Concomitant Chemotherapy and Radiotherapy with SBRT Boost for Unresectable Stage III Non-Small Cell Lung Cancer: A Phase I Study

A Phase 2 Trial of Primary Tumor Stereotactic Body Radiation Therapy Boost Before Concurrent Chemoradiation for Locally Advanced Non-Small Cell Lung Cancer

PURPOSE

Primary tumor failure is common in patients treated with chemoradiation (CRT) for locally advanced NSCLC (LA-NSCLC). Stereotactic body radiation therapy (SBRT) yields high rates of primary tumor control (PTC) in early-stage NSCLC. This trial tested an SBRT boost to the primary tumor before the start of CRT to improve PTC.

METHODS AND MATERIALS

Patients with LA-NSCLC received an SBRT boost in 2 fractions (central location 12 Gy, peripheral location 16 Gy) to the primary tumor, followed by standard CRT (60 Gy in 30 fractions). The primary objective was PTC rate at 1 year, and the hypothesis was that the 1-year PTC rate would be ≥90%. Secondary objectives included objective response rate, regional and distant control, disease-free survival (DFS), and overall survival (OS). Correlative studies included functional magnetic resonance imaging and blood-based miRNA analysis.

RESULTS

The study enrolled 21 patients (10 men and 11 women); the median age was 62 years (range, 52-78). The median pretreatment primary tumor size was 5.0 cm (range, 1.0-8.3). The most common nonhematologic toxicities were pneumonitis, fatigue, esophagitis/dysphagia, dyspnea, and cough. Only 1 treatment-related grade 4 nonhematologic toxicity occurred (respiratory failure/radiation pneumonitis), and no grade 5 toxicities occurred. The objective response rate at 3 and 6 months was 72.7% and 80.0%, respectively, and PTC at 1 and 2 years was 100% and 92.3%, respectively. The 2-year regional and distant control rates were 81.6% and 70.3%, respectively. Disease-free survival and overall survival at 2 years were 46.1% and 50.3%, respectively, and median survival was 37.8 months. Functional magnetic resonance imaging detected a mean relative decrease in blood oxygenation level-dependent signal of -87.1% (P = .05), and miR.142.3p was correlated with increased risk of grade ≥3 pulmonary toxicity (P = .01).

CONCLUSIONS

Dose escalation to the primary tumor using upfront SBRT appears feasible and safe. PTC was high and other oncologic endpoints compared favorably to standard treatment. Functional magnetic resonance imaging suggested changes in oxygenation with the first SBRT boost dose, and miR.142.3p was correlated with pulmonary toxicity.

Stereotactic ablative radiotherapy for locally advanced non-small cell lung cancer: A systematic review and meta-analysis

INTRODUCTION

To evaluate the feasibility, efficacy and safety of stereotactic ablative radiotherapy (SABR) to the primary tumor and lymph nodes in patients with locally advanced non-small cell lung cancer (LA-NSCLC) who are ineligible for or refused concomitant chemoradiation.

MATERIALS AND METHODS

In accordance with the PRISMA and MOOSE guidelines, a systematic review with meta-analysis was conducted. The study included reports that assessed the outcomes of SABR treatment in patients with LA-NSCLC. Studies evaluating SBRT as a boost following primary radiotherapy were excluded. The primary outcomes measured were local control (LC) and overall survival (OS). The secondary endpoint was the incidence of severe toxicity (grades 3-5). A meta-regression analysis was performed to explore the relationship between LC, OS, and severe toxicity. The Biologically Effective Dose (BED) was analyzed as a continuous variable. Statistical significance was defined as a p-value < 0.05.

RESULTS

A total of seven studies (3 prospective and 4 retrospective studies) involving 268 patients (SBRT to primary and lymph nodes) were included in the analysis. The pooled 1-year LC rate was 80 % (95 % CI: 63-94 %), and the factors significantly associated with LC were BEDGy10 (p = 0.005) and neoadjuvant chemotherapy (p = 0.005). The 1-year and 2-year OS rates were 74 % (95 % CI: 58-90 %) and 55 % (95 % CI: 34-76 %), respectively. Meta-regression analysis indicated a linear relationship between OS and LC, with a 0.7 % increase in OS for each 1 % improvement in LC (p = 0.005). The pooled rate of grade 3 acute toxicity was 5 % (95 % CI: 1-10 %), and the rate of grade 5 toxicity was 1.7 % (95 % CI: 0-3 %).

CONCLUSION

Promising results (LC and OS) with limited toxicity (feasibility) using SABR in LA-NSCLC warrant further research, emphasizing the need for larger, well-designed trials for further validation of the approach.

Accelerated Hypofractionated Chemoradiation Followed by Stereotactic Ablative Radiotherapy Boost for Locally Advanced, Unresectable Non-Small Cell Lung Cancer: A Nonrandomized Controlled Trial

Importance

Intrathoracic progression remains the predominant pattern of failure in patients treated with concurrent chemoradiation followed by a consolidation immune checkpoint inhibitor for locally advanced, unresectable non-small cell lung cancer (NSCLC).

Objective

To determine the maximum tolerated dose (MTD) and use of hypofractionated concurrent chemoradiation with an adaptive stereotactic ablative radiotherapy (SABR) boost.

Design, Setting, and Participants

This was an early-phase, single-institution, radiation dose-escalation nonrandomized controlled trial with concurrent chemotherapy among patients with clinical stage II (inoperable/patient refusal of surgery) or III NSCLC (American Joint Committee on Cancer Staging Manual, seventh edition). Patients were enrolled and treated from May 2011 to May 2018, with a median patient follow-up of 18.2 months. Patients advanced to a higher SABR boost dose if dose-limiting toxic effects (any grade 3 or higher pulmonary, gastrointestinal, or cardiac toxic effects, or any nonhematologic grade 4 or higher toxic effects) occurred in fewer than 33% of the boost cohort within 90 days of follow-up. The current analyses were conducted from January to September 2023.

Intervention

All patients first received 4 Gy × 10 fractions followed by an adaptive SABR boost to residual metabolically active disease, consisting of an additional 25 Gy (low, 5 Gy × 5 fractions), 30 Gy (intermediate, 6 Gy × 5 fractions), or 35 Gy (high, 7 Gy × 5 fractions) with concurrent weekly carboplatin/paclitaxel.

Main Outcome and Measure

The primary outcome was to determine the MTD.

Results

Data from 28 patients (median [range] age, 70 [51-88] years; 16 [57%] male; 24 [86%] with stage III disease) enrolled across the low- (n = 10), intermediate- (n = 9), and high- (n = 9) dose cohorts were evaluated. The protocol-specified MTD was not exceeded. The incidences of nonhematologic acute and late (>90 days) grade 3 or higher toxic effects were 11% and 7%, respectively. No grade 3 toxic effects were observed in the intermediate-dose boost cohort. Two deaths occurred in the high-dose cohort. Two-year local control was 74.1%, 85.7%, and 100.0% for the low-, intermediate-, and high-dose cohorts, respectively. Two-year overall survival was 30.0%, 76.2%, and 55.6% for the low-, intermediate-, and high-dose cohorts, respectively.

Conclusions and Relevance

This early-phase, dose-escalation nonrandomized controlled trial showed that concurrent chemoradiation with an adaptive SABR boost to 70 Gy in 15 fractions with concurrent chemotherapy is a safe and effective regimen for patients with locally advanced, unresectable NSCLC.

Trial Registration

ClinicalTrials.gov Identifier: NCT01345851.

Full Dose SBRT in Combination With Mediastinal Chemoradiation for Locally Advanced, Non-Small Cell Lung Cancer: A Practical Guide for Planning, Dosimetric Results From a Phase 2 Study, and a Treatment Planning Guide for the Phase 3 NRG Oncology LU-008 Trial

PURPOSE

Stereotactic body radiation therapy (SBRT) has been used with high effectiveness in early-stage non-small cell lung cancer (NSCLC) but has not been studied extensively in locally advanced NSCLC. We conducted a phase 2 study delivering SBRT to the primary tumor followed by conventionally fractionated chemoradiation to the involved lymph nodes for patients with node-positive locally advanced NSCLC. This manuscript serves as both a guide to planning techniques used on this trial and the subsequent phase 3 study, NRG Oncology LU-008, and to report patient dosimetry and toxicity results.

METHODS AND MATERIALS

We initiated a phase 2 multicenter single arm study evaluating SBRT to the primary tumor (50-54 Gy in 3-5 fractions) followed by conventionally fractionated chemoradiation to 60 Gy in 2 Gy fractions with doublet chemotherapy to the involved lymph nodes for patients with stage III or unresectable stage II NSCLC. Patients eligible for adjuvant immunotherapy received up to 12 months of durvalumab. We report a detailed guide for the entire treatment process from computed tomography simulation through treatment planning and delivery. The dosimetric outcomes from the 60 patients who completed therapy on study are reported both for target coverage and normal structure doses. We also report correlation between radiation-related toxicities and dosimetric parameters.

RESULTS

Sixty patients were enrolled between 2017 and 2022. Planning techniques used were primarily volumetric modulated arc therapy for SBRT to the primary tumor and conventionally fractionated radiation to the involved nodes, with a minority of cases using dynamic conformal arc technique or static dynamic multileaf collimator intensity modulated radiation therapy. Grade 2 or higher pneumonitis was associated with lung dose V5 Gy > 70% and grade 2 or higher pulmonary toxicity was associated with lung dose V10 Gy > 50%. Only 3 patients (5%) experienced grade 3 or higher pneumonitis. Grade 2 or higher esophagitis was associated with esophageal doses, including mean dose > 20 Gy, V60 Gy > 7%, and D1cc > 55 Gy. Only 1 patient (1.7%) experienced grade 3 esophagitis.

CONCLUSIONS

SBRT to the primary tumor followed by conventionally fractionated chemoradiation to the involved lymph nodes is feasible with planning techniques as described. Radiation-related toxicity on this phase 2 study was low. This manuscript serves as a guideline for the recently activated NRG Oncology LU-008 phase 3 trial evaluating this experimental regimen.

Hypofractionated Radiotherapy followed by Hypofractionated Boost with weekly concurrent chemotherapy for Unresectable Stage III Non-Small Cell Lung Cancer: Results of A Prospective Phase II Study (GASTO-1049)

PURPOSE

We launched a prospective phase 2 clinical trial to explore the safety and efficacy of hypofractionated radiation therapy (hypo-RT) followed by hypofractionated boost (hypo-boost) combined with concurrent weekly chemotherapy in patients with unresectable locally advanced non-small cell lung cancer (LA-NSCLC).

METHODS AND MATERIALS

Patients with newly diagnosed LA-NSCLC with unresectable stage III disease were recruited between June 2018 and June 2020. Patients were treated with hypo-RT (40 Gy in 10 fractions) followed by hypo-boost (24-28 Gy in 6-7 fractions) combined with concurrent weekly chemotherapy (docetaxel 25 mg/m2 and nedaplatin 25 mg/m2). The primary endpoint of the study was progression-free survival (PFS), and the secondary endpoints included overall survival (OS), locoregional failure-free survival (LRFS), distant metastasis-free survival (DMFS), objective response rate (ORR), and toxicities.

RESULTS

From June 2018 to June 2020, 75 patients were enrolled with a median follow-up duration of 28.0 months. The ORR of the whole cohort was 94.7%. Disease progression or death was recorded in 44 (58.7%) patients, with a median PFS of 21.6 months (95% confidence interval [CI], 15.6-27.6 months). The 1- and 2-year PFS rates were 81.3% (95% CI, 72.5%-90.1%) and 43.3% (95% CI, 31.5%-55.1%), respectively. The median OS, DMFS, and LRFS had not been reached at the time of the last follow-up. The 1- and 2-year OS rates were 94.7% (95% CI, 89.6%-99.8%) and 72.4% (95% CI, 62.0%-82.8%), respectively. The most frequent acute nonhematologic toxicity was radiation esophagitis. Grade (G) 2 and G3 acute radiation esophagitis were observed in 20 (26.7%) and 4 (5.3%) patients, respectively. Thirteen patients (13/75, 17.3%) had G2 pneumonitis and no G3-G5 acute pneumonitis occurred during follow-up.

CONCLUSIONS

Hypo-RT followed by hypo-boost combined with concurrent weekly chemotherapy could yield satisfactory local control and survival outcomes with moderate radiation-induced toxicity in patients with LA-NSCLC. The new potent hypo-CCRT regimen significantly shortened treatment time and provided the potential opportunity for the combination of consolidative immunotherapy.

Efficacy and toxicity of stereotactic body radiotherapy for un-resectable stage III non-small cell lung cancer patients unfit for concurrent chemoradiation therapy: a retrospective study

BACKGROUND

In this study, we evaluated the efficacy and toxicity of stereotactic body radiotherapy (SBRT) as replacement strategy of conventionally fractionated radiation therapy in stage III non-small cell lung cancer (NSCLC) patients unfit for concurrent chemoradiation therapy (CRT).

METHODS

We analyzed the clinical outcomes in patients with unresectable stage III NSCLC who received SBRT from January 1, 2013 to December 31, 2018. Both induction and consolidation chemotherapy were allowed. The survival rates and toxicities were calculated using the Kaplan-Meier method, and potential risk factors were investigated by multivariate Cox regression.

RESULTS

A total of 213 consecutive patients who had received SBRT were enrolled. The median overall survival (OS) and progression-free survival (PFS) were 36.5 months and 16.1 months respectively. The estimated 1-, 2- and 3-year OS rates were 90.6%, 73.7% and 52.0%, respectively and the corresponding PFS rates were 69.5%, 25.4% and 15.0%, respectively. Treatment failures were largely (n = 151, 70.9%) distant metastases, with low rates of local (n = 74, 34.74%) and regional (n = 76, 35.68%) recurrences. In 13.1% patients (n = 28), ≥ grade (G) 3 toxicities were identified, including radiation pneumonia (n = 20, 9.4%) and bronchopulmonary hemorrhage (n = 8, 3.8%). None of the patients suffered from ≥ G 3 late toxic effects. Compared with patients with peripheral tumors, patients with central tumors had lower median OS (P<0.001) and the biological effective dose (BED) was not a predictor for OS.

CONCLUSIONS

SBRT combined with chemotherapy for stage III NSCLC produced favorable treatment outcomes with acceptable toxicity. For patients with central tumors, an appropriate BED reduction can be considered. Further studies are warranted.

TRIAL REGISTRATION

Retrospectively registered.

Locally advanced non-small cell lung cancer: current issues and recent trends

The focus of this paper was to review and summarise the current issues and recent trends within the framework of locally advanced (LA) non-small cell lung cancer (NSCLC). The recently proposed 8^th tumour-node-metastases (TNM) staging system exhibited significant amendments in the distribution of the T and M descriptors. Every revision to the TNM classification should contribute to clinical improvement. This is particularly necessary regarding LA NSCLC stratification, therapy and outcomes. While several studies reported the superiority of the 8^th TNM edition in comparison to the previous 7^th TNM edition, in terms of both the discrimination ability among the various T subgroups and clinical outcomes, others argued against this interpretation. Synergistic cytotoxic chemotherapy with radiotherapy is most prevalent in treating LA NSCLC. Clinical trial experience from multiple references has reported that the risk of locoregional relapse and distant metastasis was less evident for patients treated with concomitant radiochemotherapy than radiotherapy alone. Nevertheless, concern persists as to whether major incidences of toxicity may occur due to the addition of chemotherapy. Cutting-edge technologies such as four-dimensional computed tomography (4D-CT) and volumetric modulated arc therapy (VMAT) should yield therapeutic gains due to their capability to conform radiation doses to tumours. On the basis of the preceding notion, the optimum radiotherapy technique for LA NSCLC has been a controversial and much-disputed subject within the field of radiation oncology. Notably, no single-perspective research has been undertaken to determine the optimum radiotherapy modality for LA NSCLC. The landscape of immunotherapy in lung cancer is rapidly expanding. Currently, the standard of care for patients with inoperable LA NSCLC is concurrent chemoradiotherapy followed by maintenance durvalumab according to clinical outcomes from the PACIFIC trial. An estimated 42.9% of patients randomly assigned to durvalumab remained alive at five years, and free of disease progression, thereby establishing a new benchmark for the standard of care in this setting.

Stereotactic boost on residual disease after external-beam irradiation in clinical stage III non-small cell lung cancer: mature results of stereotactic body radiation therapy post radiation therapy (SBRTpostRT) study

PURPOSE

To evaluate the role of stereotactic body radiation therapy (SBRT) delivered after external-beam fractionated irradiation in non-small-cell lung cancer (NSCLC) patients with clinical stage III A, B.

MATERIALS AND METHODS

All patients received three-dimensional conformal radiotherapy (3D-CRT) or intensity modulated radiation therapy (IMRT) (60-66 Gy/30-33 fractions of 2 Gy/5 days a week) with or without concomitant chemotherapy. Within 60 days from the end of irradiation, a SBRT boost (12-22 Gy in 1-3 fractions) was delivered on the residual disease.

RESULTS

Here we report the mature results of 23 patients homogeneously treated and followed up for a median time of 5.35 years (range 4.16-10.16). The rate of overall clinical response after external beam and stereotactic boost was 100%. No treatment-related mortality was recorded. Radiation-related acute toxicities with a grade ≥ 2 were observed in 6/23 patients (26.1%): 4/23 (17.4%) had esophagitis with mild esophageal pain (G2); in 2/23 (8.7%) clinical radiation pneumonitis G2 was observed. Lung fibrosis (20/23 patients, 86.95%) represented a typical late tissue damage, which was symptomatic in one patient. Median disease-free survival (DFS) and overall survival (OS) were 27.8 (95% CI, 4.2-51.3) and 56.7 months (95% CI, 34.9-78.5), respectively. Median local progression-free survival (PFS) was 17 months (range 11.6-22.4), with a median distant PFS of 18 months (range 9.6-26.4). The 5-year actuarial DFS and OS rates were 28.7% and 35.2%, respectively.

CONCLUSIONS

We confirm that a stereotactic boost after radical irradiation is feasible in stage III NSCLC patients. All fit patients who have no indication to adjuvant immunotherapy and presenting residual disease after curative irradiation could benefit from stereotactic boost because outcomes seem to be better than might be historically assumed.

Stereotactic body radiation therapy in unresectable stage III non-small cell lung cancer: A systematic review

In unresectable stage III non-small cell lung cancer (NSCLC), the standard of care for most fit patients is concurrent chemotherapy with normofractionated radiotherapy (NFRT), followed by durvalumab consolidation. Nevertheless, almost half of patients will present locoregional or metastatic intrathoracic relapse. Improving locoregional control thus remains an important objective. For this purpose, stereotactic body radiotherapy (SBRT) may be a relevant treatment modality. We performed a systematic review of the literature that evaluate the efficacy and safety of SBRT in this situation, either instead of or in addition to NFRT. Among 1788 unique reports, 18 met the inclusion criteria. They included 447 patients and were mainly prospective (n = 10, including 5 phase 2 trials). In none, maintenance durvalumab was administered. Most reported SBRT boost after NFRT (n = 8), or definitive tumor and nodal SBRT (n = 7). Median OS varied from 10 to 52 months, due to the heterogeneity of the included populations and according to treatment regimen. The rate of severe side effects was low, with <5 % grade 5 toxicity, and mainly observed when mediastinal SBRT was performed without dose constraints to the proximal bronchovascular tree. It was suggested that a biologically effective dose higher than 112.3 Gy may increase locoregional control. SBRT for selected stage III NSCLC bears potential to improve loco-regional tumor control, but at present, this should only be done in prospective clinical trials.

Recurrence patterns and progression-free survival after chemoradiotherapy with or without consolidation durvalumab for stage III non-small cell lung cancer

Chemoradiotherapy followed by consolidation durvalumab (CCRT+D) improves survival in patients with stage III non-small-cell lung cancer (NSCLC). We compared recurrence patterns and survival in the CCRT+D and CCRT cohorts. We conducted a multicenter, retrospective study in Japan. Patients who received CCRT for stage III NSCLC were included in this study. Of 178 eligible patients, 136 were in the CCRT+D and 42 were in the CCRT cohorts. Locoregional recurrence (LR), LR plus distant metastases (DM), and DM were observed in 20.6%, 8.8%, 27.9% of the CCRT+D, and 26.2%, 16.7% and 33.3% of the CCRT cohorts, respectively. In-field recurrence was the most common LR pattern in both cohorts. Squamous cell carcinoma and PD-L1 expression < 1%, and female sex and EGFR mutations were significantly associated with an increased risk of LR and DM. In patients with any risk factors for LR, the incidence of LR was similar in the CCRT+D and CCRT (39.5% vs 45.5%). The 24 month progression-free survival (PFS) and overall survival (OS) were 40.3% and 69.4% in the CCRT+D and 24.7% and 61.0% in the CCRT cohorts, respectively. Poor performance status and no consolidation durvalumab were significantly associated with shorter PFS. There was a significant difference in PFS between the CCRT+D and CCRT in the propensity score-matched cohort (HR = 0.51, P = 0.005). In conclusion, consolidation durvalumab decreased both LR and DM, and significantly improved PFS. However, in-field recurrence was still a major problem, as well as DM.

High-risk patients with locally advanced non-small cell lung cancer treated with stereotactic body radiation therapy to the peripheral primary combined with conventionally fractionated volumetric arc therapy to the mediastinal lymph nodes

Introduction

A very narrow therapeutic window exists when delivering curative chemoradiotherapy for inoperable locally advanced non-small cell lung cancer (NSCLC), particularly when large distances exist between areas of gross disease in the thorax. In the present study, we hypothesize that a novel technique of stereotactic body radiation therapy (SBRT) to the primary tumor in combination with volumetric arc therapy (VMAT) to the mediastinal lymph nodes (MLN) is a suitable approach for high-risk patients with large volume geographically distant locally advanced NSCLC.

Patients and methods

In this single institutional review, we identified high-risk patients treated between 2014 and 2017 with SBRT to the parenchymal lung primary as well as VMAT to the involved MLN using conventional fractionation. Dosimetrically, comparative plans utilizing VMAT conventionally fractionated delivered to both the primary and MLN were analyzed. Clinically, toxicity (CTCAE version 5.0) and oncologic outcomes were analyzed in detail.

Results

A total of 21 patients were identified, 86% (n=18) of which received chemotherapy as a portion of their treatment. As treatment phase was between 2014 and 2017, none of the patients received consolidation immunotherapy. Target volume (PTV) dose coverage (99 vs. 87%) and CTV volume (307 vs. 441 ml) were significantly improved with SBRT+MLN vs. for VMAT alone (p<0.0001). Moreover, low-dose lung (median V5Gy [%]: 71 vs. 77, p<0.0001), heart (median V5Gy [%]: 41 vs. 49, p<0.0001) and esophagus (median V30Gy [%]: 54 vs. 55, p=0.03) dose exposure were all significantly reduced with SBRT+MLN. In contrast, there was no difference observed in high-dose exposure of lungs, heart, and spinal cord. Following SBRT+MLN treatment, we identified only one case of high-grade pneumonitis. As expected, we observed a higher rate of esophagitis with a total of seven patients experience grade 2+ toxicity. Overall, there were no grade 4+ toxicities identified. After a median 3 years follow up, disease progression was observed in 70% of patients irradiated using SBRT+MLN, but never in the spared 'bridging' tissue between pulmonary SBRT and mediastinal VMAT.

Conclusion

For high risk patients, SBRT+MLN is dosimetrically feasible and can provide an alternative to dose reductions necessitated by otherwise very large target volumes.

Predicting personalised and progressive adaptive dose escalation to gross tumour volume using knowledge-based planning models for inoperable advanced-stage non-small cell lung cancer patients treated with volumetric modulated arc therapy

OBJECTIVES

Increased radiation doses could improve local control and overall survival of lung cancer patients, however, this could be challenging without exceeding organs at risk (OAR) dose constraints especially for patients with advanced-stage disease. Increasing OAR doses could reduce the therapeutic ratio and quality of life. It is therefore important to investigate methods to increase the dose to target volume without exceeding OAR dose constraints.

METHODS

Gross tumour volume (GTV) was contoured on synthetic computerised tomography (sCT) datasets produced using the Velocity adaptive radiotherapy software for eleven patients. The fractions where GTV volume decreased compared to that prior to radiotherapy (reference plan) were considered for personalised progressive dose escalation. The dose to the adapted GTV (GTVAdaptive) was increased until OAR doses were affected (as compared to the original clinical plan). Planning target volume (PTV) coverage was maintained for all plans. Doses were also escalated to the reference plan (GTVClinical) using the same method. Adapted, dose-escalated, plans were combined to estimate accumulated dose, D99 (dose to 99%) of GTVAdapted, PTV D99 and OAR doses and compared with those in the original clinical plans. Knowledge-based planning (KBP) model was developed to predict D99 of the adapted GTV with OAR doses and PTV coverage kept similar to the original clinical plans; prediction accuracy and model verification were performed using further data sets.

RESULTS

Compared to the original clinical plan, dose to GTV was significantly increased without exceeding OAR doses. Adaptive dose-escalation increased the average D99 to GTVAdaptive by 15.1Gy and 8.7Gy compared to the clinical plans. The KBP models were verified and demonstrated prediction accuracy of 0.4% and 0.7% respectively.

CONCLUSION

Progressive adaptive dose escalation can significantly increase the dose to GTV without increasing OAR doses or compromising dose to microscopic disease. This may increase overall survival without increasing toxicities.

Voxel-Level BED Corrected Dosimetric and Radiobiological Assessment of 2 Kinds of Hybrid Radiotherapy Planning Methods for Stage III NSCLC

Background/purpose: To access the comparative dosimetric and radiobiological advantages of two methods of intensity-modulated radiation therapy (IMRT)-based hybrid radiotherapy planning for stage III nonsmall cell lung cancer (NSCLC). Methods: Two hybrid planning methods were respectively characterized by conventional fraction radiotherapy (CFRT) and stereotactic body radiotherapy (SBRT) and CFRT and simultaneous integrated boost (SIB) planning. All plans were retrospectively completed using the 2 methods for 20 patients with stage III NSCLC. CFRT and SBRT dose regimes 2 Gy  ×  30 f and 12.5 Gy  ×  4 f were, respectively, used for planning target volume of lymph node (PTV_LN) and planning target volume of the primary tumor (PTV_PT), while dose regimes 2 Gy  ×  26 f for PTV_LN and sequential 2 Gy  ×  4 f for PTV_LN combined with 12.5 Gy  ×  4 f for PTV_PT were adopted for CFRT and SIB plans. SBRT and SIB EQD₂ dose were calculated voxel by voxel, and then, respectively, superimposed with 30-fraction and 26-fraction CFRT plan dose to achieve biological equivalent dose (BED) dosimetric parameters of CFRT and SBRT and CFRT and SIB plans. Tumor control probability (TCP)/normal tissue complication probability (NTCP) was, respectively, calculated by equivalent uniform dose/Lyman–Kutcher–Burman models. BED plan parameters and TCP/NTCP were analyzed between 2 methods of hybrid planning. Primary tumor/lymph node (LN)/total TCP values were, respectively, evaluated as a function of the radiation dose needed to control 50% of tumor (TCD₅₀) for 20 patients. Dosimetric errors were analyzed by nontransit electronic portal imaging device dosimetry measurement during hybrid plan delivery. Results: Statistically lower BED plan parameters of PTV_LN D₂ and homogeneity index resulted in slightly lower averaged LN/total TCP curves by CFRT and SIB planning. The gaps between Max and Min LN/total TCP curves were significantly closer for CFRT and SIB planning, which indicated better robustness of LN/total TCPs. A lower esophagus dose resulted in a lower esophagus NTCP by CFRT and SIB planning, which may be compromised by 1 week shorter overall treatment time by CFRT and SIB irradiation. Spinal cord D_max was significantly reduced by CFRT and SIB plans. The dose verification results of the subplans involved in hybrid plans were acceptable, which showed that the 2 methods of hybrid planning could be delivered accurately in our center. Conclusion: CFRT and SIB plannings have more advantages on BED plan parameters and TCP/NTCP than CFRT and SBRT planning, and both methods of IMRT-based hybrid planning could be executed accurately for stage III NSCLC. The effectiveness of the results needs to be validated in the hybrid trial.

Feasibility of Stereotactic Body Radiation Therapy on Unresectable Stage III NSCLC with Peripheral Primary Tumor: A Prospective Study (GFPC 01-14)

Concomitant radiochemotherapy (RTCT) is the standard treatment for unresectable stage III non-small cell lung cancer (NSCLC). However, in patients with a peripheral primary tumor, the irradiated volume may include a large portion of normal lung and RT-CT is not possible. This multicenter phase II trial in unresectable stage III NSCLC with peripheral primary tumor evaluated the feasibility of stereotactic body radiation therapy (SBRT) in peripheral tumor after concomitant radio-chemotherapy (RT-CT). Nineteen patients were included and analyzed (median age, 60.9 years; male, 78%; adenocarcinoma, 74%; median size of peripheral primary tumor, 19 mm). At 6 months, the disease control rate was 79% (15/19). SBRT toxicity was generally mild with one (5%) patient having grade 3 lung toxicity. Recruitment for this study was stopped prior to completion, firstly due to the approval of adjuvant durvalumab after RT-CT, which was not anticipated in the design, and secondly due to the small number of stage III NSCLC patients with a peripheral tumor that was accessible to SBRT. Nevertheless, the combination of RT-CT and SBRT appeared to be feasible and safe.

Regression models for predicting physical and EQD2 plan parameters of two methods of hybrid planning for stage III NSCLC

Background/purpose

To establish regression models of physical and equivalent dose in 2 Gy per fraction (EQD₂) plan parameters of two kinds of hybrid planning for stage III NSCLC.

Methods

Two kinds of hybrid plans named conventional fraction radiotherapy & stereotactic body radiotherapy (C&S) and conventional fraction radiotherapy & simultaneous integrated boost (C&SIB) were retrospectively made for 20 patients with stage III NSCLC. Prescription dose of C&S plans was 2 Gy × 30f for planning target volume of lymph node (PTV_LN) and 12.5 Gy × 4f for planning target volume of primary tumor (PTV_PT), while prescription dose of C&SIB plans was 2 Gy × 26f for PTV_LN and sequential 2 Gy × 4f for PTV_LN combined with 12.5 Gy × 4f for PTV_PT. Regression models of physical and EQD₂ plan parameters were established based on anatomical geometry features for two kinds of hybrid plans. The features were mainly characterized by volume ratio, min distance and overlapping slices thickness of two structures. The possibilities of regression models of EQD₂ plan parameters were verified by spearman’s correlation coefficients between physical and EQD₂ plan parameters, and the influence on the consistence of fitting goodness between physical and EQD₂ models was investigated by the correlations between physical and EQD₂ plan parameters. Finally, physical and EQD₂ models predictions were compared with plan parameters for two new patients.

Results

Physical and EQD₂ plan parameters of PTV_LN CI_60Gy have shown strong positive correlations with PTV_LN volume and min distance_{(PT to LN)}, and strong negative correlations with PTV_PT volume for two kinds of hybrid plans. PTV_(PT+LN) CI_60Gy is not only correlated with above three geometry features, but also negatively correlated with overlapping slices thickness_{(PT and LN)}. When neck lymph node metastasis was excluded from PTV_LN volume, physical and EQD₂ total lung V₂₀ showed a high linear correlation with corrected volume ratio_{(LN to total lung).} Meanwhile, physical total lung mean dose (MLD) had a high linear correlation with corrected volume ratio_{(LN to total lung)}, while EQD₂ total lung MLD was not only affected by corrected volume ratio_{(LN to total lung)} but also volume ratio_{(PT to total lung).} Heart D₅, D₃₀ and mean dose (MHD) would be more susceptible to overlapping structure_{(heart and LN)}. Min distance_{(PT to ESO)} may be an important feature for predicting EQD₂ esophageal max dose for hybrid plans. It’s feasible for regression models of EQD₂ plan parameters, and the consistence of the fitting goodness of physical and EQD₂ models had a positive correlation with spearman’s correlation coefficients between physical and EQD₂ plan parameters. For total lung V₂₀, ipsilateral lung V₂₀, and ipsilateral lung MLD, the models could predict that C&SIB plans were higher than C&S plans for two new patients.

Conclusion

The regression models of physical and EQD₂ plan parameters were established with at least moderate fitting goodness in this work, and the models have a potential to predict physical and EQD₂ plan parameters for two kinds of hybrid planning.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-021-01848-9.

Radiotherapy in the Era of Immunotherapy With a Focus on Non-Small-Cell Lung Cancer: Time to Revisit Ancient Dogmas?

Radiation-induced immune effects have been extensively deciphered over the last few years, leading to the concept of the dual immune effect of radiotherapy with both immunostimulatory and immunosuppressive effects. This explains why radiotherapy alone is not able to drive a strong anti-tumor immune response in most cases, hence underlining the rationale for combining both radiotherapy and immunotherapy. This association has generated considerable interest and hundreds of trials are currently ongoing to assess such an association in oncology. However, while some trials have provided unprecedented results or shown much promise, many hopes have been dashed. Questions remain, therefore, as to how to optimize the combination of these treatment modalities. This narrative review aims at revisiting the old, well-established concepts of radiotherapy relating to dose, fractionation, target volumes and organs at risk in the era of immunotherapy. We then propose potential innovative approaches to be further assessed when considering a radio-immunotherapy association, especially in the field of non-small-cell lung cancer (NSCLC). We finally propose a framework to optimize the association, with pragmatic approaches depending on the stage of the disease.

Piperlongumine inhibits the growth of non-small cell lung cancer cells via the miR-34b-3p/TGFBR1 pathway

BACKGROUND

Non-small cell lung cancer is a common type of lung cancer. Piperlongumine (PL), which is extracted from the roots of piperaceae plant, long pepper, and peppercorn, is an alkaloid amide that inhibits tumor growth and metastasis. However, whether it affects lung cancer cells remains unclear.

METHODS

We assessed the effects of PL on the proliferation and apoptosis of A549 and H1299 NSCLC cell lines.

RESULTS

PL was mildly toxic to normal human bronchial epithelial cells and significantly suppressed growth and facilitated apoptosis of A549 and H1299 cells. It also upregulated microRNA (miR)-34b-3p and downregulated the transforming growth factor beta type I receptor (TGFBR1). The dual-luciferase reporter assay showed that TGFBR1 is a target gene of miR-34b-3p. Silencing of miR-34b-3p or overexpression of TGFBR1 partially attenuated the effects of PL on A549 and H1299 cells.

CONCLUSIONS

PL inhibits proliferation and induces apoptosis of A549 and H1299 cells by upregulating miR-34b-3p and modulating TGFBR1 signaling pathway.

Systematic review of stereotactic body radiotherapy in stage III non-small cell lung cancer

Despite adequate treatment, 50% of stage III locally advanced inoperable non-small cell lung cancer (NSCLC) patients have a locoregional relapse. Local control on early stages on the contrary, is as high as 85-90% with stereotactic body radiotherapy (SBRT). The addition of SBRT to conventional chemoradiation or its use in monotherapy in stage III NSCLC is a novel strategy to decrease local failure that has been explored by various authors. This is a systematic review of studies using SBRT in inoperable stage III NSCLC. Search results obtained 141 articles of which only 6 original studies were pointed as relevant. Three of these studies were prospective, of which 2 were phase I dose-scalation studies and remaining 3 were retrospective. In summary, SBRT outcomes on 134 patients were included. Median dose in the SBRT treatment was 22.5 Gy in 2 to 7 fractions. Obtained global toxicity was 3.7% grade 5 and 14.17% grade 3. Dose-escalation studies proposed a 2 fraction SBRT schedule of 20-24 Gy, obtaining a 78% local control rate at 1 year and an OS of 67%. Initial improvement in local control with this innovative therapeutic strategy has led to ongoing phase II and III clinical trials that will evaluate the efficiency of SBRT in stage III NSCLC clinical scenario.

Immunotherapy for Lung Cancer-Improving Outcomes in Patients With Locally Advanced Non-Small Cell Lung Cancer With Immunotherapy

Patients with locally advanced non-small cell lung cancer (NSCLC), a heterogenous group encompassing stage IIIA-IIIC disease, often have surgically unresectable cancer and are managed with concurrent chemoradiation. Since the establishment of platinum-based chemoradiation as standard of care for unresectable locally advanced NSCLC, various strategies including escalating radiation dose, targeted therapies, antiangiogenic agents, and induction or consolidation chemotherapy have failed to show improvement in outcomes. However, recently, use of consolidation immunotherapy with durvalumab following concurrent chemoradiation therapy has been associated with improvement in survival and has led to a paradigm shift. In this review, we will summarize results from trials of immunotherapy in locally advanced NSCLC and comment on ongoing trials and potential future investigations.

Concurrent Chemo-Proton Therapy Using Adaptive Planning for Unresectable Stage 3 Non-Small Cell Lung Cancer: A Phase 2 Study

PURPOSE

This study prospectively evaluated the efficacy and safety of concurrent chemo-proton therapy (CCPT) using adaptive planning for unresectable stage III non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

The primary endpoint was overall survival (OS). Secondary endpoints were local control rate (LCR), progression-free survival (PFS), incidence of grade 3 or higher adverse events, and changes in quality of life (QOL). Patients received cisplatin (60 mg/m²) on day 1 and S-1 (∼40 mg/m² twice daily) on days 1 to 14, q4w, for up to 4 cycles, plus concurrent proton therapy at a total dose of 70 GyRBE for the primary lesion and 66 GyRBE for lymph node metastasis with 2 GyRBE per day. Proton therapy was performed using respiratory-gated and image guided techniques, and adaptive plans were implemented.

RESULTS

Forty-seven patients were enrolled between August 2013 and August 2018. Four cycles of cisplatin plus S-1 were completed in 34 patients. The mean number of cycles was 4 (range, 1-4). The median follow-up of all and surviving patients was 37 (range, 4-84) and 52 months (range, 26-84), respectively. The mean number of replanning sessions was 2.5 (range, 1-4). The 2- and 5-year OS, LCR, and PFS were 77% (95% confidence interval 64%-89%) and 59% (43%-76%), 84% (73%-95%) and 61% (44%-78%), and 43% (28%-57%) and 37% (22%-51%), respectively. The median OS was not reached. No grade 3 or higher radiation pneumonitis was observed. There was no significant deterioration in the QOL scores after 24 months except for alopecia.

CONCLUSIONS

CCPT with adaptive planning was well tolerated and yielded remarkable OS for unresectable stage III NSCLC.

The Therapeutic Potential of DNA Damage Repair Pathways and Genomic Stability in Lung Cancer

Despite advances in our understanding of the molecular biology of the disease and improved therapeutics, lung cancer remains the most common cause of cancer-related deaths worldwide. Therefore, an unmet need remains for improved treatments, especially in advanced stage disease. Genomic instability is a universal hallmark of all cancers. Many of the most commonly prescribed chemotherapeutics, including platinum-based compounds such as cisplatin, target the characteristic genomic instability of tumors by directly damaging the DNA. Chemotherapies are designed to selectively target rapidly dividing cells, where they cause critical DNA damage and subsequent cell death (1, 2). Despite the initial efficacy of these drugs, the development of chemotherapy resistant tumors remains the primary concern for treatment of all lung cancer patients. The correct functioning of the DNA damage repair machinery is essential to ensure the maintenance of normal cycling cells. Dysregulation of these pathways promotes the accumulation of mutations which increase the potential of malignancy. Following the development of the initial malignancy, the continued disruption of the DNA repair machinery may result in the further progression of metastatic disease. Lung cancer is recognized as one of the most genomically unstable cancers (3). In this review, we present an overview of the DNA damage repair pathways and their contributions to lung cancer disease occurrence and progression. We conclude with an overview of current targeted lung cancer treatments and their evolution toward combination therapies, including chemotherapy with immunotherapies and antibody-drug conjugates and the mechanisms by which they target DNA damage repair pathways.

Hypofractionated Proton Therapy with Concurrent Chemotherapy for Locally Advanced Non-Small Cell Lung Cancer: A Phase 1 Trial from the University of Florida and Proton Collaborative Group

PURPOSE

We report the safety data from the first multicenter phase 1 trial investigating the use of hypofractionated proton therapy with concurrent chemotherapy for patients with stage II or III non-small cell lung cancer.

METHODS AND MATERIALS

From 2013 through 2018, patients with newly diagnosed stage II or III non-small cell lung cancer were enrolled in a multicenter phase 1 clinical trial evaluating concurrent chemotherapy with increasing dose-per-fraction proton therapy. This was a stepwise 5 + 2 dose-intensification protocol with the following dose arms: (1) 2.5 GyRBE per fraction to 60 GyRBE; (2) 3.0 GyRBE per fraction to 60 GyRBE; (3) 3.53 GyRBE per fraction to 60.01 GyRBE; and (4) 4.0 GyRBE per fraction to 60 GyRBE. A dose arm was considered tolerable if no radiation therapy-attributable severe adverse event (SAE) occurred within 90 days of treatment among 5 patients enrolled on the arm or if 1 SAE occurred among 7 patients enrolled. Dose constraints to the heart, brachial plexus, and spinal cord were more conservative at higher doses per fraction.

RESULTS

The study closed early because of slow accrual and competing enrollment in NRG 1308 before accrual was met, with no maximum tolerated dose identified. Eighteen patients were treated, including 5 patients on arms 1 and 2, 7 patients on arm 3, and 1 patient on arm 4. Two SAEs occurred among 7 patients treated at 3.53 GyRBE per fraction; however, per outside expert review, both were attributed to chemotherapy and unrelated to radiation therapy.

CONCLUSIONS

Hypofractionated proton therapy delivered at 2.5 to 3.53 GyRBE per fraction to a dose of 60 GyRBE with concurrent chemotherapy has an acceptable toxicity profile. Further exploration of this regimen is warranted on a phase 2 clinical trial.

Chemo-radiotherapy integration in unresectable locally advanced non-small-cell lung cancer: a review

Approximately one-third of all non-small-cell lung cancer (NSCLC) are locally-advanced at diagnosis, and 15-17% of these tumors are unresectable at presentation. Definitive chemo-radiotherapy (CRT) represents the standard therapeutic approach. However, the literature has shown that only 15% of patients are alive at 5 years and this percentage has remained unchanged despite various attempts of improvement. The recent introduction of immunotherapy has not only strongly changed the clinical scenario but has also drawn attention to a stage of disease apparently forgotten for decades. Stage III NSCLC can represent an interesting setting for the combined use of chemo-radiation and immunotherapy, due to the potential synergistic effect between radiation and immune checkpoint inhibitors. We reviewed the available literature in order to report the state of art of stage III NSCLC, by focusing on trials that evaluate different combinations of CRT and new drugs of PD-1/PD-L1 axis, and anti-CTLA-4. The future goal in the management of unresectable stage III NSCLC will be the optimal patients' selection combined with the use of individualized immuno/chemotherapies that could potentially improve clinical outcomes.

SBRT combined with concurrent chemoradiation in stage III NSCLC: Feasibility study of the phase I Hybrid trial

PURPOSE

To assess the technical and clinical feasibility of the phase I Hybrid trial (NCT01933568), combining SBRT of the primary tumor (PT) and fractionated radiotherapy (FRT) to the lymph nodes (LN).

MATERIALS AND METHODS

Ten patients with stage III NSCLC with a peripheral PT < 5 cm were prospectively selected. The EQD₂ corrected normal tissue dose parameters of the FRT plan of 24×2.75 Gy to PT and 24×2.42 Gy to LN (IMRT) was compared with 3×18 Gy on the PT and 24×2.42 Gy on the LN (VMAT) using a Wilcoxon signed-rank test. To anticipate differential motion between PT and LN, worst-case scenarios for OAR were calculated. Electronic portal imaging device (EPID) dosimetry analysis was performed to rule out dosimetric errors during delivery.

RESULTS

The Hybrid plans revealed a significant decrease of esophagus EUD n = 0.13, lung V5 and V20 and a significant increase in D_max of the PRV of the mediastinal envelope. Plans were robust against differential motion of 5 mm between PT and LN in 8 patients and failed in 2 patients due to spinal cord constraints. Average pass rates were ≥87% for EPID dosimetry.

CONCLUSIONS

SBRT and FRT could be combined within the given OAR constraints. Safety will be assessed in the Hybrid trial.

Immunotherapy in inoperable stage III non-small cell lung cancer: a review

The leading cause of cancer-related deaths in the United States continues to be lung cancer. Approximately 25–30% of patients are diagnosed with locally advanced non-small cell lung cancer (NSCLC). Concurrent chemoradiation with a platinum-based doublet is the current standard of care for patients with inoperable stage III NSCLC. Unfortunately, only 15–20% of patients treated with definitive chemoradiation are alive at 5 years. Thus, there has been a major unmet need in this area. In this article, we summarize the current status and ongoing clinical trials incorporating immunotherapy into the management of inoperable stage III NSCLC, and we also present our perspective on the future directions.

A current review of dose-escalated radiotherapy in locally advanced non-small cell lung cancer

Background The mainstay therapy for locally advanced non-small cell lung cancer is concurrent chemoradiotherapy. Loco-regional recurrence constitutes the predominant failure patterns. Previous studies confirmed the relationship between increased biological equivalent doses and improved overall survival. However, the large randomized phase III study, RTOG 0617, failed to demonstrate the benefit of dose-escalation to 74 Gy compared with 60 Gy by simply increasing fraction numbers. Conclusions Though effective dose-escalation methods have been explored, including altered fractionation, adapting individualized increments for different patients, and adopting new technologies and new equipment such as new radiation therapy, no consensus has been achieved yet.

The evolving toxicity profile of SBRT for lung cancer

Stereotactic body radiation therapy (SBRT) is an effective and well tolerated treatment for early stage non-small cell lung cancer (NSCLC). The high doses used in thoracic SBRT can sometimes cause adverse effects ranging from mild fatigue and transient esophagitis to fatal events such as pneumonitis or hemorrhage. Efforts continue to expand in both the utility of this technique as well as our understanding of the mechanisms of the adverse effects it can cause. In this review, we discuss the current literature regarding the potential mechanisms, dosimetric constraints and toxicities associated with SBRT alone and in conjunction with definitive chemoradiotherapy and immunotherapy. As the use of SBRT expands to these spheres, we examine the available recommendations for mitigating potential associated treatment related toxicities.

Dose escalation in extracranial stereotactic ablative radiotherapy (DESTROY-1): A multiarm Phase I trial

OBJECTIVE:

A multiarm Phase I clinical trial was performed to define the maximum tolerated dose (MTD) of stereotactic body radiotherapy (SBRT) delivered by non-coplanar conformal beams or volumetric modulated arc therapy technique in seven predefined clinical settings.

METHODS:

The (a) and (b) arms investigated primary and metastatic lung cancer differentiated by site of onset, arm (c) included primary or metastatic lesions outside the thorax, the (d) and (e) arms were for in-field reirradiation of recurrence, and finally, the (f) and (g) arms were for boost irradiation to the lesions after an adjuvant RT prescribed dose. A 4 months cut-off after previous irradiation course was fixed to distinguish the boost from the retreatment (<4 vs >4 months, respectively). Patients were prospectively enrolled in study arms according to tumor site, clinical stage and previous treatment. The total dose prescribed to the isocenter, ranged from 20 to 50 Gy according to the protocol design and the doses per fraction ranged from 4 to 10 Gy in 5 days.

RESULTS:

A total of 281 patients (M/F: 167/114; median age: 69 years) with 376 lesions underwent SBRT. No acute toxicity was reported in 175 patients (62.3%) while 106 (37.7%) experienced only low-grade (G < 2) acute toxicity. Four patients (all previously irradiated in the same site) showed >Grade 2 toxicity within 6 months from SBRT. With a median follow-up of 19 months, 204 patients (72.6%) did not experience late toxicity, and 77 (27.4%) experienced low grade late toxicity. On per-lesion basis, the 12-and 24 months actuarial local control inside the SBRT field were 84.3 and 73.7 %, respectively.

CONCLUSIONS:

SBRT delivered in five consecutive fractions up to the doses evaluated is well tolerated. The MTD was reached in four (a, b, c and f) of the seven study arms. Recruitment for (d), (e) and (g) arms is still ongoing.

ADVANCES IN KNOWLEDGE:

In a prospective dose-escalation trial, the MTD of 50 Gy/10 Gy fraction and 35 Gy/7 Gy fraction were defined for primary and metastatic lesions and as boost after prior RT dose ≤50 Gy, respectively.

The Integration of Radiotherapy with Immunotherapy for the Treatment of Non-Small Cell Lung Cancer

Five-year survival rates for non-small cell lung cancer (NSCLC) range from 14% to 49% for stage I to stage IIIA disease, and are <5% for stage IIIB/IV disease. Improvements have been made in the outcomes of patients with NSCLC due to advancements in radiotherapy (RT) techniques, the use of concurrent chemotherapy with RT, and the emergence of immunotherapy as first- and second-line treatment in the metastatic setting. RT remains the mainstay treatment in patients with inoperable early-stage NSCLC and is given concurrently or sequentially with chemotherapy in patients with locally advanced unresectable disease. There is emerging evidence that RT not only provides local tumor control but also may influence systemic control. Multiple preclinical studies have demonstrated that RT induces immunomodulatory effects in the local tumor microenvironment, supporting a synergistic combination approach with immunotherapy to improve systemic control. Immunotherapy options that could be combined with RT include programmed cell death-1/programmed cell death ligand-1 blockers, as well as investigational agents such as OX-40 agonists, toll-like receptor agonists, indoleamine 2,3-dioxygenase-1 inhibitors, and cytokines. Here, we describe the rationale for the integration of RT and immunotherapy in patients with NSCLC, present safety and efficacy data that support this combination strategy, review planned and ongoing studies, and highlight unanswered questions and future research needs.

Dose escalation to 84 Gy with concurrent chemotherapy in stage III NSCLC appears excessively toxic: Results from a prematurely terminated randomized phase II trial

OBJECTIVES

Concurrent chemoradiotherapy is the mainstay treatment for NSCLC stage III disease. To investigate whether radiation dose escalation based on individual normal tissue constraints can improve outcome, the Swedish lung cancer study group launched this randomized phase II trial.

MATERIALS AND METHODS

NSCLC patients with stage III disease, good performance status (0-1) and adequate lung function (FEV1 > 1.0 L and CO diffusion capacity > 40%) received three cycles of cisplatin (75 mg/m² day 1) and vinorelbine (25 mg/m² day 1 and 8) every third week. Radiotherapy started concurrently with the second cycle, with either 2 Gy daily, 5 days a week, to 68 Gy (A) or escalated therapy (B) based on constraints to the spinal cord, esophagus and lungs up to 84 Gy by adding an extra fraction of 2 Gy per week.

RESULTS

A pre-planned safety analysis revealed excessive toxicity and decreased survival in the escalated arm, and the study was stopped. Thirty-six patients were included during 2011-2013 (56% male, 78% with adenocarcinoma, 64% with PS 0 and 53% with stage IIIB). The median progression-free survival (PFS) and overall survival (OS) were 11 and 17 months in arm B compared to the encouraging results of 28 and 45 months in the standard arm. The 1- and 3-year survival rates were 56% and 33% (B) and 72% and 56% (A), respectively. There were seven toxicity-related deaths due to esophageal perforations and pneumonitis: five in the escalated group and two with standard treatment.

CONCLUSION

Dose-escalated concurrent chemoradiotherapy to 84 Gy to primary tumor and nodal disease is hazardous, with a high risk of excessive toxicity, whereas modern standard dose chemoradiotherapy with proper staging given in the control arm shows a promising outcome with a median survival of 45 months and a 3-year survival of 56% (NCT01664663).

Locally-advanced non-small cell lung cancer: shall immunotherapy be a new chance?

Locally advanced non-small cell lung cancer (NSCLC) represents approximately one third of presentations at diagnosis. Most patients are judged non-surgical due to disease extension, and chemo-radiotherapy still represents the standard therapeutic option, with unsatisfactory results in terms of overall survival (OS) despite advances in staging and radiation therapy planning and delivery. Immunotherapy, and in particular immune-checkpoint inhibitors targeting the PD-1/PD-L1 axis, gained wide popularity for NSCLC in light of the positive findings of several trials in metastatic disease. Stage III unresectable NSCLC is a remarkably interesting setting for the combined use of chemo-radiation and immunotherapy, also considering the multiple experimental evidences in favor of a synergistic effect between radiation and immune checkpoint inhibitors, with the potential of enhancing immuno-modulating effects and overcoming resistance. We here summarized the biological rationale and the initial clinical experiences testing for this combination, and we briefly discussed ongoing trials and future options in this field.

Stereotactic ablative radiotherapy after concomitant chemoradiotherapy in non-small cell lung cancer: A TITE-CRM phase 1 trial

BACKGROUND AND PURPOSE

Platinum based chemoradiotherapy is the standard of care for inoperable non-small cell lung cancer (NSCLC). With evidence that NSCLC can have a dose dependent response with stereotactic ablative radiotherapy (SABR), we hypothesize that a SABR boost on residual tumor treated with chemoradiotherapy could increase treatment efficacy. The purpose of this study was to determine feasibility of such an approach.

MATERIAL AND METHODS

A prospective phase I trial was performed including 26 patients. Time-to-event continual reassessment method (TITE-CRM) was used for dose escalation which ranged from 3 × 7 to 3 × 12 Gy for the stereotactic boost, after 46 Gy (2 Gy per day) of chemoradiotherapy.

RESULTS

Median follow-up was of 37.1 months (1.7-60.7), and 3, 4, 3, 3, 9 and 4 patients were included at the dose levels 1, 2, 3, 4, 5 and 6, respectively. During chemoradiotherapy, 9 patients experienced grade 3 toxicity. After stereotactic radiotherapy, 1 patient experienced an esophageal fistula (with local relapse) at the 3 × 11 Gy level, and 1 patient died from hemoptysis at the 3 × 12 Gy level. The 2-year rate of local control, locoregional free survival, metastasis-free survival, and overall survival was 70.3%, 55.5%, 44.5% and 50.8%, respectively.

CONCLUSION

In the treatment of NSCLC with chemoradiotherapy followed by a stereotactic boost, the safe recommended dose in our protocol was a boost dose of 3 × 11 Gy.

Efficacy and safety of image-guidance radiotherapy by helical tomotherapy in patients with lung cancer

This study aimed to explore the efficacy and toxicity of image-guided stereotactic body radiotherapy (IGSBR) by helical tomotherapy in patients with lung cancer among Chinese Han population.A total of 21 patients with stage I lung cancer were included. They received a total of 60 Gy factions IGSBR. The outcomes included complete response (CR), partial response (PR), stable disease (SD), progress disease (PD), overall response rate (ORR), and overall survival (OS). In addition, toxicities were also recorded in this study.Three-year CR, PR, SD, PD, ORR, and OS were 47.6%, 38.1%, 9.5%, 4.8%, 85.7%, and 48.0 months, respectively. Additionally, mild toxicities were found in this study.This study demonstrated that IGSBR is efficacious for patients with stage I lung cancer with mild toxicities among Chinese Han population.

Emerging Therapies for Stage III Non-Small Cell Lung Cancer: Stereotactic Body Radiation Therapy and Immunotherapy

The current standard of care for locally advanced non-small cell lung cancer (NSCLC) includes radiation, chemotherapy, and surgery in certain individualized cases. In unresectable NSCLC, chemoradiation has been the standard of care for the past three decades. Local and distant failure remains high in this group of patients, so dose escalation has been studied in both single institution and national clinical trials. Though initial studies showed a benefit to dose escalation, phase III studies examining dose escalation using standard fractionation or hyperfractionation have failed to show a benefit. Over the last 17 years, stereotactic body radiation therapy (SBRT) has shown a high degree of safety and local control for stage I lung cancers and other localized malignancies. More recently, phase I/II studies using SBRT for dose escalation after conventional chemoradiation in locally advanced NSCLC have been promising with good apparent safety. Immunotherapy also offers opportunities to address distant disease and preclinical data suggest immunotherapy in tandem with SBRT may be a rational way to induce an “abscopal effect” although there are little clinical data as yet. By building on the proven concept of conventional chemoradiation for patients with locally advanced NSCLC with a subsequent radiation dose intensification to residual disease with SBRT concurrent with immunotherapy, we hope address the issues of metastatic and local failures. This “quadmodality” approach is still in its infancy but appears to be a safe and rational approach to the improving the outcome of NSCLC therapy.