Helical tomotherapy for asymptomatic chemotherapy-refractory or -unfit multiple (3 or more) metastases

Background: Despite chemotherapy innovations, prognosis of patients with chemotherapy-refractory or -unfit multiple metastases (CRMM/CUMM) remains poor. In this prospective study, the efficacy and toxicity of helical tomotherapy for CRMM/CUMM were evaluated. Materials and methods: Between 2014 and 2020, asymptomatic patients with CRMM/CUMM with ≥ 3 lesions and no prior radiotherapy of the targets were enrolled. Patients who had intolerable toxicities to chemotherapy and those who refused chemotherapy were included in the CRMM and CUMM groups, respectively. Prostate cancer patients and patients with metastases mainly localized in the liver, lung, or brain were excluded. By helical tomotherapy, up to 10 lesions per patient were irradiated in order of volume. The standard dose was 50–60 Gy in 25–30 fractions. Results: Forty-five patients (median age, 63 years; 35 CRMM/10 CUMM) were enrolled. Primary tumors included lung, gynecological, and gastrointestinal cancers. The most frequently treated targets were lymph node metastases, followed by peritoneal/pleural disseminations and bone tumors. The 1-year survival rate was 51% (median, 12.5 months). In the 35 patients with CRMM, the median survival time was 12.5 months, and the median pre-radiation chemotherapy period was 8.8 months (p > 0.05). The 6-month target control rate was 78%. Acute adverse events (grade ≥ 2) occurred in 33 patients: hematologic toxicities in 23, dermatitis in 6, and others in 8. Late grade ≥ 2 toxicities occurred in 6 patients: pneumonitis in 4 and gastric hemorrhage in 2. Conclusion: Tomotherapy for CRMM/CUMM resulted in median survival times > 1 year. This treatment should be investigated further in larger prospective studies

CO Multi-line Imaging of Nearby Galaxies (COMING) IV. Overview of the Project

Observations of the molecular gas in galaxies are vital to understanding the evolution and star-forming histories of galaxies. However, galaxies with molecular gas maps of their whole discs having sufficient resolution to distinguish galactic structures are severely lacking. Millimeter wavelength studies at a high angular resolution across multiple lines and transitions are particularly needed, severely limiting our ability to infer the universal properties of molecular gas in galaxies. Hence, we conducted a legacy project with the 45 m telescope of the Nobeyama Radio Observatory, called the CO Multi-line Imaging of Nearby Galaxies (COMING), which simultaneously observed 147 galaxies with high far-infrared flux in $^{12}$CO, $^{13}$CO, and C$^{18}$O $J=1-0$ lines. The total molecular gas mass was derived using the standard CO-to-H$_2$ conversion factor and found to be positively correlated with the total stellar mass derived from the WISE $3.4 \mu$m band data. The fraction of the total molecular gas mass to the total stellar mass in galaxies does not depend on their Hubble types nor the existence of a galactic bar, although when galaxies in individual morphological types are investigated separately, the fraction seems to decrease with the total stellar mass in early-type galaxies and vice versa in late-type galaxies. No differences in the distribution of the total molecular gas mass, stellar mass, and the total molecular gas to stellar mass ratio was observed between barred and non-barred galaxies, which is likely the result of our sample selection criteria, in that we prioritized observing FIR bright (and thus molecular gas-rich) galaxies.Comment: Accepted for publication in PASJ; 47 pages, 5 tables, 29 figures. On-line supplementary images are available at this URL (https://astro3.sci.hokudai.ac.jp/~radio/coming/publications/). CO data is available at the Japanese Virtual Observatory (JVO) website (https://jvo.nao.ac.jp/portal/nobeyama/coming.do) and the project website (https://astro3.sci.hokudai.ac.jp/~radio/coming/data/

Clinical and dosimetric factors for symptomatic radiation pneumonitis after stereotactic body radiotherapy for early-stage non-small cell lung cancer

Background and purpose: The present study attempted to identify risk factors for symptomatic radiation pneumonitis (RP) after stereotactic body radiotherapy (SBRT) in patients with early-stage non-small cell lung cancer (NSCLC). Materials and methods: We reviewed 244 patients with early-stage NSCLC treated with SBRT. The primary endpoint was the incidence of grade ≥2 RP. Gray’s test was performed to examine the relationship between clinical risk factors and grade ≥2 RP, and the Fine-Gray model was used for a multivariate analysis. The effects of each dose parameter on grade ≥2 RP were evaluated with the Fine-Gray model and optimal thresholds were tested using receiver operating characteristic (ROC) curves. Results: With a median follow-up period of 48 months, the 4-year cumulative incidence of grade ≥2 RP was 15.3%. Gray’s test revealed that tumor size, a central tumor, interstitial pneumonia, and the biologically effective dose correlated with RP. In the multivariate analysis, a central tumor and interstitial pneumonia remained significant factors (p 16.7% was the best indicator of symptomatic RP among dose parameters. Conclusion: The present results suggest that a central tumor and interstitial pneumonia are independent risk factors for symptomatic RP and lung V10 ≤16.7% is recommended as the threshold in SBRT

Symptomatic radiation-induced rib fractures after stereotactic body radiotherapy for early-stage non-small cell lung cancer

Background and purpose: The present study investigated the relationships between the risk of radiation-induced rib fractures (RIRF) and clinical and dosimetric factors in stereotactic body radiotherapy (SBRT) for early-stage non-small cell lung cancer (NSCLC). We also examined dosimetric parameters associated with symptomatic or asymptomatic RIRF and the dosimetric threshold for symptomatic RIRF. Materials and methods: We reviewed 244 cases of early-stage NSCLC treated with SBRT. Gray’s test and the Fine-Gray model were performed to examine the relationships between clinical and dosimetric factors and grade ≥ 2 (i.e., symptomatic) RIRF. The effects of each dose parameter on grade ≥ 1 and ≥ 2 RIRF were assessed with the Fine-Gray model. The t-test was used to compare each dose parameter between the grade 1 and grade ≥ 2 groups. Optimal thresholds were tested using receiver operating characteristic (ROC) curves. Results: With a median follow-up period of 48 months, the 4-year cumulative incidence of grade ≥ 1 and grade ≥ 2 RIRF were 26.4 % and 8.0 %, respectively. Regarding clinical factors, only age was associated with the development of grade ≥ 2 RIRF (p = 0.024). Among dosimetric parameters, only V40Gy significantly differed between the grade 1 and grade ≥ 2 groups (p = 0.015). The ROC curve analysis of grade ≥ 2 RIRF showed that the optimal diagnostic thresholds for D3cc, D4cc, D5cc, and V40Gy were 45.86 Gy (area under the curve [AUC], 0.706), 39.02 Gy (AUC, 0.705), 41.62 Gy (AUC, 0.702), and 3.83 cc (AUC, 0.730), respectively. These results showed that V40Gy ≤ 3.83 cc was the best indicator of grade ≥ 2 RIRF. The 4-year incidence of grade ≥ 2 RIRF in the V40Gy ≤ 3.83 cc vs. > 3.83 cc groups was 1.8 % vs. 14.2 % (p = 0.001). Conclusion: The present results recommend V40Gy ≤ 3.83 cc as the threshold for grade ≥ 2 RIRF in SBRT

Comparison of Recurrence Patterns between Adenocarcinoma and Squamous Cell Carcinoma after Stereotactic Body Radiotherapy for Early-Stage Lung Cancer

We compared recurrence patterns between adenocarcinoma (ADC) and squamous cell carcinoma (SCC) after stereotactic body radiotherapy (SBRT) for early-stage lung cancer. Patients with ADC and SCC histology, who were treated with SBRT for clinical stage IA1-IIA lung cancer at our institution, were included in the analysis. The rates of disease-free survival (DFS), overall survival (OS), local recurrence (LR), lymph node metastasis (LNM), and distant metastasis (DM) were calculated using the Kaplan–Meier method or the cumulative incidence function. Among the 204 patients analyzed, 138 and 66 were in the ADC and SCC groups, respectively. The median follow-up period was 60 months. The five-year DFS and OS rates were 57% vs. 41% and 69% vs. 48% in the ADC and SCC groups, respectively (p = 0.015 and 0.019, respectively). In the multivariate analysis, the histological type was not associated with DFS or OS. Five-year LR, LNM, and DM rates were 10% vs. 24%, 12% vs. 20%, and 25% vs. 27% in the ADC and SCC groups, respectively (p = 0.0067, 0.074, and 0.67, respectively). The multivariate analysis identified the histological type of SCC as an independent factor for LR (hazard ratio, 2.41; 95% confidence interval, 1.21–4.77; p = 0.012). The present results suggest that the risk of LR after SBRT is higher for SCC than for ADC

Comparison of Recurrence Patterns between Adenocarcinoma and Squamous Cell Carcinoma after Stereotactic Body Radiotherapy for Early-Stage Lung Cancer

We compared recurrence patterns between adenocarcinoma (ADC) and squamous cell carcinoma (SCC) after stereotactic body radiotherapy (SBRT) for early-stage lung cancer. Patients with ADC and SCC histology, who were treated with SBRT for clinical stage IA1-IIA lung cancer at our institution, were included in the analysis. The rates of disease-free survival (DFS), overall survival (OS), local recurrence (LR), lymph node metastasis (LNM), and distant metastasis (DM) were calculated using the Kaplan–Meier method or the cumulative incidence function. Among the 204 patients analyzed, 138 and 66 were in the ADC and SCC groups, respectively. The median follow-up period was 60 months. The five-year DFS and OS rates were 57% vs. 41% and 69% vs. 48% in the ADC and SCC groups, respectively (p = 0.015 and 0.019, respectively). In the multivariate analysis, the histological type was not associated with DFS or OS. Five-year LR, LNM, and DM rates were 10% vs. 24%, 12% vs. 20%, and 25% vs. 27% in the ADC and SCC groups, respectively (p = 0.0067, 0.074, and 0.67, respectively). The multivariate analysis identified the histological type of SCC as an independent factor for LR (hazard ratio, 2.41; 95% confidence interval, 1.21–4.77; p = 0.012). The present results suggest that the risk of LR after SBRT is higher for SCC than for ADC

Comparing different boost concepts and beam configurations for proton therapy of pancreatic cancer

Background and Purpose: Interfractional geometrical and anatomical variations impact the accuracy of proton therapy for pancreatic cancer. This study investigated field-in-field (FIF) and simultaneous integrated boost (SIB) concepts for scanned proton therapy treatment with different beam configurations. Materials and Methods: Robustly optimized treatment plans for fifteen patients were generated using FIF and SIB techniques with two, three, and four beams. The prescribed dose in 20 fractions was 60 Gy(RBE) for the internal gross tumor volume (IGTV) and 46 Gy(RBE) for the internal clinical target volume. Verification computed tomography (vCT) scans was performed on treatment days 1, 7, and 16. Initial treatment plans were recalculated on the rigidly registered vCTs. V100% and D95% for targets and D2cm3 for the stomach and duodenum were evaluated. Robustness evaluations (range uncertainty of 3.5 %) were performed to evaluate the stomach and duodenum dose-volume parameters. Results: For all techniques, IGTV V100% and D95% decreased significantly when recalculating the dose on vCTs (p < 0.001). The median IGTV V100% and D95% over all vCTs ranged from 74.2 % to 90.2 % and 58.8 Gy(RBE) to 59.4 Gy(RBE), respectively. The FIF with two and three beams, and SIB with two beams maintained the highest IGTV V100% and D95%. In robustness evaluations, the ΔD2cm3 of stomach was highest in two beams plans, while the ΔD2cm3 of duodenum was highest in four beams plans, for both concepts. Conclusion: Target coverage decreased when recalculating on CTs at different time for both concepts. The FIF with three beams maintained the highest IGTV coverage while sparing normal organs the most