Is a Clinical Target Volume (CTV) Necessary in the Treatment of Lung Cancer in the Modern Era Combining 4-D Imaging and Image-guided Radiotherapy (IGRT)?

Academic Article

Abstract

  • OBJECTIVE: We hypothesized that omission of clinical target volumes (CTV) in lung cancer radiotherapy would not compromise control by determining retrospectively if the addition of a CTV would encompass the site of failure. METHODS: Stage II-III patients were treated from 2009-2012 with daily cone-beam imaging and a 5 mm planning target volume (PTV) without a CTV. PTVs were expanded 1 cm and termed CTVretro. Recurrences were scored as 1) within the PTV, 2) within CTVretro, or 3) outside the PTV. Locoregional control (LRC), distant control (DC), progression-free survival (PFS), and overall survival (OS) were estimated. RESULT: Among 110 patients, Stage IIIA 57%, IIIB 32%, IIA 4%, and IIB 7%. Eighty-six percent of Stage III patients received chemotherapy. Median dose was 70 Gy (45-74 Gy) and fraction size ranged from 1.5-2.7 Gy. Median follow-up was 12 months, median OS was 22 months (95% CI 19-30 months), and LRC at two years was 69%. Fourteen local and eight regional events were scored with two CTVretro failures equating to a two-year CTV failure-free survival of 98%. CONCLUSION: Omission of a 1 cm CTV expansion appears feasible based on only two events among 110 patients and should be considered in radiation planning.
  • Authors

    Published In

  • Cureus  Journal
  • Keywords

  • clinical target volume, image-guided radiation therapy, lung cancer, non-small cell lung cancers (nsclc), radiation treatment planning
  • Digital Object Identifier (doi)

    Author List

  • Kilburn JM; Lucas JT; Soike MH; Ayala-Peacock DN; Blackstock AW; Hinson WH; Munley MT; Petty WJ; Urbanic JJ
  • Start Page

  • e466
  • Volume

  • 8
  • Issue

  • 1