Transoral Surgery in HPV-Positive Oropharyngeal Carcinoma: Oncologic Outcomes in the Veterans Affairs System

OBJECTIVES

Most transoral robotic surgery (TORS) literature for HPV-positive oropharyngeal squamous cell carcinoma (HPV-OPC) derives from high-volume tertiary-care centers. This study aims to describe long-term recurrence and survival outcomes among Veterans Health Administration patients.

MATERIALS AND METHODS

Using the US Veterans Affairs database, we identified patients with HPV-OPC treated with TORS between January 2010 and December 2016. Patients were stratified in risk categories: low (0-1 metastatic nodes, negative margins), intermediate (close margins, 2-4 metastatic nodes, lymphovascular or perineural invasion, pT3-pT4 tumor), or high (positive margins, extranodal extension (ENE), and/or ≥5 metastatic nodes). Primary outcomes included overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS).

RESULTS

The cohort included 161 patients of which 29 (18%) were low-risk, 45 (28%) intermediate-risk, and 87 (54%) high-risk. ENE was present in 41% of node-positive cases and 24% had positive margins. Median follow-up was 5.6 years (95% CI, 3.0-9.3). The 5-year DSS for low, intermediate, and high-risk groups were: 100%, 90.0% (95% CI, 75.4-96.1%), and 88.7% (95% CI, 78.3-94.2%). Pathologic features associated with poor DSS on univariable analysis included pT3-T4 tumors (HR 3.81, 95% CI, 1.31-11; p = 0.01), ≥5 metastatic nodes (HR 3.41, 95% CI, 1.20-11; p = 0.02), and ENE (HR 3.53, 95% CI, 1.06-12; p = 0.04). Higher 5-year cumulative incidences of recurrence were observed in more advanced tumors (pT3-T4, 33% [95% CI, 14-54%] versus pT1-T2, 13% [95% CI, 8-19%]; p = 0.01).

CONCLUSIONS

In this nationwide study, patients with HPV-OPC treated with TORS followed by adjuvant therapy at Veterans Affairs Medical Centers demonstrated favorable survival outcomes comparable to those reported in high-volume academic centers and clinical trials.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:207-214, 2024.

18F-FDG PET/CT Prediction of Treatment Outcomes in Human Papillomavirus-Positive, Locally Advanced Oropharyngeal Cancer Patients Receiving Deintensified Therapy: Results from NRG-HN002

The purpose of this study was to determine the negative predictive value (NPV) of a 12- to 14-wk posttreatment PET/CT for 2-y progression-free survival (PFS) and locoregional control (LRC) in patients with p16-positive locoregionally advanced oropharyngeal cancer (LA-OPC). Study was a secondary endpoint in NRG-HN002, a noncomparative phase II trial in p16-positive LA-OPC, stage T1-T2, N1-N2b or T3, N0-N2b, and ≤10 pack-year smoking. Patients were randomized in a 1:1 ratio to reduced-dose intensity-modulated radiotherapy (IMRT) with or without cisplatin. Methods: PET/CT scans were reviewed centrally. Tumor response evaluations for the primary site, right neck, and left neck were performed using a 5-point ordinal scale (Hopkins criteria). Overall scores were then assigned as negative, positive, or indeterminate. Patients with a negative score for all 3 evaluation sites were given an overall score of negative. The hypotheses were NPV for PFS and LRC at 2-y posttreatment ≤ 90% versus >90% (1-sided P value, 0.10). Results: A total of 316 patients were enrolled, of whom 306 were randomized and eligible. Of these, 131 (42.8%) patients consented to a posttherapy PET/CT, and 117 (89.3%) patients were eligible for PET/CT analysis. The median time from the end of treatment to PET/CT scan was 94 d (range, 52-139 d). Estimated 2-y PFS and LRC rates in the analysis subgroup were 91.3% (95% CI, 84.6, 95.8%) and 93.8% (95% CI, 87.6, 97.5%), respectively. Posttreatment scans were negative for residual tumor for 115 patients (98.3%) and positive for 2 patients (1.7%). NPV for 2-y PFS was 92.0% (90% lower confidence bound [LCB] 87.7%; P = 0.30) and for LRC was 94.5% (90% LCB 90.6%; P = 0.07). Conclusion: In the context of deintensification with reduced-dose radiation, the NPV of a 12- to 14-wk posttherapy PET/CT for 2-y LRC is estimated to be >90%, similar to that reported for patients receiving standard chemoradiation. However, there is insufficient evidence to conclude that the NPV is >90% for PFS.

Imaging Biomarkers and Liquid Biopsy in Assessment of Cervical Cancer

ABSTRACT

The role of imaging has been increasing in pretherapy planning and response assessment in cervical cancer, particularly in high-resource settings that provide access to computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). In 2018, imaging was incorporated into the International Federation of Gynecology and Obstetrics staging system for cervical cancer. Magnetic resonance imaging is advantageous over CT for evaluation of the primary cervical cancer size and extent, because of superior contrast resolution. Furthermore, quantitative methods, including diffusion-weighted and dynamic contrast-enhanced MRI, show promise in improving treatment response and prognosis evaluation. Molecular imaging with fluorodeoxyglucose-PET/CT and PET/MRI can be particularly helpful in the detection of nodal disease and distant metastases. Semiautomated delineation of 3-dimensional tumor regions of interest has facilitated the development of novel PET-derived biomarkers that include metabolic volume and radiomics textural analysis features for prediction of outcomes. However, posttreatment inflammatory changes can be a confounder and lymph node evaluation is challenging, even with the use of PET/CT. Liquid biopsy has emerged as a promising tool that may be able to overcome some of the drawbacks inherent with imaging, such as limited ability to detect microscopic metastases or to distinguish between postchemoradiotherapy changes and residual tumor. Preliminary evidence suggests that liquid biopsy may be able to identify cervical cancer treatment response and resistance earlier than traditional methods. Future work should prioritize how to best synergize imaging and liquid biopsy as an integrated approach for optimal cervical cancer management.

Management of Older Adults with Locally Advanced Head and Neck Cancer

Simple Summary

Approximately one third of patients with head and neck cancer are older adults. The number of older adults with head and neck cancer continues to rise especially as life expectancy increases. However, this population remains significantly underrepresented in clinical trials. Due to this, there is no clear consensus regarding the optimal treatment for older adults with head and neck cancer. In general, older adults are a complex cohort due to variations in functional and performance status, medical comorbidities, and medication management. Treatment for head and neck cancer involves surgery, radiation therapy, systemic therapy, or a combination. These treatments are highly demanding. Additionally, they are associated with toxicity which can be especially difficult for older adults to tolerate. This may lead to treatment interruptions and compromised outcomes. In order to understand the optimal treatment for older adults with head and neck cancer, novel predictive scores are being developed. Additionally, ongoing clinical trials are investigating less intensive treatments for older adults. This review provides an overview of current clinical data, treatment considerations, and future areas of investigation for older adults with head and neck cancer.

Abstract

Thirty percent of patients with head and neck squamous cell carcinoma (HNSCC) are at least 70 years of age. This number continues to rise as life expectancy continues to increase. Still, older adults with HNSCC remain underrepresented in clinical trials, resulting in ambiguity on optimal management. Older adults are a complex patient population, often requiring increased support due to issues relating to functional and performance status, medical comorbidities, and medication management. Furthermore, in older adults with HNSCC, many of these conditions are independently associated with increased toxicity and worse outcomes. Toxicity in the older adult remains difficult to predict and to understand, and as treatment decisions are based on treatment tolerability, it is essential to understand the toxicities and how to minimize them. Novel predictive scores are being developed specifically for older adults with HNSCC to understand toxicity and to assist in personalized treatment decisions. There are clinical trials presently underway that are investigating shortened radiation courses and novel, less toxic systemic treatments in this population. In the forthcoming sections, we provide a detailed overview of the clinical data, treatment paradigms, and considerations in this population. This review provides a comprehensive overview of existing clinical data and clinical considerations in the older adult head and neck cancer population. Additionally, we provide a detailed overview of pertinent current and ongoing clinical trials, as well as future areas for investigation.

Public access to protocols of contemporary cancer randomized clinical trials

Access to randomized clinical trial (RCT) protocols is necessary for the interpretation and reproducibility of the study results, but protocol availability has been lacking. We determined the prevalence of protocol availability for all published cancer RCTs in January 2020. We found that only 36.1% (48/133) of RCTs had an accessible protocol and only 11.3% of RCTs (15/133) had a publicly accessible protocol that was not behind a paywall. Only 18.0% (24/133) of RCTs were published in conjunction with the protocol on the journal website. In conclusion, few cancer RCTs have an accessible research protocol. Journals should require publication of RCT protocols along with manuscripts to improve research transparency.

Association of Prostate-Specific Antigen Velocity With Clinical Progression Among African American and Non-Hispanic White Men Treated for Low-Risk Prostate Cancer With Active Surveillance

IMPORTANCE

The association of prostate-specific antigen velocity (PSAV) with clinical progression in patients with localized prostate cancer managed with active surveillance remains unclear and, to our knowledge, has not been studied in African American patients.

OBJECTIVES

To test the hypothesis that PSAV is associated with clinical progression in patients with low-risk prostate cancer treated with active surveillance and to identify differences between African American and non-Hispanic White patients.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective population-based cohort study using patient records from the Veterans Heath Administration Informatics and Computing Infrastructure on 5296 patients with a diagnosis of localized prostate cancer from January 1, 2001, to December 31, 2015, who were managed with active surveillance. Follow-up extended through March 31, 2020. Low-risk prostate cancer was defined as International Society of Urologic Pathology grade group (GG) 1 clinical tumor stage 2A or lower, PSA level of 10 ng/dL or lower, active surveillance, and no definitive treatment within the first year after diagnosis with at least 1 additional staging biopsy after diagnostic biopsy.

EXPOSURES

Prostate-specific antigen testing.

MAIN OUTCOMES AND MEASURES

The primary outcome was GG progression detected after repeated biopsy or prostatectomy, defined as GG2 or higher or GG3 or higher. The secondary outcome was incident metastases. Cumulative incidence functions and multivariable Cox proportional hazards regression models were used to test associations between PSAV and outcomes.

RESULTS

The final cohort (n = 5296) included 3919 non-Hispanic White men (74.0%; mean [SD] age, 65.7 [5.8] years) and 1377 African American men (26.0%; mean [SD] age, 62.8 [6.6] years). Compared with African American patients, non-Hispanic White patients were older (mean [SD] age, 65.7 [5.8] years vs 62.8 [6.6] years; P < .001), presented with higher cT stage (stage T2, 608 [15.5%] vs 111 [8.1%]; P < .001), had a higher Charlson Comorbidity Index score (1 and ≥2, 912 [23.3%] vs 273 [19.8%]; P = .002), had higher median income ($60 000 to ≥$100 000, 1223 [31.2%] vs 282 [20.5%]; P < .001), and had a higher median level of education (20% to ≥30% with college degree, 1192 [30.4%] vs 333 [24.2%]; P < .001). Progression to GG2 or higher occurred in 2062 patients (38.9%), with a cumulative incidence of 43.2%, and progression to GG3 or higher occurred in 728 patients (13.7%). Fifty-four patients (1.0%) developed metastases. On multivariable analysis, PSAV was significantly associated with progression to GG2 (hazard ratio, 1.32 [95% CI, 1.26-1.39]), GG3 (hazard ratio, 1.51 [95% CI, 1.41-1.62]), and metastases (hazard ratio, 1.38 [95% CI, 1.10-1.74]). Optimal PSAV thresholds that were associated with progression were significantly lower for African American patients (0.44 ng/mL/y) compared with non-Hispanic White patients (1.18 ng/mL/y).

CONCLUSIONS AND RELEVANCE

This study suggests that PSAV is significantly associated with grade progression among patients with low-risk prostate cancer managed with active surveillance, but at lower values for African American patients compared with non-Hispanic White patients. These data suggest that serial PSA measures may potentially substitute for multiple prostate biopsies and that African American patients may merit increased frequency of PSA testing.

18 FDG PET/CT prediction of treatment outcomes in patients with p16-positive, non-smoking associated, locoregionally advanced oropharyngeal cancer (LA-OPC) receiving deintensified therapy: Results from NRG-HN002

6563

Background: To determine the negative predictive value (NPV) of 12-14 week post-treatment PET/CT for 2-year progression-free survival (PFS) and 2-year locoregional control (LRC) in NRG-HN002, which is a two-arm phase II trial for patients with low-risk, non-smoking associated p16-positive LA-OPC randomized in a 1:1 ratio to reduced-dose IMRT with or without cisplatin. Methods: PET/CT scans were reviewed both centrally and locally by participating institutions. Tumor response evaluations for primary site, right neck, and left neck were carried out using a 5-point ordinal scale (‘Hopkins Criteria’). Overall scores were then assigned as ‘Negative,’ Positive,’ or ‘Indeterminate.’ Patients who had a ‘Negative’ score for all three evaluation sites were given an overall score of ‘Negative.’ The endpoints were NPV for LRC and PFS at 2 years testing NPV ≤ 90% vs > 90% (1-sided alpha 0.10 and 76% power). Results: There were 316 patients enrolled, of whom 306 were randomized and eligible. Of these, 131 (42.8%) patients consented to a post-therapy PET/CT, and 117 (89.3%) patients were eligible for PET/CT analysis. The median time from end of treatment to PET/CT scan was 94 days (range 52-139). The rates of 2-yr PFS and LRC in the analysis subgroup were 91.3% and 93.8%, respectively. Based on central review, post-treatment scans were negative for residual tumor for 115 patients (98.3%) and positive for 2 patients (1.7%). The NPV for 2-year LRC was 94.5% (90% lower confidence bound [LCB] 90.6%; p = 0.07). NPV for 2-year PFS was 92.0% (90% LCB 87.7%; p = 0.30). Similar NPV results were obtained based on analysis of local reviews. Conclusion: Within the context of deintensification with reduced-dose radiation, the NPV of a 12-14 week post-therapy PET/CT for 2-year LRC is statistically > 90%, similar to that reported for patients receiving standard chemoradiation. However, in this study, there was not enough evidence to conclude that the NPV of a 12-14 week post-therapy PET/CT for 2-year PFS is > 90%. Grant acknowledgement: This project was supported by grants U10CA180868 (NRG Oncology Operations), U10CA180822 (NRG Oncology SDMC), U24CA180803 (IROC), UG1CA189867 (NRG Oncology NCORP) from the National Cancer Institute (NCI). This project is funded, in part, under a Grant with the Pennsylvania Department of Health. The Department specifically disclaims responsibility for any analyses, interpretations or conclusions. Clinical trial information: NCT02254278 .

B Cells Improve Overall Survival in HPV-Associated Squamous Cell Carcinomas and Are Activated by Radiation and PD-1 Blockade

PURPOSE

To characterize the role of B cells on human papilloma virus (HPV)-associated cancer patient outcomes and determine the effects of radiation and PD-1 blockade on B-cell populations.

EXPERIMENTAL DESIGN

Tumor RNA-sequencing data from over 800 patients with head and neck squamous cell carcinoma (HNSCC) and cervical cancer, including a prospective validation cohort, was analyzed to study the impact of B-cell gene expression on overall survival (OS). A novel murine model of HPV⁺ HNSCC was used to study the effects of PD-1 blockade and radiotherapy on B-cell activation, differentiation, and clonality including analysis by single-cell RNA-sequencing and B-cell receptor (BCR)-sequencing. Human protein microarray was then used to quantify B-cell-mediated IgG and IgM antibodies to over 16,000 proteins in the serum of patients treated on a clinical trial with PD-1 blockade.

RESULTS

RNA-sequencing identified CD19 and IGJ as novel B-cell prognostic biomarkers for 3-year OS (HR, 0.545; P < 0.001). PD-1 blockade and radiotherapy enhance development of memory B cells, plasma cells, and antigen-specific B cells. BCR-sequencing found that radiotherapy enhances B-cell clonality, decreases CDR3 length, and induces B-cell somatic hypermutation. Single-cell RNA-sequencing identified dramatic increases in B-cell germinal center formation after PD-1 blockade and radiotherapy. Human proteome array revealed enhanced IgG and IgM antibody responses in patients who derived clinical benefit but not those with progressive disease after treatment with PD-1 blockade.

CONCLUSIONS

These findings establish a key role for B cells in patient outcomes and responses to PD-1 blockade in HPV-associated squamous cell carcinomas and demonstrate the need for additional diagnostics and therapeutics targeting B cells.

'Optimism bias' in contemporary national clinical trial network phase III trials: are we improving?

Background

Previous studies have found that overestimating treatment effects (i.e. 'optimism bias') leads to underpowered clinical trials. The prevalence of 'optimism bias' in contemporary National Clinical Trials Network (NCTN) cancer clinical trials is unknown.

Methods

We conducted a systematic review of NCTN phase III randomized trials published from January 2007 to January 2017. We compared the hypothesized versus observed treatment effects in each trial, and examined whether trial-related factors were correlated with the study results. We also reviewed the methods of each protocol to assess whether a rationale for the hypothesized effect size was provided.

Results

We identified 161 clinical trials, of which 130 were eligible for analysis. Original protocols could not be located for 8 trials (5.0%). Twenty-eight trials (21.5%) observed a statistically significant difference in the primary end point favoring the experimental treatment. The median ratio of observed-to-expected hazard ratios among trials that observed a statistically significant effect on the primary end point was 1.07 (range: 0.33-1.28) versus 1.32 (range: 0.86-2.02) for trials that did not, compared with 1.34 and 1.86, respectively, for National Cancer Institute (NCI) trials published between 1955 and 2006. An effect size at least as large as the one projected in the protocol trials was observed in 9.8% of trials, compared with 17% of NCI trials published from 1955 to 2006. Most trials (64.6%) provided no rationale to support the magnitude of the proposed treatment effect in the protocol.

Conclusions

Despite a reduction in 'optimism bias' compared with previous eras, most contemporary NCTN phase III trials failed to establish statistically significant benefits of new cancer therapies. Better rationalization of proposed effect sizes in research protocols is needed.

Role of Treatment Deintensification in the Management of p16+ Oropharyngeal Cancer: ASCO Provisional Clinical Opinion

PURPOSE

An ASCO provisional clinical opinion offers timely clinical direction to ASCO’s membership after publication or presentation of potentially practice-changing data from major studies. This provisional clinical opinion addresses the role of treatment deintensification in the management of p16+ oropharyngeal cancer (OPC).

CLINICAL CONTEXT

For patients with p16+ OPC, current treatment approaches are well established. In the good-prognosis subset of nonsmoking p16+ patients with early-stage disease, these treatments have been highly successful, albeit with significant associated acute and late toxicity. Deintensification of surgical, radiation, and medical treatment in an effort to reduce toxicity while preserving high survival rates is an appropriate therapeutic objective currently being explored in patients who are experiencing the best treatment results. However, careful delineation of this good-risk subset is essential. While the current eighth edition of the American Joint Committee on Cancer staging system is prognostically robust, it should not be interpreted as reason to alter therapeutic decisions or justify treatment deintensification. The development of transoral surgical techniques and the adoption of intensity-modulated radiation therapy planning have been transformative in disease management and suggest potentially beneficial approaches. Recent advances in systemic treatments have been notable. The optimal integration and modification of these modalities to ameliorate toxicity has not been defined and remains an important focus of current investigation.

PROVISIONAL CLINICAL OPINION

The hypothesis that de-escalation of treatment intensity for patients with p16+ OPC can reduce long-term toxicity without compromising survival is compelling and necessitates careful study and the analysis of well-designed clinical trials before changing current treatment standards. Treatment deintensification for these patients should only be undertaken in a clinical trial. Additional information is available at www.asco.org/head-neck-cancer-guidelines .

An Automated Treatment Plan Quality Control Tool for Intensity-Modulated Radiation Therapy Using a Voxel-Weighting Factor-Based Re-Optimization Algorithm

Intensity-modulated radiation therapy (IMRT) currently plays an important role in radiotherapy, but its treatment plan quality can vary significantly among institutions and planners. Treatment plan quality control (QC) is a necessary component for individual clinics to ensure that patients receive treatments with high therapeutic gain ratios. The voxel-weighting factor-based plan re-optimization mechanism has been proved able to explore a larger Pareto surface (solution domain) and therefore increase the possibility of finding an optimal treatment plan. In this study, we incorporated additional modules into an in-house developed voxel weighting factor-based re-optimization algorithm, which was enhanced as a highly automated and accurate IMRT plan QC tool (TPS-QC tool). After importing an under-assessment plan, the TPS-QC tool was able to generate a QC report within 2 minutes. This QC report contains the plan quality determination as well as information supporting the determination. Finally, the IMRT plan quality can be controlled by approving quality-passed plans and replacing quality-failed plans using the TPS-QC tool. The feasibility and accuracy of the proposed TPS-QC tool were evaluated using 25 clinically approved cervical cancer patient IMRT plans and 5 manually created poor-quality IMRT plans. The results showed high consistency between the QC report quality determinations and the actual plan quality. In the 25 clinically approved cases that the TPS-QC tool identified as passed, a greater difference could be observed for dosimetric endpoints for organs at risk (OAR) than for planning target volume (PTV), implying that better dose sparing could be achieved in OAR than in PTV. In addition, the dose-volume histogram (DVH) curves of the TPS-QC tool re-optimized plans satisfied the dosimetric criteria more frequently than did the under-assessment plans. In addition, the criteria for unsatisfied dosimetric endpoints in the 5 poor-quality plans could typically be satisfied when the TPS-QC tool generated re-optimized plans without sacrificing other dosimetric endpoints. In addition to its feasibility and accuracy, the proposed TPS-QC tool is also user-friendly and easy to operate, both of which are necessary characteristics for clinical use.

Dose-Dependent Cortical Thinning After Partial Brain Irradiation in High-Grade Glioma

PURPOSE

Radiation-induced cognitive deficits may be mediated by tissue damage to cortical regions. Volumetric changes in cortex can be reliably measured using high-resolution magnetic resonance imaging (MRI). We used these methods to study the association between radiation therapy (RT) dose and change in cortical thickness in high-grade glioma (HGG) patients.

METHODS AND MATERIALS

We performed a voxel-wise analysis of MRI from 15 HGG patients who underwent fractionated partial brain RT. Three-dimensional MRI was acquired pre- and 1 year post RT. Cortex was parceled with well-validated segmentation software. Surgical cavities were censored. Each cortical voxel was assigned a change in cortical thickness between time points, RT dose value, and neuroanatomic label by lobe. Effects of dose, neuroanatomic location, age, and chemotherapy on cortical thickness were tested using linear mixed effects (LME) modeling.

RESULTS

Cortical atrophy was seen after 1 year post RT with greater effects at higher doses. Estimates from LME modeling showed that cortical thickness decreased by -0.0033 mm (P<.001) for every 1-Gy increase in RT dose. Temporal and limbic cortex exhibited the largest changes in cortical thickness per Gy compared to that in other regions (P<.001). Age and chemotherapy were not significantly associated with change in cortical thickness.

CONCLUSIONS

We found dose-dependent thinning of the cerebral cortex, with varying neuroanatomical regional sensitivity, 1 year after fractionated partial brain RT. The magnitude of thinning parallels 1-year atrophy rates seen in neurodegenerative diseases and may contribute to cognitive decline following high-dose RT.

A deformable head and neck phantom with in-vivo dosimetry for adaptive radiotherapy quality assurance

PURPOSE

Patients' interfractional anatomic changes can compromise the initial treatment plan quality. To overcome this issue, adaptive radiotherapy (ART) has been introduced. Deformable image registration (DIR) is an important tool for ART and several deformable phantoms have been built to evaluate the algorithms' accuracy. However, there is a lack of deformable phantoms that can also provide dosimetric information to verify the accuracy of the whole ART process. The goal of this work is to design and construct a deformable head and neck (HN) ART quality assurance (QA) phantom with in vivo dosimetry.

METHODS

An axial slice of a HN patient is taken as a model for the phantom construction. Six anatomic materials are considered, with HU numbers similar to a real patient. A filled balloon inside the phantom tissue is inserted to simulate tumor. Deflation of the balloon simulates tumor shrinkage. Nonradiopaque surface markers, which do not influence DIR algorithms, provide the deformation ground truth. Fixed and movable holders are built in the phantom to hold a diode for dosimetric measurements.

RESULTS

The measured deformations at the surface marker positions can be compared with deformations calculated by a DIR algorithm to evaluate its accuracy. In this study, the authors selected a Demons algorithm as a DIR algorithm example for demonstration purposes. The average error magnitude is 2.1 mm. The point dose measurements from the in vivo diode dosimeters show a good agreement with the calculated doses from the treatment planning system with a maximum difference of 3.1% of prescription dose, when the treatment plans are delivered to the phantom with original or deformed geometry.

CONCLUSIONS

In this study, the authors have presented the functionality of this deformable HN phantom for testing the accuracy of DIR algorithms and verifying the ART dosimetric accuracy. The authors' experiments demonstrate the feasibility of this phantom serving as an end-to-end ART QA phantom.

Automatic treatment plan re-optimization for adaptive radiotherapy guided with the initial plan DVHs

Adaptive radiation therapy (ART) can reduce normal tissue toxicity and/or improve tumor control through treatment adaptations based on the current patient anatomy. Developing an efficient and effective re-planning algorithm is an important step toward the clinical realization of ART. For the re-planning process, manual trial-and-error approach to fine-tune planning parameters is time-consuming and is usually considered unpractical, especially for online ART. It is desirable to automate this step to yield a plan of acceptable quality with minimal interventions. In ART, prior information in the original plan is available, such as dose-volume histogram (DVH), which can be employed to facilitate the automatic re-planning process. The goal of this work is to develop an automatic re-planning algorithm to generate a plan with similar, or possibly better, DVH curves compared with the clinically delivered original plan. Specifically, our algorithm iterates the following two loops. An inner loop is the traditional fluence map optimization, in which we optimize a quadratic objective function penalizing the deviation of the dose received by each voxel from its prescribed or threshold dose with a set of fixed voxel weighting factors. In outer loop, the voxel weighting factors in the objective function are adjusted according to the deviation of the current DVH curves from those in the original plan. The process is repeated until the DVH curves are acceptable or maximum iteration step is reached. The whole algorithm is implemented on GPU for high efficiency. The feasibility of our algorithm has been demonstrated with three head-and-neck cancer IMRT cases, each having an initial planning CT scan and another treatment CT scan acquired in the middle of treatment course. Compared with the DVH curves in the original plan, the DVH curves in the resulting plan using our algorithm with 30 iterations are better for almost all structures. The re-optimization process takes about 30 s using our in-house optimization engine.

Impact of the introduction of a combined Haemophilus B conjugate vaccine and hepatitis B recombinant vaccine on vaccine coverage rats in a large West Coast health maintenance organization

We evaluated the effect of introduction of a combined hepatitis B-Haemophilus influenzae b vaccine on vaccine coverage rates in a large health maintenance organization and found a modest improvement in up-to-date immunization status.

Psychotropic medication use in a population of children who have attention-deficit/hyperactivity disorder

OBJECTIVE

Recent reports suggest a trend of increasing prevalence of psychotropic drug prescriptions among children with attention-deficit/hyperactivity disorder (ADHD); however, reasons for the increased use of such medications is unclear. The objectives of this study were to examine differences in nonstimulant psychotropic medication fills between children with and without identified ADHD and to assess associations with non-ADHD neurobehavioral disorders.

METHODS

A population-based retrospective matched cohort study was conducted of a large group model health maintenance organization located in western Washington State. Eligible patients were children who were ages 3 to 17 years and were continuously enrolled and used services from January 1 to December 31, 1997 (N = 57 216). Children with ADHD were identified by a diagnosis of ADHD or a pharmacy fill for a stimulant medication using automated patient files. Children without ADHD were randomly selected and matched 4:1 to children with ADHD on age and gender. Neurobehavioral disorders and pharmacy fills for psychotropic medications were measured.

RESULTS

During 1997, 2992 children were identified as having ADHD (5.2%). These children were more likely to have a diagnosis of a non-ADHD neurobehavioral disorders (adjusted odds ratio: 6.3; 95% confidence interval: 5.4-7.3) than children without ADHD. Although most (78%) were treated with stimulant medications, children who were identified as having ADHD were also more likely to receive pharmacy fills for nonstimulant medications than were children without ADHD. Nonstimulant medications were more often used along with stimulant medications and were frequently prescribed in association with ADHD after controlling for other disorders.

CONCLUSIONS

Children who were identified as having ADHD were more likely to have a diagnosis of other neurobehavioral disorders and to receive nonstimulant psychotropic medications than were children without ADHD. Because many of these drugs have little or no empirical basis in the treatment of ADHD, the rationale for their use is less clear. Future research to examine the use, effectiveness, and safety of these medications alone and in combination in children with ADHD is urgently needed.

Successful community-based laboratory services program for long-term care facilities, Part 2

Hagerstown Medical Laboratory, Inc., located in Hagerstown, Maryland, has an outreach program that currently provides laboratory services to 52 long-term care facilities. Part 1 of this series, published in the May/June 2001 issue of Clinical Leadership & Management Review, discussed general organization, staffing, and safety issues for their Nursing Home Program. Part 2 relates their experience with contracts, fees, and reimbursement.

Utilization and cost of health care services for children with attention-deficit/hyperactivity disorder

BACKGROUND

Despite an increasing prevalence of diagnosed attention-deficit/hyperactivity disorder (ADHD) among children, the impact of ADHD on utilization and costs of health care services is largely unknown.

OBJECTIVE

To examine differences in health care utilization and costs between children with and without ADHD.

DESIGN

Retrospective matched cohort study conducted from January 1 to December 31, 1997. Setting. Health maintenance organization in western Washington State.

PARTICIPANTS

Children aged 3 through 17 years who were continuously enrolled in the health maintenance organization and used services during 1997 were eligible. Children were identified with ADHD if they had a diagnosis of ADHD or a prescription for a stimulant medication using automated patient files. Children without ADHD were randomly selected as controls and matched 4:1 to children with ADHD on age and sex.

OUTCOME MEASURE

Utilization and costs of specific categories of health care services. Results. A total of 2992 children (5.2%) were identified with ADHD. Children with ADHD incurred significantly greater per capita total costs ($1465 vs $690) than children without ADHD. Children with ADHD had 9.9 times more outpatient mental health visits (1.35/year vs 0.14/year), 3.4 times more pharmacy fills (11.25/year vs 3.30/year), and 1.6 times more primary care visits (3.84/year vs 2.36/year) than children without ADHD. The adjusted incremental costs were estimated to be $375 (95% confidence interval: $336-$416) for children with ADHD alone and $812 (95% confidence interval: $671-$973) for children with ADHD plus coexisting mental health disorders.

CONCLUSIONS

Children with ADHD use significantly more health care resources and incur significantly higher costs than children without ADHD. Coexisting mental health disorders substantially increase the cost of treating ADHD. Resource allocation decisions should consider the contributions of primary care, outpatient mental health, and pharmacy costs to the overall costs of care for children with ADHD.

Successful community-based laboratory services program for long-term care facilities, Part 1

Hagerstown Medical Laboratory, Inc. (HML) is a regional reference laboratory in Hagerstown, Maryland, that provides laboratory services to more than 50 long-term care facilities (LTCFs, or nursing homes) in Western Maryland and West Virginia. HML also operates the rapid response laboratory at Washington County Hospital and performs house calls for homebound or bedridden patients through its Nursing Home Program (NHP). This article relates HML's successful experience with an outreach program that provides laboratory services to LTCFs.

Association of lower continuity of care with greater risk of emergency department use and hospitalization in children

CONTEXT

The benefits of continuity of pediatric care remain controversial.

OBJECTIVE

To determine whether there is an association between having a continuous relationship with a primary care pediatric provider and decreased risk of emergency department (ED) visitation and hospitalization.

DESIGN

Retrospective cohort study. Setting and Population. We used claims data from 46 097 pediatric patients enrolled at Group Health Cooperative, a large staff-model health maintenance organization, between January 1, 1993, and December 31, 1998, for our analysis. To be eligible, patients had to have been continuously enrolled for at least a 2-year period or since birth and to have made at least 4 visits to one of the Group Health Cooperative clinics. MAIN EXPOSURE VARIABLE: A continuity of care (COC) index that quantifies the degree to which a patient has experienced continuous care with a provider.

MAIN OUTCOME MEASURES

ED utilization and hospitalization.

RESULTS

Compared with children with the highest COC, children with medium continuity were more likely to have visited the ED (hazard ratio [HR]: 1.28 [1.20-1.36]) and more likely to be hospitalized (HR: 1.22 [1.09-1.38]). Children with the lowest COC were even more likely to have visited the ED (HR: 1.58 [1.49-1.66]) and to be hospitalized (HR: 1.54 [1.33-1.75]). These risks were even greater for children on Medicaid and those with asthma.

CONCLUSIONS

Lower continuity of primary care is associated with higher risk of ED utilization and hospitalization. Efforts to improve and maintain continuity may be warranted.