Prognostic indicators for radiotherapy of abdominal lymph node metastases from hepatocellular carcinoma.

PURPOSE: To identify prognostic indicators in patients treated with radiotherapy (RT) for metastases from hepatocellular carcinoma (HCC) in abdominal lymph nodes (LNs). PATIENTS AND METHODS: RT was used to treat 65 patients for metastases from HCC in abdominal LNs. Total radiation dose was 30-60 Gy (median 52.8 Gy), with fraction size 1.8-3 Gy. RT was administered five times per week to an equivalent dose in 2-Gy fractions (EQD2; Gy10) of 32.5-65 Gy10 (median 54 Gy10) and an α/ßratio for tumor and acute effects of normal tissue of 10. RESULTS: Median overall survival (OS) in all patients was 8.1 months. LN responders had significantly higher median OS than nonresponders (14.5 vs. 3.7 months, p < 0.05). Multivariate analysis showed that Child-Pugh classification, status of intrahepatic tumor, number of metastatic LNs, and LN response were independently predictive of OS (p < 0.05 each). Based on results of multivariate analysis, patients were prognostically stratified according to pretreatment risk factors, including Child-Pugh classification, intrahepatic tumor status, and number of metastatic LNs; with the expected median OS in patients with ≥ 2, 1, and 0 risk factors being 2.9, 9.8, and 27.6 months, respectively (p < 0.05). CONCLUSION: Our data showed that LN response to RT was an independent prognostic factor for OS in advanced HCC patients with abdominal LN metastases, and suggested that RT for metastatic LNs might improve OS in these patients. In addition, our data suggest that Child-Pugh classification, intrahepatic tumor status, and number of metastatic LNs may be useful prognostic and therapeutic indicators for selecting treatment strategies.

Clinicopathological Outcomes in Patients With Locally Advanced Rectal Cancer Undergoing Preoperative Short-Versus Long-course Chemoradiotherapy With Delayed Surgery.

BACKGROUND/AIM: We aimed to compare the clinicopathological outcomes in patients with locally advanced rectal cancer after short- or long-course concurrent chemoradiotherapy (CCRT) followed by delayed surgery. PATIENTS AND METHODS: The records of 94 patients with cT3-4N0-2M0 rectal cancer who received CCRT between 2010 and 2017 were reviewed. Short-course radiotherapy (RT) was delivered with a median total dose of 25 Gy in five fractions (n=27), and long-course RT was delivered with a median total dose of 50.4 Gy in 28 fractions (n=67). The following concurrent chemotherapy regimens were administered: 5-fluorouracil plus leucovorin in 58 and capecitabine in 24; in 12 cases agents were unknown. The median interval between CCRT and surgery was 8 weeks. Adjuvant chemotherapy was administered after surgery in 80 patients (5-fluorouracil plus leucovorin, n=54; capecitabine, n=9; other, n=14; and unknown, n=3). Propensity-score matching analysis was conducted. RESULTS: The median follow-up duration was 4.3 years. There were no statistically significant differences between the short- and long-course RT groups in sphincter preservation (85.2% vs. 92.5%, p=0.478), pathological complete remission (18.5% vs. 14.9%, p=0.905), downstaging (44.4% vs. 26.9%, p=0.159), and negative circumferential resection margin (92.6% vs. 89.6%, p=0.947) rates. No differences were found in survival outcomes between the short- and long-course groups at 3 years (overall survival: 91.8% vs. 88.1%, p=0.790; disease-free survival, 75.2% vs. 72.5%, p=0.420; locoregional relapse-free survival, 90.5% vs. 98.4%, p=0.180; and distant metastasis-free survival, 79.6% vs. 73.5%, p=0.490). Similar results were observed after PSM. CONCLUSION: Clinically, short-course CCRT may be a feasible alternative to long-course CCRT in patients with locally advanced rectal cancer.

Proton Beam Therapy versus Photon Radiotherapy for Stage I Non-Small Cell Lung Cancer.

Proton beam therapy (PBT) and photon radiotherapy for stage I non-small cell lung cancer (NSCLC) were compared in terms of clinical outcomes and dosimetry. Data were obtained from patients who underwent PBT or photon radiotherapy at two institutions-the only two facilities where PBT is available in the Republic of Korea. Multivariate Cox proportional hazards models and propensity score-matched analyses were used to compare local progression-free survival (PFS) and overall survival (OS). Survival and radiation exposure to the lungs were compared in the matched population. Of 289 patients included in the analyses, 112 and 177 underwent PBT and photon radiotherapy, respectively. With a median follow-up duration of 27 months, the 2-year local PFS and OS rates were 94.0% and 83.0%, respectively. In the multivariate analysis, a biologically effective dose (BED10, using α/ß = 10 Gy) of ≥125 cobalt gray equivalents was significantly associated with improved local PFS and OS. In the matched analyses, the local PFS and OS did not differ between groups. However, PBT showed significantly lower lung and heart radiation exposure in the mean dose, V5, and V10 than photon radiotherapy. PBT significantly reduced radiation exposure to the heart and lungs without worsening disease control in stage I NSCLC patients.

A Comparative Analysis of Photon versus Proton Beam Therapy in Neoadjuvant Concurrent Chemoradiotherapy for Intrathoracic Squamous Cell Carcinoma of the Esophagus at a Single Institute.

BACKGROUND: Proton beam therapy (PBT), as a neoadjuvant chemoradiotherapy (nCRT) modality, is expected to result in better outcomes than photon-based radiotherapy (RT) for esophageal cancer, particularly adenocarcinoma. This study reports the results of nCRT for locally advanced esophageal squamous cell carcinoma (ESCC) using both modalities. METHODS: We retrospectively reviewed the records of patients who underwent nCRT for ESCC between 2001 and 2020. A median of 41.4 Gy or cobalt gray equivalents of radiation was delivered using either photons or protons, with concurrent chemotherapy. Dosimetric and clinical parameters were compared between the two groups. RESULTS: Of the 31 patients, the lungs and heart of the proton group (n = 15) were exposed to significantly less radiation compared to the photon group (n = 16). No significant differences in short-term postoperative outcomes or lymphocyte count were observed between the groups, and there were no significant differences between the photon and proton groups in 2-year overall survival (67.8% vs. 68.6%, p = 0.867) or 2-year disease-free survival (33.3% vs. 34.5%, p = 0.749), with a median follow-up of 17 months. CONCLUSIONS: PBT provided a significant dosimetric benefit over photon-based RT during nCRT for ESCC; however, it did not improve clinical outcomes.

Interobserver Variability Prediction of Primary Gross Tumor in a Patient with Non-Small Cell Lung Cancer.

This research addresses the problem of interobserver variability (IOV), in which different oncologists manually delineate varying primary gross tumor volume (pGTV) contours, adding risk to targeted radiation treatments. Thus, a method of IOV reduction is urgently needed. Hypothesizing that the radiation oncologist's IOV may shrink with the aid of IOV maps, we propose IOV prediction network (IOV-Net), a deep-learning model that uses the fuzzy membership function to produce high-quality maps based on computed tomography (CT) images. To test the prediction accuracy, a ground-truth pGTV IOV map was created using the manual contour delineations of radiation therapy structures provided by five expert oncologists. Then, we tasked IOV-Net with producing a map of its own. The mean squared error (prediction vs. ground truth) and its standard deviation were 0.0038 and 0.0005, respectively. To test the clinical feasibility of our method, CT images were divided into two groups, and oncologists from our institution created manual contours with and without IOV map guidance. The Dice similarity coefficient and Jaccard index increased by ~6 and 7%, respectively, and the Hausdorff distance decreased by 2.5 mm, indicating a statistically significant IOV reduction (p < 0.05). Hence, IOV-net and its resultant IOV maps have the potential to improve radiation therapy efficacy worldwide.

Photon Versus Proton Beam Therapy for T1-3 Squamous Cell Carcinoma of the Thoracic Esophagus Without Lymph Node Metastasis.

BACKGROUND AND PURPOSE: We compared treatment outcomes and toxicities of photon radiotherapy versus proton beam therapy (PBT) and evaluated radiation field effects for T1-3 squamous cell carcinoma of the thoracic esophagus (EC) without lymph node metastasis. METHODS: Medical records of 77 patients with T1-3N0M0 thoracic EC treated with radiotherapy between 2011 and 2019 were retrospectively analyzed. Among these patients, 61 (79.2%) individuals had T1 EC. The initial clinical target volume encompassed the whole esophagus with or without supraclavicular and/or abdominal lymph nodes (extended-field radiotherapy; 67 patients, 87.0%) or the area 3-5 cm craniocaudally and 1-2 cm radially from the gross tumor volume (involved-field radiotherapy; 10 patients, 13.0%). The final clinical target volume included margins of at least 1 cm from the gross tumor volume, with total radiation doses of 50-66 (median, 66) cobalt gray equivalent. Three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and PBT were used in twenty-four, five, and forty-eight patients, respectively. Concurrent chemotherapy was administered to 17 (22.0%) patients overall and only five (8.0%) T1 patients. RESULTS: PBT showed significantly lower lung and heart radiation exposure in mean dose, V5, V10, V20, and V30 than photon radiotherapy. The median follow-up for all patients was 46 (interquartile range, 22-72) months. The 5-year progression-free survival and overall survival rates were 56.5 and 64.9%, respectively, with no significant survival difference between photon radiotherapy and PBT. In patients with T1 EC, 5-year progression-free survival and overall survival rates were 62.6 and 73.5%, respectively. CONCLUSIONS: Extended-field radiotherapy using modern radiotherapy techniques without chemotherapy showed satisfactory clinical outcomes for lymph node-negative T1 EC.

Treatment outcomes of extended-field radiation therapy for thoracic superficial esophageal cancer.

PURPOSE: To evaluate the efficacy and safety of extended-field radiation therapy for patients with thoracic superficial esophageal cancer (SEC). MATERIALS AND METHODS: From May 2007 to October 2016, a total of 24 patients with thoracic SEC (T1a and T1b) who underwent definitive radiotherapy and were analyzed retrospectively. The median total radiotherapy dose was 64 Gy (range, 54 to 66 Gy) in conventional fractionation. All 24 patients received radiotherapy to whole thoracic esophagus and 23 patients received elective nodal irradiation. The supraclavicular lymph nodes, the celiac lymph nodes, and both of those nodal areas were included in 11, 3, and 9 patients, respectively. RESULTS: The median follow-up duration was 28.7 months (range 7.9 to 108.0 months). The 3-year overall survival, local control, and progression-free survival rates were 95.2%, 89.7%, and 78.7%, respectively. There were 5 patients (20.8%) with progression of disease, 2 local failures (8.3%) and 3 (12.5%) regional failures. Three patients also experienced distant metastasis and had died of disease progression. There were no treatment-related toxicities of grade 3 or higher. CONCLUSION: Definitive extended-field radiotherapy for thoracic SEC showed durable disease control rates in medically inoperable and endoscopically unfit patients. Even extended-field radiotherapy with elective nodal irradiation was safe without grade 3 or 4 toxicities.