Pain response in single-fraction 8-Gy radiotherapy for painful non-bone-metastasis tumors: a single-center retrospective study.

The effectiveness of single-fraction 8-Gy radiotherapy for painful bone metastases has been verified in numerous randomized controlled trials. However, few reports have described the effectiveness of single-fraction 8-Gy radiotherapy in painful tumors other than bone metastases. We conducted a retrospective analysis to evaluate the pain response to single-fraction 8-Gy radiotherapy in painful non-bone-metastasis tumors. We included patients who had received single-fraction 8-Gy radiotherapy for such tumors between January 2017 and December 2022, excluding those with brain metastases, hematological tumors and those who received re-irradiation. Pain response assessment was based on the best responses documented in the medical records and conducted by two radiation oncologists. A total of 36 eligible patients were included in this study. The irradiation sites included primary lesions in eight patients, lymph node metastases in eight, muscle metastases in seven, pleural dissemination in four, skin/subcutaneous metastases in four and other sites in five. Pain response was assessed in 24 patients after radiotherapy. Pain response rate was 88% in evaluable patients; 21 of the 24 patients experienced response. The median assessment date for pain response was 37 days (range: 8-156 days) after radiotherapy. Re-irradiation was performed in four patients (11%). Single-fraction 8-Gy radiotherapy seemed to be a promising treatment option for painful non-bone-metastasis tumors and warrants further investigation.

Radiation doses of medical radiation workers performing low-dose-rate brachytherapy with 198Au grains and 192Ir pins for patients with oral cancers.

OBJECTIVES: Low-dose-rate brachytherapy (LDR-BT) with 198Au grains and 192Ir pins is an essential treatment option for oral cancer due to its high rate of local control and low invasiveness. However, the radiation exposure of medical radiation workers is concerning. Thus, we aimed to determine the radiation dose delivered to medical radiation workers during LDR-BT using 198Au grains and 192Ir pins for oral cancer. METHODS: Thirty-two patients with oral cancer underwent 198Au grain interstitial LDR-BT between June 2016 and May 2023, and 23 patients with tongue cancer underwent 192Ir pin interstitial LDR-BT between March 2015 and November 2017 at our hospital. Dosimetry was performed by attaching a dosimeter to the chest pocket of the operator and assistant during 198Au grain or 192Ir pin LDR-BT. Since the operator also loads 198Au grains into the implantation device, the operator's radiation dose includes the dose received during this preparation. RESULTS: Mean radiation doses of the operators with 198Au grain and 192Ir pin LDR-BT were 165.8 and 211.2 µSv, respectively. Statistically significant differences between the radioactive sources of 198Au grain and 192Ir pin LDR-BT were observed (p = 0.0459). The mean radiation doses of the assistants with 198Au grain and 192Ir pin LDR-BT were 92.0 and 162.0 µSv, respectively. Statistically significant differences were observed between the radioactive sources of 198Au grains and 192Ir pin LDR-BT (p = 0.0003). CONCLUSIONS: Regarding radioactive source differences, 192Ir pin LDR-BT resulted in higher doses delivered to medical radiation workers than 198Au grain LDR-BT.

Efficacy of Supportive Care for Radiodermatitis in Patients with Head and Neck Cancer: Supplementary Analysis of an Exploratory Phase II Trial.

Self-care demonstrated efficacy in preventing severe acute radiation dermatitis among patients with head and neck squamous cell carcinoma undergoing chemoradiotherapy (CRT). This prospective trial aimed to confirm the feasibility and safety of transcutaneous electrical sensory stimulation while examining the relationship between changes in self-care behavior through supportive care interventions and the severity of acute radiation dermatitis during CRT. Patients underwent assessments for dermatitis grading (Grades 1 to ≥3) and were interviewed regarding self-care practices. The self-care questionnaires comprised six items, and a point was deducted for each task that the patient could not perform independently. Statistical analysis was performed to determine the association between G3 radiation dermatitis and the lowest self-care behavior scores. Of the 10 patients enrolled, three experienced G3 dermatitis. During CRT, six patients maintained their initial scores and did not develop ≥G3 dermatitis. Meanwhile, three of four patients with decreased scores exhibited ≥G3 dermatitis. The group with ≥G3 dermatitis had significantly lower scores than those with ≤G2 dermatitis, suggesting that the inability of patients to perform self-care routinely may lead to severe acute radiation dermatitis. Further prospective studies are needed to confirm the potential of self-care interventions in preventing severe dermatitis.

Novel simulation for dosimetry impact of diaphragm respiratory motion in four-dimensional volumetric modulated arc therapy for esophageal cancer.

BACKGROUND AND PURPOSE: The diaphragm respiratory motion (RM) could impact the target dose robustness in the lower esophageal cancer (EC). We aimed to develop a framework evaluating the impact of different RM patterns quantitatively in one patient, by creating virtual four-dimensional computed-tomography (v4DCT) images, which could lead to tailored treatment for the breathing pattern. We validated virtual 4D radiotherapy (v4DRT) along with exploring the acceptability of free-breathing volumetric modulated arc therapy (FB-VMAT). METHODS AND MATERIALS: We assessed 10 patients with superficial EC through their real 4DCT (r4DCT) scans. v4DCT images were derived from the end-inhalation computed tomography (CT) image (reference CT) and the v4DRT dose was accumulated dose over all phases. r4DRT diaphragm shifts were applied with magnitudes derived from r4DCT scans; clinical target volume (CTV) dose of v4DRT was compared with that of r4DRT to validate v4DRT. CTV dosage modifications and planning organ at risk volume (PRV) margins of the spinal cord were examined with the diaphragm movement. The percentage dose differences (ΔDx) were determined between the v4DRT and the dose calculated on the reference CT image. RESULTS: The CTV ΔDx between the r4DRT and v4DRT were within 1% in cases with RM ≦ 15 mm. The average ΔD100% and ΔDmean of the CTV ranging from 5 to 15 mm of diaphragm motion was 0.3% to 1.7% and 0.1% to 0.4%, respectively. All CTV index changes were within 3% and ΔD1cc and ΔD2cc of Cord PRV were within 1%. CONCLUSION: We postulate a novel method for evaluating the CTV robustness, comparable to the conventional r4DCT method under the diaphragm RM ≦ 15 mm permitting an impact of within 3% in FB-VMAT for EC on the CTV dose distribution.

Outcome of Hypofractionated Radiotherapy for Localized Gastric Mucosa-associated Lymphoid Tissue Lymphoma.

BACKGROUND/AIM: With the prevalence of COVID-19, the importance of short-course radiotherapy (RT) in many cancers has been discussed. The aim of this study was to evaluate the results of hypofractionated schedule RT for localized gastric mucosa-associated lymphoid tissue (MALT) lymphoma. PATIENTS AND METHODS: We assessed 45 patients with localized gastric MALT lymphoma who underwent RT between 2005 and 2019. The total RT dose ranged from 24-36 Gy in 10-18 fractions (median of 28 Gy/14 fractions). Patients were divided into three groups according to the dose fractionation: Group A, 30-36 Gy in 15-18 fractions; Group B, 26-28 Gy in 13-14 fractions; and Group C, 24-25 Gy in 10 fractions. RESULTS: All the patients achieved complete remission without local recurrence. The 5-year overall, cause-specific, and progression-free survival rates were 97.5%, 100%, and 97.5%, respectively, with a median follow-up period of 82 months. Among the dose fractionation groups, there were no statistically significant differences in local control or incidence of grade 2 or worse adverse events. CONCLUSION: Results of RT for localized gastric MALT lymphoma showed excellent local control and survival with no serious adverse events, regardless of dose fractionation. In situations where short-term RT is required, a hypofractionated RT schedule of 24-25 Gy in 10 fractions could be an option for RT schedules.

Effectiveness of Spacers in Brachytherapy With 198Au Grains for Patients With Buccal Mucosa Cancer.

BACKGROUND/AIM: The aim of this study was to investigate the use of spacers and their efficacy in brachytherapy with 198Au grains for buccal mucosa cancer. PATIENTS AND METHODS: Sixteen patients with squamous cell carcinoma of the buccal mucosa who were treated with 198Au grain brachytherapy were included. The distance between 198Au grains, distance between 198Au grains and the maxilla or mandible, and the maximum dose/cc to the jawbone (D1cc) with and without a spacer was investigated in three out of 16 patients. RESULTS: The median distance between 198Au grains without and with a spacer was 7.4 and 10.7 mm, respectively; this was significantly different. The median distance between 198Au grains and the maxilla without and with a spacer was 10.3 and 18.5 mm, respectively; again this was significantly different. The median distance between 198Au grains and the mandible without and with a spacer was 8.6 and 17.3 mm, respectively; the difference was significant. The D1cc to the maxilla without and with a spacer were 14.9, 68.7, and 51.8 Gy and 7.5, 21.2, and 40.7 Gy in cases 1, 2, and 3, respectively. The D1cc to the mandible without and with a spacer were 27.5, 68.7, and 85.8 Gy and 11.3, 53.6, and 64.9 Gy in cases 1, 2, and 3, respectively. No osteoradionecrosis of the jaw bones was observed in any case. CONCLUSION: The spacer enabled maintenance of the distance between 198Au grains, and between 198Au grains and the jawbone. In buccal mucosa cancer, using a spacer in brachytherapy with 198Au grains appears to reduce jawbone complications.

Image masking using convolutional networks improves performance classification of radiation pneumonitis for non-small cell lung cancer.

Radiation pneumonitis (RP) is a serious side effect of radiotherapy in patients with locally advanced non-small-cell lung cancer (NSCLC). Image cropping reduces training noise and may improve classification accuracy. This study proposes a prediction model for RP grade ≥ 2 using a convolutional neural network (CNN) model with image cropping. The 3D computed tomography (CT) images cropped in the whole-body, normal lung (nLung), and nLung regions overlapping the region over 20 Gy (nLung∩20 Gy) used in treatment planning were used as the input data. The output classifies patients as RP grade < 2 or RP grade ≥ 2. The sensitivity, specificity, accuracy, and area under the curve (AUC) were evaluated using the receiver operating characteristic curve (ROC). The accuracy, specificity, sensitivity, and AUC were 53.9%, 80.0%, 25.5%, and 0.58, respectively, for the whole-body method, and 60.0%, 81.7%, 36.4%, and 0.64, respectively, for the nLung method. For the nLung∩20 Gy method, the accuracy, specificity, sensitivity, and AUC improved to 75.7%, 80.0%, 70.9%, and 0.84, respectively. The CNN model, in which the input image is segmented in the normal lung considering the dose distribution, can help predict an RP grade ≥ 2 for NSCLC patients after definitive radiotherapy.

[Radiotherapy for Bone Metastases].

Appropriate use of radiotherapy leads to a better patient care. Oncologists may wonder when to apply radiotherapy for painful bone metastases, what patients should particularly be offered radiotherapy, when to apply re-irradiation, when to apply radiotherapy to malignant spinal cord compression, or whether to apply radiotherapy to prevent symptoms. This paper aims to offer non-radiation oncologist physicians knowledge to help them better refer patients to radiation oncology.

Pain Response Rates After Conventional Radiation Therapy for Bone Metastases Assessed Using International Consensus Pain Response Endpoints: A Systematic Review and Meta-Analysis of Initial Radiation Therapy and Reirradiation.

Previous meta-analysis of conventional radiation therapy for painful bone metastases showed overall response (OR) rates of 72% to 75% (evaluable patients), 61% to 62% (intent-to-treat patients) for initial radiation therapy, and 68% for reirradiation (evaluable patients). However, the definition of pain response differed among the studies included. Hence, we conducted a systematic review and meta-analysis to determine the pain response rates assessed by the International Consensus Pain Response Endpoints (ICPRE) for both initial radiation therapy and reirradiation. The PubMed and Scopus databases were searched for articles published between 2002 and 2021. The inclusion criteria were (1) prospective studies or studies based on prospectively collected data and (2) studies in which pain response was assessed using ICPRE. Our primary outcomes of interest were the OR rates (sum of the complete and partial response rates) for both initial radiation therapy and reirradiation. Of the 6470 articles identified in our database search, 32 and 3 met the inclusion criteria for the analysis of initial radiation therapy and reirradiation, respectively. The OR rates of initial radiation therapy in evaluable patients (n = 4775) and intent-to-treat patients (n = 6775) were 60.4% (95% confidence interval [CI], 55.2-65.4) and 45.4% (95% CI, 38.7-52.4), respectively. The OR rates of reirradiation in evaluable patients (n = 733) and intent-to-treat patients (n = 1085) were 70.8% (95% CI, 15.7-96.9) and 62.2% (95% CI, 5.3-98.0), respectively. Subgroup analyses of initial radiation therapy including the comparison of randomized and nonrandomized studies showed no significant differences in any comparison, indicating similar response rates across different study designs. For initial radiation therapy, we determined the ICPRE-assessed response rates, which were lower than previously reported. The OR and complete response rates should be benchmarks for future randomized and nonrandomized studies. For reirradiation, the wide CIs demonstrate that the response rates based on ICPRE require further investigation.

Long-term results of chemoradiotherapy with elective nodal irradiation for resectable locally advanced esophageal cancer in three-dimensional planning system.

BACKGROUND: We evaluated the long-term results of definitive chemoradiotherapy (CRT) with elective nodal irradiation (ENI) using a three-dimensional (3D) planning system for resectable, locally advanced esophageal squamous cell carcinoma (LA-ESCC). METHODS: This retrospective study included 65 patients with LA-ESCC who started CRT between 2006 and 2017. Patients with Stage I-IV LA-ESCC according to the Union for International Cancer Control TNM classification (eighth edition) were included. In stage IV, only supraclavicular lymph node (LN) metastasis was included. All patients received radiotherapy with ENI and concurrent chemotherapy with platinum and 5-fluorouracil. RESULTS: The median age of the patients was 70 years (range 52-83 years). Stage I, II, III, and IV diseases were observed in 3 (5%), 28 (43%), 22 (34%), and 12 patients (18%), respectively. The median prescription dose was 66 Gy (range 50.4-66 Gy). The median follow-up period for the survivors was 71 months (range 8-175 months). The 5-year overall survival (OS) and progression-free survival rates were 54 and 43%, respectively. The 5-year OS rates for stages I-II and III-IV were 67 and 42%, respectively. Recurrence occurred in 29 patients (45%), and recurrence of regional LNs only occurred in 2 patients (3%). Grade 3 or higher late adverse events were observed in 8 patients (12%). Grade 5 heart failure occurred in two patients (3%); both had cardiovascular disease before treatment. CONCLUSION: The long-term results of definitive CRT with ENI for resectable LA-ESCC were favorable. ENI with a 3D planning system may reduce regional LN recurrence and late adverse events.

Radiation pneumonitis prediction model with integrating multiple dose-function features on 4DCT ventilation images.

PURPOSE: Radiation pneumonitis (RP) is dose-limiting toxicity for non-small-cell cancer (NSCLC). This study developed an RP prediction model by integrating dose-function features from computed four-dimensional computed tomography (4DCT) ventilation using the least absolute shrinkage and selection operator (LASSO). METHODS: Between 2013 and 2020, 126 NSCLC patients were included in this study who underwent a 4DCT scan to calculate ventilation images. We computed two sets of candidate dose-function features from (1) the percentage volume receiving > 20 Gy or the mean dose on the functioning zones determined with the lower cutoff percentile ventilation value, (2) the functioning zones determined with lower and upper cutoff percentile ventilation value using 4DCT ventilation images. An RP prediction model was developed by LASSO while simultaneously determining the regression coefficient and feature selection through fivefold cross-validation. RESULTS: We found 39.3 % of our patients had a ≥ grade 2 RP. The mean area under the curve (AUC) values for the developed models using clinical, dose-volume, and dose-function features with a lower cutoff were 0.791, and the mean AUC values with lower and upper cutoffs were 0.814. The relative regression coefficient (RRC) on dose-function features with upper and lower cutoffs revealed a relative impact of dose to each functioning zone to RP. RRCs were 0.52 for the mean dose on the functioning zone, with top 20 % of all functioning zone was two times greater than that of 0.19 for these with 60 %-80 % and 0.17 with 40 %-60 % (P < 0.01). CONCLUSIONS: The introduction of dose-function features computed from functioning zones with lower and upper cutoffs in a machine learning framework can improve RP prediction. The RRC given by LASSO using dose-function features allows for the quantification of the RP impact of dose on each functioning zones and having the potential to support treatment planning on functional image-guided radiotherapy.

Incidence of and risk factors for non-hematologic toxicity with combined radiotherapy and CDK4/6 inhibitors in metastatic breast cancer using dose-volume parameters analysis: a multicenter cohort study.

BACKGROUND: There is a lack of data on combined radiotherapy (RT) and cyclin-dependent kinase 4 and 6 inhibitor (CDK4/6i) risk factors and toxicity. This study aimed to assess the incidence of and risk factors for non-hematologic toxicities in patients treated with combined RT and CDK4/6i using dose-volume parameter analysis. METHODS: We conducted a retrospective multicenter cohort study of patients with metastatic breast cancer receiving RT within 14 days of CDK4/6i use. The endpoint was non-hematologic toxicities. Patient characteristics and RT treatment planning data were compared between the moderate or higher toxicities (≥ grade 2) group and the non-moderate toxicities group. RESULTS: Sixty patients were included in the study. CDK4/6i was provided at a median daily dose of 125 mg and 200 mg for palbociclib and abemaciclib, respectively. In patients who received concurrent RT and CDK4/6i (N = 29), the median concurrent prescribed duration of CDK4/6i was 14 days. The median delivered RT dose was 30 Gy and 10 fractions. The rate of grade 2 and 3 non-hematologic toxicities was 30% and 2%, respectively. There was no difference in toxicity between concurrent and sequential use of CDK4/6i. The moderate pneumonitis group had a larger lung V20 equivalent dose of 2 Gy per fraction and planning target volume than the non-moderate pneumonitis group. CONCLUSIONS: Moderate toxicities are frequent with combined RT and CDK4/6i. Caution is necessary concerning the combined RT and CDK4/6i. Particularly, reducing the dose to normal organs is necessary for combined RT and CDK4/6i.

Pre-Existing Interstitial Lung Abnormalities Are Independent Risk Factors for Interstitial Lung Disease during Durvalumab Treatment after Chemoradiotherapy in Patients with Locally Advanced Non-Small-Cell Lung Cancer.

Introduction/Background: Chemoradiotherapy (CRT) followed by durvalumab, an immune checkpoint inhibitor, is the standard treatment for locally advanced non-small-cell lung cancer (NSCLC). Interstitial lung disease (ILD) is a life-threatening toxicity caused by these treatments; however, risk factors for the ILD have not yet been established. Interstitial lung abnormalities (ILAs) are computed tomography (CT) findings which manifest as minor interstitial shadows. We aimed to investigate whether ILAs could be risk factors for grade-two or higher ILD during durvalumab therapy. Patients and Methods: Patients with NSCLC who received durvalumab after CRT from July 2018 to June 2021 were retrospectively enrolled. We obtained patient characteristics, laboratory data, radiotherapeutic parameters, and chest CT findings before durvalumab therapy. Results: A total of 148 patients were enrolled. The prevalence of ILAs before durvalumab treatment was 37.8%. Among 148 patients, 63.5% developed ILD during durvalumab therapy. The proportion of patients with grade-two or higher ILD was 33.8%. The univariate logistic regression analysis revealed that older age, high dose-volume histogram parameters, and the presence of ILAs were significant risk factors for grade-two or higher ILD. The multivariate analysis showed that ILAs were independent risk factors for grade-two or higher ILD (odds ratio, 3.70; 95% confidence interval, 1.69−7.72; p < 0.001). Conclusions: We showed that pre-existing ILAs are risk factors for ILD during durvalumab treatment after CRT. We should pay attention to the development of grade-two or higher ILD during durvalumab treatment in patients with ILAs.

Predictive role of circulatory levels of high-mobility group box 1 for radiation pneumonitis in patients with non-small cell lung cancer treated with definitive thoracic radiotherapy.

BACKGROUND: High-mobility group box 1 (HMGB1) is a pro-inflammatory protein associated with the pathophysiology of lung injury and lung tumorigenesis. Here, we investigated the predictive potential of serum HMGB1 levels for radiation pneumonitis in patients with lung cancer. METHODS: This was a retrospective biomarker study of 73 patients with non-small cell lung cancer treated with definitive thoracic radiotherapy between August 2007 and January 2021. We measured HMGB1 levels in serum stored before treatment, and analyzed its association with the development of grade ≥ 2 or grade ≥ 3 radiation pneumonitis. Additionally, baseline characteristics affecting HMGB1 levels were identified. RESULTS: Of the 73 patients, 21 (28.8%) and 6 (8.2%) patients experienced grade 2 and ≥ 3 radiation pneumonitis, respectively. Univariate and multivariate logistic regression analyses revealed that higher baseline levels of serum HMGB1 were significantly associated with a higher risk of grade ≥ 3, but not grade ≥ 2, radiation pneumonitis. The incidence of grade ≥ 3 radiation pneumonitis was higher in patients with HMGB1 levels ≥ 6.2 ng/mL than in those with levels < 6.2 ng/mL (25.0% vs. 3.5%, p = 0.019). Baseline serum levels of HMGB1 were independently and positively associated with gross tumor volume. CONCLUSIONS: Higher serum HMGB1 levels were significantly associated with the risk of grade ≥ 3 radiation pneumonitis in patients with lung cancer, and therefore, HMGB1 could be a potential blood biomarker for predicting severe radiation pneumonitis.

Stereotactic body radiotherapy versus conventional radiotherapy for painful bone metastases: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: Stereotactic body radiotherapy (SBRT) is a promising approach in treating painful bone metastases. However, the superiority of SBRT over conventional external beam radiotherapy (cEBRT) remains controversial. Therefore, this systematic review and meta-analysis of randomised controlled trials was conducted to compare SBRT and cEBRT for the treatment of bone metastases. METHODS: A search was conducted using PubMed on January 22, 2022, with the following inclusion criteria: (i) randomised controlled trials comparing SBRT with cEBRT for bone metastases and (ii) endpoint including pain response. Effect sizes across studies were pooled using random-effects models in a meta-analysis of risk ratios. RESULTS: A total of 1246 articles were screened, with 7 articles comprising 964 patients (522 and 442 patients in the SBRT and cEBRT arms, respectively) meeting the inclusion criteria. The overall pain response (OR) rates of bone metastases at 3 months were 45% and 36% in the SBRT and cEBRT arms, respectively. The present analyses showed no significant difference between the two groups. In four studies included for the calculation of OR rates of spinal metastases at three months, the OR rates were 40% and 35% in the SBRT and cEBRT arms, respectively, with no significant difference between the two groups. The incidence of severe adverse effects and health-related quality of life outcomes were comparable between the two arms. CONCLUSIONS: The superiority of SBRT over cEBRT for pain palliation in bone metastases was not confirmed in this meta-analysis. Although SBRT is a standard of care for bone metastases, patients receiving SBRT should be selected appropriately.

Investigating the displacement of radio-active sources during gold-198 grain brachytherapy for hospitalized oral cancer patients.

Purpose: This study aimed to investigate status of displacement of gold-198 (198Au) grains in patients with oral cancers as well as factors and countermeasures for the displacement of 198Au grains. Material and methods: The present study included 34 patients with oral cancers, who were exclusively treated with 198Au grain brachytherapy between 2013 and 2019. Timing and duration of the 198Au grain displacement from the oral cavity and reduction in radiation dose were estimated. Location of the displaced grain was classified as either inside or outside of gross tumor volume. Number and location of the displacement of 198Au grains, primary lesion, and growth type were evaluated. Results: Of the 34 patients included in this study, 198Au grains were displaced in 4 patients (11.8%) during hospitalization. A total of 5 grains (1.4%) were displaced out of an overall count of 367 grains implanted in these 34 patients. Of the four patients who experienced displacement of 198Au grains, three had tongue cancer, and one had lip cancer. All four patients whose grains were displaced had superficial lesions. Conclusions: When performing brachytherapy with 198Au grains for superficial lesions on the tongue or lips, care should be taken to avoid grain displacement.

Development of a radiomics and machine learning model for predicting occult cervical lymph node metastasis in patients with tongue cancer.

OBJECTIVE: We aimed to develop a predictive model for occult cervical lymph node metastasis in patients with tongue cancer using radiomics and machine learning from pretreatment contrast-enhanced computed tomography. STUDY DESIGN: This study included 161 patients with tongue cancer who received local treatment. Computed tomography images were transferred to a radiomics platform. The volume of interest was the total neck node level, including levels Ia, Ib, II, III, and IVa at the ipsilateral side, and each neck node level. The dimensionality of the radiomics features was reduced using least absolute shrinkage and selection operator logistic regression analysis. We compared 5 classifiers with or without the synthetic minority oversampling technique (SMOTE). RESULTS: For the analysis at the total neck node level, random forest with SMOTE was the best model, with an accuracy of 0.85 and an area under the curve score of 0.92. For the analysis at each neck node level, a support vector machine with SMOTE was the best model, with an accuracy of 0.96 and an area under the curve score of 0.98. CONCLUSIONS: Predictive models using radiomics and machine learning have potential as clinical decision support tools in the management of patients with tongue cancer for prediction of occult cervical lymph node metastasis.

Brachytherapy with 198Au grains for cancer of the floor of the mouth: relationships between radiation dose and complications.

OBJECTIVE: This study aimed to retrospectively evaluate the radiation dose and complications in soft tissue and mandible caused by 198Au grain brachytherapy alone or the combination with other modalities in patients with the cancer of the floor of the mouth. MATERIALS AND METHODS: Twelve patients with T1 (n = 5) and T2 (n = 7) squamous cell carcinoma of the floor of the mouth, who were treated with 198Au grain brachytherapy alone (n = 5) or the combination of external beam radiotherapy (EBRT) and/or chemotherapy and 198Au grain brachytherapy (n = 7) from January 2005 to December 2016, were included. The relationships between the radiation dose and the complications of the soft tissue or mandible were investigated. RESULTS: Seven of 12 patients had died. Of these 7 patients, one with T1 and 2 with T2 had died of the causes related to the cancer of the floor of the mouth. Two with T1 and 2 with T2 had died of other diseases. Two patients had grade 2 complications of the soft tissue and mandible. These patients were treated by the combination of EBRT and/or chemotherapy and 198Au grain brachytherapy and irradiated with 123 or 139 Gy in total dose, respectively. And one of these patients was treated by the chemotherapy in addition to EBRT. CONCLUSION: Our study showed that the combination of EBRT and 198Au grains brachytherapy for the floor of the mouth cancer patients might be associated with risks of developing complications of soft tissue ulcer and mandibular bone necrosis.

Temporal changes and risk factors for esophageal stenosis after salvage radiotherapy in superficial esophageal cancer following non-curative endoscopic submucosal dissection.

BACKGROUND AND PURPOSE: Radiotherapy (RT) has recently received increasing attention as an additional treatment for organ preservation after non-curative endoscopic submucosal dissection (ESD) in patients with superficial esophageal cancer. Esophageal stenosis is an adverse event related to RT after ESD that is not widely studied. The aim of this study was to investigate esophageal stenosis related to salvage RT in superficial esophageal cancer after non-curative ESD. MATERIALS AND METHODS: Fifty patients who received salvage RT after non-curative ESD at a single institution between 2011 and 2018 were included in this study. The Common Terminology Criteria for Adverse Events, version 5.0, was used to assess esophageal stenosis. Data were compared using Fisher's exact test. Statistical significance was set at P < 0.05. RESULTS: Median follow-up time was 48 months (range, 12-95 months). Grade 2 and 3 esophageal stenosis were observed in 17 (34%), and 3 patients (6%), respectively. The frequency of grade 2 or worse esophageal stenosis decreased over time (before RT, 6 months, 1 year, and 2 years after RT: 16 (32%), 13 (26%), 10 (20%), and 6 (12%) patients, respectively). Only one patient required endoscopic balloon dilation (EBD) 1 year after RT. All grade 3 esophageal stenosis improved grade 2 or less by EBD. In univariate analysis, only tumor location was a significant risk factor for grade 3 esophageal stenosis. CONCLUSIONS: Esophageal stenosis, after salvage RT in patients with esophageal cancer who received non-curative ESD, improved naturally or after EBD; only a few cases required long-term EBD.

Reirradiation Using 198Au Grain Brachytherapy for Recurrent Oral Cancer Cases Previously Treated by Definitive Radiotherapy.

BACKGROUND/AIM: We investigated treatment outcomes and complications during reirradiation of patients with oral cancers. PATIENTS AND METHODS: Six patients who received definitive radiotherapy for oral cancer as the initial treatment and brachytherapy for recurrence were included. Local control and overall survival rates, soft tissue and mandibular complications, and tooth extraction were investigated. RESULTS: The five-year local control and overall survival rates were 83.3% and 100%, respectively. The occurrence rate of grade 2 soft tissue and mandible complications was 33.3%, and the primary sites were the buccal mucosa and the floor of mouth. The positions of the extracted tooth in the two cases were adjacent to the tumor, and one case developed grade 2 complication of the mandible. CONCLUSION: During recurrence of the buccal mucosa and the floor of mouth cancers, reirradiation should be avoided considering mandibular complications. To avoid reirradiation-related complications, tooth extraction near the radiation field should be avoided.