Probability of normal tissue complications for hematologic and gastrointestinal toxicity in postoperative whole pelvic radiotherapy for gynecologic malignancies using intensity-modulated proton therapy with robust optimization

This retrospective treatment-planning study was conducted to determine whether intensity-modulated proton therapy with robust optimization (ro-IMPT) reduces the risk of acute hematologic toxicity (H-T) and acute and late gastrointestinal toxicity (GI-T) in postoperative whole pelvic radiotherapy for gynecologic malignancies when compared with three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated X-ray (IMXT) and single-field optimization proton beam (SFO-PBT) therapies. All plans were created for 13 gynecologic-malignancy patients. The prescribed dose was 45 GyE in 25 fractions for 95% planning target volume in 3D-CRT, IMXT and SFO-PBT plans and for 99% clinical target volume (CTV) in ro-IMPT plans. The normal tissue complication probability (NTCP) of each toxicity was used as an in silico surrogate marker. Median estimated NTCP values for acute H-T and acute and late GI-T were 0.20, 0.94 and 0.58 × 10-1 in 3D-CRT; 0.19, 0.65 and 0.24 × 10-1 in IMXT; 0.04, 0.74 and 0.19 × 10-1 in SFO-PBT; and 0.06, 0.66 and 0.15 × 10-1 in ro-IMPT, respectively. Compared with 3D-CRT and IMXT plans, the ro-IMPT plan demonstrated significant reduction in acute H-T and late GI-T. The risk of acute GI-T in ro-IMPT plan is equivalent with IMXT plan. The ro-IMPT plan demonstrated potential clinical benefits for reducing the risk of acute H-T and late GI-T in the treatment of gynecologic malignances by reducing the dose to the bone marrow and bowel bag while maintaining adequate dose coverage to the CTV. Our results indicated that ro-IMPT may reduce acute H-T and late GI-T risk with potentially improving outcomes for postoperative gynecologic-malignancy patients with concurrent chemotherapy.

A Single-Institution Prospective Study To Evaluate the Safety and Efficacy of Real- Time Image-Gated Spot-Scanning Proton Therapy (RGPT) for Prostate Cancer

Purpose

In real-time image-gated spot-scanning proton therapy (RGPT), the dose distribution is distorted by gold fiducial markers placed in the prostate. Distortion can be suppressed by using small markers and more than 2 fields, but additional fields may increase the dose to organs at risk. Therefore, we conducted a prospective study to evaluate the safety and short-term clinical outcome of RGPT for prostate cancer.

Methods and Materials

Based on the previously reported frequency of early adverse events (AE) and the noninferiority margin of 10%, the required number of cases was calculated to be 43 using the one-sample binomial test by the Southwest Oncology Group statistical tools with the one-sided significance level of 2.5% and the power 80%. Patients with localized prostate cancer were enrolled and 3 to 4 pure gold fiducial markers of 1.5-mm diameter were inserted in the prostate. The prescribed dose was 70 Gy(relative biologic effectiveness) in 30 fractions, and treatment was performed with 3 fields from the left, right, and the back, or 4 fields from either side of slightly anterior and posterior oblique fields. The primary endpoint was the frequency of early AE (≥grade 2) and the secondary endpoint was the biochemical relapse-free survival rate and the frequency of late AE.

Results

Forty-five cases were enrolled between 2015 and 2017, and all patients completed the treatment protocol. The median follow-up period was 63.0 months. The frequency of early AE (≥grade 2) was observed in 4 cases (8.9%), therefore the noninferiority was verified. The overall 5-year biochemical relapse-free survival rate was 88.9%. As late AE, grade 2 rectal bleeding was observed in 8 cases (17.8%).

Conclusions

The RGPT for prostate cancer with 1.5-mm markers and 3- or 4- fields was as safe as conventional proton therapy in early AE, and its efficacy was comparable with previous studies.

Proton Beam Therapy for Intrahepatic Cholangiocarcinoma: A Multicenter Prospective Registry Study in Japan

Introduction

Intrahepatic cholangiocarcinoma (ICC) can be treated with chemotherapy in unresectable cases, but outcomes are poor. Proton beam therapy (PBT) may provide an alternative treatment and has good dose concentration that may improve local control.

Methods

Fifty-nine patients who received initial PBT for ICC from May 2016 to June 2018 at nine centers were included in the study. The treatment protocol was based on the policy of the Japanese Society for Radiation Oncology. Forty patients received 72.6-76 Gy (RBE) in 20-22 fr, 13 received 74.0-76.0 Gy (RBE) in 37-38 fr, and 6 received 60-70.2 Gy (RBE) in 20-30 fr. Overall survival (OS) and progression-free survival (PFS) were estimated by Kaplan-Meier analysis.

Results

The 59 patients (35 men, 24 women; median age: 71 years; range: 41-91 years) had PS of 0 (n = 47), 1 (n = 10), and 2 (n = 2). Nine patients had hepatitis and all 59 cases were considered inoperable. The Child-Pugh class was A (n = 46), B (n = 7), and unknown (n = 6); the median maximum tumor diameter was 5.0 cm (range 2.0-15.2 cm); and the clinical stage was I (n = 12), II (n = 19), III (n = 10), and IV (n = 18). At the last follow-up, 17 patients were alive (median follow-up: 36.7 months; range: 24.1-49.9 months) and 42 had died. The median OS was 21.7 months (95% CI: 14.8-34.4 months). At the last follow-up, 37 cases had recurrence, including 10 with local recurrence. The median PFS was 7.5 months (95% CI: 6.1-11.3 months). In multivariable analyses, Child-Pugh class was significantly associated with OS and PFS, and Child-Pugh class and hepatitis were significantly associated with local recurrence. Four patients (6.8%) had late adverse events of grade 3 or higher.

Conclusion

PBT gives favorable treatment outcomes for unresectable ICC without distant metastasis and may be particularly effective in cases with large tumors.

Impact of adaptive radiotherapy on survival in locally advanced nasopharyngeal carcinoma treated with concurrent chemoradiotherapy

PURPOSE

To investigate the clinical significance of adaptive radiotherapy (ART) in locally advanced nasopharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT).

MATERIALS AND METHODS

Eligible patients were treated with concurrent chemoradiotherapy using IMRT. Planning computed tomography in ART was performed during radiotherapy, and replanning was performed. Since ART was started in May 2011 (ART group), patients who were treated without ART up to April 2011 (non-ART group) were used as the historical control. The Kaplan-Meier method was used to calculate overall survival (OS), locoregional recurrence-free survival (LRFS), progression-free survival (PFS), and distant metastasis-free survival (DMFS). LRFS for the primary tumor (LRFS_P) and regional lymph node (LRFS_LN) were also studied for more detailed analysis. Statistical significance was evaluated using the log-rank test for survival.

RESULTS

The ART group tended to have higher radiation doses. The median follow-up period was 127 months (range, 10 to 211 months) in the non-ART group and 61.5 months (range, 5 to 129 months) in the ART group. Compared to the non-ART group, the ART group showed significantly higher 5-year PFS (53.8% vs. 81.3%, p = 0.015) and LRFS (61.2% vs. 85.3%, p = 0.024), but not OS (80.7% vs. 80.8%, p = 0.941) and DMFS (84.6% vs. 92.7%, p = 0.255). Five-year LRFS_P was higher in the ART group (61.3% vs. 90.6%, p = 0.005), but LRFS_LN did not show a significant difference (91.9% vs. 96.2%, p = 0.541).

CONCLUSION

Although there were differences in the patient backgrounds between the two groups, this study suggests the potential effectiveness of ART in improving locoregional control, especially in the primary tumor.

Proton Beam Therapy for Hepatocellular Carcinoma: Multicenter Prospective Registry Study in Japan

PURPOSE

A prospective multicenter registry study was started May 2016 in Japan to evaluate the efficacy and safety of proton beam therapy (PBT) for hepatocellular carcinoma (HCC).

METHODS AND MATERIALS

Patients who received PBT for HCC from May 2016 to June 2018 were registered in the database of the Particle Beam Therapy Committee and Subcommittee of the Japanese Society for Radiation Oncology. Overall survival (OS), progression-free survival (PFS), and local recurrence were evaluated.

RESULTS

Of the 755 registered patients, 576 with initial PBT and no duplicate cancer were evaluated. At final follow-up, 322 patients were alive and 254 had died. The median follow-up period for survivors was 39 months (0-58 months). The median OS time of the 576 patients was 48.8 months (95% CI, 42.0-55.6 months) and the 1-, 2-, 3-, and 4-year OS rates were 83.8% (95% CI, 80.5%-86.6%), 68.5% (64.5%-72.2%), 58.2% (53.9%-62.2%), and 50.1% (44.9%-55.0%), respectively. Recurrence was observed in 332 patients, including local recurrence in 45 patients. The median PFS time was 14.7 months (95% CI, 12.4-17.0 months) and the 1-, 2-, 3-, and 4-year PFS rates were 55.2% (95% CI, 51.0%-59.2%), 37.5% (33.5%-41.5%), 30.2% (26.3%-34.2%), and 22.8% (18.5%-27.4%), respectively. The 1-, 2-, 3-, and 4-year OS rates were significantly higher for tumor size <5 versus 5 to 10 cm (P < .001) and <5 versus ≥10 cm (P < .001); Child-Pugh score A/B versus C (P < .001); and distance of the tumor from the gastrointestinal tract <1 versus 1 to 2 cm (P < .008) and <1 versus >2 cm (P < .001). At final follow-up, 27 patients (4.7%) had late adverse events of grade 3 or higher, with liver failure (n = 7), and dermatitis (n = 7) being most common.

CONCLUSIONS

This multicenter prospective data registry indicated that PBT for HCC gives good therapeutic effects (3-year local control rate of 90%) with a low risk of severe late adverse events.

Daily fraction dose-adjusted radiotherapy policy to avoid prolonging the overall treatment time for early glottic squamous cell carcinoma: a single-institutional retrospective study

The objective of this study was to determine the outcomes of radical radiotherapy for early glottic squamous cell carcinoma (EGSCC) with the policy of increasing the fraction size during radiotherapy when the overall treatment time (OTT) was expected to be prolonged. Patients diagnosed with clinical T1-2N0M0 EGSCC, who were treated with radical radiotherapy between 2008 and 2019 at Hokkaido University Hospital, were included. Patients received 66 Gy in 33 fractions for T1 disease and 70 Gy in 35 fractions for T2 disease as our standard regimen (usual group [UG]). If the OTT was expected to extend for >1 week, the dose fraction size was increased from 2.0 to 2.5 Gy from the beginning or during radiotherapy (adjusted group [AG]). At this time, we performed a statistical analysis between UG and AG. In total, 116 patients were identified, and the treatment schedules of 29 patients were adjusted. The median follow-up was 60.9 months. In the T1 group, the cumulative 5-year local failure rate was 12.0% in the AG and 15.4% in the UG, and in the T2 group, the rate was 40.7% in the AG and 25.3% in the UG. There were no significant differences between the AG and UG. Similarly, no significant differences were observed for overall survival and progression-free survival rates. Our single-institutional retrospective analysis of EGSCC patients suggested that a method of adjusting the radiotherapy schedule to increase fraction size from the beginning or during the course may be effective in maintaining treatment outcomes.

Real-time tumor-tracking radiotherapy with SyncTraX for primary liver tumors requiring isocenter shift†

The SyncTraX series enables real-time tumor-tracking radiotherapy through the real-time recognition of a fiducial marker using fluoroscopic images. In this system, the isocenter should be located within approximately 5-7.5 cm from the marker, depending on the version, owing to the limited field of view. If the marker is placed away from the tumor, the isocenter should be shifted toward the marker. This study aimed to investigate stereotactic body radiotherapy (SBRT) outcomes of primary liver tumors treated with SyncTraX in cases where the isocenter was shifted marginally or outside the planning target volume (PTV). Twelve patients with 13 liver tumors were included in the analysis. Their isocenter was shifted toward the marker and was placed marginally or outside the PTV. The prescribed doses were generally 40 Gy in four fractions or 48 Gy in eight fractions. The overall survival (OS) and local control (LC) rates were calculated using the Kaplan-Meier method. All patients completed the scheduled SBRT. The median distance between the fiducial marker and PTV centroid was 56.0 (interquartile range [IQR]: 52.7-66.7) mm. By shifting the isocenter toward the marker, the median distance between the marker and isocenter decreased to 34.0 (IQR: 33.4-39.7) mm. With a median follow-up period of 25.3 (range: 6.9-70.0) months, the 2-year OS and LC rates were 100.0% (95% confidence interval: 100-100). An isocenter shift makes SBRT with SyncTraX feasible in cases where the fiducial marker is distant from the tumor.

The Japanese nationwide cohort data of proton beam therapy for liver oligometastasis in esophagogastric cancer patients

A nationwide multicenter cohort study on particle therapy was launched by the Japanese Society for Radiation Oncology in Japan in May 2016. We analyzed the outcome of proton beam therapy (PBT) for liver oligometastasis of esophagogastric cancers. Cases in which PBT was performed at all PBT facilities in Japan between May 2016 and February 2019 were enrolled. The patients were selected based on the following criteria: controlled primary cancer, liver recurrence without extrahepatic tumors and no more than three liver lesions. Twenty-two males and two females with a median age of 69 (range, 52-80) years and 35 lesions were included. This study included 6 patients with esophageal and 18 patients with gastric cancer. The median lesion size, fraction size and biological effective dose (BED)10 were 32 (7-104) mm, 3.8 gray (relative biological effect)/fractions (Gy (RBE)/fr) (2-8 Gy (RBE)/fr) and 96.9 (88.8-115.2) Gy, respectively. The median follow-up period was 18 (4-47) months. The 1-, 2- and 3-year overall survival (OS) rates were 75, 51.8 and 45.3%, respectively, and the median OS was 25.3 months. The 1-, 2- and 3-year cumulative local recurrence (LR) rates were 3, 6 and 6%, respectively. Patients' age (P < 0.01), performance status (P = 0.017) and tumor size (P = 0.024) were significant OS-related factors. No Grade 3 or higher adverse events (AEs) were observed. Owing to the low incidence of AEs and the low LR cumulative incidence, PBT is a feasible option for liver oligometastasis of esophagogastric cancers.

Implementation of the HOME core outcome set for clinical trials of atopic eczema-barriers and opportunities: the HOME IX meeting report

The Harmonising Outcome Measures for Eczema (HOME) initiative established a core outcome set (COS) for atopic eczema (AE) clinical trials in 2019. This set encompasses four core outcome domains and corresponding measurement instruments: clinical signs (EASI), patient-reported symptoms (POEM and NRS 11 point for worst itch over the last 24 h), quality of life (DLQI/CDLQI/IDQoLI), and long-term control (Recap or ADCT). Following its roadmap, the HOME initiative is now focused on supporting implementation of the COS. To identify barriers and facilitators to implementation of the COS, and to guide the effort to promote COS uptake, a virtual consensus meeting was held over 2 days (September 25-26, 2021) attended by 55 participants (26 healthcare professionals, 16 methodologists, 5 patients, 4 industry representatives, and 4 students). Implementation themes were identified by a pre-meeting survey distributed to HOME members, presentations, and whole-group discussion. Participants were divided into five multi-professional small groups which ranked their top 3 most important themes, followed by whole-group discussion and anonymous consensus voting (consensus criteria: < 30% disagreement). Three most important implementation themes were identified and agreed upon: (1) awareness and stakeholder engagement, (2) universal applicability of the COS, and (3) ensuring minimum administrative burden. Working groups to address these issues are now a priority for the HOME initiative. The results from this meeting will inform the development of a HOME Implementation Roadmap in an effort to support other COS groups planning for effective implementation of their core sets.

Factors associated with quality of life in patients receiving palliative radiotherapy for bone metastases: a secondary cross-sectional analysis of data from a prospective multicenter observational study

OBJECTIVE

To identify factors significantly associated with quality of life (QOL) and determine if these associations are strong enough to predict certain aspects of QOL without measuring them.

METHODS

We conducted an exploratory secondary analysis of baseline data of 224 patients (enrolled between December 2020 and March 2021) from a previously published prospective observational study on radiotherapy for bone metastases at 26 centres. Using univariable linear regression, we assessed the association between patient/treatment factors and QOL scale scores as measured by the European Organization for Research and Treatment of Cancer (EORTC) QOL Questionnaire Core 15-Palliative (QLQ-C15-PAL) and the EORTC QOL Questionnaire Bone Metastases module (QLQ-BM22).

RESULTS

Age and sex were not significantly associated with QOL. Worse performance status, higher pain scores, and opioid and single-fraction use were significantly associated with most QOL scales; these four factors were associated with worse global QOL, worse functioning status, and more severe symptoms. The coefficients of determination for most QOL scales were less than 0.2, indicating that most of the variability in QOL scores was not explained by any of the explanatory variables.

CONCLUSION

Performance status, pain intensity, and opioid and single-fraction use were significantly associated with most QOL scales. However, the associations were not strong enough to estimate QOL.

ADVANCES IN KNOWLEDGE

To date, the association between treatment factors and QOL in patients with bone metastases has not been fully studied. We identified the factors that were significantly associated with QOL and found that these associations were not strong enough to predict QOL.

Predicting the daily gastrointestinal doses of stereotactic body radiation therapy for pancreatic cancer based on the shortest distance between the tumor and the gastrointestinal tract using daily computed tomography images

Objectives

We aimed to investigate whether daily computed tomography (CT) images could predict the daily gastroduodenal, small intestine, and large intestine doses of stereotactic body radiation therapy (SBRT) for pancreatic cancer based on the shortest distance between the gross tumor volume (GTV) and gastrointestinal (GI) tract.

Methods

Twelve patients with pancreatic cancer received SBRT of 40 Gy in five fractions. We recalculated the reference clinical SBRT plan (PLANref) using daily CT images and calculated the shortest distance from the GTV to each GI tract. The maximum dose delivered to 0.5 cc (D0.5cc) was evaluated for each planning at-risk volume of the GI tract. Spearman's correlation test was used to determine the association between the daily change in the shortest distance (Δshortest distance) and the ratio of ΔD0.5cc dose to D0.5cc dose in PLANref (ΔD0.5cc/PLANref) for quantitative analysis.

Results

The median shortest distance in PLANref was 0 mm in the gastroduodenum (interquartile range, 0-2.7), 16.7 mm in the small intestine (10.0-23.7), and 16.7 mm in the large intestine (8.3-28.1 mm). The D0.5cc of PLANref in the gastroduodenum was >30 Gy in all patients, with 10 (83.3%) having the highest dose. A significant association was found between the Δshortest distance and ΔD0.5cc/ PLANref in the small or large intestine (p < 0.001) but not in the gastroduodenum (p = 0.404).

Conclusions

The gastroduodenum had a higher D0.5cc and predicting the daily dose was difficult. Daily dose calculations of the GI tract are recommended for safe SBRT.

Advances in knowledge

This study aimed to predict the daily doses in SBRT for pancreatic cancer from the shortest distance between the GTV and the gastrointestinal tract.Daily changes in the shortest distance can predict the daily dose to the small or large intestines, but not to the gastroduodenum.

The Japanese Nationwide Cohort Data of Particle Beam Therapy for Liver Oligometastasis in Esophagogastric Cancer Patients

PURPOSE/OBJECTIVE(S)

A nationwide multicenter cohort study on particle therapy was launched by the Japanese Society for Radiation Oncology (JASTRO) in Japan in May 2016. We analyzed the outcome of proton beam therapy (PBT) for liver oligometastasis of esophagogastric cancers.

MATERIALS/METHODS

Cases in which PBT was performed at all PBT facilities in Japan between May 2016 and February 2019 were enrolled. The patients were selected based on the following criteria: controlled primary cancer; liver recurrence without extrahepatic tumors; and no more than three liver lesions. The dose and fraction of PBT were determined using unified treatment policy established by JASTRO. We used the following protocol, 64 gray (relative biological effect) (Gy (RBE))/8 fractions (fr) for the peripheral region, and 72.6 GyE/22fr for the central region. For safety aspect, the hepatocellular carcinoma irradiation protocols of 66 Gy (RBE)/10fr, 72.6-76 Gy (RBE)/20-22fr, and 74-76 Gy (RBE)/37-38fr could be allowed. The overall survival (OS), local control (LC), and adverse events (AEs) were examined. The OS and LC rates were calculated using the Kaplan-Meier method. Factors possibly related to OS, such as tumor size (for multiple lesions, the largest size), number of liver tumors, as well as the presence or absence of prior, concurrent, and post-PBT chemotherapy, were investigated. The cut-off values were estimated using the receiver operating characteristic curve and area under the curve. Univariate analysis was performed using the log-rank test. Statistical significance was P-values < 0.05.

RESULTS

Twenty-three males and two females with a median age of 69 (range, 52-80) years and 36 lesions were included. This study included six patients with esophageal and 19 patients with gastric cancer. The median lesion size, fraction size, and biological effective dose (BED)10 were 31 (7-104) mm, 3.8 gray (relative biological effect)/fractions (Gy (RBE)/fr) (2-8 Gy (RBE)/fr), and 96.9 (88.8-115.2) Gy, respectively. The median follow-up period was 18 (4-47) months. The 1-, 2-, and 3-year OS rates were 76.0, 49.5, and 43.3%, respectively, and the median OS was 19 months. The 1-, 2-, and 3-year OS rates of esophageal cancer were 83.3% for all. The 1-, 2-, and 3-year OS rates of gastric cancer were 73.7, 40.2, and 32.2%, respectively, and the median OS was 18 months. The 1-, 2-, and 3-year LC rates were 96.3, 91.5, and 91.5%, respectively. The 1-, 2-, and 3-year LC rates of esophageal cancer were 100% for all. The 1-, 2-, and 3-year LC rates of gastric cancers were 94.7, 88.0, and 88.0%, respectively. Tumor size was the only significant OS-related factor (P < 0.01). No grade 3 or higher adverse events were observed.

CONCLUSION

Owing to the low incidence of adverse events and the high LC rate, PBT is a feasible option for liver oligometastasis of esophagogastric cancers.

Evaluation of the Possibility of Dose Realignment Adaptation by Shifting the Isocenter in Proton Beam Therapy for Pancreatic Cancer

PURPOSE/OBJECTIVE(S)

In pancreatic cancer, a tumor is surrounded by the gastrointestinal (GI) tract, which is subject to changes in location, shape, and contents. Due to these inter-fractional changes, proton beam therapy (PBT) for pancreatic cancer may result in unintentionally high doses to the GI tract. Daily adaptive re-planning can solve this problem, but is not yet established with PBT due to its resource intensive characteristics. This study aims to evaluate the GI tract dose using weekly computed tomography (CTw) and the possibility of dose realignment adaptation by shifting the isocenter (IC) of the PBT plan, which does not require re-planning.

MATERIALS/METHODS

We retrospectively analyzed 6 consecutive patients with unresectable pancreatic cancer treated with real-time-image gated PBT using a fiducial marker. The planning CT was scanned at the natural expiration of respiration and a PBT plan of 60 GyE in 25 fractions (baseline plan, PLANbase) was created. The CTw images were acquired the day before start of PBT and once a week during the PBT course thereafter. The PLANbase was rigidly transferred to the CTw based on the relationship between the three-dimensional coordinates of the fiducial marker and those of the IC in the PLANbase. The PLANeval was created by recalculating the PLANbase on the CTw. We evaluated the doses to the stomach, duodenum, and intestines in the PLANeval according to the following criteria: Dmax of the stomach < 60 GyE, duodenum and intestines < 55 GyE, and D1cc of the stomach < 55 GyE, duodenum and intestines < 54 GyE. In addition, we investigated the GI tract dose realignment adaptation for the PLANeval with its IC shifted 2mm, 4mm, and 6mm in each of 6 directions (right, left, ventral, dorsal, cranial, and caudal), respectively.

RESULTS

A total of 35 PLANeval were created for the CTw. In the PLANbase of the 6 patients, the average of Dmax and D1cc of the stomach, duodenum and intestines were 50.7 GyE (range, 46.7-53.6) and 50.0 GyE (45.0-53.2), 49.2 GyE (44.3-51.7) and 48.8 GyE (43.7-51.5), and 49.2 GyE (44.8-52.0) and 48.9 GyE (44.6-51.8), respectively. In the PLANeval, the average of Dmax and D1cc of the stomach, duodenum, and intestines were 53.3GyE (43.8-61.4) and 52.8 GyE (43.2-61.1), 51.0 GyE (36.1-60.0) and 50.3 GyE (35.4-59.8), and 52.5 GyE (36.6-61.0) and 51.9 (34.4-60.9) GyE, respectively. Twenty-two of the 35 PLANeval (63 %) did not meet at least one of the GI tract dose criteria. In 11 of 22 PLANeval with higher doses to the GI tract, the IC shift resulted in GI dose reductions and all dose criteria were met. The minimum amount of the IC shift required to meet the criteria was 2 mm for 8 plans and 4 mm for 3 plans. The remaining 11 PLANeval did not meet the criteria using dose realignment adaptation by shifting the isocenter.

CONCLUSION

Adaptive replanning is necessary for PBT for pancreatic cancers due to excessive GI tract doses in more than 60% of the plans. Dose realignment adaptation by shifting the IC, which does not require re-planning, may be an option in adaptive treatment strategies.

Multicenter Retrospective Study of Stereotactic Body Radiotherapy for Patients with Previously Untreated Initial Small Hepatocellular Carcinoma

PURPOSE/OBJECTIVE(S)

The effectiveness of stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) has been shown in many studies and its therapeutic effect is similar to radiofrequency ablation (RFA). However, many of these studies were done in combination with transcatheter chemoembolization (TACE), for recurrent HCC, or on a small scale. To better understand the specific outcomes of SBRT for HCC, we conducted a multicenter retrospective analysis of SBRT for previously untreated initial HCC at Japanese Society of Clinical Oncology (JCOG) member hospitals.

MATERIALS/METHODS

Patientswho underwent SBRT for HCC at JCOG member hospitals between July 2013 and December 2017 and met the following eligibility criteria were included: (1) initial HCC; (2) ≤ 3 nodules, ≤ 5 cm in diameter; (3) a Child-Pugh (CP) score of A or B; and (4) unsuitability for or refusal of standard treatment, such as surgery, transplantation, RFA and TACE. We evaluated the overall survival (OS), recurrence-free survival (RFS) which was defined as the first instance of intra-hepatic recurrence after SBRT, disease-specific survival (DSS) using Kaplan-Meier analysis. Using Grey's test, patients who died of other diseases were analyzed as competing risks to estimate the cumulative incidence of local recurrence (CLR). Adverse events directly related to SBRT also analyzed using Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v5.0).

RESULTS

Seventy-three patients with 79 lesions from 14 hospitals were analyzed. The median age was 77 years (range; 50-89 years), and the median tumor size was 23 mm (range; 6-50 mm). The median radiation dose was 40 Gy (range; 35-60 Gy) in five fractions (range; 4-8). The median follow-up period was 45 months (range; 0-103 months). There were three cases where follow-up was not possible due to unexpected events unrelated to SBRT, while the remaining 70 patients were successfully followed for at least six months. The 2 and 3year OS, RFS, DSS, and CLR rates were 84.3% (95% CI: 75.8-92.8%) and 69.9% (95% CI: 58.7-81%), 67.5% (95% CI: 56.0-79.0%) and 57.9% (95% CI: 45.2-70.5%), 95.1% (95% CI:89.7-100%)/87.6% (95% CI:78.8-96.3%), and 11.4% (95% CI: 5.3-20.0%) and 20.0% (95% CI: 11.2-30.5%), respectively. Four cases (5.5%) of adverse events of grade 3 or higher were reported: one case of grade 3 laboratory toxicities, one case of grade 3 liver failure, one case of grade 3 portal tumor thrombosis, and one case of grade 4 duodenal ulcer. No grade 5 toxicities were observed.

CONCLUSION

The results of our study demonstrate that SBRT for HCC is highly effective in achieving local control and is safe to administer. In addition, survival outcomes are favorable. SBRT is a promising treatment modality, especially for small HCCs for that is not suitable for standard treatment.

Abrocitinib effect on patient-reported outcomes in patients with moderate-to-severe atopic dermatitis: Results from phase 3 studies, including the long-term extension JADE EXTEND study

BACKGROUND

Abrocitinib improved signs and symptoms of moderate-to-severe atopic dermatitis (AD) at Weeks 12 and 16 in phase 3 studies, with a manageable safety profile. Patient-reported outcomes with long-term abrocitinib treatment were not reported.

OBJECTIVE

To evaluate patient-reported outcomes with long-term abrocitinib treatment in patients with moderate-to-severe AD.

METHODS

JADE EXTEND (NCT03422822) is an ongoing, phase 3, long-term extension study that enrolled patients from previous abrocitinib AD trials. This analysis includes patients from the phase 3 trials JADE MONO-1 (NCT03349060), JADE MONO-2 (NCT03575871) and JADE COMPARE (NCT03720470) who completed the full treatment period of placebo or abrocitinib (200 or 100 mg once daily) and subsequently entered JADE EXTEND and were randomised to receive once-daily abrocitinib 200 or 100 mg. Patient-reported endpoints to Week 48 included the proportion of patients who achieved Dermatology Life Quality Index (DLQI) scores of 0/1 (no effect of AD on quality of life [QoL]) and a ≥4-point improvement in Patient-Oriented Eczema Measure (POEM) score (clinically meaningful improvement). Data cut-off: April 22, 2020.

RESULTS

Baseline DLQI mean scores were 15.4 and 15.3 in the abrocitinib 200- and 100-mg groups, respectively, which corresponded to a 'very large effect' on QoL; at Week 48, mean DLQI scores were lower with abrocitinib 200 mg (4.6; 'small effect' on QoL) and abrocitinib 100 mg (5.9; 'moderate effect' on QoL). Baseline POEM mean scores were 20.4 and 20.5 in the abrocitinib 200- and 100-mg groups, respectively; at Week 48, mean POEM scores were 8.2 and 11.0. Week 48 patient-reported responses with abrocitinib 200 mg and abrocitinib 100 mg were 44% and 34% for DLQI 0/1, and 90% and 77% for a ≥4-point reduction in POEM score.

CONCLUSION

In patients with moderate-to-severe AD, long-term abrocitinib treatment resulted in clinically meaningful improvement in patient-reported symptoms of AD, including QoL.

A Risk Prediction Model for Severe Radiation Induced Lymphopenia in Patients with Pancreatic Cancer Treated with Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

In pancreatic cancer, radiation induced lymphopenia (RIL) is associated with a poor prognosis. However, normal tissue complication probability (NTCP) models predicting RIL in pancreatic cancer treated with concurrent chemoradiotherapy (CCRT) have yet to be developed. This study aims to develop a least absolute shrinkage and selection operator (LASSO)-based multivariate NTCP model to predict severe RIL in patients with pancreatic cancer during CCRT and to validate the model internally.

MATERIALS/METHODS

We retrospectively reviewed patients with localized pancreatic cancer who underwent CCRT using three-dimensional conformal radiation therapy from 2013 to 2021. The exclusion criteria were patients with distant metastasis; patients who did not complete RT due to tumor progression; patients who did not have absolute lymphocyte count (ALC) data available before or during RT. An ALC of < 0.5 K/μL during CCRT was defined as severe RIL. A NTCP model of severe RIL was developed by LASSO-based multivariate analysis. We used age, sex, Karnofsky performance status, maximum tumor size, carbohydrate antigen 19-9 level before RT, ALC before RT, volume of planning target volume (PTV), and dosimetric parameters for surrounding organs (including spleen, vertebrae, liver, bilateral kidneys, gastrointestinal tracts) as variables for LASSO. In addition, internal validation was performed by the bootstrap method. The predictive performance of the model was evaluated by the area under the curve (AUC) of the receiver operating characteristic curve and scaled Brier score.

RESULTS

Of the 131 patients included in the study, the median age was 68 years (range, 42-84), and 55% were male. The median ALC before RT was 1.37 K/µL (0.52-3.50). The median PTV volume was 315.4 ml (86.3-1079.3). The median dose of radiotherapy was 50.4 Gy (16.2-50.4), with 1.8 Gy per fraction. Combination chemotherapy was S-1 in 99 cases (75.6%) and gemcitabine in 32 cases (24.4%). Induction chemotherapy before CCRT was performed in 39 patients (29.8%). Severe RIL was observed in 84 (63.6%) patients. The LASSO showed that low baseline ALC (p = 0.0002), large PTV volume (p < 0.0001), and a large kidney V5 defined as the percentage of bilateral kidneys receiving 5 Gy or more (p = 0.0338) were selected as parameters of the prediction model for severe RIL (AUC = 0.917) and scaled Brier score was 0.511. As a result of internal validation by the bootstrap method, the average AUC was 0.918 (95% confidence interval, 0.849-0.954).

CONCLUSION

Severe RIL occurred frequently during CCRT for pancreatic cancer, and a NTCP model for severe RIL developed and validated internally in this study showed good predictive performance. External validation is needed before this NTCP model can be used as a benchmark for treatment planning to reduce the risk of severe RIL and for considering future treatment approaches.

Multicenter retrospective study of stereotactic body radiotherapy for patients with previously untreated initial small hepatocellular carcinoma

AIM

We aimed to verify the therapeutic efficacy and safety of stereotactic body radiotherapy (SBRT) for previously untreated initial small hepatocellular carcinoma (HCC) in a multicenter, retrospective study.

METHODS

Patients who underwent SBRT for HCC at the Japanese Society of Clinical Oncology (JCOG) member hospitals in Japan between July 2013 and December 2017 and met the following eligibility criteria were included: (1) initial HCC; (2) ≤3 nodules, ≤5 cm in diameter; (3) Child-Pugh score of A or B; and (4) unsuitability for or refusal of standard treatment. We analyzed the overall survival, recurrence-free survival, and cumulative incidence of local recurrence rate, and adverse events directly related to SBRT.

RESULTS

Seventy-three patients with 79 lesions from 14 hospitals were analyzed. The median age was 77 years (range: 50-89 years), and the median tumor size was 23 mm (range: 6-50 mm). The median radiation dose was 40 Gy (range: 35-60 Gy) in five fractions (range: 4-8). The median follow-up period was 45 months (range: 0-103 months). The 3-year overall survival, recurrence-free survival, and cumulative incidence of local recurrence rates were 69.9% (95% CI: 58.7%-81%), 57.9% (95% CI: 45.2%-70.5%), and 20.0% (95% CI: 11.2%-30.5%), respectively. Four cases (5.5%) of adverse events of grade 3 or higher were reported: three cases of grade 3 and one case of grade 4 (duodenal ulcer). No grade 5 toxicities were observed.

CONCLUSION

SBRT is a promising treatment modality, particularly for small HCCs, as they are not suitable for standard treatment.

Proton beam therapy for extrahepatic biliary tract cancer: Analysis with prospective multi-institutional patients' registration database, Proton-Net

Background and purpose

To examine the role of proton beam therapy (PBT) in the treatment of extrahepatic biliary tract cancer (EBC).

Methods and materials

We analyzed the data accumulated in the Proton-Net database, which prospectively registered all individual patient data treated with PBT in all Japanese proton institutions from May 2016 to June 2019. The primary endpoint was overall survival (OS), and the secondary endpoints were local control (LC), progression-free survival (PFS), and toxicity.

Results

Ninety-three patients with unresectable and/or recurrent EBC were treated with PBT using a median prescribed dose of 67.5 Gy (RBE) (range, 50-72.6 Gy) in 25 (22-30 fractions). With a median follow-up of 16.3 months, the median survival time was 20.1 months and the 2-year OS was 37.8%. Two-year PFS and LC rates were 20.6% and 66.5%, respectively. Poor liver function (Child-Pugh B, C), a narrower distance between the tumor and digestive tract (2 cm >), and a larger tumor diameter (2 cm <) were identified as poor prognostic factors for OS. PBT-related grade 3 ≤ acute and late adverse events occurred in 5.4% and 4.3% of patients, respectively, including one gastrointestinal late toxicity (duodenal ulcer).

Conclusions

This is the largest prospectively accumulated series of PBT for EBC, and PBT showed favorable outcomes with acceptable toxicity profiles.

Comprehensive analysis of Japanese nationwide cohort data of particle beam therapy for pulmonary, liver and lymph node oligometastases: particle beam therapy versus high-precision X-ray radiotherapy

Japanese national oncological experts convened to evaluate the efficacy and safety of particle beam therapy (PT) for pulmonary, liver and lymph node oligometastases (P-OM, L-OM and LN-OM, respectively) and to conduct a statistically comparative analysis of the local control (LC) rate and overall survival (OS) rate of PT versus those of X-ray stereotactic body radiotherapy (X-SBRT) and X-ray intensity-modulated radiotherapy (X-IMRT). They conducted [1] an analysis of the efficacy and safety of metastasis-directed therapy with PT for P-OM, L-OM and LN-OM using a Japanese nationwide multi-institutional cohort study data set; [2] a systematic review of X-ray high-precision radiotherapy (i.e. X-SBRT/X-IMRT) and PT for P-OM, L-OM and LN-OM; and [3] a statistical comparison between LC and OS of the cohort data set in PT and that of the extracted historical data set in X-SBRT/X-IMRT from the preceding systematic review. Safety was evaluated as the incidence of grade ≥ 3 adverse events, while statistical comparisons of LC and OS were conducted by estimating the incidence rate ratios (IRR) for local progression and mortality, respectively. This study demonstrated that PT provided durable LC (3-year LC rate: 72.8-83.2%) with acceptable OS (3-year OS rate: 38.5-68.1%) and risk of severe toxicity incidence of 0.8-3.5% in radical metastasis-directed therapy for P-OM, L-OM and LN-OM. Compared to LC with X-SBRT or X-IMRT, LC with PT was potentially superior for P-OM; superior for L-OM; and equivalent for LN-OM. In particular, this study demonstrated that PT may be a new treatment option for L-OM tumors measuring > 5 cm.

Income and Employment of Patients at the Start and in the Follow-up of Palliative Radiotherapy for Bone Metastasis

Purpose

The aim of this study was to understand the income and employment status of patients at the start of and during follow-up after palliative radiation therapy for bone metastasis.

Methods and Materials

From December 2020 to March 2021, a prospective multi-institutional observational study was conducted to investigate income and employment of patients at the start of administration of radiation therapy for bone metastasis and at 2 and 6 months after treatment. Of 333 patients referred to radiation therapy for bone metastasis, 101 were not registered, mainly because of their poor general condition, and another 8 were excluded from the follow-up analysis owing to ineligibility.

Results

In 224 patients analyzed, 108 had retired for reasons unrelated to cancer, 43 had retired for reasons related to cancer, 31 were taking leave, and 2 had lost their jobs at the time of registration. The number of patients who were in the working group was 40 (30 with no change in income and 10 with decreased income) at registration, 35 at 2 months, and 24 at 6 months. Younger patients (P = 0), patients with better performance status (P = 0), patients who were ambulatory (P = .008), and patients with lower scores on a numerical rating scale of pain (P = 0) were significantly more likely to be in the working group at registration. There were 9 patients who experienced improvements in their working status or income at least once in the follow-up after radiation therapy.

Conclusions

The majority of patients with bone metastasis were not working at the start of or after radiation therapy, but the number of patients who were working was not negligible. Radiation oncologists should be aware of the working status of patients and provide appropriate support for each patient. The benefit of radiation therapy to support patients continuing their work and returning to work should be investigated further in prospective studies.

Study of hepatic toxicity in small liver tumors after photon or proton therapy based on factors predicting the benefits of proton

OBJECTIVES

In a previous study of hepatic toxicity, the following three factors were identified to predict the benefits of proton beam therapy (PBT) for hepatocellular carcinomas (HCCs) with a maximum diameter of ≤5 cm and Child-pugh grade A (CP-A): number of tumors (1 vs ≥2), the location of tumors (hepatic hilum or others), and the sum of the diameters of lesions. The aim of this study is to analyze the association between these three factors and hepatic toxicity.

METHODS

We retrospectively reviewed patients of CP-A treated with PBT or photon stereotactic body radiotherapy (X-ray radiotherapy, XRT) for HCC ≤5 cm. For normal liver dose, the V5, V10, V20 (volumes receiving 5, 10, and 20 Gy at least), and the mean dose was evaluated. The albumin-bilirubin (ALBI) and CP score changes from the baseline were evaluated at 3 and 6 months after treatment.

RESULTS

In 89 patients (XRT: 48, PBT: 41), those with two or three (2-3) predictive factors were higher normal liver doses than with zero or one (0-1) factor. In the PBT group, the ALBI score worsened more in patients with 2-3 factors than those with 0-1 factor, at 3 months (median: 0.26 vs 0.02, p = 0.032) and at 6 months (median: 0.35 vs 0.10, p = 0.009). The ALBI score change in the XRT group and CP score change in either modality were not significantly different in the number of predictive factors.

CONCLUSION

The predictive factor numbers predicted the ALBI score change in PBT but not in XRT.

ADVANCES IN KNOWLEDGE

This study suggest that the number of predictive factors previously identified (0-1 vs 2-3) were significantly associated with dosimetric parameters of the normal liver in both modalities. In the proton group, the number of predictive factors was associated with a worsening ALBI score at 3 and 6 months, but these associations were not found in the photon SBRT group.

Brain metastases in Japanese NSCLC patients: prognostic assessment and the use of osimertinib and immune checkpoint inhibitors-retrospective study

BACKGROUND

The Graded Prognostic Assessment for lung cancer using molecular markers (Lung-molGPA) has not been validated for use with Japanese non-small cell lung cancer (NSCLC) patients with brain metastasis (BM) and the factors impacting survival need to be assessed.

METHODS

We retrospectively analyzed 294 NSCLC patients who were newly diagnosed with BM between 2013 and 2020 and had received radiotherapy for BM initially at the Hokkaido Cancer Center. We evaluated the effect on the prognosis of Lung-molGPA items, the expression of PD-L1 (classified as high, low, and no expression), and the treatment history. The main outcome was the survival measured from the day of the diagnosis of BM, and log-rank tests were performed to evaluate the results.

RESULTS

The median overall survival (OS) times for adenocarcinoma by groups of GPA scores (0‒1.0, 1.5‒2.0, 2.5‒3.0, and 3.5‒4.0) were 5.5, 14.8, 28.3, and 39.0 months (p < 0.0001), respectively. The median survival times for non-adenocarcinoma by groups of GPA scores (0‒1.0, 1.5‒2.0, and 2.5‒3.0) were 3.2, 11.0, and 16.0 months (p = 0.0011), respectively. In adenocarcinoma patients with gene mutations, osimertinib significantly improved the outcome (median OS: 34.2 and 17.6 months with and without osimertinib, respectively (p = 0.0164)). There was no significant difference in the OS between patients who were initially treated with tyrosine-kinase inhibitor for BM and those who initially received radiotherapy (p = 0.5337). In patients tested for PD-L1 expression, the median survival times after the diagnosis of BM were 5.6, 22.5, and 9.3 months for the high-, low- and no-expression groups (p = 0.2198), respectively. Also, in patients with high PD-L1 expressions, those with ICI had survival (median OS, 8.6 months) than those without (median OS, 3.6 months).

CONCLUSIONS

We confirmed that Lung-molGPA successfully classified Japanese NSCLC patients with BM by the prognosis. Osimertinib prolonged survival of EGFR-positive NSCLC patients with BM, and ICI was effective in patients with high PD-L1 expressions.

Technical note: Performance evaluation of volumetric imaging based on motion modeling by principal component analysis

PURPOSE

To quantitatively evaluate the achievable performance of volumetric imaging based on lung motion modeling by principal component analysis (PCA).

METHODS

In volumetric imaging based on PCA, internal deformation was represented as a linear combination of the eigenvectors derived by PCA of the deformation vector fields evaluated from patient-specific four-dimensional-computed tomography (4DCT) datasets. The volumetric image was synthesized by warping the reference CT image with a deformation vector field which was evaluated using optimal principal component coefficients (PCs). Larger PCs were hypothesized to reproduce deformations larger than those included in the original 4DCT dataset. To evaluate the reproducibility of PCA-reconstructed volumetric images synthesized to be close to the ground truth as possible, mean absolute error (MAE), structure similarity index measure (SSIM) and discrepancy of diaphragm position were evaluated using 22 4DCT datasets of nine patients.

RESULTS

Mean MAE and SSIM values for the PCA-reconstructed volumetric images were approximately 80 HU and 0.88, respectively, regardless of the respiratory phase. In most test cases including the data of which motion range was exceeding that of the modeling data, the positional error of diaphragm was less than 5 mm. The results suggested that large deformations not included in the modeling 4DCT dataset could be reproduced. Furthermore, since the first PC correlated with the displacement of the diaphragm position, the first eigenvector became the dominant factor representing the respiration-associated deformations. However, other PCs did not necessarily change with the same trend as the first PC, and no correlation was observed between the coefficients. Hence, randomly allocating or sampling these PCs in expanded ranges may be applicable to reasonably generate an augmented dataset with various deformations.

CONCLUSIONS

Reasonable accuracy of image synthesis comparable to those in the previous research were shown by using clinical data. These results indicate the potential of PCA-based volumetric imaging for clinical applications.

Detailed analysis of failure patterns using deformable image registration in hypopharyngeal cancer patients treated with sequential boost intensity-modulated radiotherapy

INTRODUCTION

Sequential boost intensity-modulated radiotherapy (SQB-IMRT) uses two different planning CTs (pCTs) and treatment plans. SQB-IMRT is a form of adaptive radiotherapy that allows for responses to changes in the shape of the tumour and organs at risk (OAR). On the other hand, dose accumulation with the two plans can be difficult to evaluate. The purpose of this study was to analyse patterns of loco-regional failure using deformable image registration (DIR) in hypopharyngeal cancer patients treated with SQB-IMRT.

METHODS

Between 2013 and 2019, 102 patients with hypopharyngeal cancer were treated with definitive SQB-IMRT at our institution. Dose accumulation with the 1st and 2nd plans was performed, and the dose to the loco-regional recurrent tumour volume was calculated using the DIR workflow. Failure was classified as follows: (i) in-field (≥95% of the recurrent tumour volume received 95% of the prescribed dose); (ii) marginal (20-95%); or (iii) out-of-field (<20%).

RESULTS

After a median follow-up period of 25 months, loco-regional failure occurred in 34 patients. Dose-volume histogram analysis showed that all loco-regional failures occurred in the field within 95% of the prescribed dose, with no marginal or out-of-field recurrences observed.

CONCLUSION

The dosimetric analysis using DIR showed that all loco-regional failures were within the high-dose region. More aggressive treatment may be required for gross tumours.

Particle Beam Therapy for Intrahepatic and Extrahepatic Biliary Duct Carcinoma: A Multi-Institutional Retrospective Data Analysis

To examine the efficacy and toxicity of particle beam therapy (PT) for biliary duct carcinoma (BDC) and compare the outcomes between extrahepatic BDC (eBDC) and intrahepatic BDC (iBDC). We analyzed multi-institutional data from May 2009 to December 2019. The primary endpoint was overall survival (OS), and the secondary endpoints were local control (LC), progression-free survival (PFS) and toxicity. We included 150 patients with unresectable BDC treated with PT using a median prescribed dose of 70.2 GyRBE (range, 44-77 GyRBE) in 25 fractions (range, 10-38 fractions). With a median follow-up of 13.0 months, median survival time (MST) was 21 months, and 2-year OS was 44.8%. For eBDC and iBDC, the MSTs were 20 and 23 months, respectively. Two-year PFS and LC rates were 20.6% and 66.5%, respectively. Vascular invasion, prescribed dose and serum tumor marker level (carcinoembryonic antigen: CEA) were identified as poor prognostic factors for OS. A higher radiation dose EQD2 ≥ 67 Gy showed superior OS, with a hazard ratio of 0.341. The radiation dose of PT is an important predisposing factor for overall survival. The MST for patients with eBDC given a higher radiation dose was 25 months, compared to 15 months for those given the lower dose and 23 months for patients with iBDC (all iBDC given higher doses). iBDC and eBDC duct carcinomas showed equivalent outcomes with PT, especially when treated with a high radiation dose. In detailed analysis, baseline CEA level in iBDC, and radiation dose and GTV in eBDC were statistically significant predicators for OS. Acute and late toxicity grade ≥3 occurred in 2.2% and 2.7% of patients, respectively, including two late grade-5 toxicities. In conclusion, PT showed good efficacy for BDC, both eBDC and iBDC, with a low incidence of severe toxicity.

A study on predicting cases that would benefit from proton beam therapy in primary liver tumors of less than or equal to 5 cm based on the estimated incidence of hepatic toxicity

•

An advantage of PBT is reducing the liver receiving low doses of radiation.

•

The factors predicting the benefit in PBT are different among NTCP models.

•

The tumor size, number, and location are useful in estimating the benefits of PBT.

Background

Materials and methods

Results

Conclusions

Treatment outcomes of stereotactic body radiation therapy using a real-time tumor-tracking radiotherapy system for hepatocellular carcinomas

AIM

To report the outcomes of stereotactic body radiotherapy using a real-time tumor-tracking radiotherapy system for hepatocellular carcinoma patients.

METHODS

From January 2005 to July 2018, 63 patients with 74 lesions with a maximum diameter ≤52 mm were treated by stereotactic body radiotherapy using a real-time tumor-tracking radiotherapy system. No patient with a Child-Pugh Score ≥9 was included, and 85.6% had a score of 5 or 6. Using the biological effective dose (BED) with an α/β ratio of 10 (BED₁₀ ), the median dose in BED₁₀ at the reference point was 76.8 Gy (range 60-122.5 Gy). Overall survival (OS) and local control rates were assessed using the Kaplan-Meier method.

RESULTS

With a median follow-up period of 24.6 months (range 0.9-118.4 months), the 1-year and 2-year OS rates were 86.8% (95% confidence interval [95% CI] 75.8-93.3) and 71.1% (57.8-81.6), respectively. The 2-year OS was 89.6% in patients with the baseline modified albumin-bilirubin (mALBI) grade =1, and 61.7% in patients with grade ≥2a. In the multivariate analysis, the mALBI grade (=1 vs. ≥2a) was a significant factor for OS (p = 0.028, 95% CI 1.11-6.18). The 1-year and 2-year local control rates were 100% (100-100%) and 92.0% (77.5-97.5%). The local control rates were significantly higher in the BED₁₀ ≥100 Gy group than in the BED₁₀ <100 Gy group (2-year 100% vs. 86.5%, p = 0.049) at the reference point.

CONCLUSION

This retrospective study of stereotactic body radiotherapy using real-time tumor-tracking radiotherapy for hepatocellular carcinoma showed favorable outcomes with lower incidence of toxicities, especially in patients treated with BED₁₀ ≥100 Gy to the reference point.

Real-time CT image generation based on voxel-by-voxel modeling of internal deformation by utilizing the displacement of fiducial markers

PURPOSE

To show the feasibility of real-time CT image generation technique utilizing internal fiducial markers that facilitate the evaluation of internal deformation.

METHODS

In the proposed method, a linear regression model that can derive internal deformation from the displacement of fiducial markers is built for each voxel in the training process before the treatment session. Marker displacement and internal deformation are derived from the four-dimensional computed tomography (4DCT) dataset. In the treatment session, the three-dimensional deformation vector field is derived according to the marker displacement, which is monitored by the real-time imaging system. The whole CT image can be synthesized by deforming the reference CT image with a deformation vector field in real-time. To show the feasibility of the technique, image synthesis accuracy and tumor localization accuracy were evaluated using the dataset generated by extended NURBS-Based Cardiac-Torso (XCAT) phantom and clinical 4DCT datasets from six patients, containing 10 CT datasets each. In the validation with XCAT phantom, motion range of the tumor in training data and validation data were about 10 and 15 mm, respectively, so as to simulate motion variation between 4DCT acquisition and treatment session. In the validation with patient 4DCT dataset, eight CT datasets from the 4DCT dataset were used in the training process. Two excluded inhale CT datasets can be regarded as the datasets with large deformations more than training dataset. CT images were generated for each respiratory phase using the corresponding marker displacement. Root mean squared error (RMSE), normalized RMSE (NRMSE), and structural similarity index measure (SSIM) between the original CT images and the synthesized CT images were evaluated as the quantitative indices of the accuracy of image synthesis. The accuracy of tumor localization was also evaluated.

RESULTS

In the validation with XCAT phantom, the mean NRMSE, SSIM, and three-dimensional tumor localization error were 7.5 ± 1.1%, 0.95 ± 0.02, and 0.4 ± 0.3 mm, respectively. In the validation with patient 4DCT dataset, the mean RMSE, NRMSE, SSIM, and three-dimensional tumor localization error in six patients were 73.7 ± 19.6 HU, 9.2 ± 2.6%, 0.88 ± 0.04, and 0.8 ± 0.6 mm, respectively. These results suggest that the accuracy of the proposed technique is adequate when the respiratory motion is within the range of the training dataset. In the evaluation with a marker displacement larger than that of the training dataset, the mean RMSE, NRMSE, and tumor localization error were about 100 HU, 13%, and <2.0 mm, respectively, except for one case having large motion variation. The performance of the proposed method was similar to those of previous studies. Processing time to generate the volumetric image was <100 ms.

CONCLUSION

We have shown the feasibility of the real-time CT image generation technique for volumetric imaging.

Validation of dose distribution for liver tumors treated with real-time-image gated spot-scanning proton therapy by log data based dose reconstruction

In spot scanning proton therapy (SSPT), the spot position relative to the target may fluctuate through tumor motion even when gating the radiation by utilizing a fiducial marker. We have established a procedure that evaluates the delivered dose distribution by utilizing log data on tumor motion and spot information. The purpose of this study is to show the reliability of the dose distributions for liver tumors treated with real-time-image gated SSPT (RGPT). In the evaluation procedure, the delivered spot information and the marker position are synchronized on the basis of log data on the timing of the spot irradiation and fluoroscopic X-ray irradiation. Then a treatment planning system reconstructs the delivered dose distribution. Dose distributions accumulated for all fractions were reconstructed for eight liver cases. The log data were acquired in all 168 fractions for all eight cases. The evaluation was performed for the values of maximum dose, minimum dose, D99, and D5-D95 for the clinical target volumes (CTVs) and mean liver dose (MLD) scaled by the prescribed dose. These dosimetric parameters were statistically compared between the planned dose distribution and the reconstructed dose distribution. The mean difference of the maximum dose was 1.3% (95% confidence interval [CI]: 0.6%-2.1%). Regarding the minimum dose, the mean difference was 0.1% (95% CI: -0.5%-0.7%). The mean differences of D99, D5-D95 and MLD were below 1%. The reliability of dose distributions for liver tumors treated with RGPT-SSPT was shown by the evaluation of the accumulated dose distributions.

Assessment of the confidence interval in the multivariable normal tissue complication probability model for predicting radiation-induced liver disease in primary liver cancer

We developed a confidence interval-(CI) assessing model in multivariable normal tissue complication probability (NTCP) modeling for predicting radiation-induced liver disease (RILD) in primary liver cancer patients using clinical and dosimetric data. Both the mean NTCP and difference in the mean NTCP (ΔNTCP) between two treatment plans of different radiotherapy modalities were further evaluated and their CIs were assessed. Clinical data were retrospectively reviewed in 322 patients with hepatocellular carcinoma (n = 215) and intrahepatic cholangiocarcinoma (n = 107) treated with photon therapy. Dose-volume histograms of normal liver were reduced to mean liver dose (MLD) based on the fraction size-adjusted equivalent uniform dose. The most predictive variables were used to build the model based on multivariable logistic regression analysis with bootstrapping. Internal validation was performed using the cross-validation leave-one-out method. Both the mean NTCP and the mean ΔNTCP with 95% CIs were calculated from computationally generated multivariate random sets of NTCP model parameters using variance-covariance matrix information. RILD occurred in 108/322 patients (33.5%). The NTCP model with three clinical and one dosimetric parameter (tumor type, Child-Pugh class, hepatitis infection status and MLD) was most predictive, with an area under the receiver operative characteristics curve (AUC) of 0.79 (95% CI 0.74-0.84). In eight clinical subgroups based on the three clinical parameters, both the mean NTCP and the mean ΔNTCP with 95% CIs were able to be estimated computationally. The multivariable NTCP model with the assessment of 95% CIs has potential to improve the reliability of the NTCP model-based approach to select the appropriate radiotherapy modality for each patient.

Multicenter prospective study of stereotactic body radiotherapy for previously untreated solitary primary hepatocellular carcinoma: The STRSPH study

AIM

To prospectively evaluate the efficacy and safety of stereotactic body radiotherapy (SBRT) for patients with previously untreated solitary primary hepatocellular carcinoma (HCC).

METHODS

The main eligibility criteria included the following: (1) primary solitary HCC; (2) no prior treatment for HCC; (3) Child-Turcotte-Pugh score of seven or less; and (4) unsuitability for or refusal of surgery and radiofrequency ablation (RFA). The prescribed dose of SBRT was 40 Gy in five fractions. The primary endpoint was 3-year overall survival (OS); the secondary endpoints included local progression-free survival (LPFS), local control (LC), and adverse events. The accrual target was 60 patients, expecting a 3-year OS of 70% with a 50% threshold.

RESULTS

Between 2014 and 2018, 36 patients were enrolled; enrollment was closed early because of slow accrual. The median tumor size was 2.3 cm. The median follow-up at the time of evaluation was 20.8 months. The 3-year OS was 78% (95% confidence interval [CI]: 53%-90%). The 3-year LPFS and LC proportion were 73% (95% CI: 48%-87%) and 90% (95% CI: 65%-97%), respectively. Grade 3 or higher SBRT-related toxicities were observed in four patients (11%), and grade five toxicities were not observed.

CONCLUSIONS

This study showed acceptably low incidence of SBRT-related toxicities. LC and OS after SBRT were comparable for previously untreated solitary HCC for patients unfit for resection and RFA. Although a definitive conclusion cannot be drawn by this study, the promising results indicate that SBRT may be an alternative option in the management of early HCC.

Analysis of acute-phase toxicities of intensity-modulated proton therapy using a model-based approach in pharyngeal cancer patients

Pharyngeal cancer patients treated with intensity-modulated proton therapy (IMPT) using a model-based approach were retrospectively reviewed, and acute toxicities were analyzed. From June 2016 to March 2019, 15 pharyngeal (7 naso-, 5 oro- and 3 hypo-pharyngeal) cancer patients received IMPT with robust optimization. Simulation plans for IMPT and intensity-modulated X-ray therapy (IMXT) were generated before treatment. We also reviewed 127 pharyngeal cancer patients with IMXT in the same treatment period. In the simulation planning comparison, all of the normal-tissue complication probability values for dysphagia, dysgeusia, tube-feeding dependence and xerostomia were lower for IMPT than for IMXT in the 15 patients. After completing IMPT, 13 patients completed the evaluation, and 12 of these patients had a complete response. The proportions of patients who experienced grade 2 or worse acute toxicities in the IMPT and IMXT cohorts were 21.4 and 56.5% for dysphagia (P < 0.05), 46.7 and 76.3% for dysgeusia (P < 0.05), 73.3 and 62.8% for xerostomia (P = 0.43), 73.3 and 90.6% for mucositis (P = 0.08) and 66.7 and 76.4% for dermatitis (P = 0.42), respectively. Multivariate analysis revealed that IMPT was independently associated with a lower rate of grade 2 or worse dysphagia and dysgeusia. After propensity score matching, 12 pairs of IMPT and IMXT patients were selected. Dysphagia was also statistically lower in IMPT than in IMXT (P < 0.05). IMPT using a model-based approach may have clinical benefits for acute dysphagia.

Recommended core outcome instruments for health-related quality of life, long-term control and itch intensity in atopic eczema trials: results of the HOME VII consensus meeting

Background

The Harmonising Outcome Measures for Eczema (HOME) initiative has established a core outcome set of domains for atopic eczema (AE) clinical trials. Previous consensus meetings have agreed on preferred instruments for clinician‐reported signs (Eczema Area and Severity Index, EASI) and patient‐reported symptoms (Patient‐Oriented Eczema Measure, POEM). This paper reports consensus decisions from the HOME VII meeting.

Objectives

To complete the core outcome set for AE by agreeing on core outcome instruments for the domains of quality of life (QoL), long‐term control and itch intensity.

Methods

A face‐to‐face consensus meeting was held in Tokyo, Japan (8–10 April 2019) including 75 participants (49 healthcare professionals/methodologists, 14 patients, 12 industry representatives) from 16 countries. Consensus decisions were made by presentations of evidence, followed by whole and small group discussions and anonymous voting using predefined consensus rules.

Results

It was agreed by consensus that QoL should be measured using the Dermatology Life Quality Index (DLQI) for adults, the Children’s Dermatology Life Quality Index (CDLQI) for children and the Infant’s Dermatology Quality of Life Index (IDQoL) for infants. For long‐term control, the Recap of Atopic Eczema (RECAP) instrument or the Atopic Dermatitis Control Test (ADCT) should be used. Consensus was not reached over the frequency of data collection for long‐term control. The peak itch numerical rating scale (NRS)‐11 past 24 h was recommended as an additional instrument for the symptom domain in trials of older children and adults. Agreement was reached that all core outcome instruments should be captured at baseline and at the time of primary outcome assessment as a minimum.

Conclusions

For now, the core outcome set for clinical trials in AE is complete. The specified domains and instruments should be used in all new clinical trials and systematic reviews of eczema treatments.

What is already known about this topic?

Core outcomes sets improve the design and reporting of clinical trials, reduce selective outcome reporting bias and facilitate meta‐analysis of results in systematic reviews.

The HOME core outcome set for eczema recommends the inclusion of four core domains in all atopic eczema trials: clinician‐reported signs, patient‐reported symptoms, health‐related quality of life (HrQoL) and long‐term control.

Clinician‐reported signs should be captured using the Eczema Area and Severity Index (EASI) and patient‐reported symptoms using the Patient‐Oriented Eczema Measure (POEM).

What does this study add?

The HOME core outcome set is now complete and recommended core outcome instruments have been agreed on for all four domains.

Core outcome instruments for HrQoL: Dermatology Life Quality Index (DLQI) for adults, Children’s Dermatology Life Quality Index (CDLQI) for children and Infant’s Dermatology Quality of Life Index (IDQoL) for infants.

Core outcome instruments for long‐term control: either the Recap of Atopic Eczema (RECAP) or the Atopic Dermatitis Control Test (ADCT).

In addition, itch intensity should be measured using the peak NRS‐11 past 24 h for trials including older children and adults.

What are the clinical implications of this work?

If all future trials of eczema treatments include the HOME core outcome instruments, then trial results will be more readily incorporated into meta‐analyses in systematic reviews and clinical care will be informed by the best available evidence.

Linked Comment: D.F. Murrell and C.F. Paul. Br J Dermatol 2021; 185:13–14.

Are simple verbal instructions sufficient to ensure that bladder volume does not deteriorate prostate position reproducibility during spot scanning proton therapy?

Objectives:

The purpose of this study is to investigate whether verbal instructions are sufficient for bladder volume (BV) control not to deteriorate prostate position reproducibility in image-guided spot scanning proton therapy (SSPT) for localized prostate cancer.

Methods:

A total of 268 treatment sessions in 12 consecutive prostate cancer patients who were treated with image-guided SSPT with fiducial markers were retrospectively analyzed. In addition to strict rectal volume control procedures, simple verbal instructions to void urine one hour before the treatment were used here. The BV was measured by a Bladder Scan just before the treatment, and the prostate motion was measured by intraprostatic fiducial markers and two sets of X-ray fluoroscopy images. The correlation between the BV change and prostate motion was assessed by linear mixed-effects models and systematic and random errors according to the reproducibility of the BV.

Results:

The mean absolute BV change during treatment was from −98.7 to 86.3 ml (median 7.1 ml). The mean absolute prostate motion of the patients in the left-right direction was −1.46 to 1.85 mm; in the cranial-caudal direction it was −6.10 to 3.65 mm, and in the anteroposterior direction −1.90 to 5.23 mm. There was no significant relationship between the BV change and prostate motion during SSPT. The early and late genitourinary and gastrointestinal toxicity was minimal with a minimum follow up of 4.57 years.

Conclusions:

Simple verbal instructions about urination was suggested to be sufficient to control the BV not to impact on the prostate motion and clinical outcomes in image-guided SSPT. Careful attention to BV change is still needed when the seminal vesicle is to be treated.

Advances in knowledge:

Our data demonstrated that there was no apparent relationship between BV changes and prostate position reproducibility and simple verbal instruction about urination could be sufficient for image-guided SSPT.

Tralokinumab for moderate-to-severe atopic dermatitis: results from two 52-week, randomized, double-blind, multicentre, placebo-controlled phase III trials (ECZTRA 1 and ECZTRA 2)

Background

Tralokinumab, a fully human monoclonal antibody, specifically neutralizes interleukin‐13, a key cytokine driving peripheral inflammation in atopic dermatitis (AD). In phase II studies, tralokinumab combined with topical corticosteroids provided early and sustained improvements in AD signs and symptoms.

Objectives

To evaluate the efficacy and safety of tralokinumab monotherapy in adults with moderate‐to‐severe AD who had an inadequate response to topical treatments.

Methods

In two 52‐week, randomized, double‐blind, placebo‐controlled, phase III trials, ECZTRA 1 and ECZTRA 2, adults with moderate‐to‐severe AD were randomized (3 : 1) to subcutaneous tralokinumab 300 mg every 2 weeks (Q2W) or placebo. Primary endpoints were Investigator’s Global Assessment (IGA) score of 0 or 1 at week 16 and ≥ 75% improvement in Eczema Area and Severity Index (EASI 75) at week 16. Patients achieving an IGA score of 0 or 1 and/or EASI 75 with tralokinumab at week 16 were rerandomized to tralokinumab Q2W or every 4 weeks or placebo, for 36 weeks. The trials were registered with ClinicalTrials.gov: NCT03131648 and NCT03160885.

Results

At week 16, more patients who received tralokinumab vs. placebo achieved an IGA score of 0 or 1: 15·8% vs. 7·1% in ECZTRA 1 [difference 8·6%, 95% confidence interval (CI) 4·1–13·1; P = 0·002] and 22·2% vs. 10·9% in ECZTRA 2 (11·1%, 95% CI 5·8–16·4; P < 0·001) and EASI 75: 25·0% vs. 12·7% (12·1%, 95% CI 6·5–17·7; P < 0·001) and 33·2% vs. 11·4% (21·6%, 95% CI 15·8–27·3; P < 0·001). Early improvements in pruritus, sleep interference, Dermatology Life Quality Index, SCORing Atopic Dermatitis and Patient‐Oriented Eczema Measure were observed from the first postbaseline measurements. The majority of week 16 tralokinumab responders maintained response at week 52 with continued tralokinumab treatment without any rescue medication (including topical corticosteroids). Adverse events were reported in 76·4% and 61·5% of patients receiving tralokinumab in ECZTRA 1 and ECZTRA 2, respectively, and in 77·0% and 66·0% of patients receiving placebo in ECZTRA 1 and ECZTRA 2, respectively, in the 16‐week initial period.

Conclusions

Tralokinumab monotherapy was superior to placebo at 16 weeks of treatment and was well tolerated up to 52 weeks of treatment.

What is already known about this topic?

Atopic dermatitis (AD) is a chronic interleukin (IL)‐13‐mediated disease.

There is a need for safe and effective long‐term treatment options for AD.

Tralokinumab is a fully human monoclonal antibody that binds specifically to IL‐13 with high affinity, thereby preventing receptor interaction and subsequent downstream signalling.

Tralokinumab combined with topical corticosteroids showed early and sustained efficacy and safety in a 12‐week, phase IIb trial in moderate‐to‐severe AD.

What does this study add?

These are the first pivotal phase III trials demonstrating that by specifically targeting IL‐13 alone, patients can achieve significant improvements in AD signs and symptoms and quality of life, and maintain these improvements over time without the requirement for topical corticosteroids.

These trials provide evidence that tralokinumab offers a long‐term, well‐tolerated treatment option for patients with moderate‐to‐severe AD.

Linked Comment: Morra and Drucker. Br J Dermatol 2021; 184:386–387.

Plain language summary available online

Recommended core outcome instruments for health-related quality of life, long-term control and itch intensity in atopic eczema trials: results of the HOME VII consensus meeting

BACKGROUND

The Harmonising Outcome Measures for Eczema (HOME) initiative has established a core outcome set of domains for atopic eczema clinical trials. Previous consensus meetings have agreed upon preferred instruments for clinician-reported signs (Eczema Area and Severity Index - EASI) and patient-reported symptoms (Patient-Oriented Eczema Measure - POEM). This paper reports consensus decisions from the HOME VII meeting.

OBJECTIVE

To complete the core outcome set for atopic eczema by agreeing upon core outcome instruments for the domains of quality of life, long-term control and itch intensity.

METHODS

Face-to-face consensus meeting held in Tokyo, Japan (8th to 10th April, 2019) including 74 participants (47 healthcare professionals/methodologists, 14 patients, 13 industry representatives), from 16 countries. Consensus decisions were made by presentations of evidence, followed by whole and small group discussions and anonymous voting using pre-defined consensus rules.

RESULTS

It was agreed by consensus that quality of life should be measured using the Dermatology Life Quality Index (DLQI) for adults, the Children's Dermatology Life Quality Index (CDLQI) for children, and the Infant's Dermatology Quality of Life Index (IDQoL) for infants. For long-term control, the Recap of Atopic Eczema (RECAP) instrument or the Atopic Dermatitis Control Test (ADCT) should be used. Consensus was not reached over the frequency of data collection for long-term control. The peak itch numerical rating scale(NRS)-11 past 24 hours was recommended as an additional instrument for the symptom domain in trials of older children and adults. Agreement was reached that all core outcome instruments should be captured at baseline and at the time of primary outcome assessment as a minimum.

CONCLUSIONS

For now, the core outcome set for clinical trials in atopic eczema is complete. The specified domains and instruments should be used in all new clinical trials and systematic reviews of eczema treatments.

Quantitative analysis of treatments using real-time image gated spot-scanning with synchrotron-based proton beam therapy system log data

A synchrotron-based real-time image gated spot-scanning proton beam therapy (RGPT) system with inserted fiducial markers can irradiate a moving tumor with high accuracy. As gated treatments increase the beam delivery time, this study aimed to investigate the frequency of intra-field adjustments corresponding to the baseline shift or drift and the beam delivery efficiency of a synchrotron-based RGPT system. Data from 118 patients corresponding to 127 treatment plans and 2810 sessions between October 2016 and March 2019 were collected. We quantitatively analyzed the proton beam delivery time, the difference between the ideal beam delivery time based on a simulated synchrotron magnetic excitation pattern and the actual treatment beam delivery time, frequency corresponding to the baseline shift or drift, and the gating efficiency of the synchrotron-based RGPT system according to the proton beam delivery machine log data. The mean actual beam delivery time was 7.1 min, and the simulated beam delivery time in an ideal environment with the same treatment plan was 2.9 min. The average difference between the actual and simulated beam delivery time per session was 4.3 min. The average frequency of intra-field adjustments corresponding to baseline shift or drift and beam delivery efficiency were 21.7% and 61.8%, respectively. Based on our clinical experience with a synchrotron-based RGPT system, we determined the frequency corresponding to baseline shift or drift and the beam delivery efficiency using the beam delivery machine log data. To maintain treatment accuracy within ± 2.0 mm, intra-field adjustments corresponding to baseline shift or drift were required in approximately 20% of cases. Further improvements in beam delivery efficiency may be realized by shortening the beam delivery time.

Pooled safety analysis of baricitinib in adult patients with atopic dermatitis from 8 randomized clinical trials

BACKGROUND

Janus kinase (JAK) inhibition is a new mode of action in atopic dermatitis (AD); clarity about drug class safety considerations in the context of AD is important. Baricitinib, an oral, reversible, selective inhibitor of JAK1/JAK2, is in late-stage development for adult patients with moderate-to-severe AD.

OBJECTIVE

To report pooled safety data for baricitinib in patients with moderate-to-severe AD in the clinical development program including long-term extension (LTE) studies.

METHODS

This analysis included patient-level safety data from six double-blinded, randomized, placebo-controlled studies (one phase 2 and five phase 3), one double-blinded, randomized, LTE study and one open-label LTE study, reported in three data sets: placebo-controlled, 2-mg - 4-mg extended and All-bari AD. Safety outcomes include treatment-emergent adverse events, adverse events of special interest and abnormal laboratory changes. Proportions of patients with events and incidence rates were calculated.

RESULTS

Data were collected for 2531 patients who were given baricitinib for 2247 patient-years (median duration 310 days). The frequency of serious infections, opportunistic infections and conjunctival disorders was low and similar between treatment groups in the placebo-controlled period. The most common serious infections were eczema herpeticum [n = 11, incidence rates (IR) = 0.5], cellulitis (n = 6, IR = 0.3) and pneumonia (n = 3, IR = 0.1). There were four opportunistic infections (IR = 0.2). No malignancies, gastrointestinal perforations, positively adjudicated cardiovascular events or tuberculosis were reported in the placebo-controlled period in baricitinib-treated patients. Frequency of herpes simplex was higher in the 4-mg group (6.1%) vs. the 2-mg (3.6%) and placebo group (2.7%); IRs in the extended data set (2-mg IR = 9.6; 4-mg IR = 14.5) were lower vs. the placebo-controlled data set (2-mg IR = 12.4; 4-mg IR = 21.3). In the All-bari AD data set, there were two positively adjudicated major adverse cardiovascular events (2-mg group): two venous thrombosis events (4-mg group) and one death.

CONCLUSION

This integrated safety analysis in patients with moderate-to-severe AD confirms the established safety profile of baricitinib.

Analysis of treatment process time for real-time-image gated-spot-scanning proton-beam therapy (RGPT) system

We developed a synchrotron‐based real‐time‐image gated‐spot‐scanning proton‐beam therapy (RGPT) system and utilized it to clinically operate on moving tumors in the liver, pancreas, lung, and prostate. When the spot‐scanning technique is linked to gating, the beam delivery time with gating can increase, compared to that without gating. We aim to clarify whether the total treatment process can be performed within approximately 30 min (the general time per session in several proton therapy facilities), even for gated‐spot‐scanning proton‐beam delivery with implanted fiducial markers. Data from 152 patients, corresponding to 201 treatment plans and 3577 sessions executed from October 2016 to June 2018, were included in this study. To estimate the treatment process time, we utilized data from proton beam delivery logs during the treatment for each patient. We retrieved data, such as the disease site, total target volume, field size at the isocenter, and the number of layers and spots for each field, from the treatment plans. We quantitatively analyzed the treatment process, which includes the patient load (or setup), bone matching, marker matching, beam delivery, patient unload, and equipment setup, using the data obtained from the log data. Among all the cases, 90 patients used the RGPT system (liver: n = 34; pancreas: n = 5; lung: n = 4; and prostate: n = 47). The mean and standard deviation (SD) of the total treatment process time for the RGPT system was 30.3 ± 7.4 min, while it was 25.9 ± 7.5 min for those without gating treatment, excluding craniospinal irradiation (CSI; head and neck: n = 16, pediatric: n = 31, others: n = 15); for CSI (n = 11) with two or three isocenters, the process time was 59.9 ± 13.9 min. Our results demonstrate that spot‐scanning proton therapy with a gating function can be achieved in approximately 30‐min time slots.

Combination of FDG-PET and FMISO-PET as a treatment strategy for patients undergoing early-stage NSCLC stereotactic radiotherapy

Background

We investigated the prognostic predictive value of the combination of fluorodeoxyglucose (FDG)- and fluoromisonidazole (FMISO)-PET in patients with non-small cell lung carcinoma (NSCLC) treated with stereotactic body radiation therapy (SBRT).

Patients and methods

We prospectively examined patients with pathologically proven NSCLC; all underwent FDG and FMISO PET/CT scans before SBRT. PET images were acquired using a whole-body time-of-flight PET-CT scanner with respiratory gating. We classified them into recurrent and non-recurrent groups based on their clinical follow-ups and compared the groups' tumor diameters and PET parameters (i.e., maximum of the standardized uptake value (SUVmax), metabolic tumor volume, tumor-to-muscle ratio, and tumor-to-blood ratio). We performed univariate analysis to evaluate the impact of the PET variables on the patients' progression-free survival (PFS). We divided the patients by thresholds of FDG SUVmax and FMISO SUVmax obtained from receiver operating characteristic analysis for assessment of recurrence rate and PFS.

Results

Thirty-two NSCLC patients (19 male and 13 females; median age, 83 years) were enrolled. All received SBRT. At the study endpoint, 23 patients (71.9%) were non-recurrent and nine patients (28.1%) had recurrent disease. Significant between-group differences were observed in tumor diameter and all the PET parameters, demonstrating that those were significant predictors of the recurrence in all patients. In the 22 patients with tumors > 2 cm, tumor diameter and FDG SUVmax were not significant predictors. Thirty-two patients were divided into three patterns from the thresholds of FDG SUVmax (6.81) and FMISO SUVmax (1.89); A, low FDG and low FMISO (n = 14); B, high FDG and low FMISO (n = 8); C, high FDG and high FMISO (n = 10). No pattern A patient experienced tumor recurrence, whereas two pattern B patients (25%) and seven pattern C patients (70%) exhibited recurrence. A Kaplan-Meier analysis of all patients revealed a significant difference in PFS between patterns A and B (p = 0.013) and between patterns A and C (p < 0.001). In the tumors > 2 cm patients, significant differences in PFS were demonstrated between pattern A and C patients (p = 0.002).

Conclusion

The combination of FDG- and FMISO-PET can identify patients with a baseline risk of recurrence and indicate whether additional therapy might be performed to improve survival.

Efficacy and safety of dupilumab in Japanese adults with moderate-to-severe atopic dermatitis: a subanalysis of three clinical trials

Background

Dupilumab, a human monoclonal antibody, blocks the shared receptor unit for interleukin‐4 and interleukin‐13. International phase II and III studies have evaluated the efficacy and safety of dupilumab in adults with moderate‐to‐severe atopic dermatitis (AD), but the effects of dupilumab in Japanese patients have not been reported.

Objectives

To evaluate the efficacy and safety of dupilumab in Japanese patients with moderate‐to‐severe AD.

Methods

We analysed the efficacy and safety of dupilumab in the Japanese cohorts of a 16‐week, phase IIb dose‐finding trial (AD‐1021; NCT01859988); a 16‐week, phase III, placebo‐controlled monotherapy trial (LIBERTY AD SOLO 1; NCT02277743) and a 52‐week, phase III, placebo‐controlled study of dupilumab with topical corticosteroids (LIBERTY AD CHRONOS; NCT02260986).

Results

Twenty‐seven, 106 and 117 Japanese patients were enrolled in AD‐1021, SOLO 1 and CHRONOS, respectively. Baseline disease severity was numerically higher in the Japanese cohort than in the overall study population. Generally, dupilumab significantly improved signs and symptoms of AD, including pruritus and patient quality of life, compared with placebo in the Japanese cohort, consistent with the overall study population. The combined safety profile of dupilumab in the Japanese cohort was similar to that in the total study populations; dupilumab was associated with an increased incidence of injection‐site reactions and conjunctivitis compared with placebo. Dupilumab was associated with rapid reduction in thymus and activation‐regulated chemokine and gradual IgE reductions.

Conclusions

Dupilumab alone or with topical corticosteroids improved signs and symptoms of AD, had an acceptable safety profile, and suppressed biomarkers of type 2 inflammation compared with placebo in Japanese adult patients with moderate‐to‐severe AD.

What's already known about this topic?

Differences in atopic dermatitis (AD) pathology have been reported between Asian and Western populations, in which distinct helper T‐cell activation profiles have been observed.

International clinical studies in adults with moderate‐to‐severe AD have evaluated the efficacy and safety of dupilumab, which blocks interleukin‐4 and interleukin‐13, key molecules in type 2 inflammation.

The effects of dupilumab in Japanese patients specifically have not yet been reported.

What does this study add?

Dupilumab alone or with topical corticosteroids improved signs and symptoms of AD and had an acceptable safety profile compared with placebo in Japanese patients with moderate‐to‐severe AD.

The effects were comparable with those observed in the overall study population.

Reported immunological differences in AD pathology in Asian patients may be secondary to type 2 immune activation.

Plain language summary available online

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Impact of organ motion on volumetric and dosimetric parameters in stomach lymphomas treated with intensity-modulated radiotherapy

Purpose

Interplay effects may influence dose distributions to a moving target when using dynamic delivery techniques such as intensity‐modulated radiotherapy (IMRT). The aim of this study was to evaluate the impact of organ motion on volumetric and dosimetric parameters in stomach lymphomas treated with IMRT.

Methods

Ten patients who had been treated with IMRT for stomach lymphomas were enrolled. The clinical target volume (CTV) was contoured as the whole stomach. Considering interfractional uncertainty, the internal target volume (ITV) margin was uniformly 1.5 cm to the CTV and then modified based on the 4DCT images in case of the large respiratory motion. The planning target volume (PTV) was created by adding 5 mm to the ITV. The impact of organ motion on the volumetric and dosimetric parameters was evaluated retrospectively (4D simulation). The organ motion was reproduced by shifting the isocenter on the radiation treatment planning system. Several simulation plans were created to test the influence of the beam‐on timing in the respiration cycle on the dose distribution. The homogeneity index (HI), volume percentage of stomach covered by the prescribed dose (V_p), and D₉₉ of the CTV were evaluated.

Results

The organ motion was the largest in the superior‐inferior direction (10.1 ± 4.5 mm [average ± SD]). Stomach volume in each respiratory phase compared to the mean volume varied approximately within a ± 5% range in most of the patients. The PTV margin was sufficiently large to cover the CTV during the IMRT. There was a significant reduction in V_p and D₉₉ but not in HI in the 4D simulation in free‐breathing and multiple fractions compared to the clinically‐used plan (P < 0.05) suggesting that interplay effects deteriorate the dose distribution. The absolute difference of D₉₉ was less than 1% of the prescribed dose.

Conclusions

There were significant interplay effects affecting the dose distribution in stomach IMRT. The magnitude of the dose reduction was small when patients were treated on free‐breathing and multiple fractions.