Study objective: To evaluate the effects of induction concurrent chemoradiotherapy (cCRT) on pulmonary function and postoperative acute respiratory complications (PARCs).
Design: A retrospective review of our patients treated with induction cCRT to determine the impact on pulmonary function and identify predictors of PARCs. Correlations were sought between patient demographics, clinical characteristics, pre-cCRT and post-cCRT pulmonary function, radiotherapy dose, chemotherapy agents, and the development of PARCs.
Participants: One hundred fifty-five patients treated in three separate clinical trials were identified; 47 patients received 30 Gy (150 cGy bid) of radiation concurrently with a single course of cisplatin/5-fluorouracil (5FU), and 108 patients received 45 Gy (150 cGy bid in a split course) concurrent with two courses of either cisplatin/5FU (n = 69) or cisplatin/paclitaxel (n = 39). Esophagectomy was performed in 141 of these 155 patients following cCRT.
Results: cCRT was only associated with significant worsening of the diffusion capacity of the lung for carbon monoxide (Dlco), which decreased a median of 21.7% in the 45-Gy group (p = 0.007), and 8.6% in the 30-Gy group (p = 0.07). This Dlco decrease was statistically greater in the 45-Gy group than in the 30-Gy group (p = 0.02). PARCs developed in 18 patients. Percentage of predicted FEV1 and FVC, both before and after cCRT, were both significantly higher in patients without PARCs than in patients with PARCs (p = 0.031 and p = 0.010, respectively). Post-cCRT Dlco was also significantly worse in patients with PARCs (p = 0.002). PARCs occurred significantly more often among those treated with 45 Gy (17 of 102 patients) compared to those treated with 30 Gy (1 of 39 patients) [p = 0.025]. In the 18 patients with PARCs, the median survival was only 2.1 months. This was significantly less than the 16.4-month median survival in the 123 patients who did not have PARCs (p = 0.001).
Conclusions: In patients treated with induction cCRT, higher radiation doses result in increasing impairment of gas exchange. PARCs were more likely in those patients with lower lung volumes, lower post-cCRT Dlco, and in those receiving higher radiation doses. These acute respiratory complications were also associated with a significant reduction in patient survival.