Advantages of CyberKnife for inoperable stage I peripheral non-small-cell lung cancer compared to three-dimensional conformal radiotherapy

Abstract

Abstract. This study was conducted to compare the clinical curative effect and acute radiation lung reactions between CyberKnife (CK) and three-dimensional conformal radiotherapy (3DCRT) treatment for inoperable stage I peripheral non-small-cell lung cancer (NSCLC). We retrospectively analyzed 68 patients with inoperable stage I peripheral NSCLC between 2012 and 2013 in our institution. The CK patients were treated with 42-60 Gy in three fractions, while the 3DCRT patients were treated with a total of 60 Gy, at 2 Gy per fraction. The patients were followed up and the clinical outcome was evaluated according to the Response Evaluation Criteria in Solid Tumours. We assessed the presence of acute radiation pneumonitis and pulmonary function status by thoracic scan and pulmonary function tests following CK and 3DCRT treatment. The binary univariate logistic regression analysis demonstrated that treatment method and forced expiratory volume in 1 sec̸forced vital capacity (FEV1̸FVC) prior to treatment (pre-FEV1̸FVC) were the main factors affecting the risk of radiation pneumonitis. The analysis of these factors through multivariate logistic regression method demonstrated that treatment method for grade 1 and 2 [odds ratio (OR)=7.866 and 11.334, respectively) and pre-FEV1/FVC for grade 1, 2 and 3 (OR=5.062, 11.498 and 15.042, respectively) were significant factors affecting the risk of radiation pneumonitis (P<0.05). The 68 patients were divided into two subgroups using the threshold of pre-FEV1/FVC selected by the receiver operating characteristic curve. There were significant differences between the 3DCRT and CK treatment in both the pre-FEV1̸FVC <68% and ≥68% subgroups for radiation pneumonitis (P=0.023 and 0.002, respectively). There was no statistically significant change in FVC, FEV1 and carbon monoxide diffusion capacity (DCLO) in the CK group, whereas there was a decrease in DCLO in the 3DCRT group. The complete remission rate was 40 vs. 34.2% at 1 year in the CK and 3DCRT groups, respectively. In conclusion, in this cohort of patients with inoperable stage I peripheral NSCLC, CK appears to be a safe and superior alternative to conventionally fractionated radiotherapy.

A meta-analysis comparing stereotactic body radiotherapy vs conventional radiotherapy in inoperable stage I non-small cell lung cancer

“…intervention and comparison: SBRT versus CRT (including conventional radiotherapy, [ 15 , 16 , 19 , 21 , 26 ] conventional fractionated radiotherapy, [ 17 , 20 , 23 , 25 , 27 ] 3D conformal radiotherapy, [ 9 , 11 , 13 , 14 , 18 ] and accelerated hypofractionated radiotherapy [ 13 ] );…”

Cyberknife® stereotactic radiation therapy for stage I lung cancer and pulmonary metastases: evaluation of local control at 24 months

“…Cyberknife ® stereotactic radiation therapy for stage I lung cancer and pulmonary metastases: evaluation of local control at 24 months movement, loco-regional control and survival have proven to be disappointing with conventional radiation therapy even if the SPACE phase II randomized study showed encouraging results for high precision 3D radiotherapy. This is probably due to a reduced biological dose-effect and a lower conformity index (1).…”

“…Prior studies of CyberKnife ® have reported local control rates of 90-97% at 2-3 years of follow-up, with low toxicities (1,(5)(6)(7). Treatment with CyberKnife ® can also allow for a sustainable local control rate of 89% with a median follow-up of 12 months in oligometastatic lesions, with few morbidities (8).…”

“…Stereotactic body radiotherapy (SBRT) is a curative option for patients with stage I NSCLC who refuse to undergo surgery or who are medically inoperable. Real-time tracking with CyberKnife ® offers a highly precise treatment with narrow margins (1,2). SBRT also appears to be a suitable alternative to surgery for lung metastases (3,4), although the literature is less abundant in this regard.…”

Protein Oxidation in the Lungs of C57BL/6J Mice Following X-Irradiation

“…Pulmonary injuries are limiting factors for the use of radiotherapy for the treatment of thoracic cancers [1,2,3,4,5,6]. Clinically significant lung injury has been estimated to occur in ~10%–30% of patients undergoing radiotherapy for cancers in the thoracic region [7,8], and pulmonary effects have also been observed in patients undergoing radiotherapy for cancer treatment or bone marrow transplantation [9,10,11,12].…”