Definitive radiation therapy in locally advanced non-small cell lung cancer: Executive summary of an American Society for Radiation Oncology (ASTRO) evidence-based clinical practice guideline

Therapeutic management options for stage III non-small cell lung cancer

Lung cancer is the leading cause of cancer death worldwide. Majority of newly diagnosed lung cancers are non-small cell lung cancer (NSCLC), of which up to half are considered locally advanced at the time of diagnosis. Patients with locally advanced stage III NSCLC consists of a heterogeneous population, making management for these patients complex. Surgery has long been the preferred local treatment for patients with resectable disease. For select patients, multi-modality therapy involving systemic and radiation therapies in addition to surgery improves treatment outcomes compared to surgery alone. For patients with unresectable disease, concurrent chemoradiation is the preferred treatment. More recently, research into different chemotherapy agents, targeted therapies, radiation fractionation schedules, intensity-modulated radiotherapy, and proton therapy have shown promise to improve treatment outcomes and quality of life. The array of treatment approaches for locally advanced NSCLC is large and constantly evolving. An updated review of past and current literature for the roles of surgery, chemotherapeutic agents, radiation therapy, and targeted therapy for stage III NSCLC patients are presented.

Persistence of dysphagia and odynophagia after mediastinal radiation and chemotherapy in patients with lung cancer or lymphoma

Esophageal symptoms are common during radiation and chemotherapy. It is unclear how often these symptoms persist after therapy. We retrospectively reviewed medical records of 320 adults treated for nonmetastatic breast cancer (84), lung cancer (109), or Hodgkin and non-Hodgkin lymphoma (127) who were disease-free at 10-14 months after therapy. Treatment included chemotherapy with or without nonmediastinal radiation therapy (150 patients), chemotherapy plus sequential mediastinal radiation therapy (MRT) (48 patients), chemotherapy plus concurrent MRT (61 patients), or non-MRT only (61 patients). Proton pump inhibitor use was documented. All treatment groups had similar prevalence of the esophageal symptom of heartburn before therapy. Rates were higher during treatment in those who received MRT with or without chemotherapy, but declined by 10-14 months after treatment. However, low baseline rates of dysphagia (4%) and odynophagia (2%) increased significantly after combined chemotherapy and MRT to 72% for dysphagia and 62% for odynophagia (P < 0.01) during treatment and stayed significantly elevated over baseline with 27% of the patients having dysphagia and 11% having odynophagia at 10-14 months after treatment. The use of proton pump inhibitors by patients who had MRT with chemotherapy was significantly increased during and after treatment (P = 0.002). Dysphagia, odynophagia and the use of proton pump inhibitors were significantly more common both during and after treatment than before treatment in patients who received both chemotherapy and mediastinal radiation. Our data highlight the important challenge for clinicians of managing patients with lung cancer and lymphoma who have persistent esophageal problems, particularly dysphagia and odynophagia, at approximately 1 year after treatment.

Results of a Single Institution Experience with Dose-Escalated Chemoradiation for Locally Advanced Unresectable Non-Small Cell Lung Cancer

Background

We determined factors associated with morbidity and outcomes of a series of non-small cell lung cancer (NSCLC) patients treated with dose-escalated chemoradiotherapy at the University of Pittsburgh Lung Cancer Program.

Methods and materials

The records of 170 stage III NSCLC patients treated with definitive intent were retrospectively reviewed. All patients received four-dimensional CT simulation scan and had respiratory gating if tumor movement exceeded 5 mm. Overall survival (OS), locoregional control (LRC), and freedom from distant metastasis (FFDM) were calculated using log-rank and Cox regression analysis.

Results

For the present series of patients, median follow-up was 36.6 months, median survival 27.4 months, and the 2- and 4-year OS was 56.0 and 30.7%, respectively. The 4-year LRC and FFDM were 43.9 and 40.7%, respectively. No benefit was associated with irradiation doses above 66 Gy in OS (p = 0.586), LRC (p = 0.440), or FFDM (p = 0.230). On univariate analysis, variables associated with worse survival included: clinical stage IIIB (p = 0.037), planning target volume (PTV) over 450 cc (p < 0.001), heart V₃₀ over 40% (p = −0.048), and esophageal mean dose over 20% (p = 0.024), V₅ (p = −0.015), and V₆₀ (p = −0.011). On multivariable analysis, PTV above 450 cc (52.2 vs. 25.3 months, p < 0.001) and esophageal V₆₀ >20% (43.8 vs. 21.3 months, p = −0.01) were associated with lower survival. Grade 2 or higher acute lung toxicity and esophagitis were detected in 9.5 and 59.7%, respectively of patients. Grade 2 or higher acute lung toxicity was reduced if lung V₅ was ≤65 (7.4 vs. 23.8%, p = 0.03). Grade 2 or higher acute esophagitis was reduced if V₆₀ ≤ 20% (62 vs. 81.3%, p = 0.018). The use of intensity-modulated radiation therapy was more frequent in stage IIIB compared to stage IIIA patients (56.5 vs. 39.5%, p = 0.048) and was associated with a higher lung V₅ and V₁₀.

Conclusion

The outcomes of a program of dose-escalated chemoradiotherapy for unresectable stage IIIA and IIIB NSCLC patients were consistent with other studies and showed no benefit to radiation doses above 66 Gy. Furthermore, maintaining low esophageal V₆₀ and lung V₅ were associated with lower morbidity and mortality.

Potential for adaptive dose escalation in radiotherapy for patients with locally advanced non-small-cell lung cancer in a low mid income setting

OBJECTIVE

To evaluate the effect of tumour volume regression on adaptive treatment planning, reduction in doses to organs at risk (OARs) and dose escalation.

METHODS

20 patients undergoing radical chemoradiotherapy were imaged in the fifth week of radiotherapy (CT_45) to evaluate differences in tumour volume regression between concurrent and sequential chemoradiotherapy. Replanning was carried out in the CT_45 in those with >20% regression (n = 10) and evaluated for change in target coverage indices (the coverage index and external volume index) and doses to the OAR [mean lung dose, V₂₀ and V₅ of whole and ipsilateral lung (MLD_WL, V_20WL, V_5WL, MLD_IL, V_20IL, V_5IL); mean oesophagus dose, V_50oesophagus; and maximum spinal cord doses]. The feasibility of maximum dose escalation was explored keeping the limit of the OAR below their tolerance limits.

RESULTS

Tumour regression was higher with concurrent chemoradiotherapy as compared with sequential chemoradiotherapy (p = 0.02). With the adaptive plan, the mean coverage index improved from 0.96 (±0.14) to 1.29 (±0.36), the mean external volume index changed from 1.39(±0.60) to 1.41(±0.56) and the reduction in doses to the OARs were MLD_WL 10.6%, V_20WL 1.3%, V_5WL 1.2%, MLD_IL 6.6%, V_20IL 1.5%, V_5IL 2.3%, mean oesophagus dose 7%, V_50oesophagus 31% and maximum cord dose 0.35%. Dose escalation was possible in four patients in CT_45.

CONCLUSION

There is 35% reduction in tumour volume with chemoradiotherapy at 45 Gy which allows improvement in conformality, reduction in doses to the OARs and dose escalation in 40% of patients. Advances in knowledge: This article emphasizes that adaptive planning with a single diagnostic scan at 45 Gy has the potential for improvement of radiotherapy planning indices, dose escalation while respecting the dose to the OAR. This simple strategy can be helpful in radiotherapy planning upto 60 Gy in 40% of the patients of locally advanced non-small-cell lung cancer in countries with limited resources.

Management of stage I and II nonsmall cell lung cancer

The incidence of stage I and II nonsmall cell lung cancer is likely to increase with the ageing population and introduction of screening for high-risk individuals. Optimal management requires multidisciplinary collaboration. Local treatments include surgery and radiotherapy and these are currently combined with (neo)adjuvant chemotherapy in specific cases to improve long-term outcome. Targeted therapies and immunotherapy may also become important therapeutic modalities in this patient group. For resectable disease in patients with low cardiopulmonary risk, complete surgical resection with lobectomy remains the gold standard. Minimally invasive techniques, conservative and sublobar resections are suitable for a subset of patients. Data are emerging that radiotherapy, especially stereotactic body radiation therapy, is a valid alternative in compromised patients who are high-risk candidates for surgery. Whether this is also true for good surgical candidates remains to be evaluated in randomised trials. In specific subgroups adjuvant chemotherapy has been shown to prolong survival; however, patient selection remains important. Neoadjuvant chemotherapy may yield similar results as adjuvant chemotherapy. The role of targeted therapies and immunotherapy in early stage nonsmall cell lung cancer has not yet been determined and results of randomised trials are awaited.

From chemotherapy to target therapies associated with radiation in the treatment of NSCLC: a durable marriage?

INTRODUCTION

The integration between radiotherapy and drugs, from chemotherapy to recently available target therapies, continues to have a relevant role in the treatment of locally advanced and metastatic Non-small cell lung cancer (NSCLC). Aim of the present review is to evaluate the promising and emerging application of the best interaction between new drugs and new modalities of radiotherapy. Areas covered: We searched Medline, Google Scholar, PubMed, ProQuest Dissertation, and Theses databases for reports published in English. A study was included when it reported on cancer-related radiotherapy and included patients with NSCLC treated with chemo and/or target therapies. Review articles were excluded from the analysis. Expert commentary: Chemo-radiotherapy still represents the standard of choice in locally advanced NSCLC, while to date the addition of target therapies to chemo-radiotherapy did not demonstrate any robust advantage in this stage of disease. Considering the absence of randomized controlled trials, the role of target therapies in early stage adjuvant NSCLC is not yet recommended in clinical practice. On the contrary, in the setting of oligometastatic and oligoprogressive disease, new molecules demonstrated to be safe and effective, opening to a promising and emerging application of the best interaction between new drugs and new modalities of radiotherapy.

Radio(chemo)therapy in locally advanced nonsmall cell lung cancer

Definitive radiochemotherapy is the standard treatment for many patients with locally advanced nonsmall cell lung cancer (NSCLC). Treatment outcomes have improved over the last decades. Several treatment regimens have been shown effective and safe. This review summarises the results of significant studies between 1996 and 2015 on concomitant and sequential radiochemotherapy regimens and radiation dose per fraction. Beside therapy regimens, optimised radiotherapy planning is indispensable to improve outcome and minimise radiation-induced toxicity. An insight into the rationale of radiotherapy planning for stage III NSCLC is also provided.

Concomitant radiochemotherapy is an established standard treatment for locally advanced nonsmall cell lung cancerhttp://ow.ly/TTkkc

Dose and Fractionation in Radiation Therapy of Curative Intent for Non-Small Cell Lung Cancer: Meta-Analysis of Randomized Trials

PURPOSE

The optimum dose and fractionation in radiation therapy of curative intent for non-small cell lung cancer remains uncertain. We undertook a published data meta-analysis of randomized trials to examine whether radiation therapy regimens with higher time-corrected biologically equivalent doses resulted in longer survival, either when given alone or when given with chemotherapy.

METHODS AND MATERIALS

Eligible studies were randomized comparisons of 2 or more radiation therapy regimens, with other treatments identical. Median survival ratios were calculated for each comparison and pooled.

RESULTS

3795 patients in 25 randomized comparisons of radiation therapy dose were studied. The median survival ratio, higher versus lower corrected dose, was 1.13 (95% confidence interval [CI] 1.04-1.22) when radiation therapy was given alone and 0.83 (95% CI 0.71-0.97) when it was given with concurrent chemotherapy (P for difference=.001). In comparisons of radiation therapy given alone, the survival benefit increased with increasing dose difference between randomized treatment arms (P for trend=.004). The benefit increased with increasing dose in the lower-dose arm (P for trend=.01) without reaching a level beyond which no further survival benefit was achieved. The survival benefit did not differ significantly between randomized comparisons where the higher-dose arm was hyperfractionated and those where it was not. There was heterogeneity in the median survival ratio by geographic region (P<.001), average age at randomization (P<.001), and year trial started (P for trend=.004), but not for proportion of patients with squamous cell carcinoma (P=.2).

CONCLUSIONS

In trials with concurrent chemotherapy, higher radiation therapy doses resulted in poorer survival, possibly caused, at least in part, by high levels of toxicity. Where radiation therapy was given without chemotherapy, progressively higher radiation therapy doses resulted in progressively longer survival, and no upper dose level was found above which there was no further benefit. These findings support the consideration of further radiation therapy dose escalation trials, making use of modern treatment methods to reduce toxicity.

Factors Associated With the Use of Radiation Therapy in Patients With Stage III Non-small Cell Lung Cancer in Alberta, Canada: A Population-based Study

Background

Cancer care in Alberta, Canada is publicly funded and provides patients with access to health care facilities and providers. The distribution of patients and health services across Alberta presents challenges to the delivery of cancer care, especially radiation therapy. In this study, we examined the association between patient and health system factors, the use of radiation therapy and survival outcomes in patients with stage III non-small cell lung cancer (NSCLC).

Patients and methods

The provincial cancer registry was used to identify all patients who presented with clinical stage III NSCLC, diagnosed from 2005 to 2007, in Alberta. Patient characteristics, diagnostic method, treatment modality and treatment outcomes were collected from provincial health information systems for analyses. Factors influencing overall survival (OS) were analyzed using Cox proportional hazards models.

Results

Nine hundred twenty-nine patients were identified. Sixty-two percent of patients received radiation therapy (RT) as part of their initial cancer treatment and had a median OS of 1.04 vs. 0.34 years with a hazard ratio (HR) of 0.54. On multivariable analysis, patients who were less likely to receive any therapy were older, had higher comorbidity scores and were registered in community cancer centers without radiation therapy infrastructure. Patients registered in tertiary cancer centers had a higher likelihood of accessing multimodality treatment than patients in community centers, with a statistical significance of P<0.001 after correcting for age, gender, histology, substage, and comorbidity.

Interpretation

Improving access to radiotherapy treatment for patients presenting to non-radiation therapy centers at diagnosis has the potential to decrease variations in cancer care and improve cancer control outcomes in clinical stage III NSCLC.

Outcomes of Elderly Patients Who Receive Combined Modality Therapy for Locally Advanced Non-Small-Cell Lung Cancer

BACKGROUND

The objective of this study was to review our institution's experience among patients with locally advanced non-small-cell lung cancer (LA-NSCLC) treated with chemotherapy and radiation and to determine the prognostic significance of age.

PATIENTS AND METHODS

Patients were included if they underwent sequential or concurrent chemoradiotherapy from 2006 to 2014 for LA-NSCLC. Patients were stratified according to age ≤70 and >70 years. Kaplan-Meier and Cox regression methods were performed to evaluate overall survival (OS) and progression-free survival (PFS).

RESULTS

One hundred twenty-three patients were identified. Ninety-eight patients were 70 years of age or younger and 25 patients were older than 70 years of age. The median radiotherapy dose was 6660 cGy (range, 3780-7600 cGy). A greater percentage of elderly patients were men, 72% (18 patients) versus 39% (38 patients) (P = .006) and received carboplatin/paclitaxel-based chemotherapy, 60% (15 patients) versus 21% (20 patients) (P < .001). Median follow-up for OS was 25.9 (95% confidence interval [CI], 21.3-33.9) months. There was no difference in the PFS of older patients versus younger patients (hazard ratio [HR], 1.15; P = .64), adjusted for significant covariates. The 1-year PFS rate for patients 70 years of age or younger was 51% (95% CI, 42%-63%) versus 45% (95% CI, 28%-71%) in patients older than 70 years. After adjusting for significant covariates, there was no difference in the OS of older patients compared with younger patients (HR, 1.18; P = .65). The 1-year OS rate for patients 70 years of age or younger was 77% (95% CI, 68%-86%) versus 56% (95% CI, 39%-81%) in patients younger than 70 years.

CONCLUSION

Chemoradiotherapy is an effective treatment in elderly patients with LA-NSCLC, with outcomes similar to that in younger patients. Appropriately selected elderly patients should be considered for chemoradiation.

Should we include SPECT lung perfusion in radiotherapy treatment plans of thoracic targets? Evidences from the literature

PURPOSE

To report the available data about the potential impact of integrating lung perfusion SPECT/CT in treatment plans optimization for the irradiation of thoracic targets.

MATERIALS AND METHODS

We searched in the PubMed and Scopus databases, English-written articles published from 2000 to June 2015 dealing with the integration of perfusion SPECT/CT in radiotherapy.

RESULTS

We found and analyzed 16 research articles (10 dosimetric, 6 clinical) for a total of 578 patients. Available data suggest dosimetric and clinical improvements when perfusion SPEC/CT is integrated in the radiotherapy treatment planing of selected patients with thoracic targets. In particular, patients presenting emphysema and/or large areas of deficit of perfusion show the most important improvements. Moreover, some studies show different risk of radiation pneumonitis (RP) depending on the localization of the tumor in the lungs: patients with low-located tumors, present an increased risk of RP, and functional data could be a benefit in treatment plan optimization. Unfortunately, none of the available studies finally reports any dosimetric constraint, which could be used in the clinical practice, even if most of them used the cut-off of the 30% of the maximal perfusion value to define the well-functioning lung.

CONCLUSIONS

Published data support the integration of lung perfusion scintigraphy in some selected categories of patients. Prospective studies should be designed to define the best candidates, and to assess the clinical advantage of this kind of optimization.

Clinical and research priorities for combined modality therapy in stage III NSCLC

Stage III NSCLC comprises of a heterogeneous group of patients with regard to stage, extent of disease and prognosis. Disease presentation can often be complex in clinical practice, and the challenges are not well-defined in clinical trials or practice guidelines. In order to improve the therapeutic ratio of treatment, one needs to either increase the benefit of treatment or reduce toxicities, or both. Priorities in radiation therapy include dose escalation, imaging advances, improved target delineation, reduced planning target volume margin, intensity-modulated radiotherapy, image-guided radiotherapy, motion management and the use of cytoprotectants. Priorities in systemic therapy include the incorporation of molecularly targeted and immune-modulatory agents.

Outcomes of Hypofractionated High-Dose Radiotherapy in Poor-Risk Patients with "Ultracentral" Non-Small Cell Lung Cancer

INTRODUCTION

We defined "ultracentral" lung tumors as centrally located non-small cell lung cancers with planning target volumes overlapping the trachea or main bronchi. Increased toxicity has been reported after both conventional and stereotactic radiotherapy for such lesions. We studied outcomes after 12 fractions of 5 Gy (BED10 = 90 Gy, heterogeneous dose distribution) to ultracentral tumors in patients unfit for surgery or conventional chemoradiotherapy.

METHODS

Clinical outcomes and dosimetric details were analyzed in 47 consecutive patients with single primary or recurrent ultracentral non-small cell lung cancer treated between 2010 and 2015. Those irradiated previously or with metastasis to sites other than the brain and adrenal glands were excluded. Treatments were delivered using volumetric modulated arc therapy.

RESULTS

The median age was 77.5 years, 49% of patients had a World Health Organization performance score of 2 or higher, and the median planning target volume was 104.5cm(3) (range 17.7-508.5). At a median follow-up of 29.3 months, median overall survival was 15.9 months, and 3-year survival was 20.1%. No isolated local recurrences were observed. Grade 3 or higher toxicity was recorded in 38% of patients, with 21% scored as having a "possible" (n = 2) or "likely" (n = 8) treatment-related death between 5.2 and 18.2 months after treatment. Fatal pulmonary hemorrhage was observed in 15% of patients.

CONCLUSIONS

Unfit patients with ultracentral tumors who were treated using this scheme had a high local control and a median survival of 15.9 months. Despite manifestation of rates of a fatal lung bleeding comparable to those seen with conventional radiotherapy for endobronchial tumors, the overall rate of G5 toxicity is of potential concern. Additional work is needed to identify tumor and treatment factors related to hemorrhage.

Raman spectroscopy identifies radiation response in human non-small cell lung cancer xenografts

External beam radiation therapy is a standard form of treatment for numerous cancers. Despite this, there are no approved methods to account for patient specific radiation sensitivity. In this report, Raman spectroscopy (RS) was used to identify radiation-induced biochemical changes in human non-small cell lung cancer xenografts. Chemometric analysis revealed unique radiation-related Raman signatures that were specific to nucleic acid, lipid, protein and carbohydrate spectral features. Among these changes was a dramatic shift in the accumulation of glycogen spectral bands for doses of 5 or 15 Gy when compared to unirradiated tumours. When spatial mapping was applied in this analysis there was considerable variability as we found substantial intra- and inter-tumour heterogeneity in the distribution of glycogen and other RS spectral features. Collectively, these data provide unique insight into the biochemical response of tumours, irradiated in vivo, and demonstrate the utility of RS for detecting distinct radiobiological responses in human tumour xenografts.

Cone-beam CT-guided radiotherapy in the management of lung cancer: Diagnostic and therapeutic value

BACKGROUND

Recent studies have demonstrated an increase in the necessity of adaptive planning over the course of lung cancer radiation therapy (RT) treatment. In this study, we evaluated intrathoracic changes detected by cone-beam CT (CBCT) in lung cancer patients during RT.

METHODS AND MATERIALS

A total of 71 lung cancer patients treated with fractionated CBCT-guided RT were evaluated. Intrathoracic changes and plan adaptation priority (AP) scores were compared between small cell lung cancer (SCLC, n = 13) and non-small cell lung cancer (NSCLC, n = 58) patients.

RESULTS

The median cumulative radiation dose administered was 54 Gy (range 30-72 Gy) and the median fraction dose was 1.8 Gy (range 1.8-3.0 Gy). All patients were subjected to a CBCT scan at least weekly (range 1-5/week). We observed intrathoracic changes in 83 % of the patients over the course of RT [58 % (41/71) regression, 17 % (12/71) progression, 20 % (14/71) atelectasis, 25 % (18/71) pleural effusion, 13 % (9/71) infiltrative changes, and 10 % (7/71) anatomical shift]. Nearly half, 45 % (32/71), of the patients had one intrathoracic soft tissue change, 22.5 % (16/71) had two, and three or more changes were observed in 15.5 % (11/71) of the patients. Plan modifications were performed in 60 % (43/71) of the patients. Visual volume reduction did correlate with the number of CBCT scans acquired (r = 0.313, p = 0.046) and with the timing of chemotherapy administration (r = 0.385, p = 0.013).

CONCLUSION

Weekly CBCT monitoring provides an adaptation advantage in patients with lung cancer. In this study, the monitoring allowed for plan adaptations due to tumor volume changes and to other anatomical changes.