Moderately hypofractionated proton beam therapy for localized prostate cancer: 5-year outcomes of a phase II trial.

The usefulness of moderately hypofractionated radiotherapy for localized prostate cancer has been extensively reported, but there are limited studies on proton beam therapy (PBT) using similar hypofractionation schedules. The aim of this prospective phase II study is to confirm the safety of a shortened PBT course using 70 Gy relative biological effectiveness (RBE) in 28 fractions. From May 2013 to June 2015, 102 men with localized prostate cancer were enrolled. Androgen deprivation therapy was administered according to risk classification. Toxicity was assessed using Common Terminology Criteria for Adverse Events version 4.0. Of the 100 patients ultimately evaluated, 15 were classified as low risk, 43 as intermediate risk, and 42 as high risk. The median follow-up time of the surviving patients was 96 months (range: 60-119 months). The 5-year cumulative incidences of grade 2 gastrointestinal/genitourinary adverse events were 1% (95% CI: 0.1-6.9) and 4% (95% CI: 1.5-10.3), respectively; no grade ≥ 3 gastrointestinal/genitourinary adverse events were observed. The current study revealed a low incidence of late adverse events in prostate cancer patients treated with moderately hypofractionated PBT of 70 Gy (RBE) in 28 fractions, indicating the safety of this schedule.

Rel Family Transcription Factor NFAT5 Upregulates COX2 via HIF-1α Activity in Ishikawa and HEC1a Cells.

Nuclear factor of activated T cells 5 (NFAT5) and cyclooxygenase 2 (COX2; PTGS2) both participate in diverse pathologies including cancer progression. However, the biological role of the NFAT5-COX2 signaling pathway in human endometrial cancer has remained elusive. The present study explored whether NFAT5 is expressed in endometrial tumors and if NFAT5 participates in cancer progression. To gain insights into the underlying mechanisms, NFAT5 protein abundance in endometrial cancer tissue was visualized by immunohistochemistry and endometrial cancer cells (Ishikawa and HEC1a) were transfected with NFAT5 or with an empty plasmid. As a result, NFAT5 expression is more abundant in high-grade than in low-grade endometrial cancer tissue. RNA sequencing analysis of NFAT5 overexpression in Ishikawa cells upregulated 37 genes and downregulated 20 genes. Genes affected included cyclooxygenase 2 and hypoxia inducible factor 1α (HIF1A). NFAT5 transfection and/or treatment with HIF-1α stabilizer exerted a strong stimulating effect on HIF-1α promoter activity as well as COX2 expression level and prostaglandin E2 receptor (PGE2) levels. Our findings suggest that activation of NFAT5-HIF-1α-COX2 axis could promote endometrial cancer progression.

A Case of Circumscribed Choroidal Hemangioma Treated With Proton Beam Therapy and Followed Up for 15 Years.

Circumscribed choroidal hemangiomas are rare and benign tumors but often have a progressive course and are complicated by retinal detachment and glaucoma. The effectiveness of external radiation for large tumors that are difficult to treat with photodynamic therapy was recently reported; however, few studies have conducted long-term follow-ups. We encountered a case of localized choroidal hemangioma that was treated with proton beam therapy and followed up for 15 years. A 37-year-old man was diagnosed with a 10 × 4 mm circumscribed choroidal hemangioma involving the macular area with retinal detachment. Proton beam therapy was performed at 26.4 Gy relative biological effectiveness (RBE) in 8 fractions. The choroidal hemangioma gradually shrank over three years, and the retinal detachment also improved. A cataract developed on the affected side 11 years after irradiation, and eye coordination issues developed 15 years after irradiation. Glaucoma was not observed during the follow-up period; however, visual acuity did not recover, and the patient developed light perception. Although vision was not preserved, proton beam therapy effectively shrank the tumor and maintained quality of life.

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.

Long-term follow-up of unresectable adenoid cystic carcinoma of the trachea and bronchus treated with high-dose proton beam therapy: A report of two cases.

Adenoid cystic carcinoma (ACC) of the trachea is a rare disease that is slow growing and has a risk of distant metastasis. The standard treatment for ACC of the trachea is surgery, but this tumor is often unresectable. In definitive radiotherapy using photons for unresectable ACC of the trachea, it is sometimes difficult to deliver a sufficient dose to the target without exceeding the tolerable dose to the surrounding normal tissues. Here, we report two cases of ACC of the trachea that received a high dose (74 Gy [relative biological effectiveness]) of proton beam therapy and achieved long-term survival.

Proton Beam Therapy versus Radiofrequency Ablation for Patients with Treatment-Naïve Single Hepatocellular Carcinoma: A Propensity Score Analysis.

Introduction: Proton beam therapy (PBT) is known to be an effective locoregional treatment for hepatocellular carcinoma (HCC). However, few comparative studies in treatment-naïve cases have been reported. The aim of this study was to compare the survival outcomes of PBT with those of radiofrequency ablation (RFA) in patients with treatment-naïve solitary HCC. Methods: Ninety-five consecutive patients with treatment-naïve HCC, a single nodule measuring ≤5 cm in diameter, and a Child-Pugh score of ≤8 who were treated with PBT at the University of Tsukuba Hospital between 2001 and 2013 were enrolled in the study. In addition, 836 patients with treatment-naïve HCC treated by RFA at the University of Tokyo Hospital during the same period were analyzed as controls. Recurrence-free survival (RFS) and overall survival (OS) were compared in 83 patient pairs after propensity score matching. Results: The 1-year, 3-year, and 5-year RFS rates were 86.6%, 49.5%, and 35.5%, respectively, in the PBT group and 59.5%, 34.0%, and 20.9% in the RFA group (p = 0.058); the respective OS rates were 97.6%, 77.8%, and 57.1% in the PBT group and 95.1%, 81.7%, and 67.7% in the RFA group (p = 0.16). Regarding adverse effects, no grade 3 or higher adverse events were noted in the PBT; however, two grade 3 adverse events occurred within 30 days of RFA in the RFA group: one hemoperitoneum and one hemothorax. Discussion: After propensity score matching, PBT showed no significant difference in RFS and OS compared to RFA. PBT can be an alternative for patients with solitary treatment-naïve HCC.

Analysis of the cost-effectiveness of proton beam therapy for unresectable pancreatic cancer in Japan.

BACKGROUND: Proton beam therapy (PBT) has recently been included in Japan's social health insurance benefits package. This study aimed to determine the cost-effectiveness of PBT for unresectable, locally advanced pancreatic cancer (LAPC) as a replacement for conventional photon radiotherapy (RT). METHODS: We estimated the incremental cost-effectiveness ratio (ICER) of PBT as a replacement for three-dimensional conformal RT (3DCRT), a conventional photon RT, using clinical evidence in the literature and expense complemented by expert opinions. We used a decision tree and an economic and Markov model to illustrate the disease courses followed by LAPC patients. Effectiveness was estimated as quality-adjusted life years (QALY) using utility weights for the health state. Social insurance fees were calculated as the costs. The stability of the ICER against the assumptions made was appraised using sensitivity analyses. RESULTS: The effectiveness of PBT and 3DCRT was 1.67610615 and 0.97181271 QALY, respectively. The ICER was estimated to be ¥5,376,915 (US$46,756) per QALY. According to the suggested threshold for anti-cancer therapy from the Japanese authority of ¥7,500,000 (US$65,217) per QALY gain, such a replacement would be considered cost-effective. The one-way and probabilistic sensitivity analyses demonstrated stability of the base-case ICER. CONCLUSION: PBT, as a replacement for conventional photon radiotherapy, is cost-effective and justifiable as an efficient use of finite healthcare resources. Making it a standard treatment option and available to every patient in Japan is socially acceptable from the perspective of health economics.

Proton beam therapy for hepatocellular carcinoma with bile duct invasion.

AIM: Hepatocellular carcinoma (HCC) with bile duct invasion (BDI) (BDIHCC) has a poor prognosis. Moreover, due to the paucity of reports, there is no consensus regarding optimal management of this clinical condition yet. The aim of this study was to clarify the efficacy and safety of proton beam therapy (PBT) for BDIHCC. METHODS: Between 2009 and 2018, 15 patients with BDIHCC underwent PBT at our institution. The overall survival (OS), local control (LC), and progression-free survival (PFS) curves were constructed using the Kaplan-Meier method. Toxicities were assessed using the Common Terminology Criteria of Adverse Events version 4.0. RESULTS: The median follow-up time was 23.4 months (range, 7.9-54.3). The median age was 71 years (range, 58-90 years). Many patients were Child A (n = 8, 53.3%) and most had solitary tumors (n = 11, 73.3%). Additionally, most patients had central type BDI (n = 11, 73%). The median tumor size was 4.0 cm (range, 1.5-8.0 cm). The 1-, 2-, and 3-year OS rates were 80.0%, 58.7% and 40.2%, respectively, and the corresponding LC and PFS rates were 93.3%, 93.3%, and 74.7% and 72.7%, 9.7%, and 0.0%, respectively. Acute grade 1/2 dermatitis (n = 7, 46.7%), and grades 2 (n = 1, 6.7%) and 3 (n = 1, 6.7%) cholangitis were observed. Late toxicities such as grade 3 gastric hemorrhage and pleural effusion were observed. No toxicities of grade 4 or higher were observed. CONCLUSIONS: PBT was feasible with tolerable toxicities for the treatment of BDIHCC.

[Verification of Dose Distribution in Cervical Cancer Brachytherapy Using Metal and Plastic Applicators].

PURPOSE: To validate the point-A dose and dose distribution of metal and resin applicators in comparison with those of TG-43U1. METHODS: The metal and resin applicators consisting of tandem and ovoid were modeled by the egs_brachy. The doses to point A and dose distributions considering each applicator were calculated and compared to those of TG-43U1. RESULTS: The dose to point A considering the metal applicator was 3.2% lower than that of TG-43U1, but there was no difference in the dose to point A considering the resin applicator. The dose distribution considering the metal applicator was lower than that of TG-43U1 at all calculation points, but there was no difference in the dose distribution considering the resin applicator at almost all calculation points. CONCLUSION: In this study, the dose distribution considering the metal applicator was lower than that of TG-43U1 at all calculation points, but there was no difference in the dose distribution considering the resin applicator at almost all calculation points. Therefore, TG-43U1 can accurately calculate the dose distribution when changing from the metal applicator to the resin applicator.

A Case of a Refractory Bleeding Giant Vaginal Wall Cavernous Hemangioma Successfully Managed with Sclerotherapy.

BACKGROUND Vaginal wall hemangiomas are extremely rare, benign, vascular tumors of the female genitalia. Most cases occur in childhood, but a few cases can be acquired; however, the mechanism of hemangioma formation remains unknown. Most hemangiomas involving female genital organs are small and asymptomatic. However, huge hemangiomas can cause irregular genital bleeding, infertility, and miscarriage. Surgical excision and embolization are the most common treatment options. We reveal that sclerotherapy achieved good outcomes in a patient with an intractable huge vaginal wall hemangioma. CASE REPORT A 71-year-old woman visited a local doctor with concerns of frequent urination. A ring pessary was inserted after a diagnosis of pelvic organ prolapse. However, symptoms did not improve, and the patient consulted another hospital. The previous physician diagnosed vaginal wall tumors and prolapse and performed a colporrhaphy. However, she was referred to our hospital with heavy intraoperative bleeding. Imaging examination revealed a huge hemangioma on the vaginal wall, which was histologically diagnosed as a cavernous hemangioma. Angiography revealed hemorrhage in the right peripheral vaginal artery. Owing to concerns regarding extensive vaginal wall necrosis caused by arterial embolization, sclerotherapy using monoethanolamine oleate was selected. Hemostasis was achieved 1 month after sclerotherapy, and postoperative imaging showed the lesion had shrunk in size. No recurrence of hemangioma was observed 19 months after surgery. CONCLUSIONS We report a case of a large vaginal wall intractable bleeding hemangioma. Sclerotherapy can be a suitable treatment option for large vaginal hemangiomas that are too extensive to be treated using surgery or arterial embolization.

Clinical Impact of Proton Beam Therapy for Postoperative Lymph Node Oligorecurrence of Esophageal Cancer.

BACKGROUND/AIM: Radiotherapy is a salvage therapy type for postoperative recurrence of esophageal cancer. Compared to conventional photon-based radiotherapy, proton beam therapy can reduce the irradiated dose to the surrounding organs, facilitating the management of patients who are unfit for radiotherapy. In this study, the outcomes and toxicity of proton beam therapy for postoperative lymph node oligorecurrence of esophageal cancer were investigated. PATIENTS AND METHODS: We retrospectively evaluated the clinical outcomes and toxicity of 13 sites in 11 patients treated with proton beam therapy for postoperative lymph node oligorecurrence of esophageal cancer. In total, eight men and three women with a median age of 68 years (range=46-83 years) were included. RESULTS: The median follow-up period was 20.2 months. During the follow-up period, four patients died of esophageal cancer. Eight of the 11 patients developed recurrence; of these, seven patients had recurrence outside the irradiated field, and one had recurrence inside and outside the irradiated field. The 2-year overall survival, progression-free survival, and local control rates were 48.0%, 27.3%, and 84.6%, respectively. The median survival time was 22.4 months. There were no severe acute or late adverse events. CONCLUSION: Proton beam therapy could be a safe and effective treatment method for postoperative lymph node oligorecurrence of esophageal cancer. It may be beneficial even in cases where conventional photon-based radiotherapy is difficult to administer in combination with increased doses or with chemotherapy.

Long-term Outcomes After Moderate Hypofractionated Proton Therapy for Centrally Located Non-small Cell Lung Cancer.

BACKGROUND/AIM: To investigate the outcomes of patients with centrally located non-small-cell lung cancer (NSCLC) treated with proton beam therapy (PBT) using moderate hypofractionation. PATIENTS AND METHODS: Between 2006 and 2019, 34 patients with centrally located T1-T4N0M0 NSCLC who received moderate hypofractionated PBT were retrospectively reviewed. RESULTS: The median follow-up was 50.8 months (range=5.8-100.4 months). The 3-year overall survival, progression-free survival (PFS), and local control rates were 70.4%, 55.5% and 80.5%, respectively. Grade 2 or 3 lung adverse events (AEs) after PBT were observed in five (14.7%) patients; however, grade 3 radiation pneumonitis was observed in one (2.9%) patient. Notably, no grade 4 or higher AEs were observed. Regarding the correlation between the lung dose and proximal bronchial tree maximum dose and grade 2 or higher lung AEs, a weak correlation was observed between the mean lung dose and AEs (p=0.035). Although the clinical target volume (CTV) was a risk factor for poor PFS, no significant correlation was found between the CTV and lung AEs after PBT. CONCLUSION: Moderate hypofractionated PBT may be a useful radiotherapy method for centrally located cT1-T4N0M0 NSCLC.

Effects of lymphopenia on survival in proton therapy with chemotherapy for non-small cell lung cancer.

Lymphocytes play an important role in the cancer immune system. In the present study, we aimed to evaluate the associations of lymphopenia during proton beam therapy (PBT) and concurrent chemotherapy with clinical outcomes and to determine whether lung or bone is more influential on lymphopenia during PBT. Data from 41 patients with stage III non-small cell lung cancer (NSCLC) who received PBT of 74 GyE with concurrent chemotherapy between 2007 and 2017 were reviewed retrospectively. The correlation between dosimetry parameters obtained from dose-volume histograms of the bone and lung and lymphopenia during PBT were analyzed. Minimum absolute lymphocyte count (ALCmin) and maximum neutrophil/lymphocyte ratio (NLRmax) were used as indicators of lymphopenia. Bone V5-20 and lung V5-50 were significantly correlated with the ALCmin and NLRmax during PBT. Multivariable analysis showed that the NLRmax, but not the ALCmin, was associated with overall survival (OS), progression-free survival (PFS) and distant metastasis-free survival (DMFS). The 3-year rates of OS, PFS and DMFS of patients with a low (≤ 6.3) versus high (> 6.3) NLRmax were 73.9% vs 44.4% (P = 0.042), 26.1% vs 5.6% (P = 0.022) and 39.1% vs 5.6% (P < 0.001), respectively. Lung V20 was significantly associated with DMFS on multivariable analyses (hazard ratio: 1.094, P = 0.008), whereas bone V5 had no impact on survival outcomes. We concluded that the NLRmax was a better prognostic indicator than the ALCmin, and the lung dose had more influence than the bone dose on the main survival outcomes in stage III NSCLC patients treated with PBT combined with concurrent chemotherapy.

Explainability and controllability of patient-specific deep learning with attention-based augmentation for markerless image-guided radiotherapy.

BACKGROUND: We reported the concept of patient-specific deep learning (DL) for real-time markerless tumor segmentation in image-guided radiotherapy (IGRT). The method was aimed to control the attention of convolutional neural networks (CNNs) by artificial differences in co-occurrence probability (CoOCP) in training datasets, that is, focusing CNN attention on soft tissues while ignoring bones. However, the effectiveness of this attention-based data augmentation has not been confirmed by explainable techniques. Furthermore, compared to reasonable ground truths, the feasibility of tumor segmentation in clinical kilovolt (kV) X-ray fluoroscopic (XF) images has not been confirmed. PURPOSE: The first aim of this paper was to present evidence that the proposed method provides an explanation and control of DL behavior. The second purpose was to validate the real-time lung tumor segmentation in clinical kV XF images for IGRT. METHODS: This retrospective study included 10 patients with lung cancer. Patient-specific and XF angle-specific image pairs comprising digitally reconstructed radiographs (DRRs) and projected-clinical-target-volume (pCTV) images were calculated from four-dimensional computer tomographic data and treatment planning information. The training datasets were primarily augmented by random overlay (RO) and noise injection (NI): RO aims to differentiate positional CoOCP in soft tissues and bones, and NI aims to make a difference in the frequency of occurrence of local and global image features. The CNNs for each patient-and-angle were automatically optimized in the DL training stage to transform the training DRRs into pCTV images. In the inference stage, the trained CNNs transformed the test XF images into pCTV images, thus identifying target positions and shapes. RESULTS: The visual analysis of DL attention heatmaps for a test image demonstrated that our method focused CNN attention on soft tissue and global image features rather than bones and local features. The processing time for each patient-and-angle-specific dataset in the training stage was ∼30 min, whereas that in the inference stage was 8 ms/frame. The estimated three-dimensional 95 percentile tracking error, Jaccard index, and Hausdorff distance for 10 patients were 1.3-3.9 mm, 0.85-0.94, and 0.6-4.9 mm, respectively. CONCLUSIONS: The proposed attention-based data augmentation with both RO and NI made the CNN behavior more explainable and more controllable. The results obtained demonstrated the feasibility of real-time markerless lung tumor segmentation in kV XF images for IGRT.

Light flash and odor during proton beam therapy for pediatric patients: a prospective observational study.

Light flash and odor during radiation therapy are well-known phenomena, but the details are poorly understood, particularly in pediatric patients. Therefore, we conducted a prospective observational study of these events in pediatric patients (age ≤20 years old) who received radiotherapy at our center from January 2019 to November 2021. Light flash and odor were evaluated using a patient-reported checklist including the presence, strength, and duration of the phenomenon, and color of light or type of odor. 53 patients who received proton therapy (n=47) and photon radiotherapy (n=6) were enrolled in this study. The median age of the patients was 10, ranged from 5 to 20. The patients who was able to see the light flash was 4, and all of them received retina irradiation. This was equivalent to 57% of the patients who received radiotherapy to retina (n=7). The light was bright and colored mainly blue and purple, which seemed to be consistent with Cherenkov light. Odor was sensed by 9 (17%) patients, and seven patients of the 9 received nasal cavity irradiation. This was equivalent to 41% of the patients who received nasal cavity irradiation (n=17). Other 2 patients received proton therapy to brain tumor. The odors were mainly described as plastic, burnt and disinfectant, which may be caused by ozone generated during irradiation. These data suggest that pediatric patients with retinal and nasal cavity irradiation frequently sense light flashes or odor. So adequate care is necessary so that these patients are not worried about this phenomenon.

Abnormal sensation during total body irradiation: a prospective observational study.

Light flash and odor during radiotherapy are well-known phenomena. Two prospective observational studies have indicated that 55% of patients observed a light flash during irradiation of the retina and 27% of patients sensed an odor during radiotherapy for the nasal cavity. A prospective observational study was performed in all patients at our hospital who received total body irradiation (TBI) between January 2019 to October 2021. Light flash and odor during TBI were examined using the same method as that used in previous studies. A total of 32 patients received TBI during the study period. The patients had a median age of 41 (18-60) years, and included 20 males and 12 females. A survey checklist showed that 14 patients (44%) sensed light and 14 patients (44%) sensed odor during TBI,. The color of the light during irradiation was yellow in six cases, white in four cases, and blue in four cases. The intensity of the light was 2-5 (median 3, 1 is very weak, 5 is very strong) and the time over which the light flash was felt was 4-60 s (median 10 s). Two patients each sensed smells of plastic, ozone and bleach, and others sensed one smell each. The intensity of the odor was 1-4 (median 3, 1 is very weak, 5 is very strong) and the time over which the odor was sensed was 1-25 s (median 3 s). We conclude that light flashes and odors are each sensed by 44% of patients during TBI. Various types of light flashes and odors were reported in this study.

Proton Beam Therapy in Elderly Patients With cT1-3N0M0 Non-small Cell Lung Cancer.

BACKGROUND/AIM: To investigate the outcomes of elderly patients with cT1-3N0M0 non-small cell lung cancer (NSCLC) undergoing proton beam therapy (PBT). PATIENTS AND METHODS: Between 2009 and 2019, 110 patients receiving hypofractionated PBT for cT1-3N0M0 NSCLC were retrospectively reviewed. RESULTS: The median follow-up was 36.5 months (range=4.9-131.0 months). In the elderly group (80 years or older), the 3-year overall survival and progression-free survival rates were 79.8% and 73.9%, respectively, and the corresponding rates in the younger group were 80.5% and 61.2%, respectively. Grade 3 radiation pneumonitis (RP) was observed in 4.4% patients in the young group, whereas no grade 3 RP was observed in the elderly group. Age was not a risk factor for symptomatic RP. There were no significant differences in the survival and adverse events between the elderly and younger groups. CONCLUSION: PBT may be a reasonable approach for treating lung cancer in elderly patients with T1-3N0M0 NSCLC.

Stereotactic Body Radiotherapy for Stage I Lung Cancer With a New Real-time Tumor Tracking System.

BACKGROUND/AIM: Suppression of respiratory movement is crucial for safe and effective stereotactic body radiotherapy (SBRT). SyncTraX FX4 is a novel device for synchronous respiratory irradiation. The purpose of this study was to evaluate the efficacy and toxicity of SBRT using SyncTraX FX4 for patients with lung cancer. PATIENTS AND METHODS: Patients treated with SBRT using SyncTraX FX4 between November 2017 and August 2020 were included. In all cases, fiducial markers were inserted into the lung, and the total dose administered was 55 or 60 Gy, depending on the distance from the central region of the lung. Acute and late toxicities were reported, and local control, progression-free survival, cancer-specific survival, and overall survival were analyzed. RESULTS: We evaluated 16 patients and 17 sites. The median follow-up period was 14.4 months. In both the acute and late phases, one patient experienced grade 3 radiation pneumonitis; however, grade 4 or higher toxicities were not observed. There was no local recurrence during the observation period, and the overall survival, cancer-specific survival, and progression-free survival at 2 years were 54.6%, 85.1%, and 33.7%, respectively. CONCLUSION: SBRT with SyncTraX FX4 can provide safe and effective treatment for lung cancer patients in poor condition.

Analysis of diaphragm movements to specify geometric uncertainties of respiratory gating near end-exhalation for irradiation fields involving the liver dome.

BACKGROUND AND PURPOSE: The technique of gating near end-exhalation is commonly adopted to reduce respiration-associated geometric uncertainties for particle beam therapy. However, for irradiation fields involving the liver dome, how diaphragm movements generating liver-lung interface change, alongside geometric uncertainties, remain unspecified. METHODS AND MATERIALS: Patients receiving respiratory-gated computed tomography (RGCT) with four-dimensional computed tomography (4DCT) scans during simulation were retrospectively reviewed. Differences (Δ) between RGCT and 4DCT images, including diaphragm displacements and liver-lung interface changes, were investigated to specify geometric uncertainties during early inhalation phases. Craniocaudal displacements (Δy, in sagittal/coronal planes) of diaphragm segments (dorsal/ventral/right lateral/medial), liver area changes (ΔA, in axial planes), and liver extent changes in specific directions of incidence (Δr, in axial planes) were analyzed. RESULTS: Altogether, 162 patients received simulating RGCT and 4DCT scans. In 22 of them, both images involved the liver dome. For most cases during early inhalation phases, the Δy values in the dorsal diaphragm were significantly greater than those in the ventral diaphragm (p < 0.05), the ΔA values were significantly enlarged with inhalation progressing (p < 0.05), and the Δr values in the dorsal direction were significantly larger than those in the ventral direction (p < 0.05). These results suggested that the dorsal diaphragm moves earlier and more in a caudal direction than the ventral diaphragm during early inhalation phases. CONCLUSIONS: For respiratory-gated radiotherapy near end-exhalation and irradiation fields involving the liver dome, components of geometric uncertainties are temporospatial, including diaphragm segment movements, inhalation phases of irradiation, and beam angles of incidence.

A Case Report of Radiotherapy for Skull Lesions of Langerhans Cell Histiocytosis With Dural Invasion.

Background: Langerhans cell histiocytosis (LCH) is a rare disease, especially in adults. It is often associated with non-fatal bone and skin lesions and has relatively good radiosensitivity. In contrast, brain and lymph node metastases from LCH lesions are considered to be less sensitive to radiotherapy. Case Report: At our institution, 30 Gy radiotherapy was used to treat bone lesions with dural invasion in a patient with adult-onset LCH. The patient was treated with chemotherapy and radiotherapy for 21 years since the initial diagnosis. After radiotherapy, the tumor shrank rapidly, and a complete response was achieved 1 year after treatment. The patient survived without local recurrence. Conclusion: Here, we report the details of this case, along with a review of the literature. We suggest that even with invasion of the tissues around the bone lesions in LCH, local recurrence can be prevented by middle radiation doses.