Purpose: Primary mediastinal large B-cell lymphoma (PMBCL) is a rare subtype of diffuse large B-cell lymphoma.Radiation therapy (RT) has served as the primary treatment option for PMBCL; however, its role has been questioned with the advent of intensified immunochemotherapy. This study aimed to investigate the role of consolidative RT in the primary treatment of PMBCL. Methods: This single-center retrospective study analyzed the survival outcomes of 65 patients newly diagnosed with PMBCL. The patients were divided into three treatment groups: (1) EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab), (2) R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), and (3) R-CHOP with consolidative RT. Results: The objective response and complete remission rates were 86.2% and 63.1%, respectively, with 3-year pro‑ gression-free survival (PFS) and overall survival (OS) rates of 72% and 81%, respectively. All patients in the R-CHOP + RT group achieved an objective response with better PFS) than those who did not receive consolidative RT (p = 0.028), although there was no significant difference in OS (p = 0.102). Consolidative RT benefited patients with an initially bulky disease or insufficient end-of-treatment response. The predictive value of  18 F-fluorodeoxyglucose positronemission tomography-computed tomography (PET-CT) in assessing the treatment response in PMBCL was revali‑ dated, showing that patients who achieved negative end-of-treatment PET-CT had significantly better survival outcomes than others. Conclusions R-CHOP is a useful alternative regimen when intensified chemotherapy is not feasible. Consolidative RT should be considered in cases with an initially bulky disease and insufficient end-of-treatment response.

Purpose: There is few evidence regarding the optimal salvage treatment options for loco-reginal recurrence of esophageal cancer. This study aimed to evaluate the clinical outcomes of salvage radiotherapy (RT) in patients with loco-regional recurrence (LRR) after surgery for esophageal cancer. Materials and Methods: We retrospectively reviewed 147 esophageal cancer patients who received salvage RT for loco-regional recurrence between 1996 and December 2019. A total dose of 60 Gy in 20 fractions was used for RT alone and 60-70 Gy in 30-35 fractions for concurrent chemoradiotherapy (CCRT). Results: The patients’ median age was 65 years (range, 41 to 86 years). The median disease-free interval was 13.5 months (1.0 to 97.4 months). After a median 18.8 months follow-up, the 2-year overall survival (OS) and progression-free survival (PFS) rates were 38.1% and 25.9%, respectively. The median OS and PFS were 18.8 and 8.4 months, respectively. The CCRT could not improve OS compared to RT (p=0.336), but there was a trend of better PFS in the CCRT group. Regarding toxicities, the rate of grade 3 or higher toxicity was 10.9% occurring in 16 patients, and it was higher in patients who received CCRT than in the RT alone group (19.6% vs. 6.3%, p=0.023). Conclusion Salvage RT alone as well as CCRT could be effective in patients with locoregionally recurrent esophageal cancer.

Purpose: Primary mediastinal large B-cell lymphoma (PMBCL) is a rare subtype of diffuse large B-cell lymphoma.Radiation therapy (RT) has served as the primary treatment option for PMBCL; however, its role has been questioned with the advent of intensified immunochemotherapy. This study aimed to investigate the role of consolidative RT in the primary treatment of PMBCL. Methods: This single-center retrospective study analyzed the survival outcomes of 65 patients newly diagnosed with PMBCL. The patients were divided into three treatment groups: (1) EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab), (2) R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), and (3) R-CHOP with consolidative RT. Results: The objective response and complete remission rates were 86.2% and 63.1%, respectively, with 3-year pro‑ gression-free survival (PFS) and overall survival (OS) rates of 72% and 81%, respectively. All patients in the R-CHOP + RT group achieved an objective response with better PFS) than those who did not receive consolidative RT (p = 0.028), although there was no significant difference in OS (p = 0.102). Consolidative RT benefited patients with an initially bulky disease or insufficient end-of-treatment response. The predictive value of  18 F-fluorodeoxyglucose positronemission tomography-computed tomography (PET-CT) in assessing the treatment response in PMBCL was revali‑ dated, showing that patients who achieved negative end-of-treatment PET-CT had significantly better survival outcomes than others. Conclusions R-CHOP is a useful alternative regimen when intensified chemotherapy is not feasible. Consolidative RT should be considered in cases with an initially bulky disease and insufficient end-of-treatment response.

Purpose: There is few evidence regarding the optimal salvage treatment options for loco-reginal recurrence of esophageal cancer. This study aimed to evaluate the clinical outcomes of salvage radiotherapy (RT) in patients with loco-regional recurrence (LRR) after surgery for esophageal cancer. Materials and Methods: We retrospectively reviewed 147 esophageal cancer patients who received salvage RT for loco-regional recurrence between 1996 and December 2019. A total dose of 60 Gy in 20 fractions was used for RT alone and 60-70 Gy in 30-35 fractions for concurrent chemoradiotherapy (CCRT). Results: The patients’ median age was 65 years (range, 41 to 86 years). The median disease-free interval was 13.5 months (1.0 to 97.4 months). After a median 18.8 months follow-up, the 2-year overall survival (OS) and progression-free survival (PFS) rates were 38.1% and 25.9%, respectively. The median OS and PFS were 18.8 and 8.4 months, respectively. The CCRT could not improve OS compared to RT (p=0.336), but there was a trend of better PFS in the CCRT group. Regarding toxicities, the rate of grade 3 or higher toxicity was 10.9% occurring in 16 patients, and it was higher in patients who received CCRT than in the RT alone group (19.6% vs. 6.3%, p=0.023). Conclusion Salvage RT alone as well as CCRT could be effective in patients with locoregionally recurrent esophageal cancer.

Purpose: Primary mediastinal large B-cell lymphoma (PMBCL) is a rare subtype of diffuse large B-cell lymphoma.Radiation therapy (RT) has served as the primary treatment option for PMBCL; however, its role has been questioned with the advent of intensified immunochemotherapy. This study aimed to investigate the role of consolidative RT in the primary treatment of PMBCL. Methods: This single-center retrospective study analyzed the survival outcomes of 65 patients newly diagnosed with PMBCL. The patients were divided into three treatment groups: (1) EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab), (2) R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), and (3) R-CHOP with consolidative RT. Results: The objective response and complete remission rates were 86.2% and 63.1%, respectively, with 3-year pro‑ gression-free survival (PFS) and overall survival (OS) rates of 72% and 81%, respectively. All patients in the R-CHOP + RT group achieved an objective response with better PFS) than those who did not receive consolidative RT (p = 0.028), although there was no significant difference in OS (p = 0.102). Consolidative RT benefited patients with an initially bulky disease or insufficient end-of-treatment response. The predictive value of  18 F-fluorodeoxyglucose positronemission tomography-computed tomography (PET-CT) in assessing the treatment response in PMBCL was revali‑ dated, showing that patients who achieved negative end-of-treatment PET-CT had significantly better survival outcomes than others. Conclusions R-CHOP is a useful alternative regimen when intensified chemotherapy is not feasible. Consolidative RT should be considered in cases with an initially bulky disease and insufficient end-of-treatment response.

Purpose: There is few evidence regarding the optimal salvage treatment options for loco-reginal recurrence of esophageal cancer. This study aimed to evaluate the clinical outcomes of salvage radiotherapy (RT) in patients with loco-regional recurrence (LRR) after surgery for esophageal cancer. Materials and Methods: We retrospectively reviewed 147 esophageal cancer patients who received salvage RT for loco-regional recurrence between 1996 and December 2019. A total dose of 60 Gy in 20 fractions was used for RT alone and 60-70 Gy in 30-35 fractions for concurrent chemoradiotherapy (CCRT). Results: The patients’ median age was 65 years (range, 41 to 86 years). The median disease-free interval was 13.5 months (1.0 to 97.4 months). After a median 18.8 months follow-up, the 2-year overall survival (OS) and progression-free survival (PFS) rates were 38.1% and 25.9%, respectively. The median OS and PFS were 18.8 and 8.4 months, respectively. The CCRT could not improve OS compared to RT (p=0.336), but there was a trend of better PFS in the CCRT group. Regarding toxicities, the rate of grade 3 or higher toxicity was 10.9% occurring in 16 patients, and it was higher in patients who received CCRT than in the RT alone group (19.6% vs. 6.3%, p=0.023). Conclusion Salvage RT alone as well as CCRT could be effective in patients with locoregionally recurrent esophageal cancer.

Purpose: This study aims to investigate the diagnostic significance of positron emission tomography/computed tomography (PET/CT) in assessing bone marrow (BM) involvement through a comparison of PET/CT findings with BM biopsy in extranodal natural killer/T-cell lymphoma. Materials and Methods: The medical records of 193 patients were retrospectively reviewed. Patients were categorized as having early-stage (PET-ES) or advanced-stage (PET-AS) disease based on PET/CT results. The BM involvement was classified into three groups according to BM biopsy: gross BM involvement, minimal BM involvement (defined as the presence of a limited number of Epstein-Barr virus–positive cells in BM), and no involvement. Calculations of the accuracy of PET/CT in detecting BM involvement and analysis of the clinical outcomes (progression-free survival [PFS] and overall survival [OS]) according to the BM biopsy status were performed. Results: PET/CT exhibited a sensitivity of 64.7% and a specificity of 96.0% in detecting gross BM involvement. For detecting any (both gross and minimal) BM involvement, the sensitivity was 30.4%, while the specificity was 99.0%. Only one patient (0.7%) demonstrated gross BM involvement among the PET-ES group. Survival outcomes of the PET-ES group with minimal BM involvement (3-year PFS, 55.6%; OS, 77.0%) were closer to those of the PET-ES group with no BM involvement (3-year PFS, 62.2%; OS, 80.6%) than to those of the PET-AS group (3-year PFS, 20.1%; OS, 29.9%). Conclusion PET/CT exhibits high specificity, but moderate and low sensitivity in detecting gross and minimal BM involvement, respectively. The clinical significance of minimal BM involvement for patients in the PET-ES group may be limited.

Purpose: This retrospective study aimed to compare clinical outcomes and dosimetric parameters between radiation therapy (RT) techniques in patients with thymic epithelial tumor (TET). Materials and Methods: From January 2016 to December 2020, 101 patients with TET received adjuvant RT (median, 52.8 Gy; range, 48.4 to 66.0). Three different RT techniques were compared: three-dimensional conformal RT (3D-CRT; n = 59, 58.4%), intensity-modulated RT (IMRT; n = 23, 22.8%), and proton beam therapy (PBT; n = 19, 18.8%). Results: The median age of the patients and the follow-up period were 55 years (range, 28 to 79) and 43.4 months (range, 7.7 to 77.2). Patients in the PBT group were of the youngest age (mean age, 45.4 years), while those in IMRT group had the largest clinical target volume (mean volume, 149.6 mL). Patients in the PBT group had a lower mean lung dose (4.4 Gy vs. 7.6 Gy vs. 10.9 Gy, respectively; p < 0.001), lower mean heart dose (5.4 Gy vs. 10.0 Gy vs. 13.1 Gy, respectively; p = 0.003), and lower mean esophageal dose than patients in the 3D-CRT and IMRT groups (6.3 Gy vs. 9.8 Gy vs. 13.5 Gy, respectively; p = 0.011). Twenty patients (19.8%) showed disease recurrence, and seven patients (6.9%) died. The differences in the survival rates between RT groups were not statistically significant. Conclusion In patients with TET who underwent adjuvant RT, PBT resulted in a lower dose of exposure to adjacent organs at risk. Survival outcomes for patients in PBT group were not significantly different from those in other groups.

Purpose: This phase II study investigated whether durvalumab/tremelimumab with proton therapy improves the objective response rate (ORR), overall survival (OS), and progression-free survival (PFS) in heavily treated recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) patients. Materials and Methods: Patients who previously received more than one chemotherapy, including at least one platinum-based regimen, and who had at least two measurable lesions were enrolled. Patients received 1,500 mg durvalumab intravenously combined with 75 mg tremelimumab intravenously every 4 weeks for four cycles followed by 1,500 mg durvalumab every 4 weeks. After one cycle of the durvalumab/tremelimumab treatment, proton therapy was given with a total dose of 25 Gy in 5 Gy daily fractions to one of the measurable lesions. We also assessed the ORR in the target lesion outside the radiation field to evaluate the abscopal effect. Results: Thirty-one patients were enrolled between March 2018 and July 2020. With 8.6 months of follow-up, the ORR was 22.6% (7/31), including one complete response and six partial responses. The median OS was 8.4 months (95% confidence interval [CI], 2.5 to 14.3) and the median PFS was 2.4 months (95% CI, 0.6 to 4.2). Among the 23 evaluable patients who completed proton therapy, the ORR was 30.4% (7/23). The median OS was 11.1 months (95% CI, 6.5 to 15.8), and the median PFS was 3.7 months (95% CI, 1.6 to 5.7). Grade 3 or higher adverse events were observed in six patients (19.4%) as follows: anemia (n=1), constipation (n=1), electrolyte imbalances (n=2), hyperglycemia (n=1), and pneumonia (n=1). Conclusion The combination of durvalumab/tremelimuab with proton therapy was tolerated well and had encouraging anti-tumor efficacy in non-irradiated tumor lesions of heavily treated HNSCC patients.

Purpose: This study aimed to investigate the oncologic outcomes and prognostic factors of salvage treatments in patients with recurrent oropharyngeal squamous cell carcinoma (OPSCC) after radiotherapy (RT)-based treatment. Materials and Methods: A cancer registry was used to retrieve the records of 337 patients treated with definitive RT or concurrent chemoradiotherapy (CRT) from 2008 to 2018 at a single institution. The poor-responder group (PRG) was defined as patients with residual or recurrent disease after primary treatment, and the oncologic outcomes for each salvage treatment method were analyzed. In addition, prognostic indicators of recurrence-free survival (RFS) and overall survival (OS) were identified in patients who underwent salvage treatment. Results: After initial (C)RT, the PRG comprised 71 of the 337 patients (21.1%): 18 patients had residual disease, and 53 had recurrence after primary treatment (mean time to recurrence 19.5 months). Of these, 63 patients received salvage treatment (surgery 57.2%, re-(C)RT 23.8%, and chemotherapy 19.0%), and the salvage success rate was 47.6% at the last follow-up. The overall 2-year OS for salvage treatments was 56.4% (60.8% for the salvage surgery group and 46.2% for the salvage re-(C)RT). Salvage surgery patients with negative resection margins had better oncologic outcomes than those with close/positive resection margins. Using multivariate analyses, locoregional recurrence and residual disease after primary surgery were associated with poor outcome after salvage treatment. In Kaplan-Meier analyses, p16 status was significantly associated with OS in the initial treatment setting but not in the salvage setting. Conclusion In recurrent OPSCC after RT-based treatment, successful salvage was achieved in 56.4% patients who had undergone salvage surgery and radiation treatment. Salvage treatment methods should be selected carefully, given recurrence site as a prognostic factor for RFS.