Role of Esophagectomy after Chemoradiation Therapy in Patients with Locally Advanced Squamous Cell Carcinoma: A Comparative Analysis Stratified by Clinical Response to Chemoradiation Therapy.

PURPOSE: This study aimed to evaluate the long-term effect of esophagectomy in patients with esophageal squamous cell carcinoma (ESCC) by comparing the chemoradiotherapy (CRT)-only group and the trimodality treatment (TMT) group who received concurrent CRT followed by surgery. MATERIALS AND METHODS: We included 412 operable ESCC patients treated with TMT or CRT between January 2005 and December 2015. The oncological outcomes of the two groups were compared using a weighted Cox proportional-hazards model with inverse probability of treatment weighting (IPTW). RESULTS: The median survival time was 64 and 32 months in the TMT (n=270) and CRT (n=142) groups, respectively (p < 0.001). After IPTW, the median overall survival (OS) remained significantly higher in the TMT group than in the CRT group (61 months vs. 32 months, p=0.016). Moreover, the TMT group showed a better local recurrence-free rate (LRFR, p < 0.001) and distant metastasis-free rate (p=0.007). In the subgroup of patients with clinical complete response (cCR), the OS was not significantly different between the two groups, both before and after IPTW adjustment (p=0.35 and p=0.93). However, among non-cCR patients, the OS was significantly higher in the TMT group (64% vs. 45%, p < 0.001). CONCLUSION: In patients with locally advanced ESCC, TMT was superior to CRT in terms of OS and LRFR. Such difference was more prominent in the non-cCR subgroup. In patients who achieved cCR, esophagectomy was effective in improving LRFR but not OS, suggesting that esophagectomy may be omitted in complete responders.

Definitive chemoradiotherapy versus esophagectomy in patients with clinical T1bN0M0 esophageal squamous cell carcinoma: A retrospective study.

BACKGROUND AND PURPOSE: This study aimed to determine the equivalence between definitive chemoradiotherapy (DCRT) and radical esophagectomy in clinical T1bN0M0 esophageal squamous cell carcinoma (ESCC). MATERIALS AND METHODS: Among 282 patients with cT1bN0M0 ESCC, 238 underwent radical esophagectomy and 44 underwent DCRT. Both treatments were retrospectively compared overall survival (OS), progression-free survival (PFS), and complications. RESULTS: The DCRT group exhibited poorer patient characteristics than the surgery group, especially with mean age (73 vs. 63 years), Eastern Cooperative Oncology Group (ECOG) status, and Charlson Comorbidity Index (p < 0.001, each). The median follow-up duration was 49.5 (range, 0.4-97.0) and 45.5 months (range, 5.0-112.0) in the surgery and DCRT groups, respectively. In the DCRT group, clinical complete response was achieved in 43 patients (97.7%) at 1 month after treatment. The 5-year OS rates were 75.8% and 68.8% (p = 0.135) and the 5-year PFS were 63.8% and 57.8% (p = 0.637) for the surgery and DCRT groups, respectively. Local recurrence rates were identical between the two groups (11.4% and 11.4%), but the distant metastasis rate was lower in the DCRT group (n = 1, 2.27% vs. n = 29, 12.15%). Grade 3-4 hematologic toxicities were observed in 11 patients (25%) of the DCRT group, and 56 patients (23.5%) in the surgery group showed grade 3-5 surgical complications, including mortality (n = 5). CONCLUSION: Based on the non-inferior survival rates, recurrence patterns, and complication rates without critical surgical mortality, DCRT was comparable to esophagectomy for cT1bN0 esophageal squamous cell carcinoma.

Feasibility of automated planning for whole-brain radiation therapy using deep learning.

PURPOSE: The purpose of this study was to develop automated planning for whole-brain radiation therapy (WBRT) using a U-net-based deep-learning model for predicting the multileaf collimator (MLC) shape bypassing the contouring processes. METHODS: A dataset of 55 cases, including 40 training sets, five validation sets, and 10 test sets, was used to predict the static MLC shape. The digitally reconstructed radiograph (DRR) reconstructed from planning CT images as an input layer and the MLC shape as an output layer are connected one-to-one via the U-net modeling. The Dice similarity coefficient (DSC) was used as the loss function in the training and ninefold cross-validation. Dose-volume-histogram (DVH) curves were constructed for assessing the automatic MLC shaping performance. Deep-learning (DL) and manually optimized (MO) approaches were compared based on the DVH curves and dose distributions. RESULTS: The ninefold cross-validation ensemble test results were consistent with DSC values of 94.6 ± 0.4 and 94.7 ± 0.9 in training and validation learnings, respectively. The dose coverages of 95% target volume were (98.0 ± 0.7)% and (98.3 ± 0.8)%, and the maximum doses for the lens as critical organ-at-risk were 2.9 Gy and 3.9 Gy for DL and MO, respectively. The DL technique shows the consistent results in terms of the DVH parameter except for MLC shaping prediction for dose saving of small organs such as lens. CONCLUSIONS: Comparable with the MO plan result, the WBRT plan quality obtained using the DL approach is clinically acceptable. Moreover, the DL approach enables WBRT auto-planning without the time-consuming manual MLC shaping and target contouring.

Prognostic significance of lymph node ratio after neoadjuvant chemoradiation therapy for esophageal squamous cell carcinoma.

PURPOSE: We retrospectively evaluated the prognostic significance of lymph node ratio (LNR) in patients with esophageal squamous cell carcinoma who underwent neoadjuvant concurrent chemoradiation therapy (NCRT) followed by surgery. MATERIALS AND METHODS: In total, 270 patients who underwent NCRT followed by surgery between August 2005 and December 2015 were included. They were divided into three groups: LNR 0 (n = 196), LNR low (0 < LNR ≤ 0.1; n = 63), and LNR high (>0.1; n = 11). The primary endpoint was overall survival (OS), and the secondary endpoints were freedom from local recurrence (FFLR), distant metastasis-free survival (DMFS), and disease-free survival (DFS). RESULTS: The median number of retrieved lymph nodes per patient was 33. Pathologically, 74 patients had positive lymph nodes. The median follow-up duration was 36.1 months, and the median survival period was 68.4 months. There was a significant correlation between LNR and the number of positive lymph nodes (correlation coefficient = 0.763, p < 0.001). There was a substantial difference in the OS among the LNR groups, with 2-year survival rates of 79.0%, 54.0%, and 9.1% in the LNR 0, LNR low, and LNR high groups, respectively (p < 0.001). A marked decrease in FFLP, DMFS, and DFS was observed with the increasing LNR. In subgroup analysis, the survival results of patients with clinically positive lymph node were similar from those of entire cohort. CONCLUSION: LNR is a significant prognostic factor in patients with esophageal squamous cell carcinoma who underwent NCRT followed by surgery. Additional treatment and closer follow-up would be necessary for patients with a high LNR.

Survival and long-term toxicities of pediatric Hodgkin lymphoma after combined modality treatment: a single institute experience.

PURPOSE: To analyze the clinical outcomes and long-term toxicity of pediatric patients with Hodgkin lymphoma after combined-modality treatment (CMT) with involved-field or involved-nodal radiotherapy (RT). MATERIALS AND METHODS: We retrospectively reviewed the records of 27 pediatric Hodgkin lymphoma patients who received CMT at a single institution between January 1990 and July 2017. Patients with stage I-III received a heterogeneous chemotherapy regimen depending on their risk group followed by 19.8-36 Gy RT, with the dose based on their response to the chemotherapy before RT. An optional 9-20 Gy boost was delivered to residual sites. The risk group was determined based on the initial stage, the presence of bulky disease, and any B symptoms. We evaluated overall survival, event-free survival, and long-term toxicities. RESULTS: A total of 27 patients completed the CMT. At a median follow-up of 125 months (range, 9 to 337 months), the estimated 5-year event-free survival and overall survival were 88.9% and 96.3%, respectively. Late symptomatic cardiopulmonary toxicity was not observed, and only one patient was positive on a subclinical obstructive pulmonary function test. The incidence of hypothyroidism was 58.3% among 12 patients with an available thyroid function test. There was one papillary thyroid cancer diagnosed 7.2 years after treatment. CONCLUSION: CMT for pediatric Hodgkin lymphoma with involved-field and involved-nodal RT achieved an excellent survival with only modest long-term toxicity. Smaller-field RT seemed to decrease long-term toxicities and had good local control.