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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.
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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.
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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.
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Purpose@#This study explored the potential feasibility of cell-free DNA (cfDNA) in monitoring treatment response through the measurement of chromosomal instabilities using I-scores in the context of radiation therapy (RT) for other solid tumors. @*Materials and Methods@#This study enrolled 23 patients treated with RT for lung, esophageal, and head and neck cancer. Serial cfDNA monitoring was performed before RT, 1 week after RT, and 1 month after RT. Low-depth whole-genome sequencing was done using Nano kit and NextSeq 500 (Illumina Inc.). To measure the extent of genome-wide copy number instability, I-score was calculated. @*Results@#Pretreatment I-score was elevated to more than 5.09 in 17 patients (73.9%). There was a significant positive correlation between the gross tumor volume and the baseline I-score (Spearman rho = 0.419, p = 0.047). The median I-scores at baseline, post-RT 1 week (P1W), and post-RT 1 month (P1M) were 5.27, 5.13, and 4.79, respectively. The I-score at P1M was significantly lower than that at baseline (p = 0.002), while the difference between baseline and P1W was not significant (p = 0.244). @*Conclusion@#We have shown the feasibility of cfDNA I-score to detect minimal residual disease after RT in patients with lung cancer, esophageal cancer, and head and neck cancer. Additional studies are ongoing to optimize the measurement and analysis of I-scores to predict the radiation response in cancer patients.
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Background and Objectives@#For T1–T2 early glottic cancer, single modality treatment with radiation therapy (RT) or transoral laser microsurgery is the standard therapeutic option. However, the choice between surgery and RT has been debated for decades. Even though patient selection bias for each modality inherently exists in the retrospective study, this study aimed to compare the oncologic outcomes of the actual treatment of these patients between surgery-based treatment and RT.Materials and Method The medical records of 417 patients with T1–T2N0 glottic squamous cell carcinoma were reviewed who were treated at our institution between 1995 and 2014. The patients were divided into two groups; primarily surgery-based treatment (OP, n=209) or RT (n=208). @*Results@#In the T1 stage, local failure, overall survival (OS), and disease-free survival (DFS) rates were not different between the OP and RT groups. However, in the T2 stage, the local failure rate was higher in the RT group (p65), presence of multiple primary cancer, and treatment modality were significant variables influencing OS and DFS. @*Conclusion@#Surgery-based treatment provided better local control rates, DFS, and OS in patients with T1–T2N0 glottic SCC. In the T1 stage, treatment outcomes were similar between OP and RT groups. In the T2 stage, OP showed better results than RT, suggesting that refined strategies are required to improve the oncologic outcomes of RT for T2 glottic cancer.
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Purpose@#The purpose of the study was to validate the Korean version of Patient-Reported Outcomes Measurement Information System 29 Profile v2.1 (K-PROMIS-29 V2.1) among cancer survivors. @*Materials and Methods@#Participants were recruited from outpatient clinics of the Comprehensive Cancer Center at the Samsung Medical Center in Seoul, South Korea, from September to October 2018. Participants completed a survey questionnaire that included the K-PROMIS-29 V2.1 and the European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire (EORTC QLQ-C30). Principal component analysis and confirmatory factor analysis (CFA) and Pearson’s correlations were used to evaluate the reliability and validity of the K-PROMIS-29 V2.1. @*Results@#The mean age of the study participants was 54.4 years, the mean time since diagnosis was 1.2 (±2.4) years, and 349 (87.3%) completed the entire questionnaire. The Cronbach’s alpha coefficients of the seven domains in the K-PROMIS-29 V2.1 ranged from 0.81 to 0.96, indicating satisfactory internal consistency. In the CFA, the goodness-of-fit indices for the K-PROMIS-29 V2.1 were high (comparative fit index, 0.91 and standardized root-mean-squared residual, 0.06). High to moderate correlations were found between comparable subscales of the K-PROMIS-29 V2.1 and subscales of the EORTC QLQ-C30 (r=0.52-0.73). @*Conclusion@#The K-PROMIS-29 V2.1 is a reliable and valid measure for assessing the health-related quality of life domains in a cancer population, thus supporting their use in studies and oncology trials.
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Purpose@#This study aimed to evaluate the effect of radiotherapy (RT) on the risk of diabetes by assessing hemoglobin A1c (HbA1c) levels in patients with gastroduodenal indolent lymphoma. @*Materials and Methods@#This retrospective study included patients with stage I extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue or follicular lymphoma of the gastroduodenal region who were treated with Helicobacter pylori eradication and/or RT between 2000 and 2019 in our institution. Of total 79 patients with HbA1c test, 17 patients received RT (RT group), while 62 patients did not receive RT (control group). A diabetes-associated event (DAE) was defined as a ≥ 0.5% increase in HbA1c levels from baseline, and diabetes event (DE) were defined as HbA1c level of ≥ 6.5%. @*Results@#During the median follow-up of 49 months, no local failure occurred after RT and no patients died of lymphoma. The RT group had significantly higher risk for DAEs on univariable analysis (hazard ratio [HR], 4.18; 95% confidence interval [CI], 1.64 to 10.66; p < 0.01) and multivariable analysis (HR, 3.68; 95% CI, 1.42 to 9.56; p=0.01). Further, the DE risk was significantly higher in the RT group than in the control group (HR, 4.32; 95% CI, 1.08 to 17.30; p=0.04) and in patients with increased baseline HbA1c levels (HR, 35.83; 95% CI, 2.80 to 459.19; p=0.01). On multivariable analysis, RT significantly increased the risk of DEs (HR, 4.55; 95% CI, 1.08 to 19.19; p=0.04), even after adjusting baseline HbA1c level (HR, 40.97; 95% CI, 3.06 to 548.01; p=0.01). @*Conclusion@#Patients who received RT for gastroduodenal indolent lymphoma had an increased risk of diabetes compared to those who did not.
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Purpose@#This study aimed to analyze the treatment outcomes of locally recurrent nasopharyngeal cancer (NPC) patients following moderate hypo-fractionation re-irradiation (re-RT). @*Materials and Methods@#Sixty locally recurrent NPC patients underwent hypo-fractionation re-RT. Forty-eight point three percentage had rT3-4, and 30.0% did keratinizing squamous cell carcinoma. Intensity-modulated radiation therapy (IMRT), with or without intensity-modulated proton therapy (IMPT), was used in 66.7% of patients. @*Results@#With the median follow-up of 22 months (range, 2 to 254 months), 31 patients (51.7%) died, 38 (63.3%) developed further treatment failure, and 30 (50.0%) developed ≥ grade 3 toxicity (including seven grade 5) at time of analysis. The 2- and 5-year rates of overall survival, local failure-free survival, and ≥ grade 3 toxicity-free survival were 57.9% and 45.8%, 64.1% and 52.5%, and 54.8% and 44.9%, respectively. In multivariate analyses, worse factors for overall survival (OS) were iT3-4 (p=0.010) and age at re-RT ≥ 53 years (p=0.003), those for local failure-free survival (LFFS) were rT3-4 (p=0.022) and rN0-1 (p=0.035), and those for toxicity-free survival (TFS) were iT3-4 (p=0.020) and re-IMRT/IMPT (p=0.030), respectively. Cumulative dose or fraction size ≥ 3 Gy at re-RT, however, showed no significance for OS, LFFS and TFS. @*Conclusion@#Current re-RT with modern RT techniques by moderate hypo-fractionation scheme seemed feasible in treating locally recurrent NPC patients.
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Purpose@#Larynx-preserving surgery (LPS) have recently gained popularity and achieved comparable oncologic outcomes to conventional radical surgery for localized hypopharyngeal cancer (HPC). In the current study, the role of LPS has been assessed thoroughly in comparison with upfront radiation therapy (RT). @*Materials and Methods@#We retrospectively reviewed 185 candidates for LPS with cT1-2 disease; 59 patients underwent upfront LPS while 126 patients received upfront RT, respectively. Oncological and functional outcomes were investigated and compared. @*Results@#Following LPS, safe margin (≥ 5 mm) was achieved in 37.3% of patients. Overall, better clinical outcomes at 5 years were achieved following upfront LPS than those following upfront RT: overall survival (OS) (72.7% vs. 59.0%, p=0.045), disease-free survival (DFS) (59.8% vs. 45.0%, p=0.039), and functional laryngeal preservation (100% vs. 89.7%, p=0.010). Although similar outcomes were observed in patients with cT1 disease, better 5-year DFS was achieved following upfront LPS in patients with cT2 disease (57.0% vs. 36.4%, p=0.023) by virtue of better local control. Despite frequent cN2-3 disease in upfront LPS group, comparable outcomes were observed between upfront RT and LPS group. However, multivariable analyses revealed that performance status and double primary cancer diagnosed within 6 months of HPC diagnosis affected OS significantly, while treatment modality per se did not. @*Conclusion@#Although upfront LPS could provide better local control than upfront RT in patients with cT2 disease, overall outcomes were comparable following either modality. Treatment selection of larynx-preserving approach for HPC should be individualized based on tumor and patient factors.
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Background@#The purpose of the study was to translate and linguistically validate a Korean language version of the PROMIS (K-PROMIS) for the six profile adult domains: Fatigue, Pain Intensity, Pain Interference, Physical Function, Sleep Disturbance, and Ability to Participate in Social Roles and Activities. @*Methods@#A total of 268 items were translated into Korean according to the Functional Assessment of Chronic Illness Therapy multilingual translation methodology. Participants first completed approximately 27 to 35 items and were then interviewed to evaluate the conceptual equivalence of the translation to the original English language source.The K-PROMIS items that met the a priori threshold of ≥ 20% of respondents with comprehension difficulties in the cognitive interview. @*Results@#54 of the 268 items were identified as difficult items to comprehend for at least 20% of respondents in Round 1. The most frequently identified K-PROMIS domain on difficult items to comprehend was the Physical function (24.5%). Most items with linguistic difficulties were Fatigue and Physical function. Cultural difficulties were only included the Physical function and Ability to Participate in Social Roles and Activities domains. 25 of 54 items were slightly revised, and then these revised items were tested with additional six participants in Round 2, and most participants had no problems to understand modified items. @*Conclusion@#The six profile adult domains of K-PROMIS have been linguistically validated.Further psychometric validation of the K-PROMIS items will provide additional information of meaningful outcomes for chronic disease and clinical setting.
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Intensity-modulated radiation therapy (IMRT) using X-rays is a standard technique implemented for treating head and neck cancer (HN C). Compared to 3D conformal RT, IMRT can significantly reduce the radiation dose to surrounding normal tissues by using a highly conformal dose to the tumor. Proton therapy is a type of RT that uses positively charged particles named protons. Proton therapy has a unique energy deposit (i.e., Bragg peak) and greater biological effectiveness than that of therapy using X-rays. These inherent properties of proton therapy make the technique advantageous for HNC treatment. Recently, advanced techniques such as intensity-modulated proton therapy have further decreased the dose to normal organs with a higher conformal dose to the tumor. The usage of proton therapy for HNC is becoming widespread as the number of operational proton therapy centers has increased worldwide. This paper aims to present the current clinical evidence of proton therapy utility to HNC clinicians through a literature review. It also discusses the challenges associated with proton therapy and prospective development of the technique.
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Purpose@#This study aimed to evaluate the clinical outcomes and toxicities of salvage proton beam therapy (PBT) in patients with locoregional recurrent non-small cell lung cancer (NSCLC). @*Materials and Methods@#We retrospectively reviewed 53 patients who received salvage PBT for locoregionally recurrent NSCLC between January 2016 and December 2019. The median clinical target volume (CTV) was 71.2 cm3 (range, 13.3 to 1,200.7 cm3). The median prescribed dose was 64.0 cobalt gray equivalent (CGE) (range, 45.0 to 70.0 CGE). One-third of the patients (32.1%) received concurrent chemoradiotherapy (CCRT). @*Results@#The patients’ median age was 67 years (range, 44 to 86 years). The initial treatments were surgery in 31 (58.5%), definitive CCRT in 12 (22.6%), and definitive radiotherapy in 10 (18.9%) patients. The median disease-free interval (DFI) was 14 months (range, 3 to 112 months). Thirty-seven patients (69.8%) had a previous radiotherapy history. Among them, 18 patients (48.7%) had in-field recurrence. The median follow-up time after salvage PBT was 15.0 months (range, 3.5 to 49.3 months). During the follow-up period, 26 patients (49.1%) experienced disease progression: local in 13 (24.5%), regional in 14 (26.5%), and distant metastases in 15 (26.5%). The 2-year overall survival (OS) rate, local control rate, and progression-free survival rate were 79.2%, 68.2%, and 37.1%, respectively. Shorter DFI (≤12 months; p = 0.015) and larger CTV (>80 mL; p = 0.014) were associated with poor OS. Grade 3 toxicities occurred in 8 patients (15.1%): esophagitis in 2, dermatitis in 3, and pulmonary toxicities in 4. @*Conclusion@#Salvage PBT for locoregionally recurrent NSCLC was effective, and treatment-related toxicities were tolerable.
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Purpose@#Studies on de-escalation in radiation therapy (RT) for human papillomavirus-related (HPV(+)) oropharyngeal cancer (OPC) are currently ongoing. This study investigated the current practice regarding the radiation dose and field in the treatment of HPV(+) OPC. @*Materials and Methods@#The Korean Society for Head and Neck Oncology conducted a questionnaire on the primary treatment policy. Among them, for HPV(+) OPC scenarios, radiation oncologists were questioned regarding the field and dose of RT. @*Results@#Forty-two radiation oncologists responded to the survey. In definitive concurrent chemoradiotherapy (CCRT) treatment for stage T2N1M0 OPC, most respondents prescribed a dose of >60 Gy to the primary tonsil and involved ipsilateral lymph nodes. However, eight of the respondents prescribed a relatively low dose of ≤54 Gy. For stage T2N1M0 OPC, postoperative adjuvant RT was prescribed by eight and nine respondents with a lower dose of ≤50 Gy for the ipsilateral tonsil and involved neck, respectively. In definitive CCRT in complete remission after induction chemotherapy for initial stage T2N3M0 OPC, de-escalation of the tonsil and involved neck were performed by eight and seven respondents, respectively. Regarding whether de-escalation is applied in radiotherapy for HPV(+) OPC, 27 (64.3%) did not do it at present, and 15 (35.7%) were doing or considering it. @*Conclusion@#The field and dose of prescribed treatment varied between institutions in Korea. Among them, dose de-escalation of RT in HPV(+) OPC was observed in approximately 20% of the respondents. Consensus guidelines will be set in the near future after the completion of ongoing prospective trials.
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Purpose@#This study aimed to reduce radiation doses to the tongue, a patient-specific semi-customized tongue immobilization device (SCTID) was developed using a 3D printer for helical tomotherapy (HT) of nasopharyngeal cancer (NPCa). Dosimetric characteristics and setup stability of the SCTID were compared with those of a standard mouthpiece (SMP). @*Materials and Methods@#For displacement and robust immobilization of the tongue, the SCTID consists of four parts: upper and lower tooth stoppers, tongue guider, tongue-tip position guide bar, and connectors. With the SCTID and SMP, two sets of planning computed tomography and HT plans were obtained for 10 NPCa patients. Dosimetric and geometric characteristics were compared. Position reproducibility of the tongue with SCTID was evaluated by comparing with planned dose and adaptive accumulated dose of the tongue and base of the tongue based on daily setup mega-voltage computed tomography. @*Results@#Using the SCTID, the tongue was effectively displaced from the planning target volume compared to the SMP. The median mucosa of the tongue (M-tongue) dose was significantly reduced (20.7 Gy vs. 27.8 Gy). The volumes of the M-tongue receiving a dose of 15 Gy, 30 Gy, and 45 Gy and the volumes of the mucosa of oral cavity and oropharynx (M-OC/OP) receiving a dose of 45 Gy and 60 Gy were significantly lower than using the SMP. No significant differences was observed between the planned dose and the accumulated adaptive dose in any dosimetric characteristics of the tongue and base of tongue. @*Conclusion@#SCTID can not only reduce the dose to the M-tongue and M-OC/OP dramatically, when compared to SMP, but also provide excellent reproducibility and easy visual verification.
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Clinical trials have not consistently supported the use of induction chemotherapy (IC) for locally advanced head and neck squamous cell cancer. Hypopharynx and base of tongue (BOT) cancer has shown relatively poor survival. We investigated the role of IC in improving outcome over current chemoradiotherapy (CRT) in patients with hypopharynx and BOT cancer. Methods: Treatment-naïve patients with stage III/IV (M0) hypopharynx or BOT cancer were randomly assigned to receive CRT alone (CRT arm: cisplatin 100 mg/m2 on D1 3-weekly, two times plus radiotherapy 68.4 Gy/30 fractions on weekdays) versus two 21-day cycles of IC with TPF (docetaxel & cisplatin 75 mg/m2 on D1, and fluorouracil 75 mg/m2 on D1-4) followed by the same CRT regimen (IC arm). The primary endpoint was progression-free survival (PFS). Results: This study closed early after enrollment of 36 patients (19 in the CRT arm, 17 in the IC arm). After a median follow-up of 47.2 months, there was no significant difference in PFS: the median PFS was 26.8 months for the CRT arm and was not reached for the IC arm (p = 0.13). However, the survival curves were widely separated with a plateau after 3 years, suggesting a potential survival benefit from IC: 3-year PFS rates were 45% and 68%, and 3-year overall survival rates were 56% and 86%, in the CRT and IC arms, respectively. Conclusions: This study failed to demonstrate that induction TPF chemotherapy improves survival in patients with BOT and hypopharynx cancer. However, it suggested a favorable outcome with IC to this population.
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Background@#The purpose of the study was to translate and linguistically validate a Korean language version of the PROMIS (K-PROMIS) for the six profile adult domains: Fatigue, Pain Intensity, Pain Interference, Physical Function, Sleep Disturbance, and Ability to Participate in Social Roles and Activities. @*Methods@#A total of 268 items were translated into Korean according to the Functional Assessment of Chronic Illness Therapy multilingual translation methodology. Participants first completed approximately 27 to 35 items and were then interviewed to evaluate the conceptual equivalence of the translation to the original English language source.The K-PROMIS items that met the a priori threshold of ≥ 20% of respondents with comprehension difficulties in the cognitive interview. @*Results@#54 of the 268 items were identified as difficult items to comprehend for at least 20% of respondents in Round 1. The most frequently identified K-PROMIS domain on difficult items to comprehend was the Physical function (24.5%). Most items with linguistic difficulties were Fatigue and Physical function. Cultural difficulties were only included the Physical function and Ability to Participate in Social Roles and Activities domains. 25 of 54 items were slightly revised, and then these revised items were tested with additional six participants in Round 2, and most participants had no problems to understand modified items. @*Conclusion@#The six profile adult domains of K-PROMIS have been linguistically validated.Further psychometric validation of the K-PROMIS items will provide additional information of meaningful outcomes for chronic disease and clinical setting.
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Intensity-modulated radiation therapy (IMRT) using X-rays is a standard technique implemented for treating head and neck cancer (HN C). Compared to 3D conformal RT, IMRT can significantly reduce the radiation dose to surrounding normal tissues by using a highly conformal dose to the tumor. Proton therapy is a type of RT that uses positively charged particles named protons. Proton therapy has a unique energy deposit (i.e., Bragg peak) and greater biological effectiveness than that of therapy using X-rays. These inherent properties of proton therapy make the technique advantageous for HNC treatment. Recently, advanced techniques such as intensity-modulated proton therapy have further decreased the dose to normal organs with a higher conformal dose to the tumor. The usage of proton therapy for HNC is becoming widespread as the number of operational proton therapy centers has increased worldwide. This paper aims to present the current clinical evidence of proton therapy utility to HNC clinicians through a literature review. It also discusses the challenges associated with proton therapy and prospective development of the technique.
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Purpose@#This study aimed to evaluate the clinical outcomes and toxicities of salvage proton beam therapy (PBT) in patients with locoregional recurrent non-small cell lung cancer (NSCLC). @*Materials and Methods@#We retrospectively reviewed 53 patients who received salvage PBT for locoregionally recurrent NSCLC between January 2016 and December 2019. The median clinical target volume (CTV) was 71.2 cm3 (range, 13.3 to 1,200.7 cm3). The median prescribed dose was 64.0 cobalt gray equivalent (CGE) (range, 45.0 to 70.0 CGE). One-third of the patients (32.1%) received concurrent chemoradiotherapy (CCRT). @*Results@#The patients’ median age was 67 years (range, 44 to 86 years). The initial treatments were surgery in 31 (58.5%), definitive CCRT in 12 (22.6%), and definitive radiotherapy in 10 (18.9%) patients. The median disease-free interval (DFI) was 14 months (range, 3 to 112 months). Thirty-seven patients (69.8%) had a previous radiotherapy history. Among them, 18 patients (48.7%) had in-field recurrence. The median follow-up time after salvage PBT was 15.0 months (range, 3.5 to 49.3 months). During the follow-up period, 26 patients (49.1%) experienced disease progression: local in 13 (24.5%), regional in 14 (26.5%), and distant metastases in 15 (26.5%). The 2-year overall survival (OS) rate, local control rate, and progression-free survival rate were 79.2%, 68.2%, and 37.1%, respectively. Shorter DFI (≤12 months; p = 0.015) and larger CTV (>80 mL; p = 0.014) were associated with poor OS. Grade 3 toxicities occurred in 8 patients (15.1%): esophagitis in 2, dermatitis in 3, and pulmonary toxicities in 4. @*Conclusion@#Salvage PBT for locoregionally recurrent NSCLC was effective, and treatment-related toxicities were tolerable.
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Purpose@#Studies on de-escalation in radiation therapy (RT) for human papillomavirus-related (HPV(+)) oropharyngeal cancer (OPC) are currently ongoing. This study investigated the current practice regarding the radiation dose and field in the treatment of HPV(+) OPC. @*Materials and Methods@#The Korean Society for Head and Neck Oncology conducted a questionnaire on the primary treatment policy. Among them, for HPV(+) OPC scenarios, radiation oncologists were questioned regarding the field and dose of RT. @*Results@#Forty-two radiation oncologists responded to the survey. In definitive concurrent chemoradiotherapy (CCRT) treatment for stage T2N1M0 OPC, most respondents prescribed a dose of >60 Gy to the primary tonsil and involved ipsilateral lymph nodes. However, eight of the respondents prescribed a relatively low dose of ≤54 Gy. For stage T2N1M0 OPC, postoperative adjuvant RT was prescribed by eight and nine respondents with a lower dose of ≤50 Gy for the ipsilateral tonsil and involved neck, respectively. In definitive CCRT in complete remission after induction chemotherapy for initial stage T2N3M0 OPC, de-escalation of the tonsil and involved neck were performed by eight and seven respondents, respectively. Regarding whether de-escalation is applied in radiotherapy for HPV(+) OPC, 27 (64.3%) did not do it at present, and 15 (35.7%) were doing or considering it. @*Conclusion@#The field and dose of prescribed treatment varied between institutions in Korea. Among them, dose de-escalation of RT in HPV(+) OPC was observed in approximately 20% of the respondents. Consensus guidelines will be set in the near future after the completion of ongoing prospective trials.
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Background@#Canine adenovirus type 2 (CAV-2) induces infectious laryngotracheitis in members of the family Canidae, including dogs. To date, no ELISA kits specific for CAV-2 antibody have been commercialized for dogs in Korea. @*Objectives@#We aimed to develop new indirect enzyme-linked immunosorbent assay (I-ELISA) to perform rapid, accurate serological surveys of CAV-2 in dog serum samples. @*Methods@#In total, 165 serum samples were collected from dogs residing in Chungbuk and Gyeongbuk provinces between 2016 and 2018. The Korean CAV-2, named the APQA1701-40P strain, was propagated in Madin–Darby canine kidney cells and purified in an anion-exchange chromatography column for use as an antigen for I-ELISA. The virus-neutralizing antibody titers of CAV-2 in the dog sera were measured by virus neutralization (VN) test. @*Results@#We compared the results obtained between the VN and new I-ELISA tests. The sensitivity, specificity, and accuracy of new I-ELISA were 98.6%, 86.4% and 97.0% compared with VN test, respectively. New I-ELISA was significantly correlated with VN (r = 0.91). @*Conclusions@#These results indicate that new I-ELISA is useful for sero-surveillance of CAV-2 in dog serum.