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Background: Hypofractionated proton therapy (HFPT) is expected to become an effective treatment approach for localized prostate cancer (PCa). The purpose of this study was to evaluate differences in acute toxicity among patients with localized PCa treated with either conventional fractionated proton therapy (CFPT) or HFPT., Methods: A total of 526 eligible patients treated with proton therapy between February 2013 and May 2016 in three phase II trials were analyzed. We prescribed 74 gray relative biological effectiveness equivalents [Gy (RBE)]/37 fractions for low-risk patients and 78 Gy (RBE)/39 fractions for intermediate- and high-risk patients in the CFPT group (n = 254) and 60 Gy (RBE)/20 fractions for low-risk and 63 Gy (RBE)/21 fractions for intermediate- and high-risk patients in the HFPT group (n = 272). Patients were evaluated for acute toxicity with the Common Terminology Criteria for Adverse Events, version 4.0, and urinary quality-of-life change using the International Prostate Symptom Score (IPSS)., Results: No grade ≥3 acute toxicity was observed in either group. Among acute genitourinary toxicities, grade 2 rates were 15% (n = 38) in CFPT and 5.9% (n = 16) in HFPT (P ≤ 0.001). The median baseline IPSSs of the CFPT and HFPT groups were 7 (0-29) and 6 (0-31), respectively (P = 0.70). One-month post-treatment scores were 9 (0-32) and 11 (0-32), respectively (P = 0.036), and 6-month post-treatment scores were 7 (0-30) and 7 (0-33), respectively (P = 0.88). There were no significant differences in acute gastrointestinal toxicity between the two groups., Conclusion: Our results demonstrated the safety of HFPT for localized PCa patients in terms of acute toxicity.

Background: In this phase I/II study, we assessed the safety and initial efficacy of stereotactic body radiotherapy (SBRT) for lung tumors with real-time tumor tracking using CyberKnife based on the Monte Carlo algorithm., Methods: Study subjects had histologically confirmed primary non-small-cell lung cancer staged as T1a-T2aN0M0 and pulmonary oligometastasis. The primary endpoint was the incidence of Grade ≥3 radiation pneumonitis (RP) within 180 days of the start of SBRT. The secondary endpoint was local control and overall survival rates. Five patients were initially enrolled at level 1 [50 Gy/4 fractions (Fr)]; during the observation period, level 0 (45 Gy/4 Fr) was opened. The dose was escalated to the next level when grade ≥3 RP was observed in 0 out of 5 or 1 out of 10 patients. Virtual quality assurance planning was performed for 60 Gy/4 Fr; however, dose constraints for the organs at risk did not appear to be within acceptable ranges. Therefore, level 2 (55 Gy/4 Fr) was regarded as the upper limit. After the recommended dose (RD) was established, 15 additional patients were enrolled at the RD. The prescribed dose was normalized at the 95% volume border of the planning target volume based on the Monte Carlo algorithm., Results: Between September 2011 and September 2015, 40 patients (primary 30; metastasis 10) were enrolled. Five patients were enrolled at level 0, 15 at level 1, and 20 at level 2. Only one grade 3 RP was observed at level 1. Two-year local control and overall survival rates were 98 and 81%, respectively., Conclusion: The RD was 55 Gy/4 Fr. SBRT with real-time tumor tracking using CyberKnife based on the Monte Carlo algorithm was tolerated well and appeared to be effective for solitary lung tumors.

The purpose of this paper is to describe an outline of a proton therapy system in Nagoya Proton Therapy Center (NPTC). The NPTC has a synchrotron with a linac injector and three treatment rooms: two rooms are equipped with a gantry and the other one is equipped with a fixed horizontal beamline. One gantry treatment room has a pencil beam scanning treatment delivery nozzle. The other two treatment rooms have a passive scattering treatment delivery nozzle. In the scanning treatment delivery nozzle, an energy absorber and an aperture system to treat head and neck cancer have been equipped. In the passive treatment delivery nozzle, a multi-leaf collimator is equipped. We employ respiratory gating to treat lung and liver cancers for passive irradiation. The proton therapy system passed all acceptance tests. The first patient was treated on February 25, 2013, using passive scattering fixed beams. Respiratory gating is commonly used to treat lung and liver cancers in the passive scattering system. The MLCs are our first choice to limit the irradiation field. The use of the aperture for scanning irradiation reduced the lateral fall off by half or less. The energy absorber and aperture system in scanning delivery is beneficial to treat head and neck cancer.

The aim of the present study was to evaluate the safety and feasibility of hypofractionated stereotactic radiotherapy (SRT) with CyberKnife for growth hormone-secreting pituitary adenoma (GH-PA). Fifty-two patients with GH-PA were treated with hypofractionated SRT between September 2001 and October 2012. Eight patients had clinically silent GH-PA and 44 were symptomatic. Only 1 patient was inoperable. The other patients had recurrent or postoperative residual tumors on MRI. All patients had received pharmacotherapy prior to SRT with a somatostatin analog, dopamine agonist, and/or GH receptor antagonist. The marginal doses were 17.4-26.8 Gy for the 3-fraction schedule and 20.0-32.0 Gy for the 5-fraction schedule. Endocrinological remission was assessed by the Cortina consensus criteria 2010 (random GH <1 ng/ml or nadir GH after an oral glucose tolerance test <0.4 ng/ml and normalization of age- and sex-adjusted insulin-like growth factor-1). The median follow-up period was 60 months (range 27-137). The 5-year overall survival, local control, and disease-free survival rates were 100, 100, and 96 %, respectively. Nine patients (5 clinically silent and 4 symptomatic patients) satisfied the Cortina criteria without receiving further pharmacotherapy, whereas the remaining 43 patients did not. No post-SRT grade 2 or higher visual disorder occurred. Symptomatic post-SRT hypopituitarism was observed in 1 patient. CyberKnife hypofractionated SRT is safe and effective when judged by imaging findings for GH-PA. However, it may be difficult to satisfy the Cortina consensus criteria in most symptomatic patients with SRT alone. Further investigations of optimal treatments are warranted.

Purposes: The prognosis of localized extranodal natural killer/T-cell lymphoma, nasal type (ENKTL), has improved with the development of chemoradiotherapy. However, conventional extended-field radiotherapy may cause optic disorders. Our group has employed smaller radiation fields in an attempt to avoid toxicity. The efficacy and toxicity of treatments were evaluated., Materials and Methods: Chemoradiotherapy was delivered with a shrinking-field radiotherapy strategy. The endpoints of this study were overall survival (OS), local control (LC), progression-free survival (PFS), and toxicity., Results: Fifteen patients with localized ENKTL were treated. After irradiation (median, 40 Gy) to the tumor plus a prophylactic volume, a reduced treatment volume to the tumor was boosted (median, 10 Gy). Twelve patients underwent chemoradiotherapy and 3 patients received radiotherapy alone. A complete response was achieved in 12 and a partial response in 3 patients. The 5-year OS, PFS, and LC rates were 80, 67, and 93 %, respectively. Distant recurrence occurred in 4 patients and locoregional and distant recurrence in 1 patient. Cataract (grade 3) and dry eye (grade 2) were observed as late adverse events in 1 patient each., Conclusions: Sufficiently high OS and LC were achieved with acceptable toxicities. Appropriate target volumes may be smaller with newer chemotherapy regimens.

Background: Organizing pneumonia (OP), so called bronchiolitis obliterans organizing pneumonia after postoperative irradiation for breast cancer has been often reported. There is little information about OP after other radiation modalities. This cohort study investigated the clinical features and risk factors of OP after stereotactic ablative radiotherapy of the lung (SABR)., Methods: Patients undergoing SABR between 2004 and 2010 in two institutions were investigated. Blood test and chest computed tomography were performed at intervals of 1 to 3 months after SABR. The criteria for diagnosing OP were: 1) mixture of patchy and ground-glass opacity, 2) general and/or respiratory symptoms lasting for at least 2 weeks, 3) radiographic lesion in the lung volume receiving < 0.5 Gy, and 4) no evidence of a specific cause., Results: Among 189 patients (164 with stage I lung cancer and 25 with single lung metastasis) analyzed, nine developed OP. The incidence at 2 years was 5.2% (95% confidence interval; 2.6-9.3%). Dyspnea were observed in all patients. Four had fever. These symptoms and pulmonary infiltration rapidly improved after corticosteroid therapy. Eight patients had presented with symptomatic radiation pneumonitis (RP) around the tumor 2 to 7 months before OP. The prior RP history was strongly associated with OP (hazard ratio 61.7; p = 0.0028) in multivariate analysis., Conclusions: This is the first report on OP after SABR. The incidence appeared to be relatively high. The symptoms were sometimes severe, but corticosteroid therapy was effective. When patients after SABR present with unusual pneumonia, OP should be considered as a differential diagnosis, especially in patients with prior symptomatic RP.