A retrospective long-term follow-up study of stereotactic body radiotherapy for non-small cell lung cancer from a single institution: Incidence of late local recurrence
Menée au Japon à partir de données portant sur 216 patients atteints d'un cancer primitif ou récidivant du poumon non à petites cellules et traités par radiothérapie corporelle stéréotaxique entre 1998 et 2014, cette étude évalue le délai avant récidive ainsi que le taux de récidive locale à long terme, puis identifie les facteurs pronostiques associés
Purpose : To assess the local recurrence (LR) rate and timing after stereotactic body radiotherapy (SBRT) for non-small cell lung cancer (NSCLC) using long-term follow-up data from a single institution. Methods and Materials : Patients with primary or recurrent NSCLC with or without pathologic verification, with tumors <3 cm, treated with SBRT (isocenter prescription of 48 Gy in four fractions) between April 1998 and August 2014, and with more than 6 months follow-up were eligible. LR rate was calculated by the cumulative incidence function, accounting for death as a competing risk. Univariate and multivariate analyses were performed to identify prognostic factors for LR. Results : A total of 216 patients and 230 tumors were analyzed. Median follow-up time of tumors without LR was 3.9 years and the crude number of LR cases was 49 (21%). The actuarial rate of LR was 19% (95%CI, 14–25) at 5 years. The number of LR cases in each time period was 10 in year 1, 17 in year 2, 9 in year 3, 3 in year 4, 3 in year 5, and 7 after 5 years. Among 73 tumors with more than 5 years follow-up, we observed 7 late LRs. The number of tumor histology with late LR was 3/2/2 for adenocarcinoma/squamous cell carcinoma/unknown (one of the unknown cases was confirmed as adenocarcinoma following salvage surgery). Median time to LR was 2.1 years (IQR, 1.5–4.2) for adenocarcinoma compared with 1.3 years (IQR, 1.0–2.3) for squamous cell carcinoma. Multivariate analysis revealed that larger tumor size, squamous cell histology compared with adenocarcinoma, and use of abdominal compression for respiratory motion management were independent negative prognostic factors for LR. Conclusions : Long-term follow-up data demonstrated that late LR was not uncommon and that careful follow-up after SBRT is needed, especially in patients with adenocarcinoma.
http://www.redjournal.org/article/S0360-3016(18)30116-0/fulltext 2018