Comparison of outcomes for patients with medically inoperable Stage I non–small-cell lung cancer treated with two-dimensional vs. three-dimensional radiotherapy

Outcomes Following SBRT vs. IMRT and 3DCRT for Older Patients with Stage IIA Node-Negative Non-Small Cell Lung Cancer > 5 cm

BACKGROUND

To describe outcomes and compare the effectiveness of stereotactic body radiotherapy (SBRT) versus 3-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT) in patients with stage IIA lymph node-negative (N0) non-small cell lung cancer (NSCLC) tumors > 5 cm.

METHODS

We used the SEER-Medicare database (2005-2015) to identify patients > 65 years with stage IIA (AJCC TNM7) N0 NSCLC > 5 cm tumors who were treated with SBRT, IMRT, and 3DCRT. We used propensity score methods with inverse probability weighting to compare lung cancer-specific survival (LCSS), overall survival (OS), and toxicity.

RESULTS

Of 584 patients, 88 (15%), 140 (24%), and 356 (61%) underwent SBRT, IMRT, and 3DCRT, respectively. The SBRT group was older (P = .004), had more comorbidities (P = .02), smaller tumors (P = .03), and more adenocarcinomas (P < .0001). We found a trend towards higher median unadjusted OS with SBRT compared to IMRT and 3DCRT (19 vs. 13 and 14 months, respectively, P = .37). In our propensity score-adjusted analyses, SBRT was significantly associated with better OS and LCSS compared to IMRT (HR_OS: 0.78, 95% CI: 0.68-0.89, HR_LCSS: 0.70, 95% CI: 0.60-0.81) and 3DCRT (HR_OS: 0.81, 95% CI: 0.72-0.93, HR_LCSS: 0.80, 95% CI: 0.68-0.93). SBRT-treated patients also had lower overall adjusted complication rates compared to IMRT (OR: 0.74, 95% CI: 0.55-0.99) and 3DCRT (OR: 0.53, 95% CI: 0.40-0.71).

CONCLUSION

For patients with NSCLC tumors > 5 cm, SBRT trends towards fewer toxicities and improved survival compared to other forms of radiotherapy. Our findings support SBRT as an appropriate treatment strategy for older patients with larger inoperable NSCLC tumors.

A meta-analysis comparing stereotactic body radiotherapy vs conventional radiotherapy in inoperable stage I non-small cell lung cancer

BACKGROUND

Stereotactic body radiotherapy (SBRT) superseded conventional radiotherapy (CRT) for the treatment of patients with inoperable early stage non-small cell lung cancer (NSCLC) over a decade ago. However, the direct comparisons of the outcomes of SBRT and CRT remain controversial. This meta-analysis was performed to compare the survival and safety of SBRT and CRT in patients with inoperable stage I NSCLC.

METHODS

We systematically searched the Cochrane Library, Embase, PubMed, Web of Science, Ovid MEDLINE, ScienceDirect, Scopus and Google Scholar for relevant articles. Overall survival (OS), progression-free survival (PFS), lung cancer-specific survival (LCSS), local control rate (LCR) and adverse effects (AEs) were the primary outcomes.

RESULTS

We identified 11,110 articles, 17 of which were eventually included in this study; these 17 articles had 17,973 patients (SBRT: 7395; CRT: 10,578). Compared to CRT for the treatment of inoperable stage I NSCLC, SBRT had superior survival in terms of OS (hazard ratio [HR]: 0.66, 95% confidence interval [CI]: 0.62-0.70, P < .00001), LCSS (HR: 0.42 [0.35-0.50], P < .00001), and PFS (HR: 0.34 [0.25-0.48], P < .00001). The 4-year OS rate (OSR); 4-year LCSS rate (LCSSR); 3-year local control rate (LCR); 5-year PFS rate (PFSR) with SBRT were all higher than those with CRT. With regard to all-grade AEs, the SBRT group had a significantly lower rate of dyspnea, esophagitis and radiation pneumonitis; no significant difference was found in grade 3-5 AEs (risk ratio [RR]: 0.68 [0.30-1.53], P = .35).

CONCLUSIONS

With better survival and a lower rate of dyspnea, esophagitis and radiation pneumonitis than CRT, SBRT appears to be more suitable for patients with inoperable stage I NSCLC.

Alternatives to Surgery for Early-Stage Non-Small Cell Lung Cancer: Stereotactic Radiotherapy

Lung cancer is the leading cause of cancer death worldwide. Diagnosis of early-stage disease is becoming more common. In an aging population, more and more patients have substantial comorbidities that might limit feasibility of surgical management of early-stage disease. Stereotactic body radiotherapy (SBRT) enables delivery of high-dose, precisely delivered radiation to early-stage lung cancers without surgical risk. This technique has rates of local control similar to surgery and can be considered in medically operable patients who refuse surgery. This article details the technique of SBRT, the data for its efficacy, as well as the potential toxicities of treatment.

Real-time intrafraction motion monitoring in external beam radiotherapy

Radiotherapy (RT) aims to deliver a spatially conformal dose of radiation to tumours while maximizing the dose sparing to healthy tissues. However, the internal patient anatomy is constantly moving due to respiratory, cardiac, gastrointestinal and urinary activity. The long term goal of the RT community to 'see what we treat, as we treat' and to act on this information instantaneously has resulted in rapid technological innovation. Specialized treatment machines, such as robotic or gimbal-steered linear accelerators (linac) with in-room imaging suites, have been developed specifically for real-time treatment adaptation. Additional equipment, such as stereoscopic kilovoltage (kV) imaging, ultrasound transducers and electromagnetic transponders, has been developed for intrafraction motion monitoring on conventional linacs. Magnetic resonance imaging (MRI) has been integrated with cobalt treatment units and more recently with linacs. In addition to hardware innovation, software development has played a substantial role in the development of motion monitoring methods based on respiratory motion surrogates and planar kV or Megavoltage (MV) imaging that is available on standard equipped linacs. In this paper, we review and compare the different intrafraction motion monitoring methods proposed in the literature and demonstrated in real-time on clinical data as well as their possible future developments. We then discuss general considerations on validation and quality assurance for clinical implementation. Besides photon RT, particle therapy is increasingly used to treat moving targets. However, transferring motion monitoring technologies from linacs to particle beam lines presents substantial challenges. Lessons learned from the implementation of real-time intrafraction monitoring for photon RT will be used as a basis to discuss the implementation of these methods for particle RT.

Phase II study of compensator-based non-coplanar intensity-modulated radiotherapy for Stage I non-small-cell lung cancer

We conducted a Phase II study to evaluate the usefulness of compensator-based non-coplanar intensity-modulated radiotherapy (ncIMRT) for patients with surgically inaccessible Stage I non-small-cell lung cancer (NSCLC). Patients with pathologically proven or clinically diagnosed surgically inaccessible Stage I NSCLC were enrolled in this study from May 2011 to April 2014. These patients underwent ncIMRT of 75 Gy in 30 fractions regardless of the tumor location. The primary end point was 3-year overall survival, and the secondary end points were local control rate and treatment-related toxicities. A total of 48 patients (50 tumors) were enrolled in this study. Of the 50 tumors, the Stage T1 to T2 ratio was 31 to 19, and the ratio of tumors located in the central to peripheral areas was 11 to 39. During the median follow-up time of 35.9 months, the 3-year actuarial local progression-free and overall survival rates were 82.6% and 87.1%, respectively. No patients experienced toxicities of Grade 3 or greater. Standard-fractionated ncIMRT was effective and safe for patients with surgically inaccessible stage I NSCLC, regardless of the tumor location.

Proton Therapy in Non-small Cell Lung Cancer

OPINION STATEMENT

Non-small cell lung cancer (NSCLC) accounts for 85% of new lung cancer cases and has 5-year survival rates ranging from 92% in early-stage disease to as low as 13% in locally advanced cases. Radiation therapy is a key component in the treatment repertoire for NSCLC, where it is currently used alone or in combinations with chemotherapy and surgery. Despite the broad use of modern photon radiation techniques, as many as 25% of patients experience isolated locoregional recurrences, and toxicity has been proven to be a limiting factor in many cases. Proton beam therapy (PBT) has emerged as a potential solution to improve upon clinical outcomes in both early-stage and locally advanced disease. The proton beam allows for a sharp dose build-up and drop-off, which is particularly important in lung cancer where nearby structures include the heart, spinal cord, esophagus, and uninvolved lung. There are now numerous studies showing dosimetric advantages of PBT in early and locally advanced NSCLC, particularly in the heart and lung doses. Randomized data comparing clinical outcomes between proton and photon radiation are limited to a small number of studies. Despite early results suggesting improvements or at least comparable outcomes with PBT, the most recent randomized comparisons have failed to show significant differences in toxicity and local control between photon and proton therapy. As newer PBT techniques (e.g., intensity-modulated proton therapy) are increasingly utilized, more dramatic improvements in tumor control and toxicity may be demonstrated. It is also important to recognize that there may be certain subpopulations in which the benefits of proton therapy are greater, such as central early-stage tumors, previously irradiated tumors, and locally advanced tumors, while others may best be treated with traditional photon techniques. As immunotherapy becomes more prevalent in the treatment of NSCLC, improving local control and limiting the toxicity contributed by radiation will be increasingly important. The unique dosimetric advantages of PBT may allow for tumor dose escalation while maintaining normal tissue doses to improve local control, or treating the tumor to the standard dose while decreasing normal tissue doses to improve toxicity. Finally, given the high costs of proton therapy, where low insurance approval rates have limited trial enrollment, it will be important to determine the overall cost-benefit ratio.

Evaluation of Radiomics to Predict the Accuracy of Markerless Motion Tracking of Lung Tumors: A Preliminary Study

Template-based matching algorithms are currently being considered for markerless motion tracking of lung tumors. These algorithms use tumor templates derived from the planning CT scan, and track the motion of the tumor on single energy fluoroscopic images obtained at the time of treatment. In cases where bone may obstruct the view of the tumor, dual energy fluoroscopy may be used to enhance soft tissue contrast. The goal of this study is to predict which tumors will have a high degree of accuracy for markerless motion tracking based on radiomic features obtained from the planning CT scan, using peak-to-sidelobe ratio (PSR) as a surrogate of tracking accuracy. In this study, CT imaging data of 8 lung cancer patients were obtained and analyzed through the open source IBEX program to generate 2,287 radiomic features. Agglomerative hierarchical clustering was used to narrow down these features into 145 clusters comprised of the highest correlation to PSR. The features among the clusters with the least inter-correlation were then chosen to limit redundancy in the data. The results of this study demonstrated a number of radiomic features that are positively correlated to PSR. The features with the highest degree of correlation included complexity, orientation and range. This approach may be used to determine patients for whom markerless motion tracking would be beneficial.

Implications for high-precision dose radiation therapy planning or limited surgical resection after percutaneous computed tomography-guided lung nodule biopsy using a tract sealant

Purpose

Precision radiation therapy such as stereotactic body radiation therapy and limited resection are being used more frequently to treat intrathoracic malignancies. Effective local control requires precise radiation target delineation or complete resection. Lung biopsy tracts (LBT) on computed tomography (CT) scans after the use of tract sealants can mimic malignant tract seeding (MTS) and it is unclear whether these LBTs should be included in the calculated tumor volume or resected. This study evaluates the incidence, appearance, evolution, and malignant seeding of LBTs.

Methods and materials

A total of 406 lung biopsies were performed in oncology patients using a tract sealant over 19 months. Of these patients, 326 had follow-up CT scans and were included in the study group. Four thoracic radiologists retrospectively analyzed the imaging, and a pathologist examined 10 resected LBTs.

Results

A total of 234 of 326 biopsies (72%, including primary lung cancer [n = 98]; metastases [n = 81]; benign [n = 50]; and nondiagnostic [n = 5]) showed an LBT on CT. LBTs were identified on imaging 0 to 3 months after biopsy. LBTs were typically straight or serpiginous with a thickness of 2 to 5 mm. Most LBTs were unchanged (92%) or decreased (6.3%) over time. An increase in LBT thickness/nodularity that was suspicious for MTS occurred in 4 of 234 biopsies (1.7%). MTS only occurred after biopsy of metastases from extrathoracic malignancies, and none occurred in patients with lung cancer.

Conclusions

LBTs are common on CT after lung biopsy using a tract sealant. MTS is uncommon and only occurred in patients with extrathoracic malignancies. No MTS was found in patients with primary lung cancer. Accordingly, potential alteration in planned therapy should be considered only in patients with LBTs and extrathoracic malignancies being considered for stereotactic body radiation therapy or wedge resection.

Lung Cancer: Posttreatment Imaging: Radiation Therapy and Imaging Findings

Over the last few decades, advances in radiation therapy technology have markedly improved radiation delivery. Advancements in treatment planning with the development of image-guided radiotherapy and techniques such as proton therapy, allow precise delivery of high doses of radiation conformed to the tumor. These advancements result in improved locoregional control while reducing radiation dose to surrounding normal tissue. The radiologic manifestations of these techniques can differ from radiation induced lung disease seen with traditional radiation therapy. Awareness of these radiologic manifestations and correlation with radiation treatment plans are important to differentiate expected radiation induced lung injury from recurrence, infection and drug toxicity.

Lung Cancer: Posttreatment Imaging: Radiation Therapy and Imaging Findings

In this review, we discuss the different radiation delivery techniques available to treat non-small cell lung cancer, typical radiologic manifestations of conventional radiotherapy, and different patterns of lung injury and temporal evolution of the newer radiotherapy techniques. More sophisticated techniques include intensity-modulated radiotherapy, stereotactic body radiotherapy, proton therapy, and respiration-correlated computed tomography or 4-dimensional computed tomography for radiotherapy planning. Knowledge of the radiation treatment plan and technique, the completion date of radiotherapy, and the temporal evolution of radiation-induced lung injury is important to identify expected manifestations of radiation-induced lung injury and differentiate them from tumor recurrence or infection.

Imaging of Radiation Treatment of Lung Cancer

Radiation therapy is an important modality in the treatment of patients with lung cancer. Recent advances in delivering radiotherapy were designed to improve loco-regional tumor control by focusing higher doses on the tumor. More sophisticated techniques in treatment planning include 3-dimensional conformal radiation therapy, intensity-modulated radiotherapy, stereotactic body radiotherapy, and proton therapy. These methods may result in nontraditional patterns of radiation injury and various radiologic appearances that can be mistaken for recurrence, infection and other lung diseases. Knowledge of radiological manifestations, awareness of new radiation delivery techniques and correlation with radiation treatment plans are essential in order to correctly interpret imaging in these patients.

Sublobar resection is associated with improved outcomes over radiotherapy in the management of high-risk elderly patients with Stage I non-small cell lung cancer: a systematic review and meta-analysis

Background and Aim

A matched-pair comparison was performed to compare the efficacy and safety of sublobar resection versus radiotherapy for high-risk elderly patients with Stage I non-small cell lung cancer (NSCLC).

Patients and Methods

We searched the Cochrane Library, MEDLINE, CENTRAL, EMBASE and manual searches. The meta-analysis was performed to compare overall survival, pattern of failure, and toxicity among the homogeneous studies. Subdivided analyses were also performed.

Results

Sixteen studies containing 11540 patients were included in the meta-analysis. Among these studies, 9 were propensity-score matched (PSM) cohort studies, and 7 were cohort studies. Sublobar resection, compared with radiotherapy (either conventional fraction radiation therapy or stereotactic body radiation therapy), significantly improved the overall survival regardless in both PSM and non-PSM analyses (all p < 0.05). However, the difference in the pattern of failure and toxicity were not significant (all p > 0.05).

Conclusions

Sublobar resection was associated with improved outcomes in high-risk elderly patients with Stage I NSCLC, which supports the need to compare both treatments in large prospective, randomized, controlled clinical trials.

Recent advances in the management of non-small cell lung cancer

Lung cancer is the number one cause of cancer-related death in both men and women. However, over the last few years, we have witnessed improved outcomes that are largely attributable to early detection, increased efforts in tobacco control, improved surgical approaches, and the development of novel targeted therapies. Currently, there are several novel therapies in clinical practice, including those targeting actionable mutations and more recently immunotherapeutic agents. Immunotherapy represents the most significant step forward in eradicating this deadly disease. Given the ever-changing landscape of lung cancer management, here we present an overview of the most recent advances in the management of non-small cell lung cancer.

Patterns of Treatment and Outcomes for Definitive Therapy of Early Stage Non-Small Cell Lung Cancer

BACKGROUND

Definitive surgical and radiation therapy (RT) treatments are evolving rapidly for stage I non-small cell lung cancer (NSCLC). We hypothesized that utilization of definitive therapies increased between 2000 and 2010 and that survival improved for stage I NSCLC patients over the same time period. Secondary objectives were determining trends in patterns of care and predictors of utilization.

METHODS

Population-based, observational, comparative effectiveness study used Surveillance, Epidemiology, and End Results-18 data from 2000 to 2010. The main outcome measure was 2-year risk of death for stage I NSCLC.

RESULTS

Between 2000 and 2010, 40,589 patients (62%) underwent surgery, 10,048 (15%) received RT, 2,130 (3%) received both surgery and RT, and 11,537 (18%) received neither surgery nor RT. Annually, the odds of receiving either definitive RT or undergoing surgery increased relative to the odds of receiving no treatment (odds ratio [OR] radiation 1.04, 95% confidence interval [CI]: 1.03 to 1.05; OR surgery 1.05, 95% CI: 1.04 to 1.05). Among surgical patients, the proportion of sublobar resections steadily increased from 12.9% to 17.9%. For all patients, the 2-year risk of death decreased by 3.5% each year (hazard ratio [HR] 0.965, 95% CI: 0.962 to 0.969), driven primarily by improved survival for surgical (annualized HR 0.959, 95% CI: 0.954 to 0.964) and RT (annualized HR 0.942, 95% CI: 0.935 to 0.949) patients.

CONCLUSIONS

Between 2000 and 2010, stage I NSCLC patients were more likely to receive definitive treatment with either surgery or RT, leading to a decline in the number of untreated patients. Survival also improved substantially for stage I NSCLC patients, with the largest survival improvements observed in patients undergoing definitive RT.

Reduced toxicity with three-dimensional conformal radiotherapy or intensity-modulated radiotherapy compared with conventional two-dimensional radiotherapy for esophageal squamous cell carcinoma: a secondary analysis of data from four prospective clinical trials

We conducted a retrospective analysis to assess the toxicity and long-term survival of esophageal squamous cell carcinoma patients treated with three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT) versus conventional two-dimensional radiotherapy (2DRT). All data in the present study were based on four prospective clinical trials conducted at our institution from 1996 to 2004 and included 308 esophageal squamous cell carcinoma patients treated with 2DRT or 3DCRT/IMRT. Based on the inclusion and exclusion criteria, 254 patients were included in the analysis. Of these patients, 158 were treated with 2DRT, whereas 96 were treated with 3DCRT/IMRT. The rates of ≥Grade3 acute toxicity of the esophagus and lung were 11.5% versus 28.5% (P = 0.002) and 5.2% versus 10.8% (P = 0.127) in the 3DCRT/IMRT and 2DRT groups, respectively. The incidences of ≥Grade 3 late toxicity of the esophagus and lungs were 3.1% versus 10.7% (P = 0.028) and 3.1% versus 5.7% (P = 0.127) in the 3DCRT/IMRT and 2DRT groups, respectively. The 1-year, 3-year and 5-year estimated overall survival rates were 81%, 38% and 34% in the 3DCRT/IMRT group and 79%, 44% and 31% in the 2DRT group, respectively (P = 0.628). The 1-year, 3-year and 5-year local control rates were 88%, 71% and 66% in the 3DCRT/IMRT group and 84%, 66% and 60% in the 2DRT group, respectively (P = 0.412). Fewer incidences of acute and late toxicities were observed in esophageal squamous cell carcinoma patients treated with 3DCRT/IMRT compared with those treated with 2DRT. No significant survival benefit was observed with the use of 3DCRT/IMRT.

Intensity-Modulated Radiation Therapy May Improve Local-Regional Tumor Control for Locally Advanced Non-Small Cell Lung Cancer Compared With Three-Dimensional Conformal Radiation Therapy

BACKGROUND

Consistent results are lacking as regards the comparative effectiveness of intensity-modulated radiotherapy (IMRT) versus three-dimensional conformal radiotherapy (3DCRT) in patients with locally advanced non-small cell lung cancer (LA-NSCLC).

PATIENTS AND METHODS

Patients treated with definitive radiotherapy (RT) between 2002 and 2010 were retrospectively reviewed. Overall survival (OS), local-regional progression-free survival (LRPFS), distant metastasis-free survival (DMFS), and progression-free survival (PFS) were compared among patients irradiated with different techniques. The association between RT technique and survival indexes was assessed in a Cox proportional hazard regression model. Propensity score matching (PSM) was used to balance known confounding factors.

RESULTS

A total of 652 patients were eligible for analysis, including 206 with 3DCRT and 446 with IMRT. The median OS of the 3DCRT and IMRT groups were 19.4 and 23.3 months, with the 5-year rate of 13% and 19%, respectively (p = .043). Multivariate analysis identified IMRT as an independent favorable factor associated with LRPFS and DMFS. PSM analysis further verified the beneficial effect of IMRT on LRPFS. No difference in OS or PFS was observed between the two techniques. Subgroup analysis revealed that IMRT might be differentially more effective in both OS and LRPFS among patients who were female, nonsmokers, with adenocarcinoma, or without weight loss. There was a significant reduction of lung toxicity and similar esophagus toxicity in the IMRT group when compared with the 3DCRT group.

CONCLUSION

IMRT may confer superior LRPFS and comparable OS than can be achieved with 3DCRT in LA-NSCLC, along with the reduction of pulmonary toxicity.

IMPLICATIONS FOR PRACTICE

Based on the largest number of patients from a single institution, the present study demonstrated that intensity-modulated radiotherapy (IMRT) could provide superior local-regional progression-free survival and similar overall survival compared with the traditional three-dimensional conformal radiotherapy (3DCRT) for stage III non-small cell lung cancer (NSCLC). IMRT was also found to be associated with the significantly decreased incidence of pulmonary toxicity. These results suggest that IMRT should be considered a surrogate for 3DCRT in locally advanced NSCLC and might be the preferred option for a female nonsmoker with adenocarcinoma and a potentially high risk of pulmonary toxicity from radiotherapy.

Postoperative radiotherapy is associated with better survival in non-small cell lung cancer with involved N2 lymph nodes: results of an analysis of the National Cancer Data Base

INTRODUCTION

Use of postoperative radiotherapy (PORT) in non-small-cell lung cancer remains controversial. Limited data indicate that PORT may benefit patients with involved N2 nodes. This study evaluates this hypothesis in a large retrospective cohort treated with chemotherapy and contemporary radiation techniques.

METHODS

The National Cancer Data Base was queried for patients diagnosed 2004-2006 with resected non-small-cell lung cancer and pathologically involved N2 (pN2) nodes also treated with chemotherapy. Multivariable Cox proportional hazards model was used to assess factors associated with overall survival (OS). Inverse probability of treatment weighting (IPTW) using the propensity score was used to reduce selection bias. OS was compared between patients treated with versus without PORT using the adjusted Kaplan-Meier estimator and weighted log-rank test based on IPTW.

RESULTS

Two thousand and one hundred and fifteen patients were eligible for analysis. 918 (43.4%) received PORT, 1197 (56.6%) did not. PORT was associated with better OS (median survival time 42 months with PORT versus 38 months without, p = 0.048). This effect was significant in multivariable and IPTW Cox models (hazard ratio: 0.87, 95% confidence interval: 0.78-0.98, p = 0.026, and hazard ratio: 0.89, 95% confidence interval: 0.79-1.00, p = 0.046, respectively). No interaction was seen between the effects of PORT and number of involved lymph nodes (p = 0.615).

CONCLUSIONS

PORT was associated with better survival for patients with pN2 nodes also treated with chemotherapy. No interaction was seen between benefit of PORT and number of involved nodes. These findings reinforce the benefit of PORT for N2 disease in modern practice using the largest, most recent cohort of chemotherapy-treated pN2 patients to date.

Tumor necrosis targeted radiotherapy of non-small cell lung cancer using radioiodinated protohypericin in a mouse model

Lung cancer is the leading cause of cancer-related death. About 80% of lung cancers are non-small cell lung cancers (NSCLC). Radiotherapy is widely used in treatment of NSCLC. However, the outcome of NSCLC remains unsatisfactory. In this study, a vascular disrupting agent (VDA) combretastatin-A4-phosphate (CA4P) was used to provide massive necrosis targets. (131)I labeled necrosis-avid agent protohypericin ((131)I-prohy) was explored for therapy of NSCLC using tumor necrosis targeted radiotherapy (TNTR). Gamma counting, autoradiography, fluorescence microscopy and histopathology were used for biodistribution analysis. Magnetic resonance imaging (MRI) was used to monitor tumor volume, ratios of necrosis and tumor doubling time (DT). The biodistribution data revealed 131I-prohy was delivered efficiently to tumors. Tracer uptake peaked at 24 h in necrotic tumor of (131)I-prohy with and without combined CA4P (3.87 ± 0.38 and 2.96 ± 0.34%ID/g). (131)I-prohy + CA4P enhanced the uptake of (131)I-prohy in necrotic tumor compared to (131)I-prohy alone. The TNTR combined with CA4P prolonged survival of tumor bearing mice relative to vehicle control group, CA4P control group and (131)I-prohy control group with median survival of 35, 20, 22 and 27 days respectively. In conclusion, TNTR appeared to be effective for the treatment of NSCLC.

Clarithromycin Attenuates Radiation-Induced Lung Injury in Mice

Radiation-induced lung injury (RILI) is a common and unavoidable complication of thoracic radiotherapy. The current study was conducted to evaluate the ability of clarithromycin (CLA) to prevent radiation-induced pneumonitis, oxidative stress, and lung fibrosis in an animal model. C57BL/6J mice were assigned to control, irradiation only, irradiation plus CLA, and CLA only groups. Test mice received single thoracic exposures to radiation and/or oral CLA (100 mg/kg/day). Histopathologic findings and markers of inflammation, fibrosis, and oxidative stress were compared by group. On a microscopic level, CLA inhibited macrophage influx, alveolar fibrosis, parenchymal collapse, consolidation, and epithelial cell changes. The concentration of collagen in lung tissue was lower in irradiation plus CLA mice. Radiation-induced expression of tumor necrosis factor (TNF)-α, TNF receptor 1, acetylated nuclear factor kappa B, cyclooxygenase 2, vascular cell adhesion molecule 1, and matrix metallopeptidase 9 were also attenuated by CLA. Expression levels of nuclear factor erythroid 2-related factor 2 and heme oxygenase 1, transforming growth factor-β1, connective tissue growth factor, and type I collagen in radiation-treated lungs were also attenuated by CLA. These findings indicate that CLA ameliorates the deleterious effects of thoracic irradiation in mice by reducing pulmonary inflammation, oxidative damage, and fibrosis.

Complications from Stereotactic Body Radiotherapy for Lung Cancer

Stereotactic body radiotherapy (SBRT) has become a standard treatment option for early stage, node negative non-small cell lung cancer (NSCLC) in patients who are either medically inoperable or refuse surgical resection. SBRT has high local control rates and a favorable toxicity profile relative to other surgical and non-surgical approaches. Given the excellent tumor control rates and increasing utilization of SBRT, recent efforts have focused on limiting toxicity while expanding treatment to increasingly complex patients. We review toxicities from SBRT for lung cancer, including central airway, esophageal, vascular (e.g., aorta), lung parenchyma (e.g., radiation pneumonitis), and chest wall toxicities, as well as radiation-induced neuropathies (e.g., brachial plexus, vagus nerve and recurrent laryngeal nerve). We summarize patient-related, tumor-related, dosimetric characteristics of these toxicities, review published dose constraints, and propose strategies to reduce such complications.

Racial disparities in the use of SBRT for treating early-stage lung cancer

OBJECTIVES

Prior studies have shown that the surgical resection rate for black patients with early-stage lung cancer is significantly lower than that of white patients, which may partially explain the worse outcomes observed in this group. Over the past decade, however, there has been increasing utilization of stereotactic body radiotherapy (SBRT) as an alternative to surgical resection for inoperable patients. We undertook a population-based study to evaluate potential racial disparities in the use of SBRT.

MATERIALS AND METHODS

Using the National Cancer Database, black and white patients with Stage I NSCLC between 2003 and 2011 were identified. Patients were categorized based on primary treatment modality. Univariable and multivariable analyses were performed to identify demographic predictors of SBRT utilization in the non-operative population.

RESULTS

A total of 113,312 patients met the inclusion criteria. When compared to white patients, black patients were less likely to receive surgical intervention (66% vs. 58%, P<0.001) or SBRT (6.1% vs. 5.5%, P<0.001), and more likely to receive standard fractionated external beam radiation (EBRT) or no treatment. When confined to the non-operative cohort, multivariable logistic regression confirmed black race to be negatively associated with SBRT use compared to less aggressive therapy.

CONCLUSION

In this national dataset, we confirmed prior observations that black patients are less likely to receive surgery than white patients, and also found that black patients are less likely to receive SBRT. This suggests that even with emerging utilization of SBRT for inoperable candidates, black patients continue to receive less aggressive therapy.

Comparative effectiveness research in radiation oncology: assessing technology

Technological advances are a major contributor to rising costs in health care, including radiation oncology. Despite the large amount spent on new technologies, technology assessment remains inadequate, leading to potentially costly and unnecessary use of new technologies. Comparative effectiveness studies have an important role to play in evaluating the benefits and harms of new technologies compared with older technologies and have been identified as a priority area for research by the Radiation Oncology Institute. This article outlines the elements of effective technology assessment, identifies key challenges to comparative effectiveness studies of new radiation oncology technologies, and reviews several examples of comparative effectiveness studies in radiation oncology, including studies on conformal radiation, IMRT, proton therapy, and other concurrent new technologies.

Radiation dose and survival of patients with stage IV non-small cell lung cancer undergoing concurrent chemotherapy and thoracic three-dimensional radiotherapy: reanalysis of the findings of a single-center prospective study

BACKGROUND

The objective of this study was to evaluate the radiation dose and response in terms of local-regional progression-free survival (LRPFS) and overall survival (OS) of patients with stage IV non-small cell lung cancer (NSCLC) undergoing concurrent chemotherapy and thoracic three-dimensional radiotherapy.

METHODS

In all, we enrolled 201 patients with stage IV NSCLC in this study and analyzed OS in 159 patients and LRPFS in 120.

RESULTS

The 1-, 2-, 3-, and 5-year OS rates were 46.2%, 19.5%, 11.7%, and 5.8%, respectively, the median survival time being 12 months. The median survival times in differential treatment response of primary tumors were 19 of complete response, 13 of partial response, 8 of stable disease, and 6 months of progressive disease, respectively (P = 0.000). The 1-, 2-, 3-, and 5-year LRPFS rates of patients undergoing four to five cycles with doses ≥63 Gy and <63 Gy were 77.4% and 32.6%, 36.2% and 21.7%, 27.2% and 0, and 15.9% and 0, respectively (P = 0.002). According to multivariate analyses, four to five cycles of chemotherapy, gross tumor volume <175.00 cm3 and post-treatment Karnofsky Performance Status score stable or increased by at least 10 units were independent prognostic factors for better OS (P = 0.035, P = 0.008, and P = 0.000, respectively). Radiation dose to the primary tumor ≥63 Gy resulted in better OS (P = 0.057) and LRPFS (P = 0.051), both findings being of borderline significance.

CONCLUSIONS

Treatment of IV NSCLC with joint administration of four to five cycles of chemotherapy and three-dimensional radiotherapy may prolong survival, particularly in patients receiving ≥63 Gy radiotherapy, with gross tumor volume <175.00 cm3 and post-treatment Karnofsky Performance Status score not lower than pretreatment values.

Novel treatment options in stage I non-small-cell lung cancer

In the last 5 years, the current management of stage I non-small-cell lung cancer has been challenged due to novel surgical approaches and advances in radiation technology. The outcome after a sublobar resection is promising, especially for tumors less than 2 cm. Other treatment opportunities are available for high risk patients with comorbidity and impaired pulmonary function. Stereotactic ablative body radiotherapy is a good alternative treatment to surgery, especially in elderly and comorbid patients. However, randomized evidence comparing sublobar resection and stereotactic radiotherapy is presently lacking. The most recent development in radiotherapy is hadron therapy with a presumed reduced toxicity because of its peculiar physical and biological effects. Promising thermal and microwave ablative techniques are in development and have specific niche indications.

Changes in functional lung regions during the course of radiation therapy and their potential impact on lung dosimetry for non-small cell lung cancer

PURPOSE

To study changes in functional activity on ventilation (V)/perfusion (Q) single-photon emission computed tomography (SPECT) during radiation therapy (RT) and explore the impact of such changes on lung dosimetry in patients with non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

Fifteen NSCLC patients with centrally located tumors were enrolled. All patients were treated with definitive RT dose of ≥60 Gy. V/Q SPECT-CT scans were performed prior to and after delivery of 45 Gy of fractionated RT. SPECT images were used to define temporarily dysfunctional regions of lung caused by tumor or other potentially reversible conditions as B3. The functional lung (FL) was defined on SPECT by 2 separate approaches: FL1, a threshold of 30% of the maximum uptake of the patient's lung; and FL2, FL1 plus B3 region. The impact of changes in FL between initiation of RT and delivery of 45 Gy on lung dosimetry were analyzed.

RESULTS

Fourteen patients (93%) had larger FL2 volumes than FL1 pre-RT (P<.001). Dysfunctional lung became functional in 11 patients (73%) on V SPECT and in 10 patients (67%) on Q SPECT. The dosimetric parameters generated from CT-based anatomical lung had significantly lower values in FL1 than FL2, with a median reduction in the volume of lung receiving a dose of at least 20 Gy (V20) of 3%, 5.6%, and mean lung dose of 0.95 and 1.55 on V and Q SPECT respectively.

CONCLUSIONS

Regional ventilation and perfusion function improve significantly during RT in centrally located NSCLC. Lung dosimetry values vary notably between different definitions of functional lung.

Alternatives to surgery in early stage disease-stereotactic body radiotherapy

The management of early stage non-small cell lung carcinoma (NSCLC) has been revolutionized by the introduction of stereotactic body radiotherapy (SBRT). SBRT is now the standard of care for medically inoperable patients with early stage NSCLC. However, the role of SBRT in medically operable patients remains controversial. This article will review the indications, the technical considerations, image guidance principles, potential toxicities and special circumstances in lung SBRT.

American College of Chest Physicians and Society of Thoracic Surgeons consensus statement for evaluation and management for high-risk patients with stage I non-small cell lung cancer

BACKGROUND

The standard treatment of stage I non-small cell lung cancer (NSCLC) is lobectomy with systematic mediastinal lymph node evaluation. Unfortunately, up to 25% of patients with stage I NSCLC are not candidates for lobectomy because of severe medical comorbidity.

METHODS

A panel of experts was convened through the Thoracic Oncology Network of the American College of Chest Physicians and the Workforce on Evidence-Based Surgery of the Society of Thoracic Surgeons. Following a literature review, the panel developed 13 suggestions for evaluation and treatment through iterative discussion and debate until unanimous agreement was achieved.

RESULTS

Pretreatment evaluation should focus primarily on measures of cardiopulmonary physiology, as respiratory failure represents the greatest interventional risk. Alternative treatment options to lobectomy for high-risk patients include sublobar resection with or without brachytherapy, stereotactic body radiation therapy, and radiofrequency ablation. Each is associated with decreased procedural morbidity and mortality but increased risk for involved lobe and regional recurrence compared with lobectomy, but direct comparisons between modalities are lacking.

CONCLUSIONS

Therapeutic options for the treatment of high-risk patients are evolving quickly. Improved radiographic staging and the diagnosis of smaller and more indolent tumors push the risk-benefit decision toward parenchymal-sparing or nonoperative therapies in high-risk patients. Unbiased assessment of treatment options requires uniform reporting of treatment populations and outcomes in clinical series, which has been lacking to date.

Developments in stereotactic ablative radiotherapy for the treatment of early-stage lung cancer

SUMMARY Stereotactic ablative radiotherapy (SABR), also known as stereotactic body radiation therapy, has emerged as an effective treatment for inoperable early-stage non-small-cell lung cancer. SABR differs from conventional radiotherapy by virtue of its tight spatial tolerances and use of oligofractionated radiation. The modern technique is characterized by management of tumor motion, image guidance before each fraction and specialized radiation delivery techniques. The result is a highly conformal target dose with a sharp gradient that spares normal tissues with great accuracy. This enables delivery of very potent (ablative) doses, causing more rapid and durable responses than traditional radiation therapy treatment regimens can achieve. The established techniques, new developments and ongoing questions related to SABR for early-stage non-small-cell lung cancer are reviewed herein.

New era of radiotherapy: an update in radiation-induced lung disease

Over the last few decades, advances in radiotherapy (RT) technology have improved delivery of radiation therapy dramatically. Advances in treatment planning with the development of image-guided radiotherapy and in techniques such as proton therapy, allows the radiation therapist to direct high doses of radiation to the tumour. These advancements result in improved local regional control while reducing potentially damaging dosage to surrounding normal tissues. It is important for radiologists to be aware of the radiological findings from these advances in order to differentiate expected radiation-induced lung injury (RILD) from recurrence, infection, and other lung diseases. In order to understand these changes and correlate them with imaging, the radiologist should have access to the radiation therapy treatment plans.

Change in diffusing capacity after radiation as an objective measure for grading radiation pneumonitis in patients treated for non-small-cell lung cancer

PURPOSE

Scoring of radiation pneumonitis (RP), a dose-limiting toxicity after thoracic radiochemotherapy, is subjective and thus inconsistent among studies. Here we investigated whether the extent of change in diffusing capacity of the lung for carbon monoxide (DLCO) after radiation therapy (RT) for non-small-cell lung cancer (NSCLC) could be used as an objective means of quantifying RP.

PATIENTS AND METHODS

We analyzed potential correlations between DLCO and RP in 140 patients who received definitive RT (≥ 60 Gy) with or without chemotherapy for primary NSCLC. All underwent DLCO analysis before and after RT. Post-RT DLCO values within 1 week of the RP diagnosis (Grade 0, 1, 2, or 3) were selected and compared with that individual's preradiation values. Percent reductions in DLCO and RP grade were compared by point biserial correlation in the entire patient group and in subgroups stratified according to various clinical factors.

RESULTS

Patients experiencing Grade 0, 1, 2, or 3 RP had median percentage changes in DLCO after RT of 10.7%, 13%, 22.1%, or 35.2%. Percent reduction in DLCO correlated with RP Grade ≤ 1 vs. ≥ 2 (p = 0.0004). This association held for the following subgroups: age ≥ 65 years, advanced stage, smokers, use of chemotherapy, volume of normal lung receiving at least 20 Gy ≥ 30%, and baseline DLCO or forced expiratory volume in 1 second ≥ 60%.

CONCLUSIONS

By correlating percent change in DLCO from pretreatment values at the time of diagnosis of RP with RP grade, we were able to identify categories of RP based on the change in DLCO. These criteria provide a basis for an objective scoring system for RP based on change in DLCO.

Dosimetric comparison of robotic and conventional linac-based stereotactic lung irradiation in early-stage lung cancer

We aimed to compare dosimetric characteristics of conventional linear accerator-based treatment plans to those created using the robotic CyberKnife® (CK) treatment planning system for patients with early-stage lung cancer. Eight early-stage lung cancer patients treated with stereotactic body radiotherapy (SBRT) using a conventional linac-based (LIN) system were included in this study. New treatment plans were created for the patients with the CK treatment planning system in order to compare the two platforms' dosimetric characteristics. Planning computed tomographies (CT) were obtained in three phases: free-breathing, full exhalation and inhalation. The three GTVs were then added together for internal target volume (ITV) with LIN, whereas no ITV was used for CK. Planning target volumes (PTV) were constituted by adding 5-mm margin to GTV and ITV. Treatment plan was 54 Gy in three fractions. Five-field, seven-field, and dynamic-conformal arc planning techniques were used in LIN plans. Plans were compared according to dose heterogenity (D(max)-maximum dose), volume of 54 Gy (V54) and 27 Gy isodose (V27), conformity index (CI(54) and CI(27)) and lung volumes. PTVs were significantly smaller in CK plans (p=0.012). D(max) was significantly lower in ARC plans (p=0.01). Among all plans, CK had significantly tightest isodose shell received 54 Gy and 27 Gy (p=0.0001). Among LIN plans, V54 was significantly (p=0.03) smaller in ARC plans; but no difference was observed for V27 values. LIN plans have better plan quality (CI(27) and CI(54)) than CK. No statistically significant difference was observed for lung volumes. CK plans had superior V54 and V27 values compared to LIN plans due to smaller PTV. LIN plans had better CI(27) and CI(54) values. Advantages of LIN treatment were no neccessity for fiducial marker use, which may cause pneumothorax, and significantly shorter beam-on treatment times. Both CK and LIN methods are suitable for lung SBRT.

Changes in pulmonary function after three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, or proton beam therapy for non-small-cell lung cancer

PURPOSE

To investigate the extent of change in pulmonary function over time after definitive radiotherapy for non-small-cell lung cancer (NSCLC) with modern techniques and to identify predictors of changes in pulmonary function according to patient, tumor, and treatment characteristics.

PATIENTS AND METHODS

We analyzed 250 patients who had received ≥ 60 Gy radio(chemo)therapy for primary NSCLC in 1998-2010 and had undergone pulmonary function tests before and within 1 year after treatment. Ninety-three patients were treated with three-dimensional conformal radiotherapy, 97 with intensity-modulated radiotherapy, and 60 with proton beam therapy. Postradiation pulmonary function test values were evaluated among individual patients compared with the same patient's preradiation value at the following time intervals: 0-4 (T1), 5-8 (T2), and 9-12 (T3) months.

RESULTS

Lung diffusing capacity for carbon monoxide (DLCO) was reduced in the majority of patients along the three time periods after radiation, whereas the forced expiratory volume in 1 s per unit of vital capacity (FEV1/VC) showed an increase and decrease after radiation in a similar percentage of patients. There were baseline differences (stage, radiotherapy dose, concurrent chemotherapy) among the radiation technology groups. On multivariate analysis, the following features were associated with larger posttreatment declines in DLCO: pretreatment DLCO, gross tumor volume, lung and heart dosimetric data, and total radiation dose. Only pretreatment DLCO was associated with larger posttreatment declines in FEV1/VC.

CONCLUSIONS

Lung diffusing capacity for carbon monoxide is reduced in the majority of patients after radiotherapy with modern techniques. Multiple factors, including gross tumor volume, preradiation lung function, and dosimetric parameters, are associated with the DLCO decline. Prospective studies are needed to better understand whether new radiation technology, such as proton beam therapy or intensity-modulated radiotherapy, may decrease the pulmonary impairment through greater lung sparing.

Management of early stage non-small cell lung cancer in high-risk patients

The preferred treatment of stage I non-small cell lung cancer (NSCLC) is anatomic resection with systematic mediastinal lymph node evaluation. However, 20% of patients with operable lung cancer are not candidates for this type of resection. Recent advancements in radiology-guided technologies have expanded the treatment options for high-risk patients with early-stage NSCLC. There has simultaneously been resurgence in interest and refinement of indications and techniques for sublobar resection in this population. While these treatments appear to have decreased peri-procedural morbidity and mortality, their oncologic efficacy compared to that of lobectomy remains to be determined.

[Stereotactic body radiaton therapy for 15 patients with small lung neoplasms]

背景与目的

立体定向放疗在临床应用中取得了令人振奋的成果。本研究旨在评价直线加速器大分割立体定向放疗治疗肺部小肿瘤的可行性。

方法

纳入2005年9月-2009年8月本院收治的15例符合要求的非小细胞肺癌（non-small cell lung cancer, NSCLC）及肺部转移瘤患者。放疗前在模拟机下测定肺部病灶的左右、前后、头尾三个方向的呼吸运动幅度，采用CT模拟定位，选择三维适形立体定向放疗。放疗剂量如下：5 Gy×10次/12天生物有效剂量[（biological effective dose, BED）=75 Gy]2例，6 Gy×8次/10天（BED=76.8 Gy）3例，8 Gy×6次/8天（BED=86.4 Gy）2例，12 Gy×4次/4天（BED=132 Gy）8例，病变直径1.5 cm-4 cm，毒性评价标准按照NCI-CTCAE 3.0版本进行。

结果

15例患者患者近期疗效完全缓解（complete response, CR）率为60%，部分缓解（partial response, PR）率为20%，总有效率（CR+PR）为80%。1年局部控制率为100%，1年生存率为86.67%。肺的早期放射性反应0级2例，Ⅰ级9例，Ⅱ级4例，无Ⅲ级以上的副反应。

结论

利用直线加速器对肺部小病灶实施48 Gy/4次/4天的照射是可行的。

Survival outcomes after radiation therapy for stage III non-small-cell lung cancer after adoption of computed tomography-based simulation

PURPOSE

Technical studies suggest that computed tomography (CT) -based simulation improves the therapeutic ratio for thoracic radiation therapy (TRT), although few studies have evaluated its use or impact on outcomes.

METHODS

We used the Surveillance, Epidemiology and End Results (SEER) -Medicare linked data to identify CT-based simulation for TRT among Medicare beneficiaries diagnosed with stage III non-small-cell lung cancer (NSCLC) between 2000 and 2005. Demographic and clinical factors associated with use of CT simulation were identified, and the impact of CT simulation on survival was analyzed by using Cox models and propensity score analysis.

RESULTS

The proportion of patients treated with TRT who had CT simulation increased from 2.4% in 1994 to 34.0% in 2000 to 77.6% in 2005. Of the 5,540 patients treated with TRT from 2000 to 2005, 60.1% had CT simulation. Geographic variation was seen in rates of CT simulation, with lower rates in rural areas and in the South and West compared with those in the Northeast and Midwest. Patients treated with chemotherapy were more likely to have CT simulation (65.2% v 51.2%; adjusted odds ratio, 1.67; 95% CI, 1.48 to 1.88; P < .01), although there was no significant association between use of surgery and CT simulation. Controlling for demographic and clinical characteristics, CT simulation was associated with lower risk of death (adjusted hazard ratio, 0.77; 95% CI, 0.73 to 0.82; P < .01) compared with conventional simulation.

CONCLUSION

CT-based simulation has been widely, although not uniformly, adopted for the treatment of stage III NSCLC and is associated with higher survival among patients receiving TRT.

Technical advances of radiation therapy for thymic malignancies

Radiation therapy often plays a critical role in the treatment of thymic malignancies. However, because of the location of these tumors, historically patients have been at a significant risk for radiation-related toxicity such as pericardial effusions, radiation pneumonitis, long-term pulmonary fibrosis, and occasional long-term esophageal stricture, particularly for unresectable thymoma. Recent advancements in technology have provided the treating radiation oncologist with the ability to more accurately target the region at risk while sparing normal structures. In this review, we provide an overview of key advances in radiation techniques for thymoma over the past two decades. These techniques include 3D conformal therapy, intensity-modulated radiation therapy, 4D treatment planning, adaptive radiation therapy, and proton therapy. Each advancement has brought with it unique advantages in maintaining long-term disease control while improving quality of life in this manageable disease.

Early findings on toxicity of proton beam therapy with concurrent chemotherapy for nonsmall cell lung cancer

BACKGROUND

Concurrent chemoradiation therapy, the standard of care for locally advanced nonsmall cell lung cancer (NSCLC), can cause life-threatening pneumonitis and esophagitis. X-ray (photon)-based radiation therapy (RT) often cannot be given at tumoricidal doses without toxicity to proximal normal tissues. We hypothesized that proton beam therapy for most patients with NSCLC could permit higher tumor doses with less normal-tissue toxicity than photon RT delivered as 3-dimensional conformal RT (3D-CRT) or intensity-modulated RT (IMRT).

METHODS

We compared the toxicity of proton therapy+concurrent chemotherapy in 62 patients with NSCLC (treatment period 2006-2008) with toxicity for patients with similar disease given 3D-CRT+chemotherapy (n = 74; treatment period 2001-2003) or IMRT+chemotherapy (n = 66; treatment period 2003-2005). Proton therapy to the gross tumor volume was given with weekly intravenous paclitaxel (50 mg/m²) and carboplatin (area under the curve 2 mg/mL/min). The primary endpoint was toxicity (Common Terminology Criteria for Adverse Events version 3.0).

RESULTS

Median follow-up times were 15.2 months (proton), 17.9 months (3D-CRT), and 17.4 months (IMRT). Median total radiation dose was 74 Gy(RBE) for the proton group versus 63 Gy for the other groups. Rates of severe (grade ≥ 3) pneumonitis and esophagitis in the proton group (2% and 5%) were lower despite the higher radiation dose (3D-CRT, 30% and 18%; IMRT, 9% and 44%; P<.001 for all).

CONCLUSIONS

We found that higher doses of proton radiation could be delivered to lung tumors with a lower risk of esophagitis and pneumonitis. A randomized comparison of IMRT versus proton therapy is underway.

Stereotactic body radiotherapy (SBRT) for operable stage I non-small-cell lung cancer: can SBRT be comparable to surgery?

PURPOSE

To review treatment outcomes for stereotactic body radiotherapy (SBRT) in medically operable patients with Stage I non-small-cell lung cancer (NSCLC), using a Japanese multi-institutional database.

PATIENTS AND METHODS

Between 1995 and 2004, a total of 87 patients with Stage I NSCLC (median age, 74 years; T1N0M0, n=65; T2N0M0, n=22) who were medically operable but refused surgery were treated using SBRT alone in 14 institutions. Stereotactic three-dimensional treatment was performed using noncoplanar dynamic arcs or multiple static ports. Total dose was 45-72.5 Gy at the isocenter, administered in 3-10 fractions. Median calculated biological effective dose was 116 Gy (range, 100-141 Gy). Data were collected and analyzed retrospectively.

RESULTS

During follow-up (median, 55 months), cumulative local control rates for T1 and T2 tumors at 5 years after SBRT were 92% and 73%, respectively. Pulmonary complications above Grade 2 arose in 1 patient (1.1%). Five-year overall survival rates for Stage IA and IB subgroups were 72% and 62%, respectively. One patient who developed local recurrences safely underwent salvage surgery.

CONCLUSION

Stereotactic body radiotherapy is safe and promising as a radical treatment for operable Stage I NSCLC. The survival rate for SBRT is potentially comparable to that for surgery.

Toxicity report of a phase 1/2 dose-escalation study in patients with inoperable, locally advanced nonsmall cell lung cancer with helical tomotherapy and concurrent chemotherapy

BACKGROUND

The objective of the current study was to evaluate the feasibility and toxicity of radiation dose escalation with concurrent chemotherapy using helical tomotherapy (HT) in patients with inoperable, locally advanced, stage III nonsmall cell lung cancer (LANSCLC) (grading determined according to the American Joint Committee on Cancer 6th edition grading system).

METHODS

This phase 1/2 study was designed to determine the maximum tolerated dose (MTD) of radiotherapy in patients with LANSCLC administered concurrently with docetaxel and cisplatin. Radiotherapy was delivered using HT. A dose per fraction escalation was applied starting at 2 grays (Gy), with an increase of 6% per dose cohort (DC). The Radiation Therapy Oncology Group acute radiation morbidity score was used to monitor pulmonary, esophageal, and cardiac toxicity.

RESULTS

Dose escalation was performed in 34 patients over 5 DCs to a dose per fraction of 2.48 Gy. No differences were observed in acute toxicity between the different DCs. However, a significant increase in late lung toxicity in DC IV, which received a fraction size of 2.36 Gy, necessitated a halt in further dose escalation with the MTD defined as 2.24 Gy per fraction. The overall incidence of acute grade > or =3 esophageal and pulmonary toxicity was 24% and 3%, respectively (grading determined according to the Radiation Therapy Oncology Group-European Organisation for Research and Treatment of Cancer toxicity scoring system). The overall incidence of late lung toxicity was 21%, but the incidence was an acceptable 13% in DCs I, II, and III. The local response rate was 61% on computed tomography images.

CONCLUSIONS

The use of HT to 67.2 Gy with concurrent cisplatin/docetaxel was feasible and resulted in acceptable toxicity. A full phase 2 study has been initiated to establish the true local response rate at the MTD of 2.24 Gy per fraction.