Is pectus excavatum a risk factor for radiation‐induced lung disease in patients undergoing radiation therapy following breast‐conserving surgery?

• Published in: Thoracic cancer 2019-02, Vol.10 (2), p.203-208
• Main Authors: Ishibashi, Naoya, Maebayashi, Toshiya, Aizawa, Takuya, Sakaguchi, Masakuni, Hata, Masaharu, Sakurai, Kenichi, Okada, Masahiro
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Breast cancer; Breast Neoplasms - pathology; Breast Neoplasms - radiotherapy; Breast Neoplasms - surgery; Cancer therapies; Dosimetry; Female; Follow-Up Studies; Funnel Chest - etiology; Funnel Chest - pathology; Humans; Lung diseases; Lung Diseases - etiology; Lung Diseases - pathology; Lungs; Mastectomy, Segmental - adverse effects; Middle Aged; Neoplasms, Radiation-Induced - etiology; Neoplasms, Radiation-Induced - pathology; Original; pectus excavatum; Prognosis; Radiation Injuries - etiology; Radiation Injuries - pathology; Radiation therapy; radiation‐induced lung disease; Radiotherapy, Conformal - adverse effects; Retrospective Studies; Risk Factors; Statistical analysis; Studies; Surgery; Tomography
• ISSN: 1759-7706; 1759-7714
• DOI: 10.1111/1759-7714.12933

Background The relationship between radiation dose to the ipsilateral lung and subsequent radiation‐induced lung disease (RILD) in breast cancer patients with pectus excavatum (PE) undergoing radiation therapy (RT) to residual breast tissue after breast‐conserving surgery has not yet been established. The incidence of RILD in such patients with PE, meaning that a large volume of the lung is within the radiation field, has not been determined. Therefore, the aim of this study was to determine the relationship between these factors. Methods The study cohort comprised 133 women who underwent three‐dimensional conformal RT to residual breast tissue after breast‐conserving surgery for breast cancer. Diagnoses of PE were based on Haller's, frontosagittal, and Monden's depression indices. Radiation doses to the ipsilateral lung were established from dose‐volume histograms. Results Fifty of the 133 participants (37.6%) were diagnosed with RILD; all were asymptomatic. Multivariate analysis revealed a significant correlation between the incidence of RILD and the administration of > 30 Gy (V30). Surprisingly, although patients with PE received higher ipsilateral lung doses, they were less likely to develop RILD than those without PE. Conclusions Our data indicate that the incidence of RILD is correlated with the administration of > 30 Gy (V30) and that PE is not a risk factor for RILD after RT to residual breast tissue after breast‐conserving surgery for breast cancer. Surprisingly, individuals with PE may have a lower incidence of RILD than those without this condition.