Multidisciplinary approach for repeat musculoskeletal lesion biopsy after nondiagnostic initial sampling: A 10-year single-center experience.

BACKGROUND AND OBJECTIVES: Success rates for initial image-guided biopsy of musculoskeletal (MSK) lesions have been well documented; evidence regarding success rates for repeat biopsy following initially nondiagnostic (ND) image-guided biopsy of MSK lesions is more limited. This study evaluates the outcomes of repeat computerized tomography-guided MSK biopsies following ND biopsies using a multidisciplinary approach. MATERIALS AND METHODS: Electronic medical record search covering a 10-year period identified patients that received two or more biopsies for an MSK tumor or tumor-like process. The decision for initial and repeat image-guided biopsy of each lesion was made following multidisciplinary MSK tumor board review. Lesion location, histopathology results, size of biopsy needle when available, and change in technique between biopsy attempts was documented. RESULTS: Repeat biopsy rate was 1.6%. 23 patients with repeat MSK biopsy were identified. A total of 17 of 23 (74%) repeat biopsy attempts were diagnostic. A total of 22 of 23 (96%) repeat biopsy attempts were clinically useful. Diagnostic repeat biopsies were described as employing one or more of five technical differences compared to the first biopsy attempt, the most common being improved targeting of the lesion itself. CONCLUSIONS: A multidisciplinary approach may yield improved repeat-biopsy rates and clinical utility of repeat MSK biopsies compared to prior reports.

Organ sparing of linac-based targeted marrow irradiation over total body irradiation.

PURPOSE: Targeted marrow irradiation (TMI) is an alternative conditioning regimen to total body irradiation (TBI) before bone marrow transplantation in hematologic malignancies. Intensity-modulation methods of external beam radiation therapy are intended to permit significant organ sparing while maintaining adequate target coverage, improving the therapeutic ratio. This study directly compares the dose distributions to targets and organs at risk from TMI and TBI, both modalities conducted by general-use medical linacs at our institution. METHODS: TMI treatments were planned for 10 patients using multi-isocentric feathered volumetric arc therapy (VMAT) plans, delivered by 6 MV photon beams of Elekta Synergy linacs. The computed tomography (CT) datasets used to obtain these plans were also used to generate dose distributions of TBI treatments given in the AP/PA extended-field method. We compared dose distributions normalized to the same prescription for both plan types. The generalized equivalent uniform dose (gEUD) of Niemierko for organs and target volumes was used to quantify effective whole structure dose and dose savings. RESULTS: For the clinical target volume (CTV), no significant differences were found in mean dose or gEUD, although the radical dose homogeneity index (minimum dose divided by maximum dose) was 31.7% lower (P = 0.002) and the standard deviation of dose was 28.0% greater (P = 0.027) in the TMI plans than in the TBI plans. For the TMI plans, gEUD to the lungs, brain, kidneys, and liver was significantly lower (P < 0.001) by 47.8%, 33.3%, 55.4%, and 51.0%, respectively. CONCLUSION: TMI is capable of maintaining CTV coverage as compared to that achieved in TBI, while significantly sparing organs at risk. Improvement on sparing organs at risk permits a higher prescribed dose to the target or the maximum number of times marrow conditioning may be delivered to a patient while maintaining similar typical tissue complication rates.

Postoperative hypofractionated stereotactic brain radiation (HSRT) for resected brain metastases: improved local control with higher BED10.

INTRODUCTION: HSRT directed to large surgical beds in patients with resected brain metastases improves local control while sparing patients the toxicity associated with whole brain radiation. We review our institutional series to determine factors predictive of local failure. METHODS: In a total of 39 consecutive patients with brain metastases treated from August 2011 to August 2016, 43 surgical beds were treated with HSRT in three or five fractions. All treatments were completed on a robotic radiosurgery platform using the 6D Skull tracking system. Volumetric MRIs from before and after surgery were used for radiation planning. A 2-mm PTV margin was used around the contoured surgical bed and resection margins; these were reviewed by the radiation oncologist and neurosurgeon. Lower total doses were prescribed based on proximity to critical structures or if prior radiation treatments were given. Local control in this study is defined as no volumetric MRI evidence of recurrence of tumor within the high dose radiation volume. Statistics were calculated using JMP Pro v13. RESULTS: Of the 43 surgical beds analyzed, 23 were from NSCLC, 5 were from breast, 4 from melanoma, 5 from esophagus, and 1 each from SCLC, sarcoma, colon, renal, rectal, and unknown primary. Ten were treated with three fractions with median dose 24 Gy and 33 were treated with five fractions with median dose 27.5 Gy using an every other day fractionation. There were no reported grade 3 or higher toxicities. Median follow up was 212 days after completion of radiation. 10 (23%) surgical beds developed local failure with a median time to failure of 148 days. All but three patients developed new brain metastases outside of the treated field and were treated with stereotactic radiosurgery, whole brain radiation and/or chemotherapy. Five patients (13%) developed leptomeningeal disease. With a median follow up of 226 days, 30 Gy/5 fx was associated with the best local control (93%) with only 1 local failure. A lower total dose in five fractions (ie 27.5 or 25 Gy) had a local control rate of 70%. For three fraction SBRT, local control was 100% using a dose of 27 Gy in three fractions (follow up was > 600 days) and 71% if 24 Gy in three fractions was used. A higher total biologically equivalent dose (BED10) was statistically significant for improved local control (p = 0.04) with a threshold BED10 ≥ 48 associated with better local control. CONCLUSIONS: HSRT after surgical resection for brain metastasis is well tolerated and has improved local control with BED10 ≥ 48 (30 Gy/5 fx and 27 Gy/3 fx). Additional study is warranted.

Dual institution experience of nodal marginal zone lymphoma reveals excellent long-term outcomes in the rituximab era.

Nodal marginal zone lymphoma (NMZL) is a rare non-Hodgkin lymphoma that arises from mature B-cells. We delineate outcomes, prognostic factors and treatment trends among a large cohort of patients with NMZL in the rituximab era. We identified 56 such patients treated at our institutions. The majority presented with advanced stage disease (78·6%). Over a median follow-up of 38·2 months, median progression-free survival (PFS) was 42·4 months and median overall survival (OS) was not reached. Kaplan-Meier estimates of OS at 120 months after diagnosis was 71·9%. High-risk follicular lymphoma international prognostic index (FLIPI) was associated with inferior PFS. Age >60 years and elevated serum lactate dehydrogenase (LDH) were associated with inferior OS. Transformation to diffuse large B-cell lymphoma occurred in 7 patients, 6 of who presented with advanced disease. OS was comparable to our previously reported extranodal MZL cohort. FLIPI score predicted for inferior PFS and OS when both cohorts were analysed together (n = 267). In summary, outcomes in NMZL are favourable with a large majority of patients surviving at 120 months. High risk FLIPI, age >60 years, and elevated serum LDH were associated with inferior outcomes.

Dual institution experience of extranodal marginal zone lymphoma reveals excellent long-term outcomes.

Extranodal marginal zone lymphoma (EMZL) is a B-cell lymphoma arising from mucosa-associated lymphoid tissue (MALT). The disease characteristics, clinical course and treatment vary considerably based on site of involvement. Because long-term outcome data for EMZL are limited, we sought to describe the clinical details of a large number of patients with EMZL evaluated at the Case Comprehensive Cancer Center over a 12-year period to identify prognostic markers including the impact of site of involvement. We identified 211 cases of EMZL involving the stomach (30%), ocular adnexa (19%), lungs (16%) and intestines (9%). Initial treatment included antibiotics (18%), radiation (21%), rituximab (20%), chemotherapy (3%), rituximab + chemotherapy (7%), surgery (17%) or observation (8%). After a median follow-up of 44·3 months (range 2·2-214·9), median progression-free survival (PFS) was 68·2 months (95% confidence interval [CI] 54·5-111·3) and median overall survival (OS) has not been reached. Age >60 years, elevated lactate dehydrogenase level (LDH), ≥4 lymph node groups involvement, and high follicular lymphoma international prognostic index (FLIPI) were associated with inferior PFS/OS. In summary, patients with EMZL have excellent prognosis with median OS in excess of 10 years. Age, elevated LDH, advanced disease, and high FLIPI score are associated with worse outcomes.

ACR Appropriateness Criteria® Recurrent Hodgkin Lymphoma.

This topic addresses the management of recurrent Hodgkin lymphoma. While autologous stem cell transplantation may be appropriate for select cases of recurrent disease following comprehensive combined-modality therapy, other options exist for patients treated with lower-dose therapy for early-stage disease. Additionally, innovative targeted therapies provide newer salvage options to consider. The American College of Radiology Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation, or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment. By combining the most recent medical literature and expert opinion, this revised guideline can aid clinicians in the complex decision-making associated with the management of recurrent Hodgkin lymphoma.

Unintended irradiation of internal mammary chain - Is that enough?

AIM: To evaluate the unintentional coverage of the internal mammary chain (IMC) with tangential fields irradiation to the breast, and its relation with the type of surgery employed. BACKGROUND: The dose distribution in regions adjacent to the treatment targets (mammary gland or chest wall), with incidental irradiation of the IMC, could translate into clinical benefit, due to the proximity of these regions. MATERIALS AND METHODS: One hundred and twelve consecutive conformal radiotherapy plans were correlating the average dose to the IMC with the type of surgery employed, the extent of disease and the irradiation techniques. RESULTS: The mean doses to IMC after modified radical mastectomy (MRM), modified radical mastectomy with immediate reconstruction (MRM + R), and breast conservative surgery (BCS) were 30.34 Gy, 30.26 Gy, and 18.67 Gy, respectively. Significant differences were identified between patients who underwent MRM or MRM + R over BCS (p = 0.01 and 0.003, respectively), but not between MRM and MRM + R (p = 0.88). Mean doses to IMC were greater in patients with T3-T4 tumors when compared with more initial stages (≤T2) (p = 0.0096). The lymph node involvement also correlated with higher average doses to IMC (node positive: 26.1 Gy × node negative: 17.8 Gy, p = 0.0017). CONCLUSIONS: The moderate dose level to the IMC in the unintentional irradiation scenario seems to be insufficient to treat the subclinical disease, although it could have an impact in patients undergoing mastectomy.

An Analysis of Cancer Center-Provided Rideshare Utilization for Radiation Therapy.

OBJECTIVES: The potential of rideshare services to facilitate timely radiation therapy (RT), especially for resource-limited patients, is understudied. METHODS: Patients (n = 63) who received 73 courses of RT (1,513 fractions) and utilized free hospital-provided rideshare service (537 rides) were included in this retrospective study. A multidimensional analysis was conducted including a comparison of demographic, disease characteristics, and treatment completion data; a revenue analysis to evaluate the financial impact of rideshare services; and a geospatial analysis to evaluate community-level characteristics of patients. RESULTS: Median age was 59; most were female (56%) and self-identified as Black or African American (56%), not working (91%), not partnered (83%), high school educated or less (78%), and insured with Medicaid (51%). Geospatial analysis revealed that patients lived in communities with significantly higher rates of resource deprivation. Median rideshare distance was 6.4 miles (interquartile range 3.4-11.2) with a median cost of $13.04 per rideshare (interquartile range 9-19). Of the rideshare-facilitated treatments, 100% were completed, with an overall course completion rate of 97.3% compared with 85.4% for those who did not use rideshare (P = .001); two patients discontinued RT for reasons unrelated to transportation. High rideshare utilization (n = 32), defined as utilization ≥ 45% of the treatment course, was associated with significantly shorter treatment courses and lower radiation doses compared with low rideshare utilization (P = .04). Total rideshare cost for high utilizers and whole cohort was $11,589 and $16,895, facilitating an estimated revenue of $401,952 and $1,175,119, respectively. CONCLUSIONS: Free hospital-provided rideshare service is economically feasible and associated with high RT completion rates. It may help enhance quality radiation care for those who come from resource-limited communities.

Hodgkin lymphoma, version 2.2012 featured updates to the NCCN guidelines.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Hodgkin Lymphoma (HL) include the clinical management of classical HL and lymphocyte-predominant HL (LPHL). Major changes have been incorporated into these guidelines since their inception. In the 2012 NCCN Guidelines for HL, PET scans are not recommended for interim restaging of patients with stage I to II favorable disease. After reevaluating the available evidence on the use of interim PET imaging, the panel recommends the use of diagnostic CT scan of involved sites for interim restaging after completion of chemotherapy for this group of patients. Maintenance rituximab for 2 years is included as an option for patients with stage IB to IIB or stage III to IV LPHL treated with rituximab alone in the first-line setting. Brentuximab vedotin is included as an option for patients with progressive disease or relapsed disease after second-line chemotherapy or high-dose therapy with autologous stem cell rescue.

Oligodendrogliomas in children.

Oligodendrogliomas are rare central nervous system (CNS) tumors in children. The purpose of this study was to identify prognostic factors for progression free survival (PFS) and overall survival (OS) in pediatric patients with oligodendrogliomas. We retrospectively analyzed clinical data on 37 pediatric patients with oligodendroglial tumors treated at Washington University. Kaplan-Meier method was used to calculate survival rates. Log-rank was used to detect the difference between survival curves. The median age was 11.1 years (range 10 months-18 years), and median follow-up was 4.5 years (range 2 months-30.5 years). The 5-year PFS and OS were 66.4 and 93.4%, respectively. Mixed histology was associated with worse OS compared to patients with pure oligodendroglioma, 5-year OS 77.6 versus 100% (P < 0.01). Patients who underwent gross total resection (GTR) experienced an improved 5-year PFS of 100% compared to 28.8% (P = 0.03) in patients treated with subtotal resection (STR) or biopsy alone. Age >3 years at diagnosis correlated with improved 5-year PFS, 33.3 versus 69.8% (P = 0.01). Neither post-operative chemotherapy nor radiation therapy correlated with improved outcome. GTR and age >3 years at diagnosis remained significant for improved PFS on multivariate analysis. There were no factors correlated with improved overall survival on multivariate analysis. Pediatric oligodendroglial tumors are associated with excellent OS; however, a third of patients developed progressive disease. Our data demonstrate that patients with less than GTR and <3 years at diagnosis are at increased risk for progression and may benefit from more aggressive therapy.

Phase I/II trial of vorinostat and radiation and maintenance vorinostat in children with diffuse intrinsic pontine glioma: A Children's Oncology Group report.

BACKGROUND: A phase I/II trial of vorinostat (suberoylanilide hydroxamic acid), an oral histone deacetylase inhibitor, was conducted in children with newly diagnosed diffuse intrinsic pontine glioma (DIPG) through the Children's Oncology Group (COG) to: 1) determine the recommended phase II dose (RP2D) of vorinostat given concurrently with radiation therapy; 2) document the toxicities of continuing vorinostat as maintenance therapy after radiation; and 3) to determine the efficacy of this regimen by comparing the risk of progression or death with a historical model from past COG trials. METHODS: Vorinostat was given once daily, Monday through Friday, during radiation therapy (54 Gy in 30 fractions), and then continued at 230 mg/m2 daily for a maximum of twelve 28-day cycles. RESULTS: Twelve patients enrolled in the phase I study; the RP2D of vorinostat given concurrently with radiation was 230 mg/m2/day, Monday through Friday weekly. The six patients enrolled at the RP2D and an additional 64 patients enrolled in the phase II study contributed to the efficacy assessment. Although vorinostat was well-tolerated, did not interrupt radiation therapy, and was permanently discontinued in only 8.6% of patients due to toxicities, risk for EFS-event was not significantly reduced compared with the target risk derived from historical COG data (P = 0.32; 1-sided). The 1-year EFS was 5.85% (95% CI 1.89-13.1%) and 1-year OS was 39.2% (27.8-50.5%). CONCLUSIONS: Vorinostat given concurrently with radiation followed by vorinostat monotherapy was well tolerated in children with newly diagnosed DIPG but failed to improve outcome.

Proton Beam Therapy for Locally Advanced Head and Neck Tumors: An Analysis of Dosimetric and Clinical Outcomes.

OBJECTIVE: Locally advanced tumors of the head and neck region often lie in close proximity to critical organs at risk (OARs). Providing effective treatment coverage to these malignancies while minimizing radiation dose to surrounding OARs is advantageous. Our aim is to compare dosimetric data of OARs from proton beam therapy (PBT) plans to volumetric modulated arc therapy (VMAT) treatment plans, and to evaluate clinical outcomes in patients treated with PBT. METHODS: We identified patients with locally advanced head and neck tumors treated with PBT at our institution from 2016 to 2019. Study endpoints included mean and maximum doses for the OAR structures for each treatment plan, overall survival, time to local-regional or distant progression, and presence of acute and late toxicities. Mean and maximum doses to OAR structures were compared between treatment modalities using a paired Wilcoxon signed-rank test. P-values <0.05 were considered significant. RESULTS: A total of 42 patients were identified. Clinical target volume coverage was >95% for both PBT and VMAT plans. PBT plans showed a significant reduction to the mean doses to all OARs, and max doses to most OARs (P<0.05). The largest reduction mean dose was seen in the contralateral cochlea and parotid glands at 71% and 75%, respectively. Median follow-up was 27 months. Overall survival at 4 years was 44.75%. Freedom from local-regional progression was 73.28% at 2 years. The majority of patients developed Common Terminology Criteria for Adverse Events (CTCAE) grade I dermatitis, mucositis, or both. CONCLUSIONS: PBT resulted in meaningful dose reductions to OARs while maintaining comparable target coverage when compared with VMAT plans. Further refinements to proton therapy may have the potential to further minimize dose to critical structures.

Targeted Marrow Irradiation Intensification of Reduced-Intensity Fludarabine/Busulfan Conditioning for Allogeneic Hematopoietic Stem Cell Transplantation.

Reduced-intensity conditioning (RIC) regimens frequently provide insufficient disease control in patients with high-risk hematologic malignancies undergoing allogeneic hematopoietic stem cell transplantation (HSCT). We evaluated intensification of fludarabine/busulfan (Flu/Bu) RIC with targeted marrow irradiation (TMI) in a dose escalation with expansion phase I clinical trial. TMI doses were delivered at 1.5 Gy in twice daily fractions on days -10 through -7 (dose levels: 3 Gy, 4.5 Gy, and 6 Gy), Flu (30 mg/m2 for 5 days) and Bu (area under the curve, 4800 µM*minute for 2 days). Eligible patients were age ≥18 years with high-risk hematologic malignancy and compromised organ function ineligible for myeloablative transplantation (n = 26). The median patient age was 64 years (range, 25 to 76 years). Nineteen patients (73%) had active or measurable residual disease at transplantation. One-year disease-free survival and overall survival were 55% (95% confidence interval [CI], 34% to 76%) and 65% (95% CI, 46% to 85%), respectively. Day +100 and 1 year transplantation-related mortality were 4% (95% CI, 0.6% to 27%) and 8.5% (95% CI, 2% to 32%), respectively. The 1-year cumulative incidence of relapse was 43% (95% CI, 27% to 69%). Rates of grade II-IV and III-IV acute GVHD rates were 57% (95% CI, 39% to 84%) and 22% (95% CI, 9% to 53%), respectively. Whole blood immune profiling demonstrated enrichment of central/transitional memory-like T cells with higher TMI doses, which correlated with improved survival compared with control samples from patients undergoing allogeneic HSCT. Intensification of a Flu/Bu RIC regimen with TMI is feasible with a low incidence of transplantation-related mortality in medically frail patients with advanced malignancies. The recommended phase 2 TMI dose is 6 Gy.

Right atrial cardiac angiosarcoma treated with concurrent proton beam therapy and paclitaxel: A novel approach to a rare disease.

Cardiac angiosarcoma is a rare malignancy with an aggressive course and poor prognosis. We present a 26-year old man who came to our clinic with shortness of breath and was diagnosed with a right-sided atrial mass. He underwent urgent resection of the mass. The pathology confirmed the mass to be cardiac angiosarcoma with positive microscopic margins (R1 resection). Since reresection was not feasible, the patient started treatment with concurrent paclitaxel (80 mg/m2 weekly) and proton beam therapy (61 Cobalt equivalent delivered over five weeks). After completing the concurrent chemotherapy and radiation therapy, he was treated with adjuvant chemotherapy using gemcitabine (900 mg/m2 on Days 1 and 8) and docetaxel (100 mg/m2 on Day 8) every three weeks. After three cycles, the patient developed severe dermatitis, and hence further chemotherapy was withheld. The patient is alive at 26 months since receiving his surgery and 18 months since the completion of treatment. Patients with cardiac angiosarcoma who undergo R1 resection have a median survival of six months. More radical approaches such as orthotopic heart-lung transplant or prolonged durations of chemotherapy lead to minimal improvement in survival at the cost of increased morbidity. Here, we describe a novel approach to a rare disease that resulted in prolonged survival and led to a better quality of life without any long-term morbidity to the patient.

Monte Carlo Dose Calculation Using MRI Based Synthetic CT Generated by Fully Convolutional Neural Network for Gamma Knife Radiosurgery.

The aim of this work is to study the dosimetric effect from generated synthetic computed tomography (sCT) from magnetic resonance (MR) images using a deep learning algorithm for Gamma Knife (GK) stereotactic radiosurgery (SRS). The Monte Carlo (MC) method is used for dose calculations. Thirty patients were retrospectively selected with our institution IRB's approval. All patients were treated with GK SRS based on T1-weighted MR images and also underwent conventional external beam treatment with a CT scan. Image datasets were preprocessed with registration and were normalized to obtain similar intensity for the pairs of MR and CT images. A deep convolutional neural network arranged in an encoder-decoder fashion was used to learn the direct mapping from MR to the corresponding CT. A number of metrics including the voxel-wise mean error (ME) and mean absolute error (MAE) were used for evaluating the difference between generated sCT and the true CT. To study the dosimetric accuracy, MC simulations were performed based on the true CT and sCT using the same treatment parameters. The method produced an MAE of 86.6 ± 34.1 Hundsfield units (HU) and a mean squared error (MSE) of 160.9 ± 32.8. The mean Dice similarity coefficient was 0.82 ± 0.05 for HU > 200. The difference for dose-volume parameter D95 between the ground true dose and the dose calculated with sCT was 1.1% if a synthetic CT-to-density table was used, and 4.9% compared with the calculations based on the water-brain phantom.

Proton Beam Therapy in the Treatment of Periorbital Malignancies.

PURPOSE: Periorbital tumor location presents a significant challenge with 3-dimensional conformal radiation therapy or intensity modulated radiation therapy due to high tumor dose needed in the setting of close proximity to orbital structures with lower tolerance. Proton beam therapy (PBT) is felt to be an effective modality in such cases due to its sharp dose gradient. MATERIALS AND METHODS: We reviewed our institutional PBT registry and identified 17 patients with tumor epicenters within 2 cm of the eye and optic apparatus treated with passive scatter PBT with comparison volumetric arc therapy plans available. Maximum and mean doses to organs at risk of interest, including optic nerves, optic chiasm, lens, eye ball, pituitary, cochlea, lacrimal gland, and surrounding brain, were compared using the paired Wilcoxon signed rank test. Overall survival was determined using the Kaplan-Meier method. RESULTS: Median age was 67. Median follow-up was 19.7 months. Fourteen patients underwent upfront resection and received postoperative radiation and 3 received definitive radiation. One patient received elective neck radiation, 2 underwent reirradiation, and 3 had concurrent chemotherapy. There was a statistically significant reduction in mean dose to the optic nerves and chiasm, brain, pituitary gland, lacrimal glands, and cochlea as well as in the maximum dose to the optic nerves and chiasm, pituitary gland, lacrimal glands, and cochlea with PBT. The 18-month cumulative incidence of local failure was 19.1% and 1-year overall survival was 80.9%. CONCLUSION: Proton beam therapy resulted in significant dose reductions to several periorbital and optic structures compared with volumetric arc therapy. Proton beam therapy appears to be the optimal radiation modality in such cases to minimize risk of toxicity to periorbital organs at risk.

Primary Mediastinal B Cell Lymphoma in the Positron-Emission Tomography Era Executive Summary of the American Radium Society Appropriate Use Criteria.

PURPOSE: Primary mediastinal B cell lymphoma (PMBCL) is a highly curable subtype of non-Hodgkin lymphoma that is diagnosed predominantly in adolescents and young adults. Consequently, long-term treatment-related morbidity is critical to consider when devising treatment strategies that include different chemoimmunotherapy strategies with or without radiation therapy. Furthermore, adaptive approaches using the end-of-chemotherapy (EOC) positron emission tomography (PET)/computed tomography (CT) scanning may help to determine which patients may benefit from additional therapies. We aimed to develop evidence-based guidelines for treating these patients. METHODS AND MATERIALS: We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline using the PubMed database. The ARS expert committee, composed of radiation oncologists, hematologists, and pediatric oncologists, developed consensus guidelines using the modified Delphi framework. RESULTS: Nine studies met the full criteria for inclusion based on reporting outcomes on patients with primary mediastinal B cell lymphoma with EOC PET/CT response scored with the 5-point Deauville scale. These studies formed the evidence for these guidelines in managing patients with PMBCL according to the EOC PET response, including after a 5-point Deauville scale of 1 to 3, 4, or 5, and for patients with relapsed and refractory disease. The expert group also developed guidance on radiation simulation, treatment planning, and plan evaluation based on expert opinion. CONCLUSIONS: Various treatment approaches exist in the management of PMBCL, including different chemoimmunotherapy regimens, the use of consolidative radiation therapy, and adaptive approaches based on EOC PET/CT response. These guidelines can be used by practitioners to provide appropriate treatment according to different disease scenarios.

Nodular lymphocyte predominant Hodgkin lymphoma: executive summary of the American radium society appropriate use criteria.

This guideline for nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) by the American Radium Society was developed by a multidisciplinary expert panel of medical, pediatric, and radiation oncologists convened to formulate guidelines for evaluation and treatment. The guideline development was based on an in-depth literature review and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of the recommendations by the panel. Given the scarcity of compelling data for strong recommendations for a rare lymphoma that has been shown to be more indolent than classical Hodgkin lymphoma, in instances where evidence is not available or equivocal, expert opinion guided the recommendations. Four clinical variants exemplify common scenarios and represent the consensus recommendations for patients with nodular lymphocyte Hodgkin lymphoma. A summary of the available published literature is also presented.

Planning tools for modulated electron radiotherapy.

PURPOSE: To develop tools to plan modulated electron radiotherapy (MERT) and to compare the MERT plans to conventional or intensity modulated radiotherapy (IMRT) treatment plans. METHODS: Monte Carlo dose calculations of electron fields shaped with the inherent photon multileaf collimators (MLCs) were investigated in this study. Treatment plans for four postmastectomy breast cancer patients were generated using MERT. The distances from the patient skin surfaces to the distal planning target volume surfaces were computed along the beam axis direction to determine the physical depth. Electron beam energies were selected to provide target coverage at these depths and energy bins were generated. A custom built MERT treatment planning graphical user interface (MERTgui) was used to shape the electron bins into deliverable electron segments. Monte Carlo dose distribution simulations were performed using the MLC-defined segments generated from the MERTgui. A custom built superposition gui was used to combine doses for each segment using relative weights and final MERT treatment plans were compared to the conventional or IMRT treatment plans. In addition, a demonstration of combined MERT and IMRT treatment plans was performed. RESULTS: The MERT treatment plans provided acceptable target organ coverage in all cases. Relative to 3D conventional or IMRT treatment plans, the MERT plans predicted lower heart doses in all cases; average of the heart D20 of all plans was reduced from 14.1 to 3.3 Gy. The contralateral breast and contralateral lung doses decreased substantially with MERT planning compared to IMRT (on average, contralateral breast heart D20 was reduced from 8.7 to 0.7 Gy and contralateral lung D20 was reduced from 8.4 to 1.2 Gy with MERT). Ipsilateral lung D20 was lower with MERT than with the conventional plans (44.6 vs 29.2 Gy with MERT), but greater when compared against IMRT treatment plans (25.4 vs 28.9 Gy with MERT). A MERT and IMRT combination plan was generated to benefit from the complementary advantages of MERT and IMRT, resulting in satisfactory target coverage and reduced organ at risk doses. CONCLUSIONS: MERT tools can facilitate treatment planning and provide plans for treatment of shallow targets such as the postmastectomy chest wall.

Reirradiation for Recurrent Scalp Angiosarcoma: Dosimetric Advantage of PBT over VMAT and EBT.

PURPOSE: Reirradiation in the scalp area can be challenging given the proximity to organs at risk (OARs), such as the eye and brain. Our aim is to evaluate the dosimetric differences of volumetric modulated arc therapy (VMAT) and electron beam therapy (EBT) compared with 3-dimensional proton beam therapy (PBT). PATIENTS AND METHODS: We evaluated a patient with recurrent angiosarcoma of the left temporal scalp after prior surgical resections and radiation therapy to 60 Gy in 30 fractions who needed reirradiation. We generated VMAT, EBT, and PBT plans using the Pinnacle Treatment Planning System (TPS). Both VMAT and EBT plans used a skin bolus, whereas no bolus was used for the proton plan. Doses to the OARs, including cochlea, eyes, lens, lacrimal glands, optic nerves, optic chiasm, pituitary gland, and underlying brain, were compared. RESULTS: The reirradiation treatment dose was 60 Gy(RBE). Target volume coverage was comparable in all plans. Compared with VMAT and EBT, the PBT plan showed reductions in mean and maximum doses to all OARs. Without the use of protons, several OARs would have exceeded dose tolerance utilizing VMAT or electrons. Dose reduction of up to 100% was achieved for central and contralateral OARs. CONCLUSION: Compared with VMAT and EBT, PBT resulted in dose reductions to all OARs, while maintaining excellent target coverage. PBT showed a significant advantage in treating superficially located skin cancers, such as angiosarcoma, without the need for a bolus. PBT can be considered in the upfront treatment and certainly in the reirradiation setting.