title: Treatment outcomes and patterns of radiologic appearance after hypofractionated image-guided radiotherapy delivered with helical tomotherapy (HHT) for lung tumours.
abstract: OBJECTIVE
  To evaluate treatment outcomes and patterns of CT lung injury after hypofractionated image-guided radiotherapy delivered with helical tomotherapy (HHT) in a series of inoperable lung lesions.
  
  
  METHODS
  68 patients who were medically inoperable (69 lesions) without evidence of viable extrathoracic disease were included. Dose prescription was driven by tumour location (hilar/pericentral vs peripheral) and/or target volume. 52% of the lesions received a biological equivalent dose (BED10) ≥100 Gy. Assessment of tumour response was based on the Response Evaluation Criteria in Solid Tumours 1.1 criteria coupled with fluorine-18 fludeoxyglucose/positron emission tomography-CT. Toxicity monitoring was focused on treatment-related pulmonary adverse events according to the Common Terminology Criteria for Adverse Events v. 4.0. Acute and late events were classified as radiation pneumonitis (RP) and radiation fibrosis (RF), respectively. Survival curves were calculated using the Kaplan-Meier method. Univariate and multivariate analyses of survival were performed using the Cox proportional hazards model.
  
  
  RESULTS
  After a median follow-up of 12 months (range, 3-31 months), no instances of ≥Grade 4 RP was documented, and clinically severe (Grade 3) RP occurred in 5.8% of the patients. 2 (3%) patients developed a late severe (≥Grade 3) symptomatic RF. No specific pattern of CT lung injury was demonstrated, in both acute and late settings. Median overall survival (OS) and progression-free survival (PFS) for the entire population were 30.8 and 14.1 months, respectively. At multivariate analysis (MVA), BED10≥ 100 Gy and KPS ≥ 90 emerged as significant prognostic factors for OS (p = 0.01 and p = 0.001, respectively), and BED10≥ 100 Gy for PFS (p = 0.02).
  
  
  CONCLUSIONS
  Our findings show that HHT adjusted for tumour location and/or target volume is an effective treatment with an acceptable toxicity profile in patients who are medically inoperable with lung tumours and is not associated with a specific pattern of lung injury. Therefore, it can represent a viable option when conventional stereotactic ablative radiotherapy facilities are not available. Advances in knowledge: The present study is among the largest series addressing the role of HHT for inoperable lung tumours. This technique is safe and effective and is not associated with a specific pattern of lung injury, at least at early and average time points.
authors.affiliation: 1 Department of Radiation Oncology, San Camillo-Forlanini Hospitals, Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Arcangeli
authors.affiliation: 2 Department of Radiation Oncology, S. Maria della Misericordia University Hospital, Perugia, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Falcinelli
authors.affiliation: 3 Department of Radiation Oncology, S. Andrea University Hospital, Rome, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Bracci
authors.affiliation: 3 Department of Radiation Oncology, S. Andrea University Hospital, Rome, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Greco
authors.affiliation: 1 Department of Radiation Oncology, San Camillo-Forlanini Hospitals, Rome, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Monaco
authors.affiliation: 1 Department of Radiation Oncology, San Camillo-Forlanini Hospitals, Rome, Italy.
authors.forename: Jessica
authors.initials: J
authors.lastname: Dognini
authors.affiliation: 1 Department of Radiation Oncology, San Camillo-Forlanini Hospitals, Rome, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Chiostrini
authors.affiliation: 2 Department of Radiation Oncology, S. Maria della Misericordia University Hospital, Perugia, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Bellavita
authors.affiliation: 2 Department of Radiation Oncology, S. Maria della Misericordia University Hospital, Perugia, Italy.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Aristei
authors.affiliation: 1 Department of Radiation Oncology, San Camillo-Forlanini Hospitals, Rome, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Donato
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D015641:Radiography, Interventional / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D015996:Survival Rate; D036542:Tomography, Spiral Computed / Q000379:methods*; D016896:Treatment Outcome