Journal of radiosurgery and SBRT最新文献

Purpose: Stereotactic body proton therapy (SBPT) is an emerging treatment strategy for lung tumors that aims to combine the excellent local control benefits of ultra-hypofractionation with the physical advantages of protons, which reduce the integral dose to organs at risk (OARs) compared to photons. To date, however, very little data delivering SBPT in 5 or fewer fractions to lung tumors have been reported. Given that photon stereotactic body radiation therapy can struggle to deliver ablative doses to high-risk tumors (i.e., central/ultra-central location, prior in-field radiation, tumor size >5 cm, or the presence of severe pulmonary comorbidities) while adhering to OAR dose constraints, we hypothesized that SBPT would be an effective alternative for patients with high-risk tumors.

Methods and materials: Twenty-seven high-risk patients with 29 lung tumors treated with SBPT at the New York Proton Center between December 2019 and November 2022 were retrospectively identified. Patients were divided into three major subgroups: early-stage non-small cell lung cancer (NSCLC), locally recurrent NSCLC, and metastatic cancer from lung cancer or other histologies. Patient characteristics were reported using descriptive statistics, actuarial methods were used to quantify disease control rates, and toxicities were scored using CTCAE v 5.0.

Results: The most common high-risk indications for SBPT were central/ultra-central tumor location (69.0%), severe COPD (48.1%), reirradiation (44.4%), significant pulmonary fibrosis (22.2%), and large tumor size > 5 cm (18.5%). In total, 96.6% of tumors were fully covered by the prescription dose without compromising target coverage. Three-year actuarial rates of local control for early-stage NSCLC, locally recurrent NSCLC, and metastatic patients were 89%, 100%, and 43%, respectively. Three-year actuarial rates of regional control were 89%, 67%, and 86%. Three-year actuarial rates of distant metastasis-free survival were 79%, 100%, and 0%. Two patients (7.4%), both of whom had clinically significant baseline interstitial lung disease and pre-treatment continuous oxygen demand, experienced grade ≥2 pulmonary toxicity (1 grade 3, 1 grade 5). There were no acute or late grade ≥2 toxicities related to esophagitis, cardiac injury, airway injury, pulmonary fibrosis, bronchopulmonary hemorrhage or brachial plexopathy.

Conclusions: In the largest study of proton SBRT reported to date, SBPT has a favorable toxicity profile while being an effective approach for treating most high-risk tumors without requiring dose de-escalation or compromising tumor coverage and warrants further investigation.

Our randomized clinical study comparing stereotactic body radiotherapy (SBRT) and stereotactic body proton therapy (SBPT) for early stage non-small cell lung cancer (NSCLC) was closed prematurely owing to poor enrollment, largely because of lack of volumetric imaging and difficulty in obtaining insurance coverage for the SBPT group. In this article, we describe technology improvements in our new proton therapy center, particularly in image guidance with cone beam CT (CBCT) and CT on rail (CTOR), as well as motion management with real-time gated proton therapy (RGPT) and optical surface imaging. In addition, we have a treatment planning system that provides better treatment plan optimization and more accurate dose calculation. We expect to re-start the SBPT program, including for early stage NSCLC as well as for other disease sites soon after starting patient treatment at our new proton therapy center.

Stereotactic body radiotherapy (SBRT) is well accepted for low- and intermediate-favorable risk prostate cancer. Available evidence about the application of SBRT in unfavorable- and high-risk prostate cancer is less solid. During last year's multiple variations in treatment, techniques have been reported making comparisons more complicated. This review's objective is to review current evidence in application of SBRT in intermediate unfavourable and high-risk prostate cancer and to outline variations in SBRT treatment techniques and relevant results.

This study investigated if field output correction factors (FOCFs) of Varian stereotactic cones for Edge detectorTM had dependence on cone size, measurement setup, reference field size and/or photon energy. Field output factors (FOFs) of stereotactic cones were measured at three depths (1.5 cm, 5 cm and 10 cm) in two different setups (source-to-surface distance (SSD) and source-to-axis distance (SAD)) with two photon energies (6 MV and 6 MV flattening filter free) using the Edge detector and Exradin_® W2 scintillator. Two reference fields (10 × 10 cm² and 4 × 4 cm²) were chosen. FOCFs for the Edge detector were determined by calculating FOF_W2/FOF_Edge and compared among cones and between depths, setups, reference fields and energies. It is concluded that FOCFs for the Edge detector have dependence on cone size, SSD/SAD setup and energy for small cones, but do not have dependence on depth and reference field size.

Jugulotympanic paraganglioma (JTPG), a benign slow-growing neoplasm in the skull base with a tendency to be locally invasive, poses a treatment challenge because of its proximity to nearby neurovascular structures. The authors describe 11 patents with 12 Fisch-classified JTPGs treated with GammaKnife radiosurgery (GKRS) during a 12-year period. The observed rates of subjective improvement and tumor control were 80% and 83%, respectively. Among the individuals living longer than 5 years, tumor growth developed at 77 and 180 months after radiosurgery in two patients. Treatment-related toxicity or radiation oncogenesis was not observed. GKRS seems to be a valid treatment option for all Fisch designated skull base glomus tumors. Life-long follow-up of these patients is necessary.