Predicting the need for palliative thoracic radiation after first-line chemotherapy for advanced nonsmall cell lung carcinoma.

BACKGROUND: The objective of this secondary analysis was to identify patients with selected stage IIIB/IV nonsmall cell lung carcinoma and good performance status who were at high risk for requiring subsequent palliative thoracic radiotherapy after initial treatment with first-line chemotherapy. METHODS: The authors conducted a pooled analysis of patients at a single institution who enrolled onto 10 prospective phase 2 and 3 clinical trials that involved first-line, platinum-based chemotherapy. Baseline lung-related characteristics before trial enrollment were analyzed as possible prognostic factors for freedom from pulmonary events (defined either as subsequent thoracic radiation or as a new collapsed lung, which is an indication for thoracic radiation). RESULTS: Of 244 consecutive patients who were reviewed, 42 patients received a palliative course of thoracic radiation, 40 exhibited evidence of new lobar collapse on follow-up chest imaging, and 14 received thoracic radiation for lobar collapse. On univariable analysis, pulmonary symptoms (P = .043) or pneumonia at presentation (P = .0001), increasing size of hilar disease (P < .0001), and evidence of obstruction of major bronchi or vessels (P = .0003) were associated with subsequent pulmonary events. On multivariable analysis, hilar disease measuring >3 cm (hazard ratio, 1.8; P = .003) and prechemotherapy pneumonia (hazard ratio, 2.1; P = .009) were associated with pulmonary events; patients who had both risk factors or hilar disease >5 cm in greatest dimension exhibited a >50% risk of subsequent events. CONCLUSIONS: Patients with bulky hilar disease and a history of pneumonia at presentation were at high risk for requiring palliative thoracic radiation. The authors propose studying these patients to determine whether early thoracic radiation may be beneficial by preserving quality of life and performance status.

Phase I study of concurrent weekly docetaxel, high-dose intensity-modulated radiation therapy (IMRT) and androgen-deprivation therapy (ADT) for high-risk prostate cancer.

UNLABELLED: Study Type - Therapy (phase 1) Level of Evidence 2a What's known on the subject? and What does the study add? High-risk and locally advanced prostate cancers are difficult to cure with the standard regimen of radiation therapy (RT) with concurrent androgen-deprivation therapy (ADT). Multiple studies have explored the addition of docetaxel chemotherapy in attempt to improve patient outcomes. Prior Phase I studies have shown that docetaxel 20 mg/m(2) is a safe dose, when given concurrently with 70 Gy of radiation. But current standard RT for prostate cancer uses higher doses, and it is unclear if concurrent chemotherapy is safe with modern RT. This is a Phase I study that explored the addition of concurrent docetaxel chemotherapy to modern RT (intensity-modulated RT to 78 Gy) plus ADT. The study showed that weekly docetaxel at 20 mg/m(2) is safe with modern RT. At a median follow-up of 2.2 years, biochemical progression-free survival was 94%. This triple-therapy regimen is safe and promising for further evaluation in prospective trials. OBJECTIVE: • To evaluate in a phase I trial, the feasibility of adding concurrent weekly docetaxel chemotherapy to high-dose intensity modulated radiation therapy (IMRT) and androgen-deprivation therapy (ADT) for treatment of high-risk prostate cancer. PATIENTS AND METHODS: • Patients with high-risk prostate cancer were treated with a luteinising hormone-releasing hormone agonist (starting 2-3 months before IMRT and lasting 2 years), IMRT of 78 Gy to the prostate and seminal vesicles, and weekly docetaxel during RT. • All patients had computed tomography and bone scans to exclude metastatic disease. • A standard 3 + 3 design was used for docetaxel dose escalation. Successive patients were treated on dose levels of 10, 15, and 20 mg/m(2) of weekly docetaxel. RESULTS: • In all, 18 patients participated in the study: 15 (83%) had Gleason 8-10 disease; the other three had either clinical T3 disease and/or a prostate-specific antigen (PSA) level of >20 ng/mL. • Grade 3 diarrhoea (a defined dose-limiting toxicity, DLT) occurred in one patient in each of the first two dose levels. However, when the cohorts were expanded, no further DLT was seen. • Weekly docetaxel at 20 mg/m(2) (dose level 3) was successfully given without DLT. • No patient had grade 4 or 5 toxicity. • At a median follow-up of 2.2 years, all patients achieved a PSA nadir of <1 ng/mL, including 13 patients who had an undetectable PSA level. The 2-year biochemical progression-free survival was 94%. CONCLUSION: • A dose of 20 mg/m(2) of weekly docetaxel given concurrently with high-dose IMRT and ADT appears safe for further study in patients with high-risk prostate cancer.

Local Radiotherapy Intensification for Locally Advanced Non-small-cell Lung Cancer - A Call to Arms.

Chemoradiotherapy, the standard of care for locally advanced non-small-cell lung cancer (NSCLC), often fails to eradicate all known disease. Despite advances in chemotherapeutic regimens, locally advanced NSCLC remains a difficult disease to treat, and locoregional failure remains common. Improved radiographic detection can identify patients at significant risk of locoregional failure after definitive treatment, and newer methods of escalating locoregional treatment may allow for improvements in locoregional control with acceptable toxicity. This review addresses critical issues in escalating local therapy, focusing on using serial positron emission tomography-computed tomography to select high-risk patients and employing stereotactic radiotherapy to intensify treatment. We further propose a clinical trial concept that incorporates the review's findings.

Cardiac Toxicity After Radiotherapy for Stage III Non-Small-Cell Lung Cancer: Pooled Analysis of Dose-Escalation Trials Delivering 70 to 90 Gy.

Purpose The significance of radiotherapy (RT) -associated cardiac injury for stage III non-small-cell lung cancer (NSCLC) is unclear, but higher heart doses were associated with worse overall survival in the Radiation Therapy Oncology Group (RTOG) 0617 study. We assessed the impact of heart dose in patients treated at our institution on several prospective dose-escalation trials. Patients and Methods From 1996 to 2009, 127 patients with stage III NSCLC (Eastern Cooperative Oncology Group performance status, 0 to 1) received dose-escalated RT to 70 to 90 Gy (median, 74 Gy) in six trials. RT plans and cardiac doses were reviewed. Records were reviewed for the primary end point: symptomatic cardiac events (symptomatic pericardial effusion, acute coronary syndrome, pericarditis, significant arrhythmia, and heart failure). Cardiac risk was assessed by noting baseline coronary artery disease and calculating the WHO/International Society of Hypertension score. Competing risks analysis was used. Results In all, 112 patients were analyzed. Median follow-up for surviving patients was 8.8 years. Twenty-six patients (23%) had one or more events at a median of 26 months to first event (effusion [n = 7], myocardial infarction [n = 5], unstable angina [n = 3], pericarditis [n = 2], arrhythmia [n = 12], and heart failure [n = 1]). Heart doses (eg, heart mean dose; hazard ratio, 1.03/Gy; P = .002,), coronary artery disease ( P < .001), and WHO/International Society of Hypertension score ( P = .04) were associated with events on univariable analysis. Heart doses remained significant on multivariable analysis that accounted for baseline risk. Two-year competing risk-adjusted event rates for patients with heart mean dose < 10 Gy, 10 to 20 Gy, or ≥ 20 Gy were 4%, 7%, and 21%, respectively. Heart doses were not associated with overall survival. Conclusion Cardiac events were relatively common after high-dose thoracic RT and were independently associated with both heart dose and baseline cardiac risk. RT-associated cardiac toxicity after treatment of stage III NSCLC may occur earlier than historically understood, and heart doses should be minimized.

Heart dosimetric analysis of three types of cardiac toxicity in patients treated on dose-escalation trials for Stage III non-small-cell lung cancer.

BACKGROUND AND PURPOSE: To assess associations between radiation dose/volume parameters for cardiac subvolumes and different types of cardiac events in patients treated on radiation dose-escalation trials. MATERIAL AND METHODS: Patients with Stage III non-small-cell lung cancer received dose-escalated radiation (median 74 Gy) using 3D-conformal radiotherapy on six prospective trials from 1996 to 2009. Volumes analyzed included whole heart, left ventricle (LV), right atrium (RA), and left atrium (LA). Cardiac events were divided into three categories: pericardial (symptomatic effusion and pericarditis), ischemia (myocardial infarction and unstable angina), and arrhythmia. Univariable competing risks analysis was used. RESULTS: 112 patients were analyzed, with median follow-up 8.8 years for surviving patients. Nine patients had pericardial, seven patients had ischemic, and 12 patients had arrhythmic events. Pericardial events were correlated with whole heart, RA, and LA dose (eg, heart-V30 [p=0.024], RA-V30 [p=0.013], and LA-V30 [p=0.001]), but not LV dose. Ischemic events were correlated with LV and whole heart dose (eg, LV-V30 [p=0.012], heart-V30 [p=0.048]). Arrhythmic events showed borderline significant associations with RA, LA, and whole heart dose (eg, RA-V30 [p=0.082], LA-V30 [p=0.076], heart-V30 [p=0.051]). Cardiac events were associated with decreased survival on univariable analysis (p=0.008, HR 2.09), but only disease progression predicted for decreased survival on multivariable analysis. CONCLUSIONS: Cardiac events were heterogeneous and associated with distinct heart subvolume doses. These data support the hypothesis of distinct etiologies for different types of radiation-associated cardiotoxicity.

Post-chemotherapy gross tumor volume is predictive of survival in patients with stage III non-small cell lung cancer treated with combined modality therapy.

PURPOSE: To evaluate the influence of clinical covariates, particularly pre-chemotherapy gross tumor volume (GTV), post-chemotherapy GTV, on overall survival in the treatment of stage III non-small cell lung cancer (NSCLC). METHODS AND MATERIALS: We retrospectively analyzed 102 patients who were enrolled on three consecutive clinical trials, which employed the treatment paradigm of two cycles of induction chemotherapy followed by thoracic radiation therapy. The pre-chemotherapy GTV, post-chemotherapy GTV, change in GTV, histology, disease stage, performance status, age, race, treatment with concurrent chemoradiotherapy versus radiotherapy alone were evaluated to determine their impact on overall survival. The log10 of the GTV was used to normalize the data and thereby reduce the impact of exceptionally large values. RESULTS: Both the log10 of the post-chemotherapy GTV and Eastern Cooperative Oncology Group (ECOG) performance status covariates were highly prognostic for overall survival (p = 0.006 and p = 0.008, respectively). Disease stage (at diagnosis) was also significant (p = 0.048). The log10 pre-chemotherapy GTV covariate was borderline significant (p = 0.067). The strongest prognostic model was the two-covariate model, which contained the log10 post-chemotherapy GTV and ECOG performance status covariates, (model chi2 of 18.67, with p = 0.001 for each covariate). CONCLUSIONS: The log10 post-chemotherapy GTV has significant prognostic survival value when the strategy of induction chemotherapy is employed in the treatment on stage III NSCLC. ECOG performance status and stage were also significant prognostic factors for survival.

Therapeutic advances in local-regional therapy for stage III non-small-cell lung cancer: evolving role of dose-escalated conformal (3-dimensional) radiation therapy.

Lung cancer is the leading cause of cancer-related death among men and women in the United States. Approximately 80%-85% of lung cancer cases are non-small-cell lung cancer, and approximately 30%-40% of these patients have unresectable stage IIIA/B disease at diagnosis. The standard of care for locally advanced disease in patients with a good performance status consists of combined modality therapy, chemotherapy and radiation therapy (RT). Despite improved survival with combined modality therapy, local-regional recurrences and the development of distant metastases are still problematic. The radiation dose of 60 Gy for inoperable stage III non-small-cell lung cancer, established by Radiation Therapy Oncology Group trials 7301 and 7302, has remained the standard until the present time. More recently, trials suggest that local-regional control can be improved with RT dose escalation, improved tumor targeting (eg, 3-dimensional planning and intensity-modulated RT), and altered RT fractionation. Improvements in local-regional control could translate into an overall survival benefit. This article reviews the rationale for aggressive therapy and techniques to improve local disease control. It also provides an overview of trials that utilize such techniques, with a focus on efficacy, toxicity, and overall survival. Further well-designed clinical trials that examine RT dose escalation, improved tumor targeting, altered fractionation, and incorporation of biologic agents are crucial for progress in this disease.

Systematic review evaluating the timing of thoracic radiation therapy in combined modality therapy for limited-stage small-cell lung cancer.

PURPOSE: We employed meta-analytic techniques to evaluate early (E) versus late (L) timing of thoracic radiation therapy (RT) in limited-stage small-cell lung cancer (LS-SCLC). In addition, we assessed the impact of radiation fractionation and chemotherapeutic regimen on timing. METHODS: Randomized trials published after 1985 addressing timing of RT relative to chemotherapy in LS-SCLC were included. Trials were analyzed by risk ratio (RR), risk difference, and number-needed-to-treat methods. RESULTS: Overall survival (OS) RRs for all studies were 1.17 at 2 years (95% CI, 1.02 to 1.35; P = .03) and 1.13 at 3 years (95% CI, 0.92 to 1.39; P = .2), indicating a significantly increased 2-year survival for ERT versus LRT patients and suggestive of a similar trend at 3 years. Subset analysis of studies using hyperfractionated RT revealed OS RR for ERT versus LRT of 1.44 (95% CI, 1.17 to 1.77; P = .001) and 1.39 (95% CI, 1.02 to 1.90; P = .04) at 2 and 3 years, respectively, indicating a survival benefit of ERT versus LRT. Studies using once-daily fractionation showed no difference in 2- and 3-year OS RRs for ERT compared with LRT. Studies using platinum-based chemotherapy had OS RRs of 1.30 (95% CI, 1.10 to 1.53; P = .002) and 1.35 (95% CI, 1.07 to 1.70; P = .01) at 2 and 3 years, respectively, favoring ERT. Studies using nonplatinum-based chemotherapy regimens had nonsignificant differences in OS. CONCLUSION: A small but significant improvement in 2-year OS for ERT versus LRT in LS-SCLC was observed, similar to the benefit of adding RT to chemotherapy or prophylactic cranial irradiation. A greater difference was evident for hyperfractionated RT and platinum-based chemotherapy.

Induction and concurrent chemotherapy with high-dose thoracic conformal radiation therapy in unresectable stage IIIA and IIIB non-small-cell lung cancer: a dose-escalation phase I trial.

PURPOSE: Local control rates at conventional radiotherapy doses (60 to 66 Gy) are poor in stage III non-small-cell lung cancer (NSCLC). Dose escalation using three-dimensional thoracic conformal radiation therapy (TCRT) is one strategy to improve local control and perhaps survival. PATIENTS AND METHODS: Stage III NSCLC patients with a good performance status (PS) were treated with induction chemotherapy (carboplatin area under the curve [AUC] 5, irinotecan 100 mg/m(2), and paclitaxel 175 mg/m(2) days 1 and 22) followed by concurrent chemotherapy (carboplatin AUC 2 and paclitaxel 45 mg/m(2) weekly for 7 to 8 weeks) beginning on day 43. Pre- and postchemotherapy computed tomography scans defined the initial clinical target volume (CTV(I)) and boost clinical target volume (CTV(B)), respectively. The CTV(I) received 40 to 50 Gy; the CTV(B) received escalating doses of TCRT from 78 Gy to 82, 86, and 90 Gy. The primary objective was to escalate the TCRT dose from 78 to 90 Gy or to the maximum-tolerated dose. RESULTS: Twenty-nine patients were enrolled (25 assessable patients; median age, 59 years; 62% male; 45% stage IIIA; 38% PS 0; and 38% > or = 5% weight loss). Induction CIP was well tolerated (with filgrastim support) and active (partial response rate, 46.2%; stable disease, 53.8%; and early progression, 0%). The TCRT dose was escalated from 78 to 90 Gy without dose-limiting toxicity. The primary acute toxicity was esophagitis (16%, all grade 3). Late toxicity consisted of grade 2 esophageal stricture (n = 3), bronchial stenosis (n = 2), and fatal hemoptysis (n = 2). The overall response rate was 60%, with a median survival time and 1-year survival probability of 24 months and 0.73 (95% CI, 0.55 to 0.89), respectively. CONCLUSION Escalation of the TCRT dose from 78 to 90 Gy in the context of induction and concurrent chemotherapy was accomplished safely in stage III NSCLC patients.

Chemotherapeutic issues in the management of unresectable stage III non-small cell lung cancer.

The standard of care in unresectable stage IIIA/B non-small cell lung cancer is combined-modality therapy using both chemotherapy and thoracic radiation therapy. Although there is general agreement on this principle, there remain many controversies regarding the optimal combined-modality approach in this patient population. Both induction and concurrent chemoradiotherapy strategies were initially tested, with both approaches improving survival in randomized phase III trials. Several trials have now been completed comparing sequential versus concurrent approaches. There appears to be a modest and consistent advantage to the concurrent approach at the risk of an increase in the rates of acute toxicities, particularly esophagitis and myelosuppression. The concurrent approach used in the phase III trials evaluating the question of sequence has been the use of full-dose systemic chemotherapy rather than a low-dose radio-enhancing strategy. These approaches are distinctly different, and one must recognize this difference when evaluating results from clinical trials. A number of clinical trials have established the use of both induction and consolidation chemotherapy; however, the optimal approach remains unclear. What is clear is that this population of patients needs aggressive therapy directed at achieving locoregional control as well as control of occult micrometastatic disease that is present in the majority of cases. As treatment strategies have become more aggressive, survival outcomes have improved, although the differences have been modest at best, and the risk of severe toxicity has increased. Future aggressive approaches must enhance both locoregional and distant control of occult disease, with acceptable rates of both acute and long-term toxicities.

Does more aggressive therapy improve outcomes in the treatment of unresectable stage III non-small cell lung cancer?

Concurrent chemotherapy combined with radiation therapy currently offers the best treatment strategy in stage IIIA/IIIB non-small cell lung cancer. However, inadequate radiation dose may be a contributing factor in the resultant lack of adequate control of local disease. Hypothetically, radiation doses that are higher than "standard" (eg, 60 Gy) might increase patient morbidity without improving cure rates, and data from a University of North Carolina phase I/II trial suggested that at least 74 Gy can be given safely to patients receiving cytotoxic chemotherapy, with a trend toward improved survival. Also, clinical data indicate that the cytoprotective agent amifostine (Ethyol; MedImmune Inc, Gaithersburg, MD) can be used to reduce esophagitis (and possibly pneumonitis) in patients treated with conventional radiation doses. Finally, a phase III clinical trial is proposed to: (1) test the hypothesis that higher radiation doses lead to a survival advantage in non-small cell lung cancer patients; and (2) discern the value of amifostine as a cytoprotective agent in the high-radiation dose range.

A preliminary study of the role of modulated electron beams in intensity modulated radiotherapy, using automated beam orientation and modality selection.

PURPOSE: To develop an algorithm for optimal beam arrangement selection in intensity-modulated radiotherapy (IMRT) of mixed photon and electron beams. To apply this algorithm to study the utility of modulated electron beams in the context of IMRT planning. METHODS AND MATERIALS: The optimization algorithm selects, for a user-specified number of beams, the optimal IMRT arrangement (beam orientations, and photon/electron modality for each orientation) using a novel fast heuristic intensity modulation procedure. The algorithm was employed to select optimal beam arrangements for breast (two, four, and six axial beams) and head-and-neck (three, four, five, and seven nonaxial beams) cases. RESULTS: For the two cases, increasing the number of selected beams: (1) increased the number of electron beams for the breast case, but not more than one electron beam was selected for the head-and-neck case; (2) decreased critical structure doses for both cases; and (3) decreased target homogeneity for the breast case, but improved it for the head-and-neck case. CONCLUSIONS: In the two cases analyzed using the selection algorithm, the primary role of modulated electrons differs based on treatment site-normal tissue dose reduction in breast and target homogeneity improvement in head and neck. Although this preliminary study with two cases appears to suggest that the role of intensity-modulated electrons differs based on treatment site, further investigation of large numbers of cases and varied treatment sites are required to establish a definitive conclusion.

High-dose conformal radiotherapy for treatment of stage IIIA/IIIB non-small-cell lung cancer: technical issues and results of a phase I/II trial.

PURPOSE: We completed a Phase I/II clinical trial (Lineberger Comprehensive Cancer Center 9603), in which we treated 62 Stage IIIA/IIIB inoperable non-small-cell lung cancer (NSCLC) patients with two cycles of induction carboplatin/paclitaxel chemotherapy, followed by concurrent weekly carboplatin/paclitaxel with radiation doses escalated from 60 to 74 Gy. The median survival of 24 months, 3-year survival rate of 38%, and the high dose of radiation used justified a critical analysis of the technical and clinical components of this trial. METHODS AND MATERIALS: Between 1996 and 1999, 62 sequential patients with inoperable Stage IIIA/IIIB NSCLC were enrolled and treated with two cycles of induction carboplatin (area under the concentration curve = 6 using the Calvert equation) and paclitaxel (225 mg/m(2)), followed by an escalating radiation dose of 60-74 Gy with concurrent carboplatin weekly (area under the concentration curve = 2) and paclitaxel weekly (45 mg/m(2)). The goals of the trial were to determine whether 74 Gy of radiation could be safely delivered under these circumstances and whether patients could potentially benefit in terms of survival. The radiation treatment plans for all 62 patients were reviewed to determine the prechemotherapy and postchemotherapy tumor volume, as well as the dose-volume histograms of the normal lung and esophagus. RESULTS: Of the 62 patients who entered the trial, 48 completed the entire course of treatment. At last follow-up, 20 patients were alive (crude survival rate 32%). With a median follow-up of 43 months, the median survival was 24 months. The survival rate was 50% at 2 years and 38% at 3 years. Cox regression analysis showed that survival was best predicted by whether the patient had received radiotherapy (finished the trial), performance status, disease stage, and log postchemotherapy tumor volume. The 3-year survival rate for the 48 patients finishing the trial was 45%. Eight patients (13%) suffered locoregional relapse as the only site of failure. Only 1 patient had Grade 2 radiation pneumonitis. Five patients (8%) had Radiation Therapy Oncology Group Grade 3 or 4 esophagitis; 40 (65%) had a Grade 1 or 2 esophagitis. Esophageal toxicity could be predicted by the length of esophagus receiving 40 or 60 Gy. CONCLUSION: Radiation doses of 74 Gy, when given under the guidelines of the Lineberger Comprehensive Cancer Center 9603, appear to be safe and may possibly contribute to increased survival in patients with inoperable Stage IIIA/IIIB NSCLC.

Dose optimization via index-dose gradient minimization.

This paper presents an iterative optimization algorithm based on gradient minimization of index dose, defined as the product of physical dose and a numerical index. Acting as a template the index distribution is designed to represent the dosimetry that meets the dose volume histogram-based optimization objectives. The treatment dosimetry is optimized when the uniformity of the index-dose distribution is maximized. Prior to optimization the user can select all or only some of the beams to be intensity modulated. The remaining unmodulated beams can be either open or wedged photon beams, electron beams, or beams of previous treatments. The optimization result and treatment delivery efficiency can often be enhanced by including not only the IM photon beams but also all suitable fixed-beams available on the linac in the treatment plan. In addition, the doses from previous treatments can also be considered in the optimization of current treatment. Five clinical examples with different complexities in optimization objective are presented. The effects of two nonoptimization variables, beam setup and initial beam weights, on the quality of the dose optimization are also presented. The results are analyzed in terms of isodose distribution, dose volume histograms, and a dose optimization quality factor. The optimization algorithm, implemented in our in-house TPS PLanUNC, has been used in clinical application since 1996. The primary advantages of our optimization algorithm include computational efficiency, intensity modulation selection choice, and performance reliability for a wide range of clinical beam setups and optimization objectives.

Dosimetry of a prototype retractable eMLC for fixed-beam electron therapy.

An electron multileaf collimator (eMLC) has been designed that is unique in that it retracts to 37 cm from the isocenter [63-cm source-to-collimator distance (SCD)] and can be deployed to distances of 20 and 10 cm from the isocenter (80 and 90 cm SCD, respectively). It is expected to be capable of arc therapy at 63 cm SCD; isocentric, fixed-beam therapy at 80 cm SCD; and source-to-surface distance (SSD), fixed-beam therapy at 90 cm SCD. In all positions, its leaves could be used for unmodulated or intensity-modulated therapy. Our goal in the present work is to describe the general characteristics of the eMLC and to demonstrate that its leakage characteristics and dosimetry are adequate for SSD, fixed-beam therapy as an alternative to Cerrobend cutouts with applicators once the prototype's leaves are motorized. Our eMLC data showed interleaf electron leakage at 15 MeV to be less than 0.1% based on a 0.0025 cm manufacturing tolerance, and lateral electron leakage at 5 and 15 MeV to be less than 2%. X-ray leakage through the leaves was 1.6% at 15 MeV. Our data showed that beam penumbra was independent of direction and leaf position. The dosimetric properties of square fields formed by the eMLC were very consistent with those formed by Cerrobend inserts in the 20 x 20 cm2 applicator. Output factors exhibited similar field-size dependence. Airgap factors exhibited almost identical field-size dependence at two SSDs (105 and 110 cm), consistent with the common assumption that airgap factors are applicator independent. Percent depth-dose curves were similar, but showed variations up to 3% in the buildup region. The pencil-beam algorithm (PBA) fit measured data from the eMLC and applicator-cutout systems equally well, and the resulting two-dimensional (2-D) dose distributions, as predicted by the PBA, agreed well at common airgap distance. Simulating patient setups for breast and head and neck treatments showed that almost all fields could be treated using similar SSDs as when using applicators, although head and neck treatments require placing the patient's head on a head-holder treatment table extension. The results of this work confirmed our design goals and support the potential use of the eMLC design in the clinical setting. The eMLC should allow the same treatments as are typically delivered with the electron applicator-cutout system currently used for fixed-beam therapy.

Compensators: an alternative IMRT delivery technique.

Seven years of experience in compensator intensity-modulated radiotherapy (IMRT) clinical implementation are presented. An inverse planning dose optimization algorithm was used to generate intensity modulation maps, which were delivered via either the compensator or segmental multileaf collimator (MLC) IMRT techniques. The in-house developed compensator-IMRT technique is presented with the focus on several design issues. The dosimetry of the delivery techniques was analyzed for several clinical cases. The treatment time for both delivery techniques on Siemens accelerators was retrospectively analyzed based on the electronic treatment record in LANTIS for 95 patients. We found that the compensator technique consistently took noticeably less time for treatment of equal numbers of fields compared to the segmental technique. The typical time needed to fabricate a compensator was 13 min, 3 min of which was manual processing. More than 80% of the approximately 700 compensators evaluated had a maximum deviation of less than 5% from the calculation in intensity profile. Seventy-two percent of the patient treatment dosimetry measurements for 340 patients have an error of no more than 5%. The pros and cons of different IMRT compensator materials are also discussed. Our experience shows that the compensator-IMRT technique offers robustness, excellent intensity modulation resolution, high treatment delivery efficiency, simple fabrication and quality assurance (QA) procedures, and the flexibility to be used in any teletherapy unit.

Race, insurance type, and stage of presentation among lung cancer patients.

The purpose of this study was to determine whether African-American lung cancer patients are diagnosed at a later stage than white patients, regardless of insurance type. The relationship between race and stage at diagnosis by insurance type was assessed using a Poisson regression model, with relative risk as the measure of association. The setting of the study was a large tertiary care cancer center located in the southeastern United States. Patients who were diagnosed with lung cancer between 2001 and 2010 were included in the study. A total of 717 (31%) African-American and 1,634 (69%) white lung cancer patients were treated at our facility during the study period. Adjusting for age, sex, and smoking-related histology, African-American patients were diagnosed at a statistically significant later stage (III/IV versus I/II) than whites for all insurance types, with the exception of Medicaid. Our results suggest that equivalent insurance coverage may not ensure equal presentation of stage between African-American and white lung cancer patients. Future research is needed to determine whether other factors such as treatment delays, suboptimal preventive care, inappropriate specialist referral, community segregation, and a lack of patient trust in health care providers may explain the continuing racial disparities observed in the current study.

Is primary prostate cancer treatment influenced by likelihood of extraprostatic disease? A surveillance, epidemiology and end results patterns of care study.

PURPOSE: To examine the patterns of primary treatment in a recent population-based cohort of prostate cancer patients, stratified by the likelihood of extraprostatic cancer as predicted by disease characteristics available at diagnosis. METHODS AND MATERIALS: A total of 157,371 patients diagnosed from 2004 to 2008 with clinically localized and potentially curable (node-negative, nonmetastatic) prostate cancer, who have complete information on prostate-specific antigen, Gleason score, and clinical stage, were included. Patients with clinical T1/T2 disease were grouped into categories of <25%, 25%-50%, and >50% likelihood of having extraprostatic disease using the Partin nomogram. Clinical T3/T4 patients were examined separately as the highest-risk group. Logistic regression was used to examine the association between patient group and receipt of each primary treatment, adjusting for age, race, year of diagnosis, marital status, Surveillance, Epidemiology and End Results database region, and county-level education. Separate models were constructed for primary surgery, external-beam radiotherapy (RT), and conservative management. RESULTS: On multivariable analysis, increasing likelihood of extraprostatic disease was significantly associated with increasing use of RT and decreased conservative management. Use of surgery also increased. Patients with >50% likelihood of extraprostatic cancer had almost twice the odds of receiving prostatectomy as those with <25% likelihood, and T3-T4 patients had 18% higher odds. Prostatectomy use increased in recent years. Patients aged 76-80 years were likely to be managed conservatively, even those with a >50% likelihood of extraprostatic cancer (34%) and clinical T3-T4 disease (24%). The proportion of patients who received prostatectomy or conservative management was approximately 50% or slightly higher in all groups. CONCLUSIONS: There may be underutilization of RT in older prostate cancer patients and those with likely extraprostatic disease. Because more than half of prostate cancer patients do not consult with a radiation oncologist, a multidisciplinary consultation may affect the treatment decision-making process.

The impact of local and regional disease extent on overall survival in patients with advanced stage IIIB/IV non-small cell lung carcinoma.

PURPOSE: Patients with advanced stage IIIB or stage IV non-small cell lung carcinoma are typically treated with initial platinum-based chemotherapy. A variety of factors (eg, performance status, gender, age, histology, weight loss, and smoking history) are generally accepted as predictors of overall survival. Because uncontrolled pulmonary disease constitutes a major cause of death in these patients, we hypothesized that clinical and radiographic factors related to intrathoracic disease at diagnosis may be prognostically significant in addition to conventional factors. The results have implications regarding the selection of patients for whom palliative thoracic radiation therapy may be of most benefit. METHODS AND MATERIALS: We conducted a pooled analysis of 189 patients enrolled at a single institution into 9 prospective phase II and III clinical trials involving first-line, platinum-based chemotherapy. Baseline clinical and radiographic characteristics before trial enrollment were analyzed as possible predictors for subsequent overall survival. To assess the relationship between anatomic location and volume of disease within the thorax and its effect on survival, the pre-enrollment computed tomography images were also analyzed by contouring central and peripheral intrapulmonary disease. RESULTS: On univariate survival analysis, multiple pulmonary-related factors were significantly associated with worse overall survival, including pulmonary symptoms at presentation (P=.0046), total volume of intrathoracic disease (P=.0006), and evidence of obstruction of major bronchi or vessels on prechemotherapy computed tomography (P<.0001). When partitioned into central and peripheral volumes, central (P<.0001) but not peripheral (P=.74) disease was associated with worse survival. On multivariate analysis with known factors, pulmonary symptoms (hazard ratio, 1.46; P=.042), central disease volume (hazard ratio, 1.47; P=.042), and bronchial/vascular compression (hazard ratio, 1.54; P=.022) remained significant. CONCLUSIONS: Patients with bulky central disease, bronchial/vascular compression, and/or pulmonary symptoms exhibited worse overall survival after first-line, platinum-based chemotherapy. A subset of these patients may be studied to determine whether early, planned palliative thoracic radiation could also be of benefit.

Concomitant radiotherapy and chemotherapy for high-risk nonmelanoma skin carcinomas of the head and neck.

Background. To report on the use and feasibility of a multimodality approach using concomitant radiotherapy and chemotherapy in patients with high-risk nonmelanoma skin carcinoma (NMSC) of the head and neck. Methods. Records of patients with NMSC of the head and neck who received concomitant CRT at the University of North Carolina between 2001 and 2007 were reviewed. Results. Fifteen identified patients had at least one of the following high-risk factors: T4 disease (93%), unresectability (60%), regional nodal involvement (40%), and/or recurrence (47%). Ten patients were treated in the definitive setting and five in the postoperative setting. Platinum based chemotherapy was given in 14 (93%) patients. Ten of fifteen (67%) patients completed all planned chemotherapy treatments, and thirteen patients (87%) completed at least 80% of planned chemotherapy. Mild radiation dermatitis occurred in all patients and reached grade 3 in 13% of patients. No patients experienced grade 4 or 5 toxicity. With a median followup of 31 months in surviving patients, the 2-year actuarial locoregional control and relapse-free survival were 79% and 49%, respectively. Conclusions. Definitive or postoperative chemoradiotherapy for patients with locally advanced or regionally metastasized NMSC of the head and neck appears feasible with acceptable toxicities and favorable locoregional control.