Quantifying Regional Radiation-Induced Lung Injury in Patients Using Hyperpolarized 129Xe Gas Exchange Magnetic Resonance Imaging

PURPOSE

Radiation-induced lung injury has been shown to alter regional ventilation and perfusion in the lung. However, changes in regional pulmonary gas exchange have not previously been measured.

METHODS AND MATERIALS

Ten patients receiving conventional radiation therapy (RT) for lung cancer underwent pre-RT and 3-month post-RT magnetic resonance imaging (MRI) using an established hyperpolarized 129Xe gas exchange technique to map lung function. Four patients underwent an additional 8-month post-RT MRI. The MR signal from inhaled xenon was measured in the following 3 pulmonary compartments: the lung airspaces, the alveolar membrane tissue, and the pulmonary capillaries (interacting with red blood cells [RBCs]). Thoracic 1H MRI scans were acquired, and deformable registration was used to transfer 129Xe functional maps to the RT planning computed tomography scan. The RT-associated changes in ventilation, membrane uptake, and RBC transfer were computed as a function of regional lung dose (equivalent dose in 2-Gy fractions). Pearson correlations and t tests were used to determine statistical significance, and weighted sum of squares linear regression subsequently characterized the dose dependence of each functional component. The pulmonary function testing metrics of forced vital capacity and diffusing capacity for carbon monoxide were also acquired at each time point.

RESULTS

Compared with pre-RT baseline, 3-month post-RT ventilation decreased by an average of -0.24 ± 0.05%/Gy (ρ = -0.88; P < .001), membrane uptake increased by 0.69 ± 0.14%/Gy (ρ = 0.94; P < .001), and RBC transfer decreased by -0.41 ± 0.06%/Gy (ρ = -0.92; P < .001). Membrane uptake maintained a strong positive correlation with regional dose at 8 months post-RT, demonstrating an increase of 0.73 ± 0.11%/Gy (ρ = 0.92; P = .006). Changes in membrane uptake and RBC transfer appeared greater in magnitude (%/Gy) for individuals with low heterogeneity in their baseline lung function. An increase in whole-lung membrane uptake showed moderate correlation with decreases in forced vital capacity (ρ = -0.50; P = .17) and diffusing capacity for carbon monoxide (ρ = -0.44; P = .23), with neither correlation reaching statistical significance.

CONCLUSIONS

Hyperpolarized 129Xe MRI measured and quantified regional, RT-associated, dose-dependent changes in pulmonary gas exchange. This tool could enable future work to improve our understanding and management of radiation-induced lung injury.

NCCN Guidelines® Insights: B-Cell Lymphomas, Version 6.2023

Novel targeted therapies (small molecule inhibitors, antibody-drug conjugates, and CD19-directed therapies) have changed the treatment landscape of relapsed/refractory B-cell lymphomas. Bruton's tyrosine kinase (BTK) inhibitors continue to evolve in the management of mantle cell lymphoma (MCL), in both the relapsed/refractory and the frontline setting. Anti-CD19 CAR T-cell therapies are now effective and approved treatment options for relapsed/refractory follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL), and MCL. Bispecific T-cell engagers represent a novel immunotherapeutic approach for relapsed FL and DLBCL after multiple lines of therapies, including prior CAR T-cell therapy. These NCCN Guideline Insights highlight the significant updates to the NCCN Guidelines for B-Cell Lymphomas for the treatment of FL, DLBCL, and MCL.

Acute Pulmonary Toxicity after Allogeneic Stem Cell Transplantation Using Total Body Irradiation-Based Conditioning- Myeloablative vs. Non-Myeloablative Regimens

PURPOSE/OBJECTIVE(S)

Allogeneic hematopoietic stem cell transplantation (HSCT) is associated with a high risk of acute pulmonary toxicity, especially with total body irradiation-based (TBI) conditioning regimens. High-grade acute pulmonary toxicity occurs in ∼30% of patients when a myeloablative regimen is utilized (∼12-14 Gy). The risk of pulmonary toxicity with non-myeloablative regimens (∼2 Gy) is not well described. We evaluated the incidence and predictors of acute pulmonary toxicity after HSCT comparing myeloablative and non-myeloablative TBI-based conditioning regimens.

MATERIALS/METHODS

All adult (≥ 18 y/o) patients undergoing allogeneic HSCT with TBI (1995-2020) at our institution were evaluated. The dose to the lungs was attenuated to 7-10 Gy in all patients undergoing myeloablative TBI. Acute pulmonary toxicity, occurring within 6 months of HSCT, was scored using CTCAE v5.0. The incidence of acute pulmonary toxicity was calculated using the Kaplan-Meier method, and logistic regression was performed to assess for independent risk factors.

RESULTS

Five hundred fifty-two patients were included the analysis (myeloablative- 378; non-myeloablative- 174). Myeloablative TBI was most commonly 13.5 Gy/9Fx (335/378), while non-myeloablative TBI was delivered most often as 2 Gy/1Fx (165/174). Patients undergoing myeloablative TBI were younger than non-myeloablative patients (43 vs 58 years, p<0.001), but baseline pulmonary function parameters were similar. At 6 months after transplant, the cumulative incidences of any acute pulmonary toxicity for patients receiving myeloablative and non-myeloablative TBI were 39% and 33%, respectively (p = 0.11). The risk of low-grade (1-2) and high grade (3-5) pulmonary toxicity was 10% vs 12% (p = 0.59) and 28% vs 21% (p = 0.05), respectively, comparing myeloablative and non-myeloablative TBI. Proportions of high-grade toxicities among the myeloablative and non-myeloablative cohorts were as follows: infectious pneumonia (31% and 49%), bronchopulmonary hemorrhage (25% and 3%), respiratory failure NOS (17% and 10%), pleural effusion (5% and 1%), and pneumonitis (4% and 0%). Female sex (OR 1.52, p = 0.05) and refractory disease at the time of transplant (OR 2.25, p = 0.03) were associated with a higher risk of severe pulmonary toxicity on logistic regression. Younger age (OR 0.99, p = 0.35) and non-myeloablative TBI (OR 0.21, p = 0.60) were not significantly associated with a lower risk.

CONCLUSION

The risk of acute pulmonary toxicity was high with both myeloablative and non-myeloablative TBI-based regimens, though high-grade toxicity was modestly higher in the myeloablative cohort. A better understanding of pulmonary toxicity in the setting of non-myeloablative TBI (∼2 Gy) is needed.

Long-Term Toxicity after Total Body Irradiation-Based Conditioning Regimens for Allogeneic Stem Cell Transplantation

PURPOSE/OBJECTIVE(S)

Total body irradiation (TBI) is an integral component of many conditioning regimens prior to allogeneic hematopoietic stem cell transplantation (HSCT). Few studies have investigated long-term sequelae. A large series of patients undergoing myeloablative and non-myeloablative regimens was studied.

MATERIALS/METHODS

Adult patients undergoing allogeneic HSCT utilizing TBI-based conditioning regimens from 1995-2020 at our institution were included. Baseline treatment-related factors and long-term toxicities (developing, or persisting beyond, 6 months after HSCT) were collected. The cumulative incidence of long-term toxicities and overall survival (OS) were calculated. Cox regression was used to assess for predictors of toxicity.

RESULTS

Five hundred fifty-two patients were analyzed: 378 myeloablative (typically 13.5 Gy/9fx) and 174 non-myeloablative (typically 2 Gy/1fx) TBI recipients. Median follow-up was 7.4 years for surviving patients. Cumulative incidences of long-term toxicities at 5 and 10 years are included in the Table. The most common toxicities were: pulmonary- infectious pneumonia and respiratory failure NOS; cardiac- heart failure and myocardial infarction; other endocrine- adrenal insufficiency and testosterone deficiency. The most common secondary malignancy was non-melanoma skin cancer. The proportion of all toxicities that were high-grade (3-5) for myeloablative and non-myeloablative regimens, respectively, were: pulmonary (65%, 52%), cardiac (66%, 39%), renal (23%, 27%), and other endocrine (3%, 18%). Increasing number of chemotherapy regimens (p = 0.05) and umbilical cord donor (p = 0.02) were associated with long-term pulmonary toxicity. Male sex (p = 0.03), increasing number of chemotherapy regimens (p<0.01), and elevated creatinine after transplant (p<0.01) were associated with long-term renal toxicity. Cataract development was associated with increasing age at transplant (p = 0.02). OS (5 years) was 40% (42% -myeloablative; 33%-non-myeloablative).

CONCLUSION

Allogeneic HSCT, often preceded by TBI-based conditioning regimens, has significant survivorship challenges. Recipients of non-myeloablative regimens are still at risk of significant long-term multisystem toxicity despite much lower doses of TBI and chemotherapy. Pre-transplant factors such as cumulative chemotherapy exposure and age at transplant were associated with some toxicities.

Uncertainties in the dosimetric heterogeneity correction and its potential effect on local control in lung SBRT

Objective. Dose calculation in lung stereotactic body radiation therapy (SBRT) is challenging due to the low density of the lungs and small volumes. Here we assess uncertainties associated with tissue heterogeneities using different dose calculation algorithms and quantify potential associations with local failure for lung SBRT.Approach. 164 lung SBRT plans were used. The original plans were prepared using Pencil Beam Convolution (PBC, n = 8) or Anisotropic Analytical Algorithm (AAA, n = 156). Each plan was recalculated with AcurosXB (AXB) leaving all plan parameters unchanged. A subset (n = 89) was calculated with Monte Carlo to verify accuracy. Differences were calculated for the planning target volume (PTV) and internal target volume (ITV) Dmean[Gy], D99%[Gy], D95%[Gy], D1%[Gy], and V100%[%]. Dose metrics were converted to biologically effective doses (BED) usingα/β= 10Gy. Regression analysis was performed for AAA plans investigating the effects of various parameters on the extent of the dosimetric differences. Associations between the magnitude of the differences for all plans and outcome were investigated using sub-distribution hazards analysis.Main results. For AAA cases, higher energies increased the magnitude of the difference (ΔDmean of -3.6%, -5.9%, and -9.1% for 6X, 10X, and 15X, respectively), as did lung volume (ΔD99% of -1.6% per 500cc). Regarding outcome, significant hazard ratios (HR) were observed for the change in the PTV and ITV D1% BEDs upon univariate analysis (p = 0.042, 0.023, respectively). When adjusting for PTV volume and prescription, the HRs for the change in the ITV D1% BED remained significant (p = 0.039, 0.037, respectively).Significance. Large differences in dosimetric indices for lung SBRT can occur when transitioning to advanced algorithms. The majority of the differences were not associated with local failure, although differences in PTV and ITV D1% BEDs were associated upon univariate analysis. This shows uncertainty in near maximal tumor dose to potentially be predictive of treatment outcome.

View-sharing for 4D magnetic resonance imaging with randomized projection-encoding enables improvements of respiratory motion imaging for treatment planning in abdominothoracic radiotherapy

Background and Purpose

The accuracy and precision of radiation therapy are dependent on the characterization of organ-at-risk and target motion. This work aims to demonstrate a 4D magnetic resonance imaging (MRI) method for improving spatial and temporal resolution in respiratory motion imaging for treatment planning in abdominothoracic radiotherapy.

Materials and Methods

The spatial and temporal resolution of phase-resolved respiratory imaging is improved by considering a novel sampling function based on quasi-random projection-encoding and peripheral k-space view-sharing. The respiratory signal is determined directly from k-space, obviating the need for an external surrogate marker. The average breathing curve is used to optimize spatial resolution and temporal blurring by limiting the extent of data sharing in the Fourier domain. Improvements in image quality are characterized by evaluating changes in signal-to-noise ratio (SNR), resolution, target detection, and level of artifact. The method is validated in simulations, in a dynamic phantom, and in-vivo imaging.

Results

Sharing of high-frequency k-space data, driven by the average breathing curve, improves spatial resolution and reduces artifacts. Although equal sharing of k-space data improves resolution and SNR in stationary features, phases with large temporal changes accumulate significant artifacts due to averaging of high frequency features. In the absence of view-sharing, no averaging and detection artifacts are observed while spatial resolution is degraded.

Conclusions

The use of a quasi-random sampling function, with view-sharing driven by the average breathing curve, provides a feasible method for self-navigated 4D-MRI at improved spatial resolution.

An ECG-based machine learning model for predicting new-onset atrial fibrillation is superior to age and clinical features in identifying patients at high stroke risk

BACKGROUND

Several large trials have employed age or clinical features to select patients for atrial fibrillation (AF) screening to reduce strokes. We hypothesized that a machine learning (ML) model trained to predict AF risk from 12‑lead electrocardiogram (ECG) would be more efficient than criteria based on clinical variables in indicating a population for AF screening to potentially prevent AF-related stroke.

METHODS

We retrospectively included all patients with clinical encounters in Geisinger without a prior history of AF. Incidence of AF within 1 year and AF-related strokes within 3 years of the encounter were identified. AF-related stroke was defined as a stroke where AF was diagnosed at the time of stroke or within a year after the stroke. The efficiency of five methods was evaluated for selecting a cohort for AF screening. The methods were selected from four clinical trials (mSToPS, GUARD-AF, SCREEN-AF and STROKESTOP) and the ECG-based ML model. We simulated patient selection for the five methods between the years 2011 and 2014 and evaluated outcomes for 1 year intervals between 2012 and 2015, resulting in a total of twenty 1-year periods. Patients were considered eligible if they met the criteria before the start of the given 1-year period or within that period. The primary outcomes were numbers needed to screen (NNS) for AF and AF-associated stroke.

RESULTS

The clinical trial models indicated large proportions of the population with a prior ECG for AF screening (up to 31%), coinciding with NNS ranging from 14 to 18 for AF and 249-359 for AF-associated stroke. At comparable sensitivity, the ECG ML model indicated a modest number of patients for screening (14%) and had the highest efficiency in NNS for AF (7.3; up to 60% reduction) and AF-associated stroke (223; up to 38% reduction).

CONCLUSIONS

An ECG-based ML risk prediction model is more efficient than contemporary AF-screening criteria based on age alone or age and clinical features at indicating a population for AF screening to potentially prevent AF-related strokes.

NCCN Guidelines® Insights: Hodgkin Lymphoma, Version 2.2022

Hodgkin lymphoma (HL) is an uncommon malignancy of B-cell origin. Classical HL (cHL) and nodular lymphocyte-predominant HL are the 2 main types of HL. The cure rates for HL have increased so markedly with the advent of modern treatment options that overriding treatment considerations often relate to long-term toxicity. These NCCN Guidelines Insights discuss the recent updates to the NCCN Guidelines for HL focusing on (1) radiation therapy dose constraints in the management of patients with HL, and (2) the management of advanced-stage and relapsed or refractory cHL.

NCCN Guidelines® Insights: B-Cell Lymphomas, Version 5.2021

In the last decade, a better understanding of the molecular pathogenesis of B-cell non-Hodgkin lymphomas has resulted in the development of novel targeted therapies, such as small molecule inhibitors of select kinases in the B-cell receptor pathway, antibody-drug conjugates, and small molecules that target a variety of proteins (eg, CD-19, EZH2, and XPO-1-mediated nuclear export). Anti-CD19 CAR T-cell therapy, first approved for relapsed/refractory (R/R) diffuse large B-cell lymphoma, has also emerged as a novel treatment option for R/R follicular lymphoma and mantle cell lymphoma. These NCCN Guideline Insights highlight the new targeted therapy options included in the NCCN Guidelines for B-Cell Lymphomas for the treatment of R/R disease.

NCCN Guidelines Insights: B-Cell Lymphomas, Version 3.2019

Diffuse large B-cell lymphomas (DLBCLs) and follicular lymphoma (FL) are the most common subtypes of B-cell non-Hodgkin's lymphomas in adults. Histologic transformation of FL to DLBCL (TFL) occurs in approximately 15% of patients and is generally associated with a poor clinical outcome. Phosphatidylinositol 3-kinase (PI3K) inhibitors have shown promising results in the treatment of relapsed/refractory FL. CAR T-cell therapy (axicabtagene ciloleucel and tisagenlecleucel) has emerged as a novel treatment option for relapsed/refractory DLBCL and TFL. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines for B-Cell Lymphomas regarding the treatment of TFL and relapsed/refractory FL and DLBCL.

NCCN Guidelines Insights: Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma, Version 1.2017

Chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) are different manifestations of the same disease and managed in much the same way. The advent of novel CD20 monoclonal antibodies led to the development of effective chemoimmunotherapy regimens. More recently, small molecule inhibitors targeting kinases involved in a number of critical signaling pathways and a small molecule inhibitor of the BCL-2 family of proteins have demonstrated activity for the treatment of patients with CLL/SLL. These NCCN Guidelines Insights highlight important updates to the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for CLL/SLL for the treatment of patients with newly diagnosed or relapsed/refractory CLL/SLL.

Nodal stage of surgically resected non-small cell lung cancer and its effect on recurrence patterns and overall survival

PURPOSE

Current National Comprehensive Cancer Network guidelines recommend postoperative radiation therapy (PORT) for patients with resected non-small cell lung cancer (NSCLC) with N2 involvement. We investigated the relationship between nodal stage and local-regional recurrence (LR), distant recurrence (DR) and overall survival (OS) for patients having an R0 resection.

METHODS AND MATERIALS

A multi-institutional database of consecutive patients undergoing R0 resection for stage I-IIIA NSCLC from 1995 to 2008 was used. Patients receiving any radiation therapy before relapse were excluded. A total of 1241, 202, and 125 patients were identified with N0, N1, and N2 involvement, respectively; 161 patients received chemotherapy. Cumulative incidence rates were calculated for LR and DR as first sites of failure, and Kaplan-Meier estimates were made for OS. Competing risk analysis and proportional hazards models were used to examine LR, DR, and OS. Independent variables included age, sex, surgical procedure, extent of lymph node sampling, histology, lymphatic or vascular invasion, tumor size, tumor grade, chemotherapy, nodal stage, and visceral pleural invasion.

RESULTS

The median follow-up time was 28.7 months. Patients with N1 or N2 nodal stage had rates of LR similar to those of patients with N0 disease, but were at significantly increased risk for both DR (N1, hazard ratio [HR] = 1.84, 95% confidence interval [CI]: 1.30-2.59; P=.001; N2, HR = 2.32, 95% CI: 1.55-3.48; P<.001) and death (N1, HR = 1.46, 95% CI: 1.18-1.81; P<.001; N2, HR = 2.33, 95% CI: 1.78-3.04; P<.001). LR was associated with squamous histology, visceral pleural involvement, tumor size, age, wedge resection, and segmentectomy. The most frequent site of LR was the mediastinum.

CONCLUSIONS

Our investigation demonstrated that nodal stage is directly associated with DR and OS but not with LR. Thus, even some patients with, N0-N1 disease are at relatively high risk of local recurrence. Prospective identification of risk factors for local recurrence may aid in selecting an appropriate population for further study of postoperative radiation therapy.

Chronic lymphocytic leukemia/small lymphocytic lymphoma, version 1.2015

Chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) are different manifestations of the same disease, which are managed in the same way. The advent of novel monoclonal antibodies (ofatumumab and obinutuzumab) led to the development of effective chemoimmunotherapy regimens. The recently approved small molecule kinase inhibitors (ibrutinib and idelalisib) are effective treatment options for CLL in elderly patients with decreased tolerance for aggressive regimens and in patients with poor prognostic features who do not benefit from conventional chemoimmunotherapy regimens. This portion of the NCCN Guidelines for Non-Hodgkin's Lymphomas describes the recent specific to the incorporation of recently approved targeted therapies for the management of patients with newly diagnosed and relapsed or refractory CLL/SLL.

Standardized beam bouquets for lung IMRT planning

The selection of the incident angles of the treatment beams is a critical component of intensity modulated radiation therapy (IMRT) planning for lung cancer due to significant variations in tumor location, tumor size and patient anatomy. We investigate the feasibility of establishing a small set of standardized beam bouquets for planning. The set of beam bouquets were determined by learning the beam configuration features from 60 clinical lung IMRT plans designed by experienced planners. A k-medoids cluster analysis method was used to classify the beam configurations in the dataset. The appropriate number of clusters was determined by maximizing the value of average silhouette width of the classification. Once the number of clusters had been determined, the beam arrangements in each medoid of the clusters were designated as the standardized beam bouquet for the cluster. This standardized bouquet set was used to re-plan 20 cases randomly selected from the clinical database. The dosimetric quality of the plans using the beam bouquets was evaluated against the corresponding clinical plans by a paired t-test. The classification with six clusters has the largest average silhouette width value and hence would best represent the beam bouquet patterns in the dataset. The results shows that plans generated with a small number of standardized bouquets (e.g. 6) have comparable quality to that of clinical plans. These standardized beam configuration bouquets will potentially help improve plan efficiency and facilitate automated planning.

Non-Hodgkin's lymphomas, version 2.2014

Non-Hodgkin's lymphomas (NHLs) are a heterogeneous group of lymphoproliferative disorders originating in B lymphocytes, T lymphocytes, or natural killer cells. Follicular lymphoma (FL) is the most common subtype of indolent NHL, accounting for approximately 22% of all newly diagnosed cases of NHL. The incorporation of rituximab to chemotherapy regimens has become a widely accepted standard of care for first-line therapy for patients with FL. Maintenance and consolidation therapy with rituximab and radioimmunotherapy have also been associated with improved progression-free survival in patients experiencing response to first-line therapy. Despite therapeutic advances that have improved outcomes, FL is generally considered a chronic disease characterized by multiple recurrences with current therapies. This manuscript discusses the recommendations outlined in the NCCN Guidelines for the diagnosis and management of patients with FL.

Lung

The lungs are particularly sensitive to RT, and are often the primary dose-limiting structure during thoracic therapy.

The alveolar/capillary units and pneumocytes within the alveoli appear to be particularly sensitive to RT.

Hypoxia may be important in the underlying physiology of RT-associated lung injury.

The cytokine transforming growth factor-beta (TGF-β), plays an important role in the development of RT-induced fibrosis.

The histopathological changes observed in the lung after RT are broadly characterized as diffuse alveolar damage.

The interaction between pre-treatment PFTs and the risk of symptomatic lung injury is complex. Similarly, the link between changes in PFTs and the development of symptoms is uncertain.

The incidence of symptomatic lung injury increases with increase in most dosimetric parameters. The mean lung dose (MLD) and V20 have been the most-often considered parameters. MLD might be a preferable metric since it considers the entire 3D dose distribution.

Radiation to the lower lobes appears to be more often associated with clinical symptoms than is radiation to the upper lobes. This might be related to incidental cardiac irradiation. In pre-clinical models, there appears to be a complex interaction between lung and heart irradiation.

TGF-β has been suggested in several studies to predict for RT-induced lung injury, but the data are still somewhat inconsistent.

Oral prednisone (Salinas and Winterbauer 1995), typically 40–60 mg daily for 1–2 weeks with a slow taper, is usually effective in treating pneumonitis. There are no widely accepted treatments for fibrosis.

A number of chemotherapeutic agents have been suggested to be associated with a range of pulmonary toxicities.

Low-dose whole brain radiotherapy combined with radiosurgery for primary CNS lymphoma achieving partial response to induction methotrexate-based chemotherapy

PURPOSE

For patients with primary CNS lymphoma who achieve complete response (CR) after induction methotrexate-based chemotherapy with rituximab, low-dose whole brain radiation therapy (LD-WBRT) appears effective and is well tolerated. For patients who respond to induction methotrexate-based chemotherapy with or without rituximab but have unifocal residual disease less than 3 cm in size, we hypothesized that LD-WBRT combined with radiosurgery would be effective at controlling residual disease and well tolerated.

METHODS

Four adult patients with primary CNS lymphoma with a favorable response to induction chemotherapy but had residual disease less than 3 cm were identified. Induction chemotherapy consisted of methotrexate with or without additional agents including rituximab. LD-WBRT comprised 2340 cGy in 13 fractions. This was immediately preceded or followed by a single radiosurgery treatment of 12 12.5 Gy to the focus of residual disease defined on contrast enhanced T1 weighted MRI.

RESULTS

The median follow-up was 17.1 months (range 10-23 months). All patients had residual disease after induction chemotherapy but achieved complete response (CR) following LD-WBRT and radiosurgery. Three patients remained free of disease. One patient developed distant brain recurrence 12 months after radiation but remained alive at last follow-up (17 months). No treatment-related neurotoxicity was observed.

CONCLUSIONS

The combination of induction methotrexate-based chemotherapy with or without rituximab, LD-WBRT and radiosurgery appears effective and well tolerated in patients with primary CNS lymphoma who achieve a partial response (PR) to chemotherapy with minimal residual disease. Longer follow-up and larger patient numbers are clearly needed for confirmation.

Stereotactic body radiotherapy: a critical review for nonradiation oncologists

Stereotactic body radiotherapy (SBRT) involves the treatment of extracranial primary tumors or metastases with a few, high doses of ionizing radiation. In SBRT, tumor kill is maximized and dose to surrounding tissue is minimized, by precise and accurate delivery of multiple radiation beams to the target. This is particularly challenging, because extracranial lesions often move with respiration and are irregular in shape, requiring careful treatment planning and continual management of this motion and patient position during irradiation. This review presents the rationale, process workflow, and technology for the safe and effective administration of SBRT, as well as the indications, outcome, and limitations for this technique in the treatment of lung cancer, liver cancer, and metastatic disease.

Does pneumonectomy have a role in the treatment of stage IIIA non-small cell lung cancer?

BACKGROUND

The role of surgical resection for stage IIIA non-small cell lung cancer (NSCLC) is unclear. We sought to examine outcomes after pneumonectomy for patients with stage IIIA disease.

METHODS

All patients with stage IIIA NSCLC who had pneumonectomy at a single institution between 1999 and 2010 were reviewed. The Kaplan-Meier method was used to estimate long-term survival and multivariable Cox proportional hazards regression was used to identify clinical characteristics associated with survival.

RESULTS

During the study period, 324 patients had surgical resection of stage IIIA NSCLC. Pneumonectomy was performed in 55 patients, 23 (42%) of whom had N2 disease. Induction treatment was used in 17 patients (31%) overall and in 11 of the patients (48%) with N2 disease. Perioperative mortality was 9% (n = 5) overall and 18% (n = 3) in patients that had received induction therapy (p = 0.17). Complications occurred in 32 patients (58%). Three-year survival was 36% and 5-year survival was 29% for all patients. Three-year survival was 40% for N0-1 patients and 29% for N2 patients (p = 0.59). In multivariable analysis, age over 60 years (hazard ratio [HR] 3.65, p = 0.001), renal insufficiency (HR 5.80, p = 0.007), and induction therapy (HR 2.17, p = 0.05) predicted worse survival, and adjuvant therapy (HR 0.35, p = 0.007) predicted improved survival.

CONCLUSIONS

Long-term survival after pneumonectomy for stage IIIA NSCLC is within an acceptable range, but pneumonectomy may not be appropriate after induction therapy or in patients with renal insufficiency. Patient selection and operative technique that limit perioperative morbidity and facilitate the use of adjuvant chemotherapy are critical to optimizing outcomes.

Non-Hodgkin's lymphomas, version 1.2013

These NCCN Guidelines Insights summarize several key updates to the NCCN Guidelines for Non-Hodgkin's Lymphomas (NHL) and provide a discussion of the clinical evidence that support the updates. The updates discussed in this article feature recommendations for additional treatment options in patients with chronic lymphocytic leukemia and guidance surrounding the management of hepatitis virus reactivation/infections in high-risk patients with NHL undergoing antitumor therapy.

Non-Hodgkin's Lymphomas, version 3.2012

These NCCN Guidelines Insights summarize several key updates to the 2012 NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Non-Hodgkin's Lymphomas (NHL) and describe the clinical evidence supporting the updates. The featured updates include changes to the recommendations for treatment options in patients with chronic lymphocytic leukemia (including in elderly or frail patients and patients with poor-risk cytogenetics), guidance surrounding surveillance imaging for follow-up of patients with NHL, and the addition of first-line consolidation options for patients with mantle cell lymphoma.

Association between RT-induced changes in lung tissue density and global lung function

PURPOSE

To assess the association between radiotherapy (RT)-induced changes in computed tomography (CT)-defined lung tissue density and pulmonary function tests (PFTs).

METHODS AND MATERIALS

Patients undergoing incidental partial lung RT were prospectively assessed for global (PFTs) and regional (CT and single photon emission CT [SPECT]) lung function before and, serially, after RT. The percent reductions in the PFT and the average changes in lung density were compared (Pearson correlations) in the overall group and subgroups stratified according to various clinical factors. Comparisons were also made between the CT- and SPECT-based computations using the Mann-Whitney U test.

RESULTS

Between 1991 and 2004, 343 patients were enrolled in this study. Of these, 111 patients had a total of 203 concurrent post-RT evaluations of changes in lung density and PFTs available for the analyses, and 81 patients had a total of 141 concurrent post-RT SPECT images. The average increases in lung density were related to the percent reductions in the PFTs, albeit with modest correlation coefficients (range, 0.20-0.43). The analyses also indicated that the association between lung density and PFT changes is essentially equivalent to the corresponding association with SPECT-defined lung perfusion.

CONCLUSION

We found a weak quantitative association between the degree of increase in lung density as defined by CT and the percent reduction in the PFTs.

Intensity-modulated radiotherapy for resected mesothelioma: the Duke experience

PURPOSE

To assess the safety and efficacy of intensity-modulated radiotherapy (IMRT) after extrapleural pneumonectomy for malignant pleural mesothelioma.

METHODS AND MATERIALS

Thirteen patients underwent IMRT after extrapleural pneumonectomy between July 2005 and February 2007 at Duke University Medical Center. The clinical target volume was defined as the entire ipsilateral hemithorax, chest wall incisions, including drain sites, and involved nodal stations. The dose prescribed to the planning target volume was 40-55 Gy (median, 45). Toxicity was graded using the modified Common Toxicity Criteria, and the lung dosimetric parameters from the subgroups with and without pneumonitis were compared. Local control and survival were assessed.

RESULTS

The median follow-up after IMRT was 9.5 months. Of the 13 patients, 3 (23%) developed Grade 2 or greater acute pulmonary toxicity (during or within 30 days of IMRT). The median dosimetric parameters for those with and without symptomatic pneumonitis were a mean lung dose (MLD) of 7.9 vs. 7.5 Gy (p = 0.40), percentage of lung volume receiving 20 Gy (V(20)) of 0.2% vs. 2.3% (p = 0.51), and percentage of lung volume receiving 5 Gy (V(20)) of 92% vs. 66% (p = 0.36). One patient died of fatal pulmonary toxicity. This patient received a greater MLD (11.4 vs. 7.6 Gy) and had a greater V(20) (6.9% vs. 1.9%), and V(5) (92% vs. 66%) compared with the median of those without fatal pulmonary toxicity. Local and/or distant failure occurred in 6 patients (46%), and 6 patients (46%) were alive without evidence of recurrence at last follow-up.

CONCLUSIONS

With limited follow-up, 45-Gy IMRT provides reasonable local control for mesothelioma after extrapleural pneumonectomy. However, treatment-related pulmonary toxicity remains a significant concern. Care should be taken to minimize the dose to the remaining lung to achieve an acceptable therapeutic ratio.

Radiation-induced lung injury. Assessment, management, and prevention

Radiation therapy (RT) is an important treatment modality for multiple thoracic malignancies. Incidental irradiation of the lungs, which are particularly susceptible to injury, is unavoidable and often dose-limiting. The most radiosensitive subunit of the lung is the alveolar/capillary complex, and RT-induced lung injury is often described as diffuse alveolar damage. Reactive oxygen species generated by RT are directly toxic to parenchymal cells and initiate a cascade of molecular events that alter the cytokine milieu of the microenvironment, creating a self-sustaining cycle of inflammation and chronic oxidative stress. Replacement of normal lung parenchyma by fibrosis is the culminating event. Depending on the dose and volume of lung irradiated, acute radiation pneumonitis may develop, characterized by dry cough and dyspnea. Fibrosis of the lung, which can also cause dyspnea, is the late complication. Imaging studies and pulmonary function tests can be used to quantify the extent of lung injury. While strict dose-volume constraints to minimize the risk of injury are difficult to impose, substantial data support some general guidelines. New modalities such as intensity-modulated radiation therapy and stereotactic body radiation therapy provide new treatment options but also pose new challenges in safely delivering thoracic RT.

Different models, different trees: the geographic origin of PTLV-I

Using nucleotide sequences from three genomic regions of the human and simian T-cell lymphotropic virus type I (HTLV-I/STLV-I)-consisting of 69 sequences from a 140-bp segment of the pol region, 98 sequences from a 503-bp segment of the LTR, and 154 sequences from a 386-bp segment of the env region-we tested two hypotheses concerning the geographic origin and evolution of STLV-I and HTLV-I. First, we tested the assumption of equal rates of evolution along STLV-I and HTLV-I lineages using a likelihood ratio test to ascertain whether current levels of genomic diversity can be used to determine ancestry. We demonstrated that unequal rates of evolution along HTLV-I and STLV-I lineages have occurred throughout evolutionary time, thus calling into question the use of pairwise distances to assign ancestry. Second, we constructed phylogenetic trees using multiple phylogenetic techniques to test for the geographic origin of STLV-I and HTLV-I. Using the principle of likelihood, we chose a statistically justified model of evolution for each data set. We demonstrated the utility of the likelihood ratio test to determine which model of evolution should be chosen for phylogenetic analyses, revealing that using different models of evolution produces conflicting results, and neither the hypothesis of an African origin nor the hypothesis of an Asian origin can be rejected statistically. Our best estimates of phylogenetic relationships, however, support an African origin of PTLV for each gene region.

Parallel evolution of drug resistance in HIV: failure of nonsynonymous/synonymous substitution rate ratio to detect selection

Parallel or convergent evolution at the molecular level has been difficult to demonstrate especially when rigorous statistical criteria are applied. We present sequence data from the protease gene from eight patients infected with the human immunodeficiency virus (HIV-1). These patients have been on multiple drug therapies for at least 2 years. We present sequence data from two timepoints: time zero--the initiation of drug therapy--and a subsequent timepoint between 59 and 104 weeks after the initiation of drug therapy. In addition to the sequence data, we present viral load data from both initial and final timepoints. Our phylogenetic analyses indicate significant evolution of virus from initial to final time points, even in three of eight patients who show low viral loads. Of the five patients who escaped drug therapy, identical amino acid replacements were seen in all five patients at two different codon positions, an indication of parallel evolution. We also measured genetic diversity for these patients and found no correlation between genetic diversity and viral load. Finally, we calculated the nonsynonymous and synonymous substitution rates and showed that the ratio of nonsynonymous to synonymous substitution compared to the value of one may be a poor indicator of natural selection.

Myositis and eosinophilia in a patient with sarcoidosis

We present a patient with muscle manifestations of sarcoidosis associated with raised creatine kinase levels, eosinophilia and interstitial lung disease. She had significant improvement on prednisolone 30 mg per day.

Serum amyloid P component scintigraphy and turnover studies for diagnosis and quantitative monitoring of AA amyloidosis in juvenile rheumatoid arthritis

OBJECTIVE

To evaluate aspects of the natural history of AA amyloidosis complicating juvenile rheumatoid arthritis (JRA), and its response to therapy with chlorambucil.

METHODS

Scintigraphy and 7-day turnover studies were performed in JRA patients with histologically proven (n = 35) or clinically suspected (n = 30) AA amyloidosis, following intravenous injection of 123I and 125I-labeled serum amyloid P component (SAP). Prospective monitoring studies were performed over 2-3 years in 20 patients with amyloidosis. All but 2 amyloidosis patients were treated with chlorambucil.

RESULTS

Positive scanning results were obtained in all patients in whom imaging was performed within 12 years of positive biopsy findings of amyloid and in 5 patients with clinically suspected amyloidosis. Negative scanning results with normal SAP metabolism, indicating regression of amyloid, were obtained in 4 patients whose amyloidosis had been in full clinical remission for more than 12 years. Prospective monitoring studies in patients whose JRA-associated inflammatory activity was in remission demonstrated regression of amyloid in 8 patients and no substantial changes in 8 others; however, in 4 further patients with active inflammation, there was accumulation of amyloid. There was a very poor correlation between the amount of amyloid present at a particular site and the resultant organ dysfunction.

CONCLUSION

Radiolabeled SAP scintigraphy and turnover studies are useful complementary tools in the diagnosis, screening, and quantitative monitoring of type AA amyloidosis in JRA. The amyloid deposits may progress and/or regress at different rates in different anatomic sites over short periods.

Metabolic balance studies of mineral supplementation in osteoporosis

1. We studied the effect of mineral supplementation and its duration in osteoporosis by analysing the calcium and phosphorus balances of 49 treated osteoporotic patients whose median length of calcium treatment was 19 weeks with a range of 8 days to over 4 years. Forty-four studies satisfied statistical criteria of reproducibility and included 35 women (10 also receiving oestrogen replacement therapy) and nine men. 2. Mean calcium balance was positive in women taking calcium supplements alone, +1.9 +/- 2.5 mmol daily (P less than 0.002), and was significantly more positive (P less than 0.05) in women also taking oestrogens, +4.2 +/- 2.1 mmol daily. Calcium balance was not significantly positive in men. 3. Calcium balance correlated negatively with duration of supplementation, but significantly, only when duration of supplementation was expressed logarithmically (r = -0.401, P less than 0.01) giving the regression equation y = 4.2-1.6 log x, where y = calcium balance in mol/day and x = duration of supplementation in weeks. Theoretical net calcium retention, without allowance for dermal loss, could be calculated by integration. 4. Mean phosphorus balance was significantly positive in both groups of women and in the whole population. Although its correlation with duration of supplementation did not reach statistical significance (P less than 0.1), the ratio of the regression slopes for calcium and phosphorus, 1.5:1, corresponded to their molar ratio in bone. 5. These statistics are, we believe, the first to describe an exponential decline in calcium balance during mineral treatment of osteoporosis, but they firmly suggest that such treatment, with or without oestrogen therapy, conveys temporary benefit.

Fluoride therapy and parathyroid hormone activity in osteoporosis

1. To determine the relationships between parathyroid hormone activity and long-term sodium fluoride therapy in osteoporosis, cytochemical bioassays (for biologically active parathyroid hormone) were performed in 22 osteoporotic control patients and in 18 patients after 15 +/- 10 months of treatment (60 mg of sodium fluoride daily). Ten patients were studied longitudinally by repeated metabolic balances and were therefore common to both groups. All patients were receiving mineral supplements. 2. Cross-sectional data showed a fourfold mean increase in biologically active parathyroid hormone on fluoride treatment (P less than 0.005) together with a 51% increase in serum alkaline phosphatase (P less than 0.005). Longitudinal data showed, in addition, a significant increase in the calcium balance of 2.4 +/- 1.2 (SEM) mmol daily (P less than 0.05) and the development of a positive phosphorus balance (P less than 0.02). 3. Fluoride-treated patients were then analysed in two groups according to the level of biologically active parathyroid hormone. Thirty-two per cent of values were above the upper limit of normal (18 pg/ml). The mean serum alkaline phosphatase level in this group showed no elevation above that of the control patients, the overall rise being accounted for entirely by patients with normal levels of biologically active parathyroid hormone. High levels of biologically active parathyroid hormone were also associated with relative hypophosphataemia (P less than 0.01), relative hypercalciuria (P less than 0.05) and an increased urine/faecal calcium ratio (P less than 0.025). 4. Results show that long-term fluoride and calcium therapy increase biologically active parathyroid hormone in osteoporosis and that excessive parathyroid hormone activity may account for certain features of the refractory state.

PTH bioactivity in osteoporosis

The cytochemical bioassay for parathyroid hormone was used to measure the levels of PTH bioactivity in normal elderly subjects and patients suffering from idiopathic or postmenopausal osteoporosis. In normal subjects, PTH bioactivity did not increase with age. In the osteoporotic patients levels of bioPTH discriminated between two populations, one with normal levels and the other with elevated levels. In both these groups the PTH bioactivity was neutralised by the addition of a PTH antiserum. The recovery of the bioactivity of PTH added to the plasma samples was significantly higher in the plasmas from patients with elevated levels of bioPTH. Levels of immunoreactive PTH also discriminated between the two groups of osteoporotic patient although no serum parameters indicative of increased PTH were detectable. However, patients with the high levels of bio- and immunoPTH had a lower incidence of fracture within the previous 12 months.

Dexamethasone inhibits the production of thromboxane B2 and leukotriene B4 by human alveolar and peritoneal macrophages in culture

Cultured human alveolar and peritoneal macrophages have been shown to release thromboxane B2 and leukotriene B4. The release was facilitated by stimulation of the macrophages with opsonized zymosan A (1.2 mg/ml). The release was inhibited in a concentration-dependent manner by incubation of the cells with dexamethasone (1 nmol/l to 1 mumol/l).

Synthesis of leukotriene B4, and prostanoids by human alveolar macrophages: analysis by gas chromatography/mass spectrometry

Human alveolar macrophages, obtained during diagnostic bronchoscopy, were maintained in monolayer culture. Challenge of these cells (greater than 95% purity) with 1.2 mg/ml zymosan A particles (opsonized with human serum) was followed by a rapid release of leukotriene B4 into the medium, 7.28 +/- 5.99 ng/mg cell protein at 2 h (mean +/- S.D.4, n = 4). Leukotriene B4 was identified and measured by a novel technique employing capillary column gas chromatography coupled to negative ion chemical ionization mass spectrometry. The release of thromboxane B2, prostaglandins D2, E2, F2 alpha and the lysosomal enzyme N-acetyl-beta-D-glucosaminidase was also measured. Thromboxane B2 was the most abundant metabolite of arachidonic acid released into the culture medium (65.2 +/- 14.8 ng/mg cell protein 2 h after the addition of zymosan A, n = 4), and the synthesis of thromboxane B2 was inhibited by greater than 90% in 1 microM Na flurbiprofen. Inhibition of cyclooxygenase activity was accompanied by a 2-fold increase in leukotriene B4 synthesis.

A method for assessing responses of small arteries in man: effect of physiological and pharmacological stimuli

1. A method has been developed for estimating resistance to blood flow in the collateral arteries around the elbow. Arterial pressure is recorded continuously from the radial artery and blood flow in the forearm and hand is measured by venous occlusion plethysmography. The brachial artery is occluded for short periods, and the pressure drop across the collaterals and the flow through them are determined. From these observations an index of resistance can be calculated. 2. During 2 min occlusions of the brachial artery, collateral arterial resistance fell progressively to reach a level that was on average 45% lower than the initial resistance (P less than 0.01). 3. There was an inverse relation between distending pressure in the collateral arteries and calculated resistance. 4. Ergotamine tartrate (0.25 mg intravenously) increased collateral resistance by an average of 135%. Glyceryl trinitrate (0.5 mg sublingually) reduced collateral resistance by an average of 45%. Hydrallazine and isoprenaline had an inconsistent dilator effect; the direct action of these drugs may have been offset by the reduction in distending pressure which they induced. 5. The elbow collateral arteries provide a useful model for studying physiological and pharmacological responses of small limb arteries in man.

Effects of nifedipine on resistance vessels, arteries and veins in man

1 The effect of nifedipine on peripheral blood vessels has been studied in man. 2 Nifedipine induced dilatation of the forearm resistance vessels when given either by local intra-arterial infusion or sublingually (10 mg). 3 Local infusion of the drug did not relax hand veins preconstricted by infusion of noradrenaline and neither local infusion nor sublingual administration prevented constriction mediated by the sympathetic nervous system. Nifedipine was, however, a potent inhibitor of hand vein contractions induced by high concentrations of potassium provided that the noradrenergic component of the response was suppressed by simultaneous infusion of phentolamine. 4 Sublingual nifedipine (10 mg) did not dilate the elbow collateral arteries. 5 The effects of nifedipine on peripheral blood vessels are similar, but not identical, to those of verapamil. The pattern of action, with dilatation of resistance vessels but not capacitance, resembles that of hydralazine rather than glyceryl trinitrate and this suggest that nifedipine may prove useful in the treatment of hypertension.