High-Dose Thoracic Re-irradiation of Lung Cancer Using Highly Conformal Radiotherapy Is Effective with Acceptable Toxicity
- Author:
Ji Hyun HONG
1
;
Yeon Sil KIM
;
Sea Won LEE
;
So Jung LEE
;
Jin Hyung KANG
;
Suk Hee HONG
;
Ju Young HONG
;
GeumSeong CHEON
Author Information
- Publication Type:Original Article
- Keywords: Lung neoplasms; Re-irradiation; Intensity modulated radiotherapy; Radiosurgery
- MeSH: Follow-Up Studies; Humans; Lung Neoplasms; Lung; Neoplasm Metastasis; Radiosurgery; Radiotherapy; Radiotherapy, Conformal; Re-Irradiation; Recurrence; Retrospective Studies
- From:Cancer Research and Treatment 2019;51(3):1156-1166
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: Thoracic re-irradiation (re-RT) of lung cancer has been challenged by the tolerance doses of normal tissues. We retrospectively analyzed local control, overall survival (OS) and toxicity after thoracic re-RT using highly conformal radiotherapy, such as intensity modulated radiotherapy and stereotactic body radiotherapy. MATERIALS AND METHODS: Thirty-one patients who received high-dose thoracic re-RT were analyzed. Doses were recalculated to determine biologically equivalent doses. The median interval to re-RT was 15.1 months (range, 4.4 to 56.3 months), the median initial dose was 79.2 Gy₁₀ (range, 51.75 to 150 Gy₁₀), and the median re-RT dose was 68.8 Gy₁₀ (range, 43.2 to 132 Gy₁₀). RESULTS: Eighteen (58.1%) and eleven (35.5%) patients showed loco-regional recurrence and distant metastasis, respectively, after 17.4 months of median follow-up. The 1-year and 2-year local control rates were 60.2% and 43.7%, respectively. The median loco-regional recurrence-free-survival (LRFS) was 15.4 months, and the median OS was 20.4 months. The cumulative and re-RT biologically equivalent dose for α/β=10 (BED₁₀) doses were the most significant prognostic factors. Cumulative BED₁₀ ≥145 Gy₁₀ and re-RT BED₁₀≥68.7 Gy₁₀ were significantly associated with longer OS (p=0.029 and p=0.012, respectively) and LRFS (p=0.003 and p=0.000, respectively). The most frequent acute toxicity was grade 1-2 pulmonary toxicity (41.9%). No acute grade 3 or higher toxicities occurred. CONCLUSION: Our results show that high-dose thoracic re-RT of lung cancer can be safely delivered using highly conformal radiotherapy with favorable survival and acceptable toxicity. An optimal strategy to select patients who would benefit from re-RT is crucial in extending the indications and improving the efficacy with a sufficiently high dose.
