Dosimetric validation for prospective clinical trial on GRID collimator-based spatially fractionated radiation therapy: Dose metrics consistency and heterogeneous pattern reproducibility.

PURPOSE: The purpose of this study is to characterize the dosimetric properties of a commercial brass GRID collimator for high energy photon beams including 15 and 10 MV. Then, the difference in dosimetric parameters of GRID beams among different energies and linacs was evaluated. METHOD: A water tank scanning system was used to acquire the dosimetric parameters, including the percentage depth dose (PDD), beam profiles, peak to valley dose ratios (PVDRs), and output factors (OFs). The profiles at various depths were measured at 100 cm source to surface distance (SSD), and field sizes of 10 × 10 cm2 and 20 × 20 cm2 on three linacs. The PVDRs and OFs were measured and compared with the treatment planning system (TPS) calculations. RESULTS: Compared with the open beam data, there were noticeable changes in PDDs of GRID fields across all the energies. The GRID fields demonstrated a maximal of 3 mm shift in dmax (Truebeam STX, 15MV, 10 × 10 cm2). The PVDR decreased as beam energy increases. The difference in PVDRs between Trilogy and Truebeam STx using 6MV and 15MV was 1.5% ± 4.0% and 2.1% ± 4.3%, respectively. However, two Truebeam linacs demonstrated less than 2% difference in PVDRs. The OF of the GRID field was dependent on the energy and field size. The measured PDDs, PVDRs, and OFs agreed with the TPS calculations within 3% difference. The TPS calculations agreed with the measurements when using 1 mm calculation resolution. CONCLUSION: The dosimetric characteristics of high-energy GRID fields, especially PVDR, significantly differ from those of low-energy GRID fields. Two Truebeam machines are interchangeable for GRID therapy, while a pronounced difference was observed between Truebeam and Trilogy. A series of empirical equations and reference look-up tables for GRID therapy can be generated to facilitate clinical applications.

Advancements and future directions in positron emission tomography-guided radiotherapy: a narrative review.

BACKGROUND AND OBJECTIVE: Positron emission tomography (PET) imaging has been useful in delineating tumor volumes and allowing for improved radiation treatment. The field of PET-guided radiotherapy is rapidly growing and will have significant impact on radiotherapy delivery in the future. This narrative review provides an overview of the current state of PET-guided radiotherapy as well as the future directions of the field. METHODS: For this narrative review, PubMed was searched for articles from 2010-2023. A total of 18 keywords or phrases were searched to provide an overview of PET-guided radiotherapy, radiotracers, the role of PET-guided radiotherapy in oligometastatic disease, and biology-guided radiotherapy (BgRT). The first 300 results for each keyword were searched and relevant articles were extracted. The references of these articles were also reviewed for relevant articles. KEY CONTENT AND FINDINGS: In radiotherapy, 18F-2-fluoro-2-deoxy-D-glucose (F-FDG or FDG) is the major radiotracer for PET and when combined with computed tomography (CT) scan allows for anatomic visualization of metabolically active malignancy. Novel radiotracers are being explored to delineate certain cell types and numerous tumor metrics including metabolism, hypoxia, vascularity, and cellular proliferation. This molecular and functional imaging will provide improved tumor characterization. Through these radiotracers, radiation plans can employ dose painting by creating different dose levels based upon specific risk factors of the target volume. Additionally, biologic imaging during radiotherapy can allow for adaptation of the radiation plan based on response to treatment. Dose painting and adaptive radiotherapy should improve the therapeutic ratio through more selective dose delivery. The novel PET-linear accelerator hopes to combine these techniques and more by using radiotracers to deliver BgRT. The areas of radiotracer uptake will serve as fiducials to guide radiotherapy to themselves. This technique may prove promising in the growing area of oligometastatic radiation treatment. CONCLUSIONS: Significant challenges exist for the future of PET-guided radiotherapy. However, with the advancements being made, PET imaging is set to change the delivery of radiotherapy.

A repository of grade 1 and 2 meningioma MRIs in a public dataset for radiomics reproducibility tests.

PURPOSE: Meningiomas are the most common primary brain tumors in adults with management varying widely based on World Health Organization (WHO) grade. However, there are limited datasets available for researchers to develop and validate radiomic models. The purpose of our manuscript is to report on the first dataset of meningiomas in The Cancer Imaging Archive (TCIA). ACQUISITION AND VALIDATION METHODS: The dataset consists of pre-operative MRIs from 96 patients with meningiomas who underwent resection from 2010-2019 and include axial T1post and T2-FLAIR sequences-55 grade 1 and 41 grade 2. Meningioma grade was confirmed based on the 2016 WHO Bluebook classification guideline by two neuropathologists and one neuropathology fellow. The hyperintense T1post tumor and hyperintense T2-FLAIR regions were manually contoured on both sequences and resampled to an isotropic resolution of 1 × 1 × 1 mm3 . The entire dataset was reviewed by a certified medical physicist. DATA FORMAT AND USAGE NOTES: The data was imported into TCIA for storage and can be accessed at https://doi.org/10.7937/0TKV-1A36. The total size of the dataset is 8.8GB, with 47 519 individual Digital Imaging and Communications in Medicine (DICOM) files consisting of 384 image series, and 192 structures. POTENTIAL APPLICATIONS: Grade 1 and 2 meningiomas have different treatment paradigms and are often treated based on radiologic diagnosis alone. Therefore, predicting grade prior to treatment is essential in clinical decision-making. This dataset will allow researchers to create models to auto-differentiate grade 1 and 2 meningiomas as well as evaluate for other pathologic features including mitotic index, brain invasion, and atypical features. Limitations of this study are the small sample size and inclusion of only two MRI sequences. However, there are no meningioma datasets on TCIA and limited datasets elsewhere although meningiomas are the most common intracranial tumor in adults.

Dosimetric Validation for Prospective Clinical Trial of GRID Collimator-Based Spatially Fractionated Radiation Therapy: Dose Metrics Consistency and Heterogeneous Pattern Reproducibility.

PURPOSE: Dose heterogeneity within a tumor target is likely responsible for the biologic effects and local tumor control from spatially fractionated radiation therapy (SFRT). This study used a commercially available GRID-pattern dose mudulated nonuniform radiation therapy (GRID) collimator to assess the interplan variability of heterogeneity dose metrics in patients with various bulky tumor sizes and depths. METHODS AND MATERIALS: The 3-dimensional heterogeneity metrics of 14 bulky tumors, ranging from 155 to 2161 cm3 in volume, 6 to 23 cm in equivalent diameter, and 3 to 13 cm in depth, and treated with GRID collimator-based SFRT were studied. A prescription dose of 15 Gy was given at the tumor center with 6 MV photons. The dose-volume histogram indices, dose heterogeneity parameters, and peak/valley dose ratios were derived; the equivalent uniform doses of cancer cells with various radiosensitivities in each plan were estimated. To account for the spatial fractionation, high dose core number density of the tumor target was defined and calculated. RESULTS: Among 14 plans, the dose-volume histogram indices D5, D10, D50, D90, and D95 (doses covering 5%, 10%, 50%, 90%, and 95% of the target volume) were found within 10% variation. The dose ratio of D10/D90 also showed a moderate consistency (range, 3.9-5.0; mean, 4.4). The equivalent uniform doses were consistent, ranging from 4.3 to 5.5 Gy, mean 4.6 Gy, for radiosensitive cancer cells and from 5.8 to 6.9 Gy, mean 6.2 Gy, for radioresistant cancer cells. The high dose core number density was within 20% among all plans. CONCLUSIONS: GRID collimator-based SFRT delivers a consistent heterogeneity dose distribution and high dose core density across bulky tumor plans. The interplan reproducibility and simplicity of GRID therapy may be useful for certain clinical indications and interinstitutional clinical trial design, and its heterogeneity metrics may help guide multileaf-collimator-based SFRT planning to achieve similar or further optimized dose distributions.

ACR-ARS Practice Parameter for Radiation Oncology.

BACKGROUND: This practice parameter was revised collaboratively by the American College of Radiology (ACR), and the American Radium Society. This practice parameter provides updated reference literature regarding radiation oncology practice and its key personnel. METHODS: This practice parameter was developed according to the process described under the heading The Process for Developing ACR Practice Parameters and Technical Standards on the ACR website ( https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards ) by the Committee on Practice Parameters-Radiation Oncology of the ACR Commission on Radiation Oncology in collaboration with the American Radium Society. RESULTS: This practice parameter provides a comprehensive update to the reference literature regarding radiation oncology practice in general. The overall roles of the radiation oncologist, the Qualified Medical Physicist, and other specialized personnel involved in the delivery of external-beam radiation therapy are discussed. The use of radiation therapy requires detailed attention to equipment, patient and personnel safety, equipment maintenance and quality assurance, and continuing staff education. Because the practice of radiation oncology occurs in a variety of clinical environments, the judgment of a qualified radiation oncologist should be used to apply these practice parameters to individual practices. Radiation oncologists should follow the guiding principle of limiting radiation exposure to patients and personnel while accomplishing therapeutic goals. CONCLUSION: This practice parameter can be used as an effective tool to guide radiation oncology practice by successfully incorporating the close interaction and coordination among radiation oncologists, medical physicists, dosimetrists, nurses, and radiation therapists.

StrataXRT for the prevention and treatment of radiation dermatitis: a critical review.

PURPOSE: The primary objective is to systematically review primary studies, such as randomized control trials (RCTs), feasibility, exploratory, and case studies; and the secondary objective is to evaluate all secondary articles, such as reviews, guidelines, and editorials, relevant to the use of StrataXRT for the prevention and/or management of radiation dermatitis (RD) in cancer patients. METHODS: A literature search was conducted up to February 26, 2023, for articles investigating the use of StrataXRT for the prevention and treatment of RD, in the following databases: Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar. The keywords "StrataXRT", "dermatitis", "radiotherapy", and "radiation" were used to identify relevant articles. RESULTS: Twenty-seven articles from 2018 to 2022 were identified to fulfill the inclusion criteria of this review, of which nine are primary studies and 18 are secondary papers. Significant heterogeneity was observed in the current literature studying the effects of StrataXRT, making it difficult to make cross-trial comparisons. There is a suggestion of the efficacy of StrataXRT in the prevention and treatment of RD. CONCLUSION: The findings of this review recommend further adequately powered RCTs with robust methodology including patient and clinician assessments to determine the efficacy of StrataXRT in preventing and treating RD. This is essential to improve the quality of life of patients and identify which groups of patients would benefit most from StrataXRT.

A cross-sectional study to test equivalence of low- versus intermediate-flip angle dynamic susceptibility contrast MRI measures of relative cerebral blood volume in patients with high-grade gliomas at 1.5 Tesla field strength.

Introduction: 1.5 Tesla (1.5T) remain a significant field strength for brain imaging worldwide. Recent computer simulations and clinical studies at 3T MRI have suggested that dynamic susceptibility contrast (DSC) MRI using a 30° flip angle ("low-FA") with model-based leakage correction and no gadolinium-based contrast agent (GBCA) preload provides equivalent relative cerebral blood volume (rCBV) measurements to the reference-standard acquisition using a single-dose GBCA preload with a 60° flip angle ("intermediate-FA") and model-based leakage correction. However, it remains unclear whether this holds true at 1.5T. The purpose of this study was to test this at 1.5T in human high-grade glioma (HGG) patients. Methods: This was a single-institution cross-sectional study of patients who had undergone 1.5T MRI for HGG. DSC-MRI consisted of gradient-echo echo-planar imaging (GRE-EPI) with a low-FA without preload (30°/P-); this then subsequently served as a preload for the standard intermediate-FA acquisition (60°/P+). Both normalized (nrCBV) and standardized relative cerebral blood volumes (srCBV) were calculated using model-based leakage correction (C+) with IBNeuro™ software. Whole-enhancing lesion mean and median nrCBV and srCBV from the low- and intermediate-FA methods were compared using the Pearson's, Spearman's and intraclass correlation coefficients (ICC). Results: Twenty-three HGG patients composing a total of 31 scans were analyzed. The Pearson and Spearman correlations and ICCs between the 30°/P-/C+ and 60°/P+/C+ acquisitions demonstrated high correlations for both mean and median nrCBV and srCBV. Conclusion: Our study provides preliminary evidence that for HGG patients at 1.5T MRI, a low FA, no preload DSC-MRI acquisition can be an appealing alternative to the reference standard higher FA acquisition that utilizes a preload.

Technique Pearls for Successful Cervical Disc Arthroplasty From More Than 20 Years of Surgical Experience.

STUDY DESIGN: Surgical technique paper. OBJECTIVE: To describe tips and pearls for cervical disc arthroplasty (CDA). BACKGROUND: CDA has proven to be an effective means of treatment for degenerative cervical disc disease and cervical radiculopathy in properly selected patients who have previously failed non-operative treatment. METHODS: Surgical tips and pearls garnered from more than 20 years of experience with CDA surgery are described. RESULTS: This discussion focuses on pearls for successful procedures, including patient selection, patient positioning, surgical technique, and postoperative protocols. CONCLUSIONS: In correctly selected patients, CDA can be effective in treating cervical degenerative disc disease and radiculopathy. The techniques described here can increase the chance of success and decrease complications.

Comparison of preoperative versus postoperative treatment dosimetry plans of single-fraction stereotactic radiosurgery for surgically resected brain metastases.

OBJECTIVE: Stereotactic radiosurgery (SRS) for operative brain metastasis (BrM) is usually administered 1 to 6 weeks after resection. Preoperative versus postoperative timing of SRS delivery related to surgery remains a critical question, as a pattern of failure is the development of leptomeningeal disease (LMD) in as many as 35% of patients who undergo postoperative SRS or the occurrence of radiation necrosis. As they await level I clinical data from ongoing trials, the authors aimed to bridge the gap by comparing postoperative with simulated preoperative single-fraction SRS dosimetry plans for patients with surgically resected BrM. METHODS: The authors queried their institutional database to retrospectively identify patients who underwent postoperative Gamma Knife SRS (GKSRS) after resection of BrM between January 2014 and January 2021. Exclusion criteria were prior radiation delivered to the lesion, age < 18 years, and prior diagnosis of LMD. Once identified, a simulated preoperative SRS plan was designed to treat the unresected BrM and compared with the standard postoperative treatment delivered to the resection cavity per Radiation Therapy Oncology Group (RTOG) 90-05 guidelines. Numerous comparisons between preoperative and postoperative GKSRS treatment parameters were then made using paired statistical analyses. RESULTS: The authors' cohort included 45 patients with a median age of 59 years who were treated with GKSRS after resection of a BrM. Primary cancer origins included colorectal cancer (27%), non-small cell lung cancer (22%), breast cancer (11%), melanoma (11%), and others (29%). The mean tumor and cavity volumes were 15.06 cm3 and 12.61 cm3, respectively. In a paired comparison, there was no significant difference in the planned treatment volumes between the two groups. When the authors compared the volume of surrounding brain that received 12 Gy or more (V12Gy), an important predictor of radiation necrosis, 64% of patient plans in the postoperative SRS group (29/45, p = 0.008) recorded greater V12 volumes. Preoperative plans were more conformal (p < 0.001) and exhibited sharper dose drop-off at the lesion margins (p = 0.0018) when compared with postoperative plans. CONCLUSIONS: Comparison of simulated preoperative and delivered postoperative SRS plans administered to the BrM or resection cavity suggested that preoperative SRS allows for more highly conformal lesional coverage and sharper dose drop-off compared with postoperative plans. Furthermore, V12Gy was lower in the presurgical GKSRS plans, which may account for the decreased incidence of radiation necrosis seen in prior retrospective studies.

StrataXRT for the prevention of acute radiation dermatitis in breast cancer: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: To evaluate the overall efficacy of StrataXRT, a topical gel dressing, in preventing acute radiation dermatitis (RD) in breast cancer patients undergoing radiotherapy (RT). METHODS: A systematic search was conducted on April 25, 2023 in Ovid MEDLINE, Embase, and Cochrane Central Register of Controlled Trials. Randomized controlled trials (RCTs) assessing the effectiveness of StrataXRT in preventing acute RD in breast cancer patients undergoing adjuvant RT to the breast or chest wall with or without regional nodes were included. Pooled incidence odds ratio (OR) and 95% confidence interval (CI) were calculated using a random-effects model, with analysis and forest plots generated in RevMan v5.4. RESULTS: The analysis included three RCTs with a total of 189 patients assessed using per-protocol analysis. Two RCTs compared StrataXRT to standard of care, while the third compared it with Mepitel film and was reported separately. In the former RCTs, the odds ratio (OR) for developing acute grade 3 RD favored StrataXRT at 0.05 (95% CI, 0.01-0.22; P < 0.0001). The OR for developing acute grades 2-3 RD was 0.32 (95% CI, 0.03-3.18; P = 0.33). The RCT comparing StrataXRT with Mepitel film showed insignificant ORs for grade 3 and grades 2-3 RD. One RCT reported significantly lower erythema index (P = 0.008) and melanin index (P = 0.015) in StrataXRT patients. The use of StrataXRT did not raise additional safety concerns. CONCLUSION: StrataXRT may help prevent severe acute RD in breast cancer RT patients. Further high quality, large-scale studies are needed to confirm these findings.

Mepitel film for the prevention and treatment of acute radiation dermatitis in breast cancer: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: This systematic review and meta-analysis aimed to evaluate the efficacy of Mepitel film in preventing or treating acute radiation dermatitis (RD) in patients with breast cancer in randomized controlled trials (RCTs). METHODS: Embase, APA PsychInfo, Journals@Ovid Full Text, Ovid MEDLINE, PubMed, and Cochrane Trials were searched until December 12, 2022, to identify RCTs on the use of Mepitel film for preventing or treating acute RD from breast cancer radiotherapy. Per-protocol analysis was used to compare outcomes, calculate pooled effect sizes, odds ratio (OR), and 95% confidence intervals (CI), and to create forest plots using random effects analysis in RevMan 5.4. RESULTS: Three RCTs were included in this review. Mepitel film significantly reduced the incidence of grade 3 RD (OR 0.15 95% CI 0.06, 0.37, p<0.0001) and grade 2 or 3 RD (OR 0.16 95% CI 0.04, 0.65, p=0.01) as scored on either the CTCAE or the RTOG scale. Additionally, Mepitel film significantly reduced RISRAS mean scores assessed by patients and combined researcher and patient (standardized mean difference (SMD) -7.59, 95% CI -14.42, -0.76, p=0.03; SMD -15.36, 95% CI -30.01, -0.71 p=0.04) but not the researcher component of the assessment tool (SMD -17.55, 95% CI -36.94, 1.84, p=0.08). CONCLUSION: Mepitel film reduced the incidence of acute RD and improved patient-reported outcomes with minimal side effects, the main one being itchiness. Future research should assess the feasibility of Mepitel film with respect to specific patient-reported outcomes such as health-related quality of life issues associated with its use.

Adjuvant chemotherapy, not radiotherapy, prolongs survival for node-negative non-small cell lung cancer with positive surgical margins.

Objective: The study objective was to determine differences in survival depending on adjuvant therapy type, timing, and sequence in node-negative disease with positive margins after non-small cell lung cancer resection. Methods: The National Cancer Database was queried for patients with positive margins after surgical resection of treatment-naïve cT1-4N0M0 pN0 non-small cell lung cancer who underwent adjuvant radiotherapy or chemotherapy from 2010 to 2016. Adjuvant treatment groups were defined as surgery alone, chemotherapy alone, radiotherapy alone, concurrent chemoradiotherapy, sequential chemotherapy then radiotherapy, and sequential radiotherapy then chemotherapy. The impact of adjuvant radiotherapy initiation timing on survival was evaluated using multivariable Cox regression. Kaplan-Meier curves were generated to compare 5-year survival. Results: A total of 1713 patients met inclusion criteria. Five-year survival estimates differed significantly between cohorts: surgery alone, 40.7%; chemotherapy alone, 47.0%; radiotherapy alone, 35.1%; concurrent chemoradiotherapy, 45.7%; sequential chemotherapy then radiotherapy, 36.6%; and sequential radiotherapy then chemotherapy, 32.2% (P = .033). Compared with surgery alone, adjuvant radiotherapy alone had a lower estimated survival at 5 years, although overall survival did not differ significantly (P = .8). Chemotherapy alone improved 5-year survival compared with surgery alone (P = .0016) and provided a statistically significant survival advantage over adjuvant radiotherapy (P = .002). Compared with radiotherapy-inclusive multimodal therapies, chemotherapy alone yielded similar 5-year survival (P = .066). Multivariable Cox regression showed an inverse linear association between time to adjuvant radiotherapy initiation and survival, but with an insignificant trend (10-day hazard ratio, 1.004; P = .90). Conclusions: In treatment-naïve cT1-4N0M0 pN0 non-small cell lung cancer with positive surgical margins, only adjuvant chemotherapy was associated with a survival improvement compared with surgery alone, with no radiotherapy-inclusive treatment providing additional survival benefit. Delayed timing of radiotherapy initiation was not associated with a survival reduction.

Fecal and Tissue Microbiota Are Associated with Tumor T-Cell Infiltration and Mesenteric Lymph Node Involvement in Colorectal Cancer.

Colorectal cancer (CRC) is associated with alterations of the fecal and tissue-associated microbiome. Preclinical models support a pathogenic role of the microbiome in CRC, including in promoting metastasis and modulating antitumor immune responses. To investigate whether the microbiome is associated with lymph node metastasis and T cell infiltration in human CRC, we performed 16S rRNA gene sequencing of feces, tumor core, tumor surface, and healthy adjacent tissue collected from 34 CRC patients undergoing surgery (28 fecal samples and 39 tissue samples). Tissue microbiome profiles-including increased Fusobacterium-were significantly associated with mesenteric lymph node (MLN) involvement. Fecal microbes were also associated with MLN involvement and accurately classified CRC patients into those with or without MLN involvement. Tumor T cell infiltration was assessed by immunohistochemical staining of CD3 and CD8 in tumor tissue sections. Tumor core microbiota, including members of the Blautia and Faecalibacterium genera, were significantly associated with tumor T cell infiltration. Abundance of specific fecal microbes including a member of the Roseburia genus predicted high vs. low total and cytotoxic T cell infiltration in random forests classifiers. These findings support a link between the microbiome and antitumor immune responses that may influence prognosis of locally advanced CRC.

Pilot Study Demonstrating the Value of Interdisciplinary Education on the Integration of Radiation Therapy in Lung Cancer Management.

This study aimed to understand baseline knowledge of basic principles of radiation therapy for lung cancer among medical oncology, thoracic surgery, and pulmonology trainees and practicing physicians and also assess whether a didactic lecture will improve objective knowledge and perceived comfort level in making appropriate referrals to radiation oncology (RO). Radiation oncologists at 8 academic institutions offered a presentation covering indications, logistics, efficacy, and toxicity of thoracic radiation. Participants completed a survey to assess their prior exposures to RO and perceived value of the lecture, and objective knowledge gained based on pre/post-lecture questions. Among 121 attendees, 76 completed the pre-test, and 25 the post-test (response rates 62.8% and 20.7%, respectively). Fifty-seven (75.0%) had never previously experienced a RO didactic about lung cancer, 62 (81.6%) had never seen a linear accelerator, and 65 (85.5%) had never rotated in a RO department. The mean pre-test score was 53.5% (SD 17.6%), with a trend (p = 0.066) towards thoracic surgeons (61.5%) performing better than medical oncologists (55.5%) or pulmonologists (48.3%). Level of training (p = 0.130), and prior RO exposures (p = 0.240), did not significantly impact pre-test scores. The mean post-test score of 75.1% (SD 3.6%) was significantly higher than mean pre-test score (p < 0.001). After the lecture, 25 participants (100%) felt more knowledgeable about RO, and 24 (96%) felt more comfortable making appropriate referrals to RO. A didactic lecture about RO for trainees and physicians who treat lung cancer at 8 academic institutions was feasible, filled a gap in exposure, and improved knowledge.

Integration of Universal Germline Genetic Testing for All New Breast Cancer Patients.

BACKGROUND: The American Society of Breast Surgeons recommends genetic testing (GT) for all women with breast cancer (BC), but implementation and uptake of GT has not been well-described. METHODS: A retrospective chart review was performed for newly diagnosed BC patients or patients with a newly identified recurrence of BC seen in a multidisciplinary clinic (MDBC) who were offered genetic counseling (GC) and GT. RESULTS: The 138 women attending the MDBC had a median age of 54 years and comprised non-Hispanic whites (46%), Asians (28%), Hispanics (17%), blacks (4%), and other (5%). Of the 105 (76%) patients without prior GT, 100 (95%) accepted GC, with 93 (93%) of these 100 patients undergoing GT. The patients meeting the National Comprehensive Cancer Network (NCCN) guidelines for GT were more likely to undergo GT. Testing was performed with a 67- to 84-gene panel, together with an 8- to 9-gene STAT panel if needed. Among 120 patients with reports available, including 33 patients previously tested, 15 (12%) were positive (1 BLM, 1 BRCA1, 3 BRCA2, 1 BRIP1, 1 CFTR, 1 CHEK2, 1 MUTYH, 1 PALB2, 1 PRSS1, 1 RAD50, 1 RET, and 2 TP53), 44 (37%) were negative, and 61 (51%) had an uncertain variant. The median time to STAT results (n = 50) was 8 days. The STAT results were available before surgery for 47 (98%) of the 48 STAT patients undergoing surgery. CONCLUSIONS: New BC patients attending the MDBC demonstrated high rates of acceptance of GC and GT. The combination of GC and GT can offer timely information critical to patient risk assessment and treatment planning.

The abscopal effect: systematic review in patients with brain and spine metastases.

Background: The abscopal effect is a rare phenomenon whereby local radiation induces a proposed immune-mediated anti-tumor effect at distant sites. Given the growing use of immunotherapies and systemic immune checkpoint inhibitors in neuro-oncologic practice, we aimed to review prior studies pertaining to this phenomenon in the context of tumor shrinkage both within the central nervous system as well as distant disease sites. Methods: A systematic review in accordance with the PRISMA guidelines was conducted to identify all studies which assessed the abscopal effect in patients with treated metastatic cancer to the brain and/or spine. Articles were included if they reported the abscopal effect in patients (case studies) or if the abscopal effect was explicitly analyzed in case series with cohorts of patients with metastatic brain or spine tumors. Laboratory investigations and clinical trials investigating new therapies were excluded. Results: Twenty reports met inclusion criteria [16 case reports, 4 case series (n = 160), total n = 174]. Case reports of the abscopal effect were in relation to the following cancers: melanoma (6 patients), breast cancer (3), lung adenocarcinoma (2), non-small-cell lung cancer (2), hepatocellular carcinoma (1), and renal cell carcinoma (1). Eleven patients had irradiation to the brain and 2 to the spine. Patients undergoing whole brain radiotherapy (6) had an average dose of 33.6 Gy over 8-15 fractions, and those undergoing stereotactic radiosurgery (5) had an average dose of 21.5 Gy over 1-5 fractions. One patient had radiation to the body and an intracranial abscopal effect was observed. Most common sites of extracranial tumor reduction were lung and lymph nodes. Ten case studies (57%) showed complete resolution of extra-CNS tumor burden. Median progression-free survival was 13 months following radiation. Four papers investigated incidence of abscopal effects in patients with metastatic melanoma to the brain who received immune checkpoint inhibitor therapy (n = 160); two papers found an abscopal effect in 35% and 52% of patients (n = 16, 21 respectively), and two papers found no evidence of abscopal effects (n = 61, 62). Conclusions: Abscopal effects can occur following radiotherapy in patients with brain or spine metastases and is thought to be a result of increased anti-tumor immunity. The potential for immune checkpoint inhibitor therapy to be used in combination with radiotherapy to induce an abscopal effect is an area of active investigation.