Clinical Features and Therapeutic Outcomes Comparing Primary Mediastinal Large B-cell Lymphoma to Mediastinal Hodgkin Disease.

Currently, there is limited data available comparing Primary Mediastinal Large B-cell Lymphoma (PMBL) and mediastinal Hodgkin disease, nodular sclerosis type (HDNS). This is a retrospective cohort study that compares the clinical features, histology through immunohistochemistry (IHC) and treatment outcomes of 19 cases of PMBL and 39 cases of HDNS diagnosed over 13 years at a single institution in San Juan, PR. Superior Vena Cava syndrome (SVCS) and elevated Lactate Dehydrogenase (LDH) levels were more frequently seen in the PMBL cohort. At the median follow-up visit, of 74 months, no significant difference was seen in overall survival or progression free survival between PMBL and HDNS. Almost all of the relapses in the PMBL group occurred within 12 months of diagnosis. Our data suggests that PMBL and HDNS differ in their clinical presentation and have a favorable prognosis.

Can we reduce dose to ureters as avoidance organs for MRI based brachytherapy for cervical cancer? A dosimetric feasibility study.

BACKGROUND AND PURPOSE: Ureteral stenosis (US) is an underreported complication of brachytherapy (BT) for cervical cancer (CC), with limited data on toxicity risk reduction. A previous study demonstrated ureter EQD2 D0.1cc > 77 Gy correlated with US development. We sought to assess feasibility of this constraint while maintaining similar HR-CTV coverage. MATERIALS AND METHODS: Patients with locally advanced CC treated with EBRT plus HDR MRI-based brachytherapy boost without hydronephrosis at diagnosis and with ureter dose EQD2 D0.1cc > 77 Gy were included. Replan was attempted to achieve HR-CTV D90 ≥ 80-85 Gy and ureter dose reduction. Ureter distance from lateral margin of HR-CTV and tandem was recorded. t-test was performed to compare ureteral dose and HR-CTV D90. RESULTS: Of 25 patients were identified. Hundred percent received 45 Gy in 25 fractions to the pelvis ± paraaortic lymph nodes and 80% receiving median additional parametrial dose of 5.4 Gy. Replan meeting ureteral dose of ≤77 Gy was feasible in 18 of 25 patients, with a reduction in median ureter D0.1cc from 82.3 to 76.8 Gy (p < 0.001). Median HR-CTV D90 was similar (84.7 vs. 85.0 Gy). Replan achieved D0.1cc ≤77 Gy in 56% of patients who experienced US. All unilateral US cases occurred in the ureter closest to HR-CTV. CONCLUSIONS: Optimization to reduce ureter dose to ≤77 Gy is feasible when ureters are visible and contoured. Ureters may be considered as potential OAR during MRI-based brachytherapy treatment. Reduced ring to tandem total reference air kerma (TRAK) ratio may provide an additional metric by which to lower US risk.

Treatment of intermediate-risk prostate cancer with Cs-131: Long-term results from a single institution.

PURPOSE: To evaluate our institutional outcomes utilizing Cs-131 prostate brachytherapy (PB) for the intermediate-risk (IR) group of prostate cancer patients. METHODS AND MATERIALS: We reviewed a prospectively collected database of men treated with Cs-131 PB between 2006 and 2019. Patients with less than 24-months follow-up were excluded. Patients were classified as IR if they had one of the following factors: Gleason Score 7, prostate specific antigen >10 but <20 ng/mL, or T2b-c on clinical exam. We defined unfavorable-IR (UIR) as having either Grade Group 3, >1 IR factors, or ≥50% positive core biopsies. The Kaplan-Meier method was used to estimate actuarial event-time probabilities for biochemical freedom from disease (BFD). RESULTS: A total of 335 patients with a median follow-up of 70.1 months (IQR 48.3-106.3 months) were identified. Androgen deprivation therapy (ADT) was used in 7.2% of patients. Favorable-IR (FIR) patients were commonly treated with PB alone (91.8%). FIR patients who underwent PB alone had a 5-year BFD of 98.1%. UIR patients were commonly treated with external beam radiotherapy plus PB (61.2%). These patients had 5-year BFD of 91.1%. The 5-year BFD for UIR patients treated without ADT was 90.9%, whereas it was 95.0% among UIR patients treated with ADT (log-rank p = 0.83). CONCLUSIONS: FIR patients have excellent outcomes when treated with PB alone. External beam radiotherapy plus PB is a reasonable treatment approach for UIR patients. Future studies may elucidate which IR patients would benefit from treatment intensification.

Utility of Prophylactic Cranial Irradiation for Extensive-Stage Small-Cell Lung Cancer in the MRI Screening Era.

BACKGROUND: Conflicting data exists regarding the benefit of prophylactic cranial irradiation (PCI) in patients with extensive-stage small-cell lung cancer (ES-SCLC). We sought to retrospectively review outcomes of patients within our network with ES-SCLC treated with and without PCI between 2009 and 2020. METHODS: Endpoints assessed using the Kaplan-Meier estimator were overall survival (OS), freedom from death with uncontrolled intracranial disease (UI-DFS), brain metastasis-free survival (BMFS), and symptomatic BMFS (SBMFS). Log-rank test was performed for univariate comparison of outcomes, with Cox regression performed for univariate and multivariable analysis of OS and UI-DFS. RESULTS: Some 250 patients were determined to be eligible for PCI based on any response to upfront chemotherapy, with 46 patients excluded owing to lack of negative staging brain magnetic resonance imaging (MRI). Brain MRI was performed both at diagnosis and near completion of chemotherapy in 108 patients, with brain metastases identified near completion of chemotherapy in 17 patients (15.7%), excluding them from further analysis. Median OS in remaining eligible 187 patients was 9.0 months, with 2-year Kaplan-Meier estimate of OS of 21.9%. PCI was associated with improved UI-DFS, BMFS, and SBMFS. However, PCI was not associated with improved OS in the entire cohort or the propensity matched cohort. CONCLUSION: Our study suggests screening with MRI following chemotherapy is important because of the identification of unsuspected brain metastases in nearly 16% of patients with response to chemotherapy. PCI is associated with reduction in brain metastases, without a demonstrable impact on OS in the era of MRI screening.

Do air gaps with image-guided vaginal cuff brachytherapy impact failure rates in patients with high-intermediate risk FIGO Stage I endometrial cancer?

PURPOSE: The aim of this study was to assess the impact of air gaps at the cylinder surface on the rate of vaginal cuff failure (VCF) after image-guided adjuvant vaginal cuff brachytherapy (VCBT) in the treatment of high-intermediate risk (HIR) FIGO (Fédération Internationale de Gynécologie et d'Obstétrique (International Federation of Gynecology and Obstetrics)) Stage I endometrial cancer. METHODS AND MATERIALS: A retrospective review of patients treated with image-guided VCBT from 2009 to 2016 for HIR FIGO Stage I endometrial cancer was performed. Air gaps present at the applicator surface on the first postinsertion CT were contoured. Vaginal cuff failure-free survival (VCFFS) was measured from the first fraction of VCBT to VCF. RESULTS: A total of 234 patients were identified. Air gaps were present on the first postinsertion CT scan in 82% of patients. The median number of air gaps was 2 (interquartile range [IQR] 1-3), median depth of the largest air gap was 2.7 mm (IQR 2.1-3.4 mm), and the median cumulative volume of air gaps was less than 0.1 cm3 (range < 0.1-0.7 cm3). At a median followup of 56 months (IQR 41-69), 12 patients (5%) experienced VCF, of which 4 had isolated VCF and 8 had synchronous pelvic or distant failure. Five-year VCFFS and isolated VCFFS were 96% (95% confidence interval 93-98%) and 98% (95% confidence interval 96-100%), respectively. On univariate analysis, no factors, including the presence, number, maximum depth, or cumulative volume of air gaps, were predictive for VCFFS. CONCLUSIONS: In this population, VCFFS remained high despite most patients having air gaps present on postinsertion CT scan.

Lag Time Between Evidence and Guidelines: Can Clinical Pathways Bridge the Gap?

PURPOSE:: The 2018 American Society for Radiation Oncology guidelines state that hypofractionated whole-breast irradiation (HF-WBI) may be used for early-stage breast cancer regardless of age, although evidence to support this became available years ago. Before guideline publication, we sought to change the practice pattern within an integrated, comprehensive radiation oncology network using clinical pathways. METHODS:: The breast clinical pathway was amended in January 2016 to allow HF-WBI as a pathway-concordant option for women younger than 50 years of age. In December 2016, the pathway was amended to mandate HF-WBI as the only pathway-concordant option. Women younger than 50 years of age treated for stage 0 to IIA breast cancer, without irradiation of regional nodes, were included. Potential predictors of hypofractionation use were analyzed using binary logistic regression. RESULTS:: We identified 305 patients treated between 2013 and 2017. From 2013 to December 2015, HF-WBI use was 4.2%. After the first and second amendments, use increased to 53.1% ( P < .001) and 96.5% ( P < .001), respectively. Before amendment 1, there was no difference in use of hypofractionation at academic (2.6%) versus community (4.7%) sites ( P = .568). After amendment 1, academic practices were more likely to use hypofractionation (72.0% v 44.6%; P = .026). After amendment 2, there was, again, no difference between academic (100.0%) and community (95.3%) practices ( P = .999). CONCLUSION:: With implementation of a clinical pathway that mandated use of HF-WBI regardless of age, HF-WBI use for women younger than 50 years of age rapidly increased from 4.2% to greater than 95%. Clinical pathways effectively standardize patterns of care to reflect the most up-to-date clinical evidence, independently of guideline publication.

Difficult Diagnosis between B Cell Lymphoma and Classical Hodgkin's Lymphoma.

Although primary mediastinal large B-cell lymphoma and classic Hodgkin lymphoma of nodular sclerosis type are distinct disease, they share several clinical characteristics and biologic features. However, there are mediastinal lymphomas that not fit in either category. These types of lymphomas are recognized as mediastinal gray zone lymphomas. Gray zone lymphomas are lymphatic tumors that cannot be assigned to a defined lymphoma entity due to morphological, clinical, or genetic reasons. In this report, we present a case of a 22 year-old-Hispanic-female diagnosed with B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Hodgkin lymphoma.