Vora, Sujay A.

Objective:Radiation therapy (RT) is the primary treatment of intracranial metastasis (ICM) from lung cancer (LC). Radiation necrosis (RN) has been reported post-RT with an incidence of 5% to 24%. We reviewed the spectrum of imaging changes in patients treated with RT for ICM from LC in an effort to identify potential risk factors for RN.Methods:We reviewed 63 patients with LC and ICM who received RT (radiosurgery [stereotactic radiosurgery] with/without whole brain radiation therapy) at our institution between 2013 and 2018. Data evaluated included demographics, tumor type, ICM burden and location, chemotherapy, surgery, and RT details as well as treatment choices and outcomes.Results:Of the 63 patients, clinical and radiographic criteria for RN were noted in 24 (38%) as early as 2 months and as late as 5 years posttreatment. Six patients required surgical resection due to refractory symptoms revealing pathology-proven RN and occasionally tumor. Patients were significantly more likely to develop RN if they had surgical resection of an ICM (45.8% vs. 20.5%,P=0.05). No differences were found in location, size, or genetic profile of lesions. In total, 80% of patients received treatment for symptoms and/or radiographic change. This was generally a combination of steroids, bevacizumab, laser interstitial thermal treatment, or surgical resection. Most patients required >1 treatment modality.Conclusions:This review of outcomes of RT for ICM in LC demonstrates a higher rate of RN than previously reported in the literature in those having had a surgical resection plus stereotactic radiosurgery. Our observation of RN as late as 5 years post-RT for ICM necessitates clinician awareness.

Abstract BACKGROUND Radiation is an integral component of the multidisciplinary treatment of patients with intracranial metastasis (ICM) from melanoma. The risk of radiation necrosis (RN) post-treatment can range from 5–25%. We retrospectively evaluated pre- and post-radiation clinical and radiographical characteristics in patients with ICM from melanoma to identify potential risk factors for RN. METHODS After IRB approval, patients with ICM from melanoma who received radiation at our institution between 2013 and 2018 were retrospectively reviewed. We recorded demographics, intracranial metastasis (burden and location), systemic therapy, resection, stereotactic radiosurgery versus whole brain radiation, and outcomes. Brain MRI was evaluated using the Response Assessment in Neuro-Oncology criteria (RANO). RESULTS A total of 27 patients were included in the study. RN was diagnosed in 14 patients (52%) at one month to three years following radiation. Cerebellar location (n=7) was significantly associated with RN (p=0.0058). Metastasis-associated hemorrhage was present in 7 patients, 6 of which developed RN (43% vs 8%, p=0.08). Surgical resection prior to radiation was performed in 9 patients, 7 of which developed RN (50% vs 15%, p=0.1). RN appeared to be less often diagnosed when ICM were treated with higher doses of radiation (24 Gy vs 20 Gy, p=0.07). Systemic treatment was administered prior to radiation in 25 patients and we found no relationship with systemic therapy type and RN. Presumed RN was treated in 12 of 14 patients (86%). Steroids or surgical resection were the primary treatment modalities, with laser ablation used in 1 case. Following treatment, improvement was noted in 3 patients radiographically and in 1 of these clinically. CONCLUSIONS This series of patients with radiotherapy-treated brain metastases from melanoma reveals cerebellar involvement, hemorrhage, and prior surgical resection as potential risk factors for radiation necrosis. Neoadjuvant systemic treatment did not appear to be a risk factor in our review.

Abstract Background : Sex is recognized as a significant determinant of outcome among glioblastoma patients, but the relative prognostic importance of glioblastoma features has not been thoroughly explored for sex differences. Methods : Combining multi-modal MR images, biomathematical models, and patient clinical information, this investigation assesses which pretreatment variables have a sex-specific impact on the survival of glioblastoma patients (299 males and 195 females). Results : Among males, tumor (T1Gd) radius was a predictor of overall survival (HR=1.027, p=0.044). Among females, higher tumor cell net invasion rate was a significant detriment to overall survival (HR=1.011, p<0.001). Female extreme survivors had significantly smaller tumors (T1Gd) (p=0.010 t-test), but tumor size was not correlated with female overall survival (p=0.955 CPH). Both male and female extreme survivors had significantly lower tumor cell net proliferation rates than other patients (M p=0.004, F p=0.001, t-test). Additionally, extent of resection, tumor laterality, and IDH1 mutation status were also found to have sex-specific effects on overall survival. Conclusion : Despite similar distributions of the MR imaging parameters between males and females, there was a sex-specific difference in how these parameters related to outcomes.

Retroperitoneal chordomas are exceedingly rare and account for less than 5% of all primary bone malignancies. Their etiology remains unknown. We report a rare case of an extravertebral chordoma of the retroperitoneum in a 71-year-old man treated with surgical resection and post-operative spot-scanning proton beam therapy. We describe how to safely treat a retroperitoneal target to a prescription dose over 70 Gy (relative biological effectiveness) with spot-scanning proton beam therapy and also report a dosimetric comparison of spot-scanning proton beam therapy versus intensity-modulated radiation therapy. This case not only highlights a rare diagnosis of an extravertebral retroperitoneal chordoma but it also draws attention to the dosimetric advantages of proton beam therapy and illustrates a promising radiotherapeutic option for retroperitoneal targets.

Abstract Background Guidelines to provide recommendations about driving restrictions for patients with brain metastases are lacking. We aim to determine whether clinical neurologic examination is sufficient to predict suitability to drive in these patients by comparison with an occupational therapy driving assessment (OTDA). Methods We prospectively evaluated the concordance between neurology assessment of suitability to drive (pass/fail) and OTDA in 41 individuals with brain metastases. Neuro-oncology evaluation included an interview and neurological examination. Participants subsequently underwent OTDA during which a battery of objective measures of visual, cognitive, and motor skills related to driving was administered. Results The mean age of patients who failed OTDA was age 68.9 years vs 59.3 years in the group members who passed (P = .0046). The sensitivity of the neurology assessment to predict driving fitness compared with OTDA was 16.1% and the specificity 90%. The 31 patients who failed OTDA were more likely to fail Vision Coach, Montreal Cognitive Assessment, and Trail Making B tests. Conclusions There was poor association between the assessment of suitability to drive by neurologists and the outcome of the OTDA in patients with brain metastases. Subtle deficits that may impair the ability to drive safely may not be evident on neurologic examination. The positive predictive value was high to predict OTDA failure. Age could be a factor affecting OTDA performance. The results raise questions about the choice of assessments in making recommendations about driving fitness in people with brain metastases. OTDA should be strongly considered in patients with brain metastases who wish to continue driving.

Abstract Background: Sex is recognized as a significant determinant of outcome among glioblastoma patients, but the relative prognostic importance of glioblastoma features has not been thoroughly explored for sex differences. Methods: Combining multi-modal MR images, biomathematical models, and patient clinical information, this investigation assesses which pretreatment variables have a sex-specific impact on the survival of glioblastoma patients (299 males and 195 females). Results: Among males, tumor (T1Gd) radius was a predictor of overall survival (HR=1.027, p=0.044). Among females, higher tumor cell net invasion rate was a significant detriment to overall survival (HR=1.011, p<0.001). Female extreme survivors had significantly smaller tumors (T1Gd) (p=0.010 t-test), but tumor size was not correlated with female overall survival (p=0.955 CPH). Both male and female extreme survivors had significantly lower tumor cell net proliferation rates than other patients (M p=0.004, F p=0.001, t-test). Additionally, extent of resection, tumor laterality, and IDH1 mutation status were also found to have sex-specific effects on overall survival. Conclusion: Despite similar distributions of the MR imaging parameters between males and females, there was a sex-specific difference in how these parameters related to outcomes.

e16555 Background: The ProtecT trial underscores the importance of treatment in men with prostate cancer and life expectancies > 10 years and the validity of radiation therapy (RT). RT can be given with photons or protons (PT). To address the controversy of which is better, clinical outcomes of photon-based intensity modulated RT (IMRT) and PT cohorts from 2 institutions were directly compared. Methods: Under respective IRB approvals, data from 2 cohorts were analyzed. The first was 301 men treated with ultrasound image guided IMRT from 2000-05 to 75.6 Gy in 42 fractions. The second was 1214 men treated with fiducial image guided PT from 2006-10 to 78 CGE in 39 fractions. Median age and followup were 74 y and 7.2 y for IMRT and 66 y and 5.6 y for PT. Hormone therapy (ADT) was used with IMRT and PT, respectively, in 3% and 7% of low-risk patients, 25% and 9.9% of intermediate-risk, and 91% and 57.8% of high-risk. Comparative endpoints were age-stratified 5-year (5Y) survival (OS), ≥ grade 3 gastrointestinal (GI) and urologic (GU) toxicity, and 5Y freedom from biochemical progression (FFBP). Results: There was a lower prevalence of GI (1.3% vs 0.1%, p = 0.0065) and GU (4.3% vs 0.1%, p < 0.0001) toxicity at last follow-up in the PT group. In the IMRT and PT cohorts, OS rates were 90.8% and 88.7% in men ≥75 (p = 0.4083). In men < 75, OS rates were 91.6% and 97.5% in the IMRT and PT low-risk patients (p = 0.003), 92.1% and 95.5% in the IMRT and PT intermediate-risk (p = 0.0535), and 92.0% and 90.0% (p = 0.4975) in the IMRT and PT high-risk. In the IMRT and PT cohorts, respectively, FFBP rates were 92.2% and 98.9% for low-risk patients (p < 0.0001), 87.3% and 94.5% for intermediate-risk patients(p = 0.0226), and 80.3% and 74.4% for high-risk patients (p = 0.5154). Conclusions: In this retrospective comparison of outcomes in cohorts of men treated with IMRT and PT for prostate cancer, FFBP rates were better with PT for men with low- and intermediate-risk disease and similar in men with high-risk disease despite longer and more frequent use of ADT in the IMRT cohort. This study underscores the difficulty of comparing retrospective series, with differences noted in age, RT dose, and ADT use between cohorts. However, the magnitude of improvement with PT is intriguing and warrants prospective testing.