohort of SBRT for early-stage NSCLC, there was no discernible difference in clinical outcomes between those treated with 3DCRT and IMRT.

Impact of Maximum Point Dose Within the Planning Target Volume on Local Control of Nonsmall Cell Lung Cancer Treated With Stereotactic Body Radiotherapy

“…Other studies suggest that mean PTV dose or even mean GTV dose should be the focus of lung SBRT prescriptions 11,12 . In addition, dose distributions can vary based on the treatment technique, though studies comparing 3-dimensional conformal radiotherapy and intensity-modulated radiotherapy have found no difference in clinical outcomes and toxicities for early-stage NSCLC patients treated with SBRT 16,17 . Recognizing that different approaches can achieve the same result, there is nevertheless a wide range of SBRT prescribing practices, and the ideal dose gradient or maximum dose is unclear.…”

Dosimetric Evaluation of Simplified Knowledge-Based Plan with an Extensive Stepping Validation Approach in Volumetric-Modulated Arc Therapy-Stereotactic Body Radiotherapy for Lung Cancer

“…[ 2 3 4 ] Intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) can achieve higher conformity and have greater sparing of normal organs than conventional three-dimensional conformal radiotherapy (3D-CRT) with multiple noncoplanar beams. [ 5 6 7 8 9 ] The use of SBRT with IMRT/VMAT techniques is also well-tolerated and effective for lung tumors. [ 4 10 ] However, differences in the skill and experience levels of planners and institutions can cause large variations in IMRT/VMAT plan quality.…”

Dosimetric comparison of coplanar and noncoplanar beam arrangements for radiotherapy of patients with lung cancer: A meta‐analysis

“…recent studies, [4][5][6][7][8] SBRT has exhibited favorable clinical outcomes. To achieve a high local control rate and a low toxicity, SBRT treatment of the lung cancer has been performed on gantry-mounted linear accelerators (LINACs) using noncoplanar or coplanar three-dimensional conformal radiation therapy (3DCRT), 9,10 intensity modulated radiation therapy (IMRT), 10,11 and volumetric modulated arc therapy (VMAT) [12][13][14] to acquire optimal dose distributions [15][16][17][18] and increase the efficiency of treatment delivery.…”