MRI Grading Scale Predicts Ambulatory Function After Radiotherapy for Metastatic Spinal Cord Compression: A Prospective Single-Institution Observational Study.

INTRODUCTION: Although magnetic resonance imaging (MRI) is an important modality for the diagnosis of metastatic spinal cord compression (MSCC), there are only a few reports on MSCC findings and symptoms after radiotherapy. We aimed to reveal the factors related to ambulatory function after treatment, including the MRI findings, in a prospective observational study. METHODS: Patients with suspected MSCC who were treated with radiotherapy were included in this study. Orthopedic surgeons evaluated the neurological function according to the Frankel grade. All patients underwent spinal MRI, and the degree of spinal cord compression was assessed by a radiologist and a radiation oncologist using an MRI grading scale. One month after treatment, orthopedic surgeons reassessed the Frankel grade. Twenty-three patients who were evaluated 1 month after radiotherapy were included in the analysis. RESULTS: Before radiotherapy, 17 patients were ambulatory and six were unable to walk. Furthermore, 13 patients were diagnosed with grade 3 compression on MRI (spinal cord compression with no cerebrospinal fluid seen on axial T2-weighted imaging). Patients with grade 3 MSCC were significantly more likely to be non-ambulatory at 1 month. CONCLUSIONS: The MRI grading scale for MSCC may be a prognostic factor for ambulatory function after radiotherapy. MRI findings could aid in determining the indication for radiotherapy.

Implementation rate and effects of multidisciplinary team meetings on decision making about radiotherapy: an observational study at a single Japanese institution.

BACKGROUND: Cancer treatment requires a multidisciplinary approach. Therefore, multidisciplinary team meetings (MDTMs) have been widely used to determine the direction of treatment. However, no standard provisions exist for conducting MDTMs, and recommendations discussed in MDTMs are sometimes not implemented. ​This study analyzed the indications for radiotherapy discussed and recommended at MDTMs, identified the rate of radiotherapy recommendations for patients that were not implemented, and clarified the reasons at a single academic center in Japan. METHODS: This was a cross-sectional study that analyzed the minutes and electronic medical records of cases discussed at MDTMs held between April 2012-March 2017 at Yamagata University Hospital. We categorized how radiotherapy was initially presented at MDTMs, determined the rate of radiotherapy recommendations made through MDTMs, analyzed whether treatment recommendations were subsequently implemented, and examined the causes of non-implementation. We performed a statistical analysis to assess some clinical factors (sex, age, number of multidisciplinary team meetings, and classification of planned treatment) associated with the non-implementation of radiotherapy recommendations from MDTMs. RESULTS: A total of 1813 cases were discussed at MDTMs, of which 71% (1293 cases) were presented with treatment plans, including radiotherapy. Further, 66% (1205 cases) were recommended for radiotherapy through the MDTMs. Recommendations from MDTMs were not implemented in 7% (142 cases). The most typical reason for non-implementation was the clinician's opinion (30%), followed by patient preferences (27%) and disease progression (20%). Change in cancer stage and improvement in symptoms were 12% and 4%, respectively. These ratios were similar each year. We could not find the factors associated with the non-implementation of radiotherapy recommendations from MDTMs. CONCLUSIONS: MDTMs had a significant effect on the recommendation of radiotherapy for each patient with a tumor. The primary reason for the non-implementation of decisions made at MDTMs was the opinion of clinicians and the patient's preference. These results were similar to previous studies. We need to establish a monitoring system where patients themselves can decide the treatments based on their choices while using the recommendations from MDTMs.

Prediction of the minimum spacer thickness required for definitive radiotherapy with carbon ions and photons for pelvic tumors: an in silico planning study using virtual spacers.

We aimed to predict the minimum distance between a tumor and the gastrointestinal (GI) tract that can satisfy the dose constraint by creating simulation plans with carbon-ion (C-ion) radiotherapy (RT) and photon RT for each case assuming insertion of virtual spacers of various thicknesses. We enrolled 55 patients with a pelvic tumor adjacent to the GI tract. Virtual spacers were defined as the overlap volume between the GI tract and the volume expanded 7-17 mm from the gross tumor volume (GTV). Simulation plans (70 Gy in 35 fractions for at least 95% of the planning target volume [PTV]) were created with the lowest possible dose to the GI tract under conditions that meet the dose constraints of the PTV. We defined the minimum thickness of virtual spacers meeting D2 cc of the GI tract <50 Gy as 'MTS'. Multiple regression was used with explanatory variables to develop a model to predict MTS. We discovered that MTSs were at most 9 mm and 13 mm for C-ion RT and photon RT plans, respectively. The volume of overlap between the GI tract and a virtual spacer of 14 mm in thickness (OV14)-PTV was found to be the most important explanatory variable in the MTS prediction equation for both C-ion and photon RT plans. Multiple R2 values for the regression model were 0.571 and 0.347 for C-ion RT and photon RT plans, respectively. In conclusion, regression equations were developed to predict MTS in C-ion RT and photon RT.

In silico comparison of the dosimetric impacts of a greater omentum spacer for abdominal and pelvic tumors in carbon-ion, proton and photon radiotherapy.

PURPOSE: The purpose of this study was to compare carbon-ion (C-ion), proton and photon radiotherapy (RT) plans with regard to dose reduction of the gastrointestinal (GI) tract by using a greater omentum spacer (GO spacer). METHODS: We retrospectively retrieved data for ten patients who received the GO spacer as surgical spacer placement for abdominal and pelvic tumors. Simulation plans were created on pre-spacer Computed Tomography (CT) and post-spacer CT for C-ion RT, proton RT and photon RT to compare the dose of the GI tract. The plans were normalized so that at least 95% of the planning target volume (PTV) received 70 Gy (relative biological effectiveness equivalent) delivered in 35 fractions. All plans were created with the lowest possible dose to the GI tract under conditions that meet the dose constraints for the PTV and spinal cord (maximum dose < 45 Gy). The part of the GI tract to be evaluated was defined as that most adjacent to the PTV. C-ion RT plans and proton RT plans were calculated by a spot scanning technique, and photon RT plans were calculated employing by fixed-field intensity-modulated radiation therapy. RESULTS: D2 cc and V10-70 of the GI tract were significantly lower on post-spacer plans than on pre-spacer plans for all three RT modalities. Regarding post-spacer plans, D2 cc of the GI tract was significantly lower on C-ion RT plans and proton RT plans than on photon RT plans (C-ion vs photon p = 0.001, proton vs photon p = 0.002). However, there was no significant difference between C-ion RT plans and proton RT plans for D2 cc of the GI tract (C-ion vs proton p = 0.992). In the photon RT plan for one patient, D2 cc of the GI tract did not meet < 50 Gy. CONCLUSIONS: The GO spacer shows a significant dose reduction effect on the GI tract.