Dose escalation of accelerated hypofractionated three-dimensional conformal radiotherapy (at 3 Gy/fraction) with concurrent vinorelbine and carboplatin chemotherapy in unresectable stage III non-small-cell lung cancer: a phase I trial

Dose-Volume Predictors of Radiation Pneumonitis After Thoracic Hypofractionated Radiation Therapy

PURPOSE

Hypofractionated radiation therapy (HFRT) is a common treatment for thoracic tumors, typically delivered as 60 Gy in 15 fractions. We aimed to identify dosimetric risk factors associated with radiation pneumonitis in patients receiving HFRT at 4 Gy per fraction, focusing on lung V20, mean lung dose (MLD), and lung V5 as potential predictors of grade ≥2 pneumonitis.

METHODS AND MATERIALS

All patients were treated with thoracic HFRT to 60 Gy in 15 fractions or 72 Gy in 18 fractions at a single health care system from 2013 to 2020. Tumors near critical structures (trachea, proximal tracheobronchial tree, esophagus, spinal cord, or heart) were considered central (within 2 cm), and those closer were classified as ultracentral (within 1 cm). The primary endpoint was grade ≥2 pneumonitis. Logistic regression analyses, adjusting for target size and dosimetric variables, were used to establish a dose threshold associated with <20% risk of grade ≥2 pneumonitis.

RESULTS

During a median 24.3-month follow-up, 18 patients (16.8%) developed grade ≥2 radiation pneumonitis, with no significant difference between the 2 dose regimens (17.3% vs 16.3%, P = .88). Four patients (3.7%) experienced grade ≥3 pneumonitis, including 2 grade 5 cases. Patients with grade ≥2 pneumonitis had significantly higher lung V20 (mean 23.4% vs 14.5%, P < .001), MLD (mean 13.0 Gy vs 9.5 Gy, P < .001), and lung V5 (mean 49.6% vs 40.6%, P = .01). Dose thresholds for a 20% risk of grade ≥2 pneumonitis were lung V20 <17.7%, MLD <10.6 Gy, and V5 <41.3%. Multivariable analysis revealed a significant association between lung V20 and grade ≥2 pneumonitis (adjusted odds ratio, 1.48, P = .03).

CONCLUSIONS

To minimize the risk of grade ≥2 radiation pneumonitis when delivering 4 Gy per fraction at either 60 Gy or 72 Gy, it is advisable to maintain lung V20<17.7%. MLD <10.6 Gy and V5<41.3% can also be considered as lower-priority constraints. However, additional validation is necessary before incorporating these constraints into clinical practice or trial planning guidelines.

Obtaining organ-specific radiobiological parameters from clinical data for radiation therapy planning of head and neck cancers

Objective.Different radiation therapy (RT) strategies, e.g. conventional fractionation RT (CFRT), hypofractionation RT (HFRT), stereotactic body RT (SBRT), adaptive RT, and re-irradiation are often used to treat head and neck (HN) cancers. Combining and/or comparing these strategies requires calculating biological effective dose (BED). The purpose of this study is to develop a practical process to estimate organ-specific radiobiologic model parameters that may be used for BED calculations in individualized RT planning for HN cancers.Approach.Clinical dose constraint data for CFRT, HFRT and SBRT for 5 organs at risk (OARs) namely spinal cord, brainstem, brachial plexus, optic pathway, and esophagus obtained from literature were analyzed. These clinical data correspond to a particular endpoint. The linear-quadratic (LQ) and linear-quadratic-linear (LQ-L) models were used to fit these clinical data and extract relevant model parameters (alpha/beta ratio, gamma/alpha,dTand BED) from the iso-effective curve. The dose constraints in terms of equivalent physical dose in 2 Gy-fraction (EQD2) were calculated using the obtained parameters.Main results.The LQ-L and LQ models fitted clinical data well from the CFRT to SBRT with the LQ-L representing a better fit for most of the OARs. The alpha/beta values for LQ-L (LQ) were found to be 2.72 (2.11) Gy, 0.55 (0.30) Gy, 2.82 (2.90) Gy, 6.57 (3.86) Gy, 5.38 (4.71) Gy, and the dose constraint EQD2 were 55.91 (54.90) Gy, 57.35 (56.79) Gy, 57.54 (56.35) Gy, 60.13 (59.72) Gy and 65.66 (64.50) Gy for spinal cord, optic pathway, brainstem, brachial plexus, and esophagus, respectively. Additional two LQ-L parametersdTwere 5.24 Gy, 5.09 Gy, 7.00 Gy, 5.23 Gy, and 6.16 Gy, and gamma/alpha were 7.91, 34.02, 8.67, 5.62 and 4.95.Significance.A practical process was developed to extract organ-specific radiobiological model parameters from clinical data. The obtained parameters can be used for biologically based radiation planning such as calculating dose constraints of different fractionation regimens.

Opportunities in Cancer Therapies: Deciphering the Role of Cancer Stem Cells in Tumour Repopulation

Tumour repopulation during treatment is a well acknowledged yet still challenging aspect of cancer management. The latest research results show clear evidence towards the existence of cancer stem cells (CSCs) that are responsible for tumour repopulation, dissemination, and distant metastases in most solid cancers. Cancer stem cell quiescence and the loss of asymmetrical division are two powerful mechanisms behind repopulation. Another important aspect in the context of cancer stem cells is cell plasticity, which was shown to be triggered during fractionated radiotherapy, leading to cell dedifferentiation and thus reactivation of stem-like properties. Repopulation during treatment is not limited to radiotherapy, as there is clinical proof for repopulation mechanisms to be activated through other conventional treatment techniques, such as chemotherapy. The dynamic nature of stem-like cancer cells often elicits resistance to treatment by escaping drug-induced cell death. The aims of this scoping review are (1) to describe the main mechanisms used by cancer stem cells to initiate tumour repopulation during therapy; (2) to present clinical evidence for tumour repopulation during radio- and chemotherapy; (3) to illustrate current trends in the identification of CSCs using specific imaging techniques; and (4) to highlight novel technologies that show potential in the eradication of CSCs.

Excessive esophageal toxicity in patients with locally advanced non-small cell lung cancer treated with concurrent hypofractionated chemoradiotherapy and 3-weekly platinum doublet chemotherapy

•

Concurrent full dose chemoradiotherapy (24x2.75 Gy) is toxic in multiple N2 disease.

•

Toxicity after platinum doublet chemoradiation (24x2.75 Gy) is mainly esophageal.

•

Fatal toxicity may be increased in patients with bulky centrally located tumors.

Introduction

Concurrent chemoradiation followed by immunotherapy is the standard of care for patients with stage III non-small cell lung cancer (NSCLC). Prior to the introduction of adjuvant immunotherapy, we treated patients with stage III NSCLC with concurrent platinum doublet chemotherapy and 66 Gy in 24 fractions. We determined the toxicity of this treatment.

Methods

A retrospective observational study was performed in a cohort of patients with stage III NSCLC, <70 years old, and WHO performance score 0–1. Patients were treated with concurrent platinum doublet chemotherapy and 66 Gy in 24 fractions. All patients were staged with a PET-scan and brain MRI-scan. Toxicity was scored using the common criteria for adverse events (CTCAE v4.03).

Results

Between 2012 and 2017, 41 patients were treated with mildly hypofractionated radiotherapy and platinum doublet chemotherapy. The median follow-up was 4.7 years. The median age was 57 and 58% of patients were male. The majority of patients had stage IIIB disease (68%). The median total Gross Tumor Volume (GTV) was 104 cc (range: 15–367 cc). The median lymph node GTV was 59 cc (10–341 cc). Five patients died: four due to an esophagus perforation or fistula, and one due to pulmonary bleeding. Grade ≥ 3 esophageal toxicity occurred in 16 patients. Five patients had late grade ≥ 3 esophageal toxicity (12%). The median overall survival was 19 months.

Conclusion

Toxicity was unexpectedly high in patients with stage III NSCLC (WHO 0–1) after concurrent platinum doublet chemotherapy and 66 Gy in 24 fractions.

Dose-escalation by hypofractionated simultaneous integrated boost IMRT in unresectable stage III non-small-cell lung cancer

Background

To explore the maximum tolerated dose (MTD) and evaluate the safety of dose escalation using hypofractionated simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) concurrent with chemotherapy for unresectable stage III non-small cell lung cancer (NSCLC).

Methods

Four escalating radiation dose levels were used. This study included 25 patients with previously untreated NSCLC who received six concurrent weekly chemotherapy cycles comprising cisplatin and docetaxel. Dose-limiting toxicity (DLT) was defined as any acute toxicity that interrupted radiotherapy for more than 1 week. MTD was defined as the highest dose level that didn’t induce DLT or grade 5 toxicity in two patients.

Results

All 25 patients received the prescribed escalating radiation dose from the start dose up to LEVEL 4. Two patients experienced DLT at dose LEVEL 4. One patient died because of upper gastrointestinal hemorrhage within 6 months after radiotherapy, whereas another patient among the additional five patients died because of grade 5 radiation pneumonitis within 2 months after radiotherapy. Dose LEVEL 3 was defined as MTD. The 1- and 2-year local controls were 82.8 and 67.8%, respectively. The median progression-free survival was 15.4 months, whereas the median overall survival was 27.3 months.

Conclusions

Dose escalation was safely achieved up to LEVEL 3 [the planning gross target volume (PTVG) 60.5 Gy/22 Fx, 2.75 Gy/Fx; the planning clinical target volume (PTVC) 49.5 Gy/22 Fx] using SIB-IMRT concurrently with chemotherapy for unresectable stage III NSCLC, and the acute toxicities were generally well tolerated. Further prospective studies on long-term outcomes and late toxicities are warranted.

Trial registration

Retrospective registration, ChiCTR1900027290(08/11/2019).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09099-3.

Outcomes of Image-Guided Moderately Hypofractionated Radiotherapy for Stage III Non-Small-Cell Lung Cancer

Objective

To evaluate the efficacy and toxicity of hypofractionated radiotherapy (hypo-RT) for stage III non-small-cell lung cancer (NSCLC) in the Chinese population.

Methods

Eighty-six stage III NSCLC patients who received hypo-RT (60 Gy/20 fractions, BED = 78.00 Gy: 73 patients; 62.5 Gy/25 fractions, BED = 78.13 Gy: 13 patients) were recruited. Fifty-seven patients who received conventional radiotherapy (60 Gy/30 fractions, BED = 72.00 Gy) during the same period were enrolled as the control group. All hypo-RT treatments were conducted using image-guided technology. The efficacy and toxicity of the treatment were compared between the two groups.

Results

The median duration of follow-up was 23.0 months (range: 4.0–82.0 months). Univariate and multivariate analyses of all 143 stage III NSCLC patients revealed that hypo-RT was an independent factor for progression-free survival (PFS) and overall survival (OS). The median PFS and OS of hypo-RT were significantly higher than in the conventional RT group (PFS: 14.30, 11.00 months, p=0.035; OS: 43.30, 31.50 months, p=0.045). The incidence rates of symptomatic radiation pneumonitis and radiation esophagitis (≥grade 2) were 17.77% and 27.91%, respectively, in the hypo-RT group. Compared to the conventional radiation therapy group (22.81% and 19.30%, respectively), no significant differences were found between the two common side effects (p=0.662 and p=0.241, respectively).

Conclusion

For Chinese stage III NSCLC patients, image-guided hypo-RT offers favorable prognosis, and the treatment toxicity was totally acceptable. This radiation modality deserves further prospective clinical trials.

Hypofractionation and Stereotactic Body Radiation Therapy in Inoperable Locally Advanced Non-small Cell Lung Cancer

BACKGROUND AND AIM

Radiotherapy (RT) plays a key role in the control of locally advanced non-small cell lung cancer (LA-NSCLC). Throughout the years, different doses and fractionations of RT have been used in an attempt to optimize the results. Recently, special interest has been given to hypofractionation (hypoRT) and stereotactic body radiation therapy (SBRT). HypoRT is a relatively widespread treatment, although the accompanying level of evidence is limited. For its part, SBRT has been used specially to overdose specific areas of the disease as a boost after radiochemotherapy. In both cases, the study of how to integrate these RT tools with chemotherapy and immunotherapy is fundamental. In addition, the 2020 COVID-19 pandemic situation has sparked increased interest in hypofractionated treatments. In this review, we analyze the role of SBRT and hypoRT in the management of LA-NSCLC in accordance with current scientific evidence.

RELEVANCE FOR PATIENTS

The objective of this article is to introduce professionals to the role that hypoRT and SBRT can play in the treatment of LA-NSCLC to offer the best treatment to their patients.

Study protocol: a multicentre, prospective, phase II trial of isotoxic hypofractionated concurrent chemoradiotherapy for non-small cell lung cancer

INTRODUCTION

Concurrent chemoradiotherapy with conventional fractionation has been acknowledged as one of the standard treatments for locally advanced non-small cell lung cancer (NSCLC). The radiotherapy dose of 60 Gy is far from enough for local tumour control. Due to this fact, hypofractionated radiotherapy can shorten the total treatment duration, partially counteract the accelerated repopulation of tumour cells and deliver a higher biological effective dose, it has been increasingly used for NSCLC. In theory, concurrent hypofractionated chemoradiotherapy can result in an enhanced curative effect. To date, the vast majority of radiotherapy prescriptions assign a uniform radiotherapy dose to all patients. However this kind of uniform radiotherapy prescription may lead to two consequences: excess damage to normal tissues for large tumours and insufficient dose for small tumours. Our study aims to evaluate whether delivering individualised radiotherapy dose is feasible using intensity-modulated radiotherapy.

METHODS AND ANALYSIS

Our study of individualised radiotherapy is a multicenter phase II trial. From April 2019, a total of 30 patients from three Chinese centres, with a proven histological or cytological diagnosis of inoperable NSCLC, will be recruited. The dose of radiation will be increased until one or more of the organs at risk tolerance or the maximum dose of 69 Gy is reached. The primary end point is feasibility, with response rates, progression-free survival and overall survival as secondary end points. The concurrent chemotherapy regimen will be docetaxel plus lobaplatin.

ETHICS AND DISSEMINATION

The study has been approved by medical ethics committees from three research centres. The trial is conducted in accordance with the Declaration of Helsinki.The trial results will be disseminated through academic conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03606239.

Hypofractionated Concomitant Chemoradiation in Inoperable Locally Advanced Non-small Cell Lung Cancer: A Report on 100 Patients and a Systematic Review

AIMS

Concomitant chemoradiation is the standard of care in patients with inoperable non-small cell lung cancer. The purpose of this study was to analyse the survival outcome and toxicity data of using hypofractionated chemoradiation.

MATERIALS AND METHODS

One hundred patients were treated from June 2011 to November 2016. Treatment consisted of 55 Gy in 20 daily fractions concurrently with split-dose cisplatin vinorelbine chemotherapy over 4 weeks followed by two cycles of cisplatin vinorelbine only. Survival was estimated using Kaplan-Meier and Cox regression was carried out for known prognostic factors. A systematic search of literature was conducted using Medline, Embase and Cochrane databases and relevant references included.

RESULTS

In total, 97% of patients completed radiotherapy and 73% of patients completed all four cycles of chemotherapy. One patient died of a cardiac event during consolidative chemotherapy. There were two cases of grade 4 toxicities (one sepsis, one renal impairment). Grade 3 toxicities included nausea/vomiting (17%), oesophagitis (15%), infection with neutropenia (12%) and pneumonitis (4%). Clinical benefit was seen in 86%. Two-year progression-free survival and overall survival rates were 49% and 58%, respectively. The median progression-free survival and overall survival were 23.4 and 43.4 months, respectively. The only significant prognostic factor was the number of chemotherapy cycles received (P = 0.02). The systematic review identified 13 relevant studies; a variety of regimens were assessed with variable reporting of outcomes and toxicity but with overall an improvement in survival over time.

CONCLUSION

Our experience compared with the original phase II trial showed improved treatment completion rates and survival with acceptable morbidity. With appropriate patient selection this regimen is an effective treatment option for locally advanced non-small cell lung cancer. This study helps to benchmark efficacy and toxicity rates while considering the addition of new agents to hypofractionated concurrent chemoradiotherapy. The agreement of a standard regimen for assessment in future trials would be beneficial.

Hypofractionated radiation therapy in the management of locally advanced NSCLC: a narrative review of the literature on behalf of the Italian Association of Radiation Oncology (AIRO)-Lung Working Group

A systematic literature was performed to assess the benefit in terms of effectiveness and feasibility of hypofractionated radiotherapy (HypoRT), with or without chemotherapy (CT), in the treatment of locally advanced non-small cell lung cancer (NSCLC). We have identified all studies, published from 2007 onwards, on patients with locally advanced NSCLC treated with HypoRT with radical intent, with a minimal dose per fraction of 2.4 Gy, with or without concurrent chemotherapy. Twenty-nine studies were identified, for a total of 2614 patients. Patients were divided in the concurrent chemo-radiation therapy group (CT-RT) and radiotherapy alone (RT). In RT group, the delivered dose ranged from 45 to 85.5 Gy, with a dose/fraction from 2.4 to 4 Gy. Actuarial 2-year PFS ranged from 13 to 57.8%, and 1, 2- and 3-year overall survival (OS) ranged from 51.3 to 95%, from 22 to 68.7%, and from 7 to 32%, respectively. Acute Grade ≥ 3 esophagitis occurred in 0-15%, while late esophageal toxicity was 0-16%. Acute pneumonitis occured in 0-44%, whereas late pneumonitis occured in 0-47%, most commonly grade ≤ G3. In CT-RT group, the delivered dose ranged from 52.5 to 75 Gy, with a dose/fraction ranging from 2.4 to 3.5 Gy. Actuarial 2-year PFS ranged from 19 to 57.8%, and OS at 1, 2 and 3 years ranged from 28 to 95%, 38.6 to 68.7%, and 31 to 44%, respectively. Acute Grade 2 and 3 esophagitis occurred in 3-41.7%, while late esophageal toxicity occurred in 0-8.3%. Acute pneumonitis ranged from 0 to 23%, whereas late pneumonitis occured 0-47%. HypoRT seems to be safe in patients with locally advanced NSCLC. The encouraging survival results of several studies analyzed suggest that hypofractionated radiation schemes should be further investigated in the future.

Phase 1 Study of Accelerated Hypofractionated Radiation Therapy With Concurrent Chemotherapy for Stage III Non-Small Cell Lung Cancer: CALGB 31102 (Alliance)

PURPOSE

To investigate the safety of accelerated hypofractionated radiation therapy (AHRT) with concurrent chemotherapy (CT) for inoperable stage III non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

The primary objectives were to define the maximally tolerable course of accelerated radiation therapy and to describe toxicities of therapy. Total radiation therapy remained at 60 Gy. The number of once-daily fractions in each successive cohort was reduced as follows: cohort 1, 60 Gy in 27 fractions; cohort 2, 60 Gy in 24 fractions; cohort 3, 60 Gy in 22 fractions; and cohort 4, 60 Gy in 20 fractions. Concurrent treatment consisted of weekly carboplatin area under the curve (AUC) 2 and paclitaxel 45 mg/m². Consolidation treatment consisted of carboplatin AUC 6 and paclitaxel 200 mg/m² every weeks × 2 cycles. Maximum tolerated dose: Of 6 patients/cohort, ≤2 patients experienced grade ≥3 toxicity, and ≤1 patient experienced grade ≥4 toxicity.

RESULTS

22 patients were accrued; of those, 21 patients were evaluable between July 2012 and May 2014. Grade 5 toxicity occurred in 3 patients: 1 patient in cohort 2 (hemoptysis), 2 patients in cohort 3 (hemoptysis, pneumonitis). The maximum tolerated dose (MTD) was defined by cohort 2 (60 Gy in 2.5 Gy/fraction). Time to grade 5 toxicity was 9 months, 6 months, and 9 months after the start of treatment. The median follow-up time was 23.0 months (range, 7.6-30.6 months) in living patients, the median overall survival was 19.3 months (95% confidence interval [CI] 9.3-34.0 months), and the median progression-free survival was 12.2 months (95% CI 6.1-22.5 months).

CONCLUSIONS

Only modest hypofractionation was achievable as a result of long-term toxicities. Nevertheless, the MTD of 60 Gy given at 2.5 Gy/fraction allows completion of RT in 20% fewer treatments than conventional therapy. Further investigation of AHRT may help to better define the therapeutic index.

The potential for increased tumor control probability in non-small cell lung cancer with a hypofractionated integrated boost to the gross tumor volume

Treatment outcomes in locally advanced non-small cell lung cancer (NSCLC) to date have been poor, with normal tissue toxicity often limiting the dose that can be delivered to the tumor. Treatment intensification in NSCLC via targeted dose escalation with modern delivery techniques may offer the potential for a significant increase in tumor control probability (TCP) without a clinically significant increase in organ-at-risk (OAR) toxicity. In this planning study, 20 patients were re-planned with a volumetric modulated arc therapy (VMAT) and an inhomogeneous dose distribution with iteratively escalated doses to the gross tumor volume (iGTV) (composite GTV across multiple 4-dimensional computed tomography [4DCT] phases) in a series of 20 fraction regimes. For each plan OAR doses, target coverage and predicted TCPs were collected and compared with homogenous 3-dimensional (3D) and VMAT plans, as well as with each other. In 70% of patients, it was possible to escalate to 75 Gy in 20 fractions within OAR tolerances, opening the possibility of treating these patients to a biological effective dose (BED) of 103.1 Gy₁₀. This planning study forms the basis of a clinical trial INTENSE (Inhomogeneous Targeted Dose Escalation in Non-Small CEll Lung Cancer), CTRIAL 15-47.

Effect of Midtreatment PET/CT-Adapted Radiation Therapy With Concurrent Chemotherapy in Patients With Locally Advanced Non-Small-Cell Lung Cancer: A Phase 2 Clinical Trial

Importance

Our previous studies demonstrated that tumors significantly decrease in size and metabolic activity after delivery of 45 Gy of fractionated radiatiotherapy (RT), and that metabolic shrinkage is greater than anatomic shrinkage. This study aimed to determine whether 18F-fludeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) acquired during the course of treatment provides an opportunity to deliver higher-dose radiation to the more aggressive areas of the tumor to improve local tumor control without increasing RT-induced lung toxicity (RILT), and possibly improve survival.

Objective

To determine whether adaptive RT can target high-dose radiation to the FDG-avid tumor on midtreatment FDG-PET to improve local tumor control of locally advanced non-small-cell lung cancer (NSCLC).

Design, Setting, and Participants

A phase 2 clinical trial conducted at 2 academic medical centers with 42 patients who had inoperable or unresectable stage II to stage III NSCLC enrolled from November 2008, to May 2012. Patients with poor performance, more than 10% weight loss, poor lung function, and/or oxygen dependence were included, providing that the patients could tolerate the procedures of PET scanning and RT.

Intervention

Conformal RT was individualized to a fixed risk of RILT (grade >2) and adaptively escalated to the residual tumor defined on midtreatment FDG-PET up to a total dose of 86 Gy in 30 daily fractions. Medically fit patients received concurrent weekly carboplatin plus paclitaxel followed by 3 cycles of consolidation.

Main Outcomes and Measures

The primary end point was local tumor control. The trial was designed to achieve a 20% improvement in 2-year control from 34% of our prior clinical trial experience with 63 to 69 Gy in a similar patient population.

Results

The trial reached its accrual goal of 42 patients: median age, 63 years (range, 45-83 years); male, 28 (67%); smoker or former smoker, 39 (93%); stage III, 38 (90%). Median tumor dose delivered was 83 Gy (range, 63-86 Gy) in 30 daily fractions. Median follow-up for surviving patients was 47 months. The 2-year rates of infield and overall local regional tumor controls (ie, including isolated nodal failure) were 82% (95% CI, 62%-92%) and 62% (95% CI, 43%-77%), respectively. Median overall survival was 25 months (95% CI, 12-32 months). The 2-year and 5-year overall survival rates were 52% (95% CI, 36%-66%) and 30% (95% CI, 16%-45%), respectively.

Conclusions and Relevance

Adapting RT-escalated radiation dose to the FDG-avid tumor detected by midtreatment PET provided a favorable local-regional tumor control. The RTOG 1106 trial is an ongoing clinical trial to validate this finding in a randomized fashion.

Trial Registration

clinicaltrials.gov Identifier: NCT01190527.

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.

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.

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.

Accelerated hypofractionated three-dimensional conformal radiation therapy (3 Gy/fraction) combined with concurrent chemotherapy for patients with unresectable stage III non-small cell lung cancer: preliminary results of an early terminated phase II trial

BACKGROUND

Increasing the biological effective dose (BED) of radiotherapy for non-small cell lung cancer (NSCLC) can increase local control rates and improve overall survival. Compared with conventional fractionated radiotherapy, accelerated hypofractionated radiotherapy can yield higher BED, shorten the total treatment time, and theoretically obtain better efficacy. However, currently, there is no optimal hypofractionated radiotherapy regimen. Based on phase I trial results, we performed this phase II trial to further evaluate the safety and preliminary efficacy of accelerated hypofractionated three-dimensional conformal radiation therapy(3-DCRT) combined with concurrent chemotherapy for patients with unresectable stage III NSCLC.

METHODS

Patients with previously untreated unresectable stage III NSCLC received 3-DCRT with a total dose of 69 Gy, delivered at 3 Gy per fraction, once daily, five fractions per week, completed within 4.6 weeks. At the same time, platinum doublet chemotherapy was applied.

RESULTS

After 12 patients were enrolled in the group, the trial was terminated early. There were five cases of grade III radiation esophagitis, of which four cases completed the radiation doses of 51 Gy, 51 Gy, 54 Gy, and 66 Gy, and one case had 16 days of radiation interruption. The incidence of grade III acute esophagitis in patients receiving an irradiation dose per fraction ≥2.7 Gy on the esophagus was 83.3% (5/6). The incidence of symptomatic grade III radiation pneumonitis among the seven patients who completed 69 Gy according to the plan was 28.6% (2/7). The median local control (LC) and overall survival (OS) were not achieved; the 1-year LC rate was 59.3%, and the 1-year OS rate was 78.6%.

CONCLUSION

For unresectable stage III NSCLC, the accelerated hypofractionated radiotherapy with a total dose of 69 Gy (3 Gy/f) combined with concurrent chemotherapy might result in severe radiation esophagitis and pneumonitis to severely affect the completion of the radiotherapy. Therefore, we considered that this regimen was infeasible. During the hypofractionated radiotherapy with concurrent chemotherapy, the irradiation dose per fraction to esophagus should be lower than 2.7 Gy. Further studies should be performed using esophageal tolerance as a metric in dose escalation protocols.

TRIAL REGISTRATION

NCT02720614, the date of registration: March 23, 2016.

Normal tissue considerations and dose-volume constraints in the moderately hypofractionated treatment of non-small cell lung cancer

Hypofractionated radiation therapy (RT) regimes in non-small cell lung cancer (NSCLC) have become increasingly popular with a number of international trials currently underway. The majority of the dose-volume-constraints (DVCs) published in the literature refer to conventional 2Gy per fraction deliveries. Here relevant organs-at-risk (OARs) are identified and available dose-volume constraint data discussed and summarised for moderately hypofractionated NSCLC regimes. The OARs examined include lung, brachial plexus, heart, oesophagus, airway and spinal cord. Where available the toxicity rates are also reported with all data summarised tabulated to aid its use in the clinic.

Pathways to improving combined modality therapy for stage III nonsmall-cell lung cancer

BACKGROUND

Lung cancer is the leading cause of cancer deaths, having caused an estimated 1.6 million deaths worldwide in 2012 [Ferlay J, Soerjomataram I, Dikshit R et al. Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN 2012. Int J Cancer 2015; 136: E359-E386].

MATERIALS AND METHODS

Although the majority of patients are not cured with currently available therapies, there have been significant improvements in stage-specific outcomes over time [Videtic G, Vokes E, Turrisi A et al. The survival of patients treated for stage III non-small cell lung cancer in North America has increased during the past 25 years. In The 39th Annual Meeting of the American Society of Clinical Oncology, ASCO 2003, Chicago, IL. Abstract 2557. p. 291]. This review focuses on past progress and ongoing research in the treatment of locally advanced, inoperable nonsmall-cell lung cancer (NSCLC).

RESULTS

In the past, randomized trials revealed advantages to the use of thoracic radiotherapy (TRT) and then, the addition of induction chemotherapy. This was followed by studies that determined concurrent chemoradiotherapy to be superior to sequential therapy. A recent large phase III trial found that the administration of 74 Gy of conventionally fractionated photon-based TRT provided poorer survival than did the standard 60 Gy. However, further research on other methods of applying radiotherapy (hypofractionation, adaptive TRT, proton therapy, and stereotactic TRT boosting) is proceeding and may improve outcomes. The molecular characterization of tumors has provided more effective and less toxic targeted treatments in the stage IV setting and these agents are currently under investigation for earlier stage disease. Similarly, immune-enhancing therapies have shown promise in stage IV disease and are also being tested in the locally advanced setting.

CONCLUSION

For locally advanced, inoperable NSCLC, standard therapy has evolved from TRT alone to combined modality therapy. We summarize the recent clinical trial experience and outline promising areas of investigation in an era of greater molecular and immunologic understanding of cancer care.

A novel role of long non-coding RNAs in response to X-ray irradiation

In the present study, the role of lncRNAs in response to radiation-induced DNA damage and oxidative stress were explored to improve our understanding of the biological pathways activated upon radiation-induced toxicity. The toxicity of X-ray radiation on human bronchial epithelial cell lines (HBE) was determined through a dose-dependent increase in ROS production and γ-H2AX formation and changes to lncRNA expression was observed and quantified using lncRNA-specific microarrays. 115 lncRNAs expression was increased in a dose-dependent manner following X-ray irradiation. Bioinformatic prediction algorithms determined that these lncRNAs significantly affect the p53 signaling pathway, and, more specifically, the BRCA 1 transcription factor and coding genes adjacent to BRCA 1. Our results highlight a previously uncharacterized role for lncRNAs to act via the p53-pathway in response to X-ray-induced DNA damage, and suggest lncRNAs may serve as novel indicators for radiation toxicity.

Definitive chemotherapy and radiotherapy in patients with stage II non-small cell lung cancer: A population-based outcomes study

OBJECTIVES

There is a paucity of data on non-surgical outcomes specific to stage II non-small cell lung cancer (NSCLC) patients receiving definitive chemotherapy and radiation therapy (CRT). This study reports population-based outcomes for this subgroup, and investigates a radiation dose-response for overall survival.

MATERIALS AND METHODS

The National Oncology Data Alliance (NODA), a merging of multiple tumor registries maintained by Elekta(®) medical systems, was queried for stage II patients and CRT. Only curative cases (RT doses ≥59 Gy) were included. Both sequential and concurrent CRT were allowed. Univariate and Cox multivariate techniques were used to assess factors significant for overall survival. These factors included: gender, age, race, radiation dose, radiation total treatment time, stage, histology, tumor size, and chemotherapy sequence.

RESULTS

A total of 568 patients were included in the analysis, with a median follow-up of 12.9 months for surviving patients. Patients were treated between 2004 and 2014. Median survival was 20.5 months (95% confidence interval (CI) 18-23 months), with 16% patients alive at 5 years. Only gender was found to be significantly associated with survival in the Cox model. Although median survival was higher in patients receiving greater than 60 Gy (21 months, 95% CI 18-24 moths) compared to 59-60 Gy (16.5 months 95% CI 10-23 months), this was not statistically significant (p=0.6).

CONCLUSIONS

This is the first report on outcomes for stage II NSCLC patients receiving CRT as definitive therapy. Survival approximates stage III CRT patients from historical phase III trials. As an increasing aging population may parallel a rise in medically inoperable stage II patients, this study can provide useful information when reviewing treatment options.

Radical-intent hypofractionated radiotherapy for locally advanced non-small-cell lung cancer: a systematic review of the literature

PURPOSE

To identify survival and toxicity characteristics associated with radical-intent hypofractionated radiotherapy for the treatment of stage III non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

Relevant studies were identified from a systematic PubMed search of articles published between January 1990 and January 2014. All studies were peer reviewed and included both retrospective and prospective studies of NSCLC patients being treated with radical hypofractionated radiotherapy. Data on overall survival (OS) and toxicity were extracted from each of the studies where available.

RESULTS

Of 685 studies initially identified by the search, a total of 33 studies were found to be relevant and were included in this systematic review. The number of fractions ranged from 15 to 35, the dose per fraction ranged from 2.3 to 3.5 Gy, and the delivered dose ranged from 45.0 to 85.5 Gy. Fifteen of the studies included concurrent chemotherapy, while 18 did not. OS was found to be associated with tumor biological effective dose, with the Pearson correlation coefficient ranging from 0.34 to 0.48. For both concurrent and nonconcurrent chemoradiotherapy acute pulmonary, late esophageal and late pulmonary incidences of toxicity ranged from 1.2% to 12.2%, but had 95% confidence intervals that included zero. The greatest incidence of toxicity was acute esophageal toxicity at 14.9% (95% confidence interval, 0.7%, 29.1%).

CONCLUSIONS

There is a moderate linear relationship between biological effective dose and OS, and greater acute esophageal toxicity with concurrent chemotherapy. Improving outcomes in stage III NSCLC may involve some form of hypofractionation in the context of systemic concurrent therapy.