Stereotactic ablative radiation therapy for centrally located early stage or isolated parenchymal recurrences of non-small cell lung cancer: how to fly in a "no fly zone"

Int J Radiat Oncol Biol Phys. 2014 Apr 1;88(5):1120-8. doi: 10.1016/j.ijrobp.2014.01.022.

Abstract

Purpose: We extended our previous experience with stereotactic ablative radiation therapy (SABR; 50 Gy in 4 fractions) for centrally located non-small cell lung cancer (NSCLC); explored the use of 70 Gy in 10 fractions for cases in which dose-volume constraints could not be met with the previous regimen; and suggested modified dose-volume constraints.

Methods and materials: Four-dimensional computed tomography (4DCT)-based volumetric image-guided SABR was used for 100 patients with biopsy-proven, central T1-T2N0M0 (n=81) or isolated parenchymal recurrence of NSCLC (n=19). All disease was staged with positron emission tomography/CT; all tumors were within 2 cm of the bronchial tree, trachea, major vessels, esophagus, heart, pericardium, brachial plexus, or vertebral body. Endpoints were toxicity, overall survival (OS), local and regional control, and distant metastasis.

Results: At a median follow-up time of 30.6 months, median OS time was 55.6 months, and the 3-year OS rate was 70.5%. Three-year cumulative actuarial local, regional, and distant control rates were 96.5%, 87.9%, and 77.2%, respectively. The most common toxicities were chest-wall pain (18% grade 1, 13% grade 2) and radiation pneumonitis (11% grade 2 and 1% grade 3). No patient experienced grade 4 or 5 toxicity. Among the 82 patients receiving 50 Gy in 4 fractions, multivariate analyses showed mean total lung dose >6 Gy, V20 >12%, or ipsilateral lung V30 >15% to independently predict radiation pneumonitis; and 3 of 9 patients with brachial plexus Dmax >35 Gy experienced brachial neuropathy versus none of 73 patients with brachial Dmax <35 Gy (P=.001). Other toxicities were analyzed and new dose-volume constraints are proposed.

Conclusions: SABR for centrally located lesions produces clinical outcomes similar to those for peripheral lesions when normal tissue constraints are respected.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Algorithms
  • Biopsy
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Carcinoma, Non-Small-Cell Lung / surgery*
  • Female
  • Follow-Up Studies
  • Four-Dimensional Computed Tomography
  • Humans
  • Lung Neoplasms / pathology
  • Lung Neoplasms / surgery*
  • Male
  • Middle Aged
  • Neoplasm Metastasis
  • Neoplasm Recurrence, Local / diagnostic imaging
  • Neoplasm Recurrence, Local / surgery
  • Prospective Studies
  • Radiation Pneumonitis / etiology
  • Radiosurgery / methods*
  • Radiotherapy Planning, Computer-Assisted / methods
  • Registries
  • Time Factors
  • Tomography, X-Ray Computed
  • Treatment Outcome