Tomotherapy, literally "slice therapy," is a proposal for the delivery of radiation therapy with intensity-modulated strips of radiation. The proposed method employs a linear accelerator, or another radiation-emitting device, which would be mounted on a ring gantry like a CT scanner. The patient would move through the bore of the gantry simultaneously with gantry rotation. The intensity modulation would be performed by temporally modulated multiple independent leaves that open and close across the slit opening. At any given time, any leaf would be (1) closed, covering a portion of the slit, (2) open, allowing radiation through, or (3) changing between these states. This method would result in the delivery of highly conformal radiation. Overall treatment times should be comparable with contemporary treatment delivery times. The ring gantry would make it convenient to mount a narrow multisegmented megavoltage detector system for beam verification and a CT scanner on the treatment unit. Such a treatment unit could become a powerful tool for treatment planning, conformal treatment, and verification using tomographic images. The physical properties of this treatment delivery are evaluated and the fundamental design specifications are justified.

SUMMARYBackgroundAfter brain metastasis resection, whole-brain radiation therapy (WBRT) decreases local recurrence but may cause cognitive decline. We performed this study to determine if stereotactic radiosurgery (SRS) to the surgical cavity improved local tumor tumor-free recurrence rates compared to surgical resection alone as an alternative to the need for immediate WBRT.MethodsThe main entry criteria for the study included patients >3 years of age, with a Karnofsky Performance Score ≥ 70, who were able to undergo an MRI scan and who had a complete resection of 1–3 brain metastases (the maximum diameter of the resection cavity had to be ≤4cm). Patients were assigned randomly to either SRS treatment of the resection cavity (within 30 days of surgery) or observation (OBS). Patients were stratified by histology, tumor size, and number of metastases. Patients were recruited at a single tertiary cancer center. The primary endpoint was time to local recurrence in the resection cavity assessed by blinded central review of brain MRI scans in the intention-to-treat population. The trial was registered at clinicaltrials.gov (Trial NCT00950001, status: closed to new participants).FindingsBetween 8/13/2009 and 2/16/2016, 132 patients were randomized to OBS (N=68) or SRS (N=64), with 128 patients available for analysis. We stratified by metastasis size (maximum diameter of ≥3 cm vs. <3 cm), histology (melanoma vs. other), and number of metastases (one vs. two or three). The 12-month local tumor recurrence-free rate was 43% (OBS) (95% CI 31%–59%) and 72% (SRS) (95% CI 60%–87%) (hazard ratio [HR] 0.46, 95% confidence interval [CI] 0.24–0.88, p=0.015).InterpretationThis prospective randomized trial of patients undergoing surgical resection for 1–3 brain metastases indicates that SRS administered to the resection cavity significantly lowers local recurrence compared to observation alone. Thus, the use of SRS after brain metastasis resection is an alternative to WBRT.

Summary Background This study investigated the clinical benefit of using hypofractionated stereotactic body radiotherapy (SBRT) to manage spinal metastases in patients with cancer and to reduce cancer-related symptoms. Methods Cancer patients (n=149) with mechanically stable, non–cord-compressing, spinal metastases (n=166) were treated by SBRT in a phase I/II study. Patients received a total dose of 27–30 Gy, typically in three fractions. Symptoms were measured repeatedly by the Brief Pain Inventory (BPI) and the M. D. Anderson Symptom Inventory (MDASI). The primary endpoint was to establish the safety, feasibility, and efficacy of using a CT-on-Rails or Trilogy Stereotactic Spine Radiation Therapy system to treat spinal and paraspinal tumors and to document pain relief and toxicity associated with such treatment. Symptom outcomes were estimated according to protocol using descriptive analysis and ordinal regression modeling. This is the final report for the completed enrollment and follow-up. Findings The median follow-up time was 15·9 (interquartile range 9·5–30·3) months and the mean was 20·9 (SD=17·1) months. The actuarial tumor progression-free survival rates at one year and two years post-SBRT were 80·5% and 72·4%, respectively. Patients reported significant MDASI pain reduction (p=0·00003) during the six months post-SBRT. Patients reporting no pain from bone metastases on the BPI increased from 39/149 (26·2%) before SBRT to 55/102 (53·9%) six months post-SBRT (p<0·0001). BPI pain reduction from baseline to four weeks post-SBRT was clinically meaningful (effect size=0·47, p<0·01). These improvements were accompanied by significant reduction in opioid use during the six months post-SBRT (p<0·05) and a significant reduction in MDASI symptom interference with daily life (p<0·01).. Only a few instances of nonneurological grade 3 toxicities occurred (one report each of nausea, vomiting, diarrhea, fatigue, dysphagia, neck pain, diaphoresis, two reports of pain associated with severe tongue edema and trismus, and 3 reports of noncardiac chest pain). No grade 4 toxicities occurred. Interpretation SBRT is an effective primary or salvage treatment of mechanically stable spinal metastasis. Significant reduction in patient-reported pain and other symptoms was evident six months post-SBRT, along with satisfactory progression-free survival and no late spinal cord toxicities.

Background This Phase I/II study tests the hypothesis that single-fraction SBRT for previously un-irradiated spinal metastases is a safe, feasible, and efficacious treatment approach. Methods All patients were evaluated by a multidisciplinary team. Spinal MRI was performed before treatment and at regular intervals to both define target volume and response to treatment. SBRT was delivered to a peripheral dose of 16–24 Gy in 1 fraction while limiting dose to the spinal cord. Higher doses were used for renal cell histology. The NCI Common Toxicity Criteria 2.0 and McCormick neurological function score were used as toxicity assessment tools. Results A total of 61 patients harboring 63 tumors of the non-cervical spine were enrolled and treated with SBRT between 2005 and 2010 on a prospective Phase I/II trial at the University of Texas M. D. Anderson Cancer Center. Mean follow-up was 20 months. Actuarial 18-month imaging local control for all patients was 88%. Actuarial 18-month overall survival for all patients was 64%. Median survival for all patients was 30 months. No significant differences in outcomes were noted with respect to tumor histology and SBRT dose. Two patients experienced radiation adverse events (Grade 3 or higher). Actuarial 18-month freedom from neurologic deterioration from any cause as was 82%. Conclusions This Phase I/II data support an expanded indication for SBRT as first-line treatment of selected spinal metastases patients. Additional studies that can prospectively identify predictive factors for spinal cord toxicity after SBRT are warranted to minimize the incidence of this serious yet rare complication.

BACKGROUND: Stereotactic body radiotherapy for previously irradiated, progressive spinal metastases may be a viable option in selected patients. The authors review a prospective series of spinal metastasis patients reirradiated with stereotactic body radiotherapy. METHODS: A total of 59 patients with 63 tumors of the spine were reirradiated with stereotactic body radiotherapy between 2003 and 2009. Spinal magnetic resonance imaging was performed both before treatment initiation and at regular follow-up intervals. Stereotactic body radiotherapy was delivered to a peripheral dose of 30 grays (Gy) in 5 fractions (6 Gy per fraction), or 27 Gy in 3 fractions (9 Gy per fraction). The National Cancer Institute Common Toxicity Criteria 2.0 and McCormick neurological function system were used to evaluate toxicity and neurologic status, respectively. RESULTS: Mean follow-up was 17.6 months. Actuarial 1-year radiographic local control and overall survival for all patients were both 76%. Of the tumors that progressed after stereotactic body radiotherapy, 13 (81%) of 16 patients had tumors that were within 5 mm of the spinal cord, and 6 of them eventually developed spinal cord compression. Toxicity was most commonly grade 1 or 2 fatigue. Two patients experienced mild to moderate radiation injury (lumbar plexopathy) while remaining independently ambulatory and pain free. Freedom from neurologic deterioration from any cause was 92% at 1 year. CONCLUSIONS: Reirradiation for progressive spinal metastases with stereotactic body radiotherapy results in good local control and limited toxicity. Initial surgery should be considered for tumors within 5 mm of the spinal cord. Radiation dose should be tailored for tumors near or invading the psoas muscle secondary to observed risk of lumbar plexopathy. Cancer 2011;117:3509-