BACKGROUND: Few studies have compared the clinical outcomes of patients with pelvic bone sarcomas treated surgically and those treated with particle beam therapy. This is a multicenter retrospective cohort study which compared the clinical outcomes of patients with pelvic bone sarcoma who underwent surgical treatment and particle beam therapy in Japan.
METHODS: A total of 116 patients with pelvic bone sarcoma treated at 19 specialized sarcoma centers in Japan were included in this study. Fifty-seven patients underwent surgery (surgery group), and 59 patients underwent particle beam therapy (particle beam group; carbon-ion radiotherapy: 55 patients, proton: four patients).
RESULTS: The median age at primary tumor diagnosis was 52 years in the surgery group and 66 years in the particle beam group (P < 0.001), and the median tumor size was 9 cm in the surgery group and 8 cm in the particle beam group (P = 0.091). Overall survival (OS), local control (LC), and metastasis-free survival (MFS) rates were evaluated using the Kaplan-Meier method and compared among 116 patients with bone sarcoma (surgery group, 57 patients; particle beam group, 59 patients). After propensity score matching, the 3-year OS, LC, and MFS rates were 82.9% (95% confidence interval [CI], 60.5-93.2%), 66.0% (95% CI, 43.3-81.3%), and 78.4% (95% CI, 55.5-90.5%), respectively, in the surgery group and 64.9% (95% CI, 41.7-80.8%), 86.4% (95% CI, 63.3-95.4%), and 62.6% (95% CI, 38.5-79.4%), respectively, in the particle beam group. In chordoma patients, only surgery was significantly correlated with worse LC in the univariate analysis.
CONCLUSIONS: The groups had no significant differences in the OS, LC, and MFS rates. Among the patients with chordomas, the 3-year LC rate in the particle beam group was significantly higher than in the surgery group.

Background/Objectives: Particle beam therapy (PBT) was approved in April 2018 for head and neck malignancies and has since been introduced as a radical therapy for parotid malignancies. However, its prevalence and effectiveness in relation to surgical treatment have not been investigated. Methods: In this study, we evaluated 36 patients with parotid malignancy who underwent surgery (n = 26) or PBT (n = 10) and then analyzed the annual changes in the number of patients, survival rates, and clinical factors affecting prognosis. Results: Of the ten patients who opted for PBT, two and eight patients underwent PBT before and after 2018, respectively. There was a significant difference between these two groups of patients (p = 0.04). Of the ten patients who underwent PBT, five patients were recurrent cases; meanwhile, all twenty-six patients who underwent surgery were receiving initial treatment. Only one patient in each group had local recurrence after the treatment. Conclusions: The use of PBT as a radical therapy for parotid malignancies has been increasing since 2018, and patients with recurrent tumors tended to choose PBT. The outcome of the patients who underwent PBT did not seem to be inferior compared with those of the patients who underwent surgery. The histopathological type was a crucial issue in the outcomes of patients who underwent radical therapy for parotid malignancies.

This study presents the first data of a Japanese nationwide multi-institutional cohort and compares them with the findings of systematic literature reviews on radiation therapies and inoperable stage III non-small cell lung cancer (NSCLC) conducted by the Lung Cancer Working Group in the Particle Beam Therapy (PBT) Committee and Subcommittee at Japanese Society for Radiation Oncology. The Lung Cancer Working Group extracted eight reports and compared their data with those of the PBT registry from May 2016 to June 2018. All the analyzed 75 patients aged ≤80 years underwent proton therapy (PT) with concurrent chemotherapy for inoperable stage III NSCLC. The median follow-up period of the surviving patients was 39.5 (range, 1.6-55.6) months. The 2- and 3-year overall survival (OS) and progression-free survival rates were 73.6%/64.7% and 28.9%/25.1%, respectively. During the follow-up period, six patients (8.0%) had adverse events of Grade ≥ 3, excluding abnormal laboratory values. These included esophagitis in four patients, dermatitis in one and pneumonitis in one. Adverse events of Grade ≥ 4 were not observed. The results of these PBT registry data in patients with inoperable stage III NSCLC suggest that the OS rate was at least equivalent to that of radiation therapy using X-rays and that the incidence of severe radiation pneumonitis was low. PT may be an effective treatment to reduce toxicities of healthy tissues, including the lungs and heart, in patients with inoperable stage III NSCLC.

On-line PET image-based method uses an initial particle beam to measure the particle beam range (BR) within the same fraction so that any measured range-shift with respect to the predicted BR can be compensated before the rest therapeutic beam deliveries. However, the method requires to use a low-dose initial beam to minimize the risk of beam overshooting, which leads to low image count and inaccurate BR measurement. In this in-silico study, we evaluated the feasibility of a new on-line PET imaging method that measures BR at the mid-plane of a target volume with part of the high-dose therapy beams to verify BR and guide adaptive treatment re-planning. Simulations included various processes of proton beam radiations to a tumor inside a human brain phantom, positron and PET image generation at the mid-plane with initial beams, activity range measurement, and range-shift compensated beam delivery. The results demonstrated that the new method, under the simulated conditions, can achieve ~1.1 mm mid-plane BR measurement accuracy and closely match the delivered range-shift compensated dose distribution with the planned one. Overall, it is promising that this new method may significantly improve particle therapy accuracy.

This is a case report of a male patient with previous radiation for a thymic carcinoma (20 years ago) who presented with a left breast cancer. He underwent a partial mastectomy followed by proton radiation therapy with a dose of 5040 cGy to the whole breast in 28 fractions with simultaneous boost to 5800 cGy to the lumpectomy cavity. Proton beam therapy was used instead of conventional photon radiation therapy to spare the heart and lung and to avoid any previously irradiated areas. This study describes the technique and comparative dosimetry for this case.

To evaluate the efficacy and safety of carbon-ion radiotherapy for non-squamous cell carcinoma of the head and neck, 35 patients were enrolled in this prospective study. The primary end-point was the 3-year local control rate, and the secondary end-points included the 3-year overall survival rate and adverse events. Acute and late adverse events were evaluated according to the Common Terminology Criteria for Adverse Events, version 4.0. The median follow-up time for all patients was 39 months. Thirty-two and three patients received 64.0 Gy (relative biological effectiveness) and 57.6 Gy (relative biological effectiveness) in 16 fractions, respectively. Adenoid cystic carcinoma was dominant (60%). Four patients had local recurrence and five patients died. The 3-year local control and overall survival rates were 93% and 88%, respectively. Acute grade 2-3 radiation mucositis (65%) and dermatitis (31%) was common, which improved immediately with conservative therapy. Late mucositis of grade 2, grade 3, and grade 4 were observed in 11, one, and no patients, respectively. There were no adverse events of grade 5. Carbon-ion radiotherapy achieved excellent local control and overall survival rates for non-squamous cell carcinoma. However, the late mucosal adverse events were not rare, and meticulous treatment planning is required. Trial registration no. UMIN000007886.