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.

[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.

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.

Distribution of Lymph Node Metastasis in Esophageal Squamous Cell Carcinoma After Trimodal Therapy.

BACKGROUND: Although metastatic tumors in lymph nodes (LN) are potentially affected by neoadjuvant chemoradiotherapy (NCRT), the distribution of LN metastases of esophageal squamous cell carcinoma (ESCC) after trimodal therapy has never been sufficiently estimated. PATIENTS AND METHODS: We evaluated the distribution of LN metastases, relationships between LN metastases and radiation fields, risk factors for LN metastasis, and the influence of LN metastasis on the survival of 184 patients with ESCC who underwent NCRT followed by esophagectomy. RESULTS: Neoadjuvant chemoradiotherapy resulted in down-staged LN status in 74 (49.3%) patients. Pathological LN metastases were extensive in 177 LN stations in the cervical, mediastinal, and abdominal fields, and 162 (91.5%) metastases were located inside the radiation fields. Multivariate analysis showed that clinical N stage [N0 vs. 1/2/3: hazard ratio (HR), 2.69; 95% confidence interval (CI), 1.22-5.92; p = 0.01] and clinical response of primary tumor (complete vs. noncomplete: HR, 2.93; 95% CI, 1.50-5.69; p = 0.002) were statistically significant for pathological LN metastasis. Recurrence-free and overall survivals were significantly stratified according to the number of pathological LN metastases, associations between clinical and pathological LN metastases, and presence or absence of pathological LN metastases outside radiation field. CONCLUSIONS: About 50% of patients who were clinically diagnosed with LN metastasis before treatment were downstaged by NCRT, and their prognoses were relatively good. However, LN metastases were extensive at the cervical, mediastinal, and abdominal areas, even within the radiation field. Thus, systematic and adequate lymphadenectomy is required for ESCC treated by NCRT.

Potential benefits of volumetric modulated arc therapy to reduce the incidence of ≥ grade 2 radiation pneumonitis in radiotherapy for locally advanced non-small cell lung cancer patients.

BACKGROUND: The use of volumetric modulated arc therapy is gradually widespread for locally advanced non-small cell lung cancer. The purpose of this study was to identify the factors that caused ≥ grade 2 radiation pneumonitis and evaluate the impact of using volumetric modulated arc therapy on the incidence of ≥ grade 2 radiation pneumonitis by comparing three-dimensional conformal radiation therapy. METHODS: We retrospectively evaluated 124 patients who underwent radical radiotherapy for locally advanced non-small cell lung cancer in our institution between 2008 and 2019. The following variables were analysed to detect the factors that affected ≥ grade 2 radiation pneumonitis; age, sex, the presence of interstitial lung disease, pulmonary emphysema, tumour location, stage, PTV/lung volume, lung V20Gy, total dose, concurrent chemoradiotherapy, adjuvant immune checkpoint inhibitor, radiotherapy method. Radiation pneumonitis was evaluated using the common terminology criteria for adverse events (version 5.0). RESULTS: A total of 84 patients underwent three-dimensional conformal radiation therapy (3D-CRT group) and 40 patients underwent volumetric modulated arc therapy (VMAT group). The cumulative incidence of ≥ grade 2 radiation pneumonitis at 12 months was significantly lower in the VMAT group than in the 3D-CRT group (25% vs. 49.1%). The use of volumetric modulated arc therapy was a significant factor for ≥ grade 2 radiation pneumonitis (HR:0.32, 95% CI: 0.15-0.65, P = 0.0017) in addition to lung V20Gy (≥ 24%, HR:5.72 (95% CI: 2.87-11.4), P < 0.0001) and total dose (≥ 70 Gy, HR:2.64 (95% CI: 1.39-5.03), P = 0.0031) even after adjustment by multivariate analysis. CONCLUSIONS: We identified factors associated with ≥ grade 2 radiation pneumonitis in radiotherapy for patients with locally advanced non-small cell lung cancer. Volumetric modulated arc therapy has potential benefits to reduce the risk of ≥ grade 2 radiation pneumonitis.

T2-FLAIR Mismatch Sign and Response to Radiotherapy in Diffuse Intrinsic Pontine Glioma.

PURPOSE: The T2-fluid-attenuated inversion recovery (FLAIR) mismatch sign was previously reported as a diagnostic indicator of diffuse astrocytoma, isocitrate dehydrogenase-mutant, and 1p/19q noncodeletion. Subsequently, it was reported that the same findings were observed in diffuse intrinsic pontine glioma (DIPG). We investigated the clinical significance of T2-FLAIR mismatch sign in DIPG. METHODS: Twenty-one patients with DIPG (Male: Female = 12:9) were treated at our institute between 2004 and 2019. All patients were treated with local radiotherapy of 54 Gy/30 fractions. The positive T2-FLAIR mismatch sign was defined if it fulfilled the following criteria: (1) T2-FLAIR mismatch volume was >50% of T2 high volume at nonenhanced area, (2) the FLAIR low lesion is not associated with gadolinium enhancement (inside of enhancement or just outside of enhancement defined as edema), and (3) signal-intensity of FLAIR lowest lesion at tumor is lower than the normal cerebellar cortex. RESULTS: In our patient series, T2-FLAIR mismatch sign was found in 5 out of 21 patients. Objective response rate of radiotherapy was 100% in patients positive for T2-FLAIR mismatch, while it was 25.0% in patients negative for T2-FLAIR mismatch, and this difference was statistically significant (p < 0.01, Fisher's exact test). In patients under the age of 18-years, T2-FLAIR mismatch positive had a slightly better prognosis (p < 0.05, Wilcoxon test). CONCLUSION: T2-FLAIR mismatch sign in DIPG may be an indicator for better response to radiotherapy and a better prognostic factor.

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.

Quality of palliative radiotherapy assessed using quality indicators: a multicenter survey†.

We sought to identify potential evidence-practice gaps in palliative radiotherapy using quality indicators (QIs), previously developed using a modified Delphi method. Seven QIs were used to assess the quality of radiotherapy for bone metastases (BoM) and brain metastases (BrM). Compliance rate was calculated as the percentage of patients for whom recommended medical care was conducted. Random effects models were used to estimate the pooled compliance rates. Of the 39 invited radiation oncologists, 29 (74%) from 29 centers participated in the survey; 13 (45%) were academic and 16 (55%) were non-academic hospitals. For the QIs, except for BoM-4, the pooled compliance rates were higher than 80%; however, for at least some of the centers, the compliance rate was lower than these pooled rates. For BoM-4 regarding steroid use concurrent with radiotherapy for malignant spinal cord compression, the pooled compliance rate was as low as 32%. For BoM-1 regarding the choice of radiation schedule, the compliance rate was higher in academic hospitals than in non-academic hospitals (P = 0.021). For BrM-3 regarding the initiation of radiotherapy without delay, the compliance rate was lower in academic hospitals than in non-academic hospitals (P = 0.016). In conclusion, overall, compliance rates were high; however, for many QIs, practice remains to be improved in at least some centers. Steroids are infrequently used concurrently with radiotherapy for malignant spinal cord compression.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.