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Zehentmayr F, Söhn M, Exeli AK, Wurstbauer K, Tröller A, Deutschmann H, Fastner G, Fussl C, Steininger P, Kranzinger M, Belka C, Studnicka M, Sedlmayer F. Normal tissue complication models for clinically relevant acute esophagitis (≥ grade 2) in patients treated with dose differentiated accelerated radiotherapy (DART-bid). Radiat Oncol 2015; 10:121. [PMID: 26018527 PMCID: PMC4450607 DOI: 10.1186/s13014-015-0429-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 05/25/2015] [Indexed: 12/13/2022] Open
Abstract
Background One of the primary dose-limiting toxicities during thoracic irradiation is acute esophagitis (AE). The aim of this study is to investigate dosimetric and clinical predictors for AE grade ≥ 2 in patients treated with accelerated radiotherapy for locally advanced non-small cell lung cancer (NSCLC). Patients and methods 66 NSCLC patients were included in the present analysis: 4 stage II, 44 stage IIIA and 18 stage IIIB. All patients received induction chemotherapy followed by dose differentiated accelerated radiotherapy (DART-bid). Depending on size (mean of three perpendicular diameters) tumors were binned in four dose groups: <2.5 cm 73.8 Gy, 2.5–4.5 cm 79.2 Gy, 4.5–6 cm 84.6 Gy, >6 cm 90 Gy. Patients were treated in 3D target splitting technique. In order to estimate the normal tissue complication probability (NTCP), two Lyman models and the cutoff-logistic regression model were fitted to the data with AE ≥ grade 2 as statistical endpoint. Inter-model comparison was performed with the corrected Akaike information criterion (AICc), which calculates the model’s quality of fit (likelihood value) in relation to its complexity (i.e. number of variables in the model) corrected by the number of patients in the dataset. Toxicity was documented prospectively according to RTOG. Results The median follow up was 686 days (range 84–2921 days), 23/66 patients (35 %) experienced AE ≥ grade 2. The actuarial local control rates were 72.6 % and 59.4 % at 2 and 3 years, regional control was 91 % at both time points. The Lyman-MED model (D50 = 32.8 Gy, m = 0.48) and the cutoff dose model (Dc = 38 Gy) provide the most efficient fit to the current dataset. On multivariate analysis V38 (volume of the esophagus that receives 38 Gy or above, 95 %-CI 28.2–57.3) was the most significant predictor of AE ≥ grade 2 (HR = 1.05, CI 1.01–1.09, p = 0.007). Conclusion Following high-dose accelerated radiotherapy the rate of AE ≥ grade 2 is slightly lower than reported for concomitant radio-chemotherapy with the additional benefit of markedly increased loco-regional tumor control. In the current patient cohort the most significant predictor of AE was found to be V38. A second clinically useful parameter in treatment planning may be MED (mean esophageal dose). Electronic supplementary material The online version of this article (doi:10.1186/s13014-015-0429-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Franz Zehentmayr
- Univ.-Klinik für Radiotherapie und Radio-Onkologie, Landeskrankenhaus Salzburg, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria. .,Institute for Research and Development of Advanced Radiation Technologies (radART), Paracelsus Medizinische Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria.
| | - Matthias Söhn
- Department of Radiotherapy and Radiation Oncology, Ludwig-Maximilians-Universität Munich, Marchioninistr. 15, 81377, Munich, Germany.
| | - Ann-Katrin Exeli
- Univ.-Klinik für Radiotherapie und Radio-Onkologie, Landeskrankenhaus Salzburg, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria.
| | - Karl Wurstbauer
- Institute for Research and Development of Advanced Radiation Technologies (radART), Paracelsus Medizinische Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria.
| | - Almut Tröller
- Department of Radiotherapy and Radiation Oncology, Ludwig-Maximilians-Universität Munich, Marchioninistr. 15, 81377, Munich, Germany. .,Department of Radiation Oncology, William Beaumont Health System, 3601 W. Thirteen Mile Road, Royal Oak, MI, 48073, USA.
| | - Heinz Deutschmann
- Univ.-Klinik für Radiotherapie und Radio-Onkologie, Landeskrankenhaus Salzburg, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria. .,Institute for Research and Development of Advanced Radiation Technologies (radART), Paracelsus Medizinische Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria.
| | - Gerd Fastner
- Univ.-Klinik für Radiotherapie und Radio-Onkologie, Landeskrankenhaus Salzburg, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria.
| | - Christoph Fussl
- Univ.-Klinik für Radiotherapie und Radio-Onkologie, Landeskrankenhaus Salzburg, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria.
| | - Philipp Steininger
- Institute for Research and Development of Advanced Radiation Technologies (radART), Paracelsus Medizinische Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria.
| | - Manfred Kranzinger
- Univ.-Klinik für Radiotherapie und Radio-Onkologie, Landeskrankenhaus Salzburg, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria.
| | - Claus Belka
- Department of Radiotherapy and Radiation Oncology, Ludwig-Maximilians-Universität Munich, Marchioninistr. 15, 81377, Munich, Germany.
| | - Michael Studnicka
- Univ.-Klinik für Pneumologie, Landeskrankenhaus Salzburg, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria.
| | - Felix Sedlmayer
- Univ.-Klinik für Radiotherapie und Radio-Onkologie, Landeskrankenhaus Salzburg, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria. .,Institute for Research and Development of Advanced Radiation Technologies (radART), Paracelsus Medizinische Privatuniversität, Müllner Hauptstr. 48, 5020, Salzburg, Austria.
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