Relation between elective nodal failure and irradiated volume in non-small-cell lung cancer (NSCLC) treated with radiotherapy using conventional fields and doses

Comparison of Involved Field Radiotherapy versus Elective Nodal Irradiation in Stage IIIB/C Non-Small-Cell Lung Carcinoma Patients Treated with Concurrent Chemoradiotherapy: A Propensity Score Matching Study

Background

We retrospectively compared the incidence of isolated elective nodal failure (IENF) and toxicity rates and survival outcomes after elective nodal irradiation (ENI) versus involved-field RT (IFRT) by employing the propensity score matching (PSM) methodology in stage IIIB/C inoperable non-small-cell lung cancer (NSCLC) patients treated with definitive concurrent chemoradiotherapy (C-CRT).

Methods

Our PSM examination included 1048 stage IIIB/C NSCLC patients treated with C-CRT from January 2007 to December 2016: a total dose of 66 Gy (2 Gy/fraction) radiotherapy and 1–3 cycles of platinum-based doublet chemotherapy concurrently. The primary and secondary endpoints were the IENF and toxicity rates and survival outcomes after ENI versus IFRT, respectively. Propensity scores were calculated for each group to adjust for confounding variables and facilitate well-balanced comparability by creating 1 : 1 matched study groups.

Results

The median follow-up was 26.4 months for the whole study accomplice. The PSM analysis unveiled 1 : 1 matched 646 patients for the ENI (N = 323) and IFRT (N = 323) cohorts. Intergroup comparisons discovered that the 5-year isolated ENF incidence rates (3.4% versus 4.3%; P=0.52) and median overall survival (25.2 versus 24.6 months; P=0.69), locoregional progression-free survival (15.3 versus 15.1 months; P=0.52), and progression-free survival (11.7 versus 11.2 months; P=0.57) durations were similar between the ENI and IFRT cohorts, separately. However, acute grade 3-4 leukopenia (P=0.0012), grade 3 nausea-vomiting (P=0.006), esophagitis (P=0.003), pneumonitis (P=0.002), late grade 3-4 esophageal toxicity (P=0.038), and the need for hospitalization (P < 0.001) were all significantly higher in the ENI than in the IFRT group, respectively.

Conclusion

Results of the present large-scale PSM cohort established the absence of meaningful IENF or survival differences between the IFRT and ENI cohorts and, consequently, counseled the IFRT as the elected RT technique for such patients since ENI increased the toxicity rates.

An improved method for analyzing and reporting patterns of in-field recurrence after stereotactic ablative radiotherapy in early-stage non-small cell lung cancer

INTRODUCTION

Patterns of local, regional, and distant failure after stereotactic ablative radiotherapy (SABR) for early-stage non-small cell lung cancer (NSCLC) have been widely reported. However, reliable methods for analyzing causes of local failure are lacking. We describe a method for analyzing and reporting patterns of in-field recurrence after SABR, incorporating dosimetric parameters from initial treatment plan as well as geometric information from diagnostic images at recurrence.

MATERIAL AND METHODS

Diagnostic CT images at recurrence were registered with initial treatment planning images and radiation dose by deformable image registration. Recurrent gross tumor volume (rGTV) and centroid (geometric center of rGTV) were delineated. In-field failure was classified as centroids originating within the original planning target volume. Dose-volume histograms for each rGTV were used to further classify in-field recurrences as central high-dose (dose to 95% of rGTV [rGTVD95%] ≥95% of dose prescribed to PTV) or peripheral high-dose (rGTVD95% <95% of dose prescribed to PTV).

RESULTS

634 patients received SABR from 2004 to 2014 with 48 local recurrences. 35 of these had evaluable images with 16 in-field recurrences: 9 central high-dose, 6 peripheral high-dose, and 1 had both. Time to and volume of recurrence were not statistically different between central versus peripheral high-dose recurrences. However mean rGTV dose, mean centroid dose, and rGTVD95% were higher for central versus peripheral high-dose recurrences.

CONCLUSION

We report a standardized method for analysis and classification of in-field recurrence after SABR. There were more central as opposed to peripheral high-dose recurrences, suggesting biological rather than technical issues underlying majority of in-field failures.

The dosimetric effects of limited elective nodal irradiation in volumetric modulated arc therapy treatment planning for locally advanced non-small cell lung cancer

OBJECTIVE

Contemporary radiotherapy guidelines for locally advanced non-small cell lung carcinoma (LA-NSCLC) recommend omitting elective nodal irradiation, despite the fact that evidence supporting this came primarily from older reports assessing comprehensive nodal coverage using 3D conformal techniques. Herein, we evaluated the dosimetric implications of the addition of limited elective nodal irradiation (LENI) to standard involved field irradiation (IFI) using volumetric modulated arc therapy (VMAT) planning.

METHOD

Target volumes and organs-at-risk (OARs) were delineated on CT simulation images of 20 patients with LA-NSCLC. Two VMAT plans (IFI and LENI) were generated for each patient. Involved sites were treated to 60 Gy in 30 fractions for both IFI and LENI plans. Adjacent uninvolved nodal regions, considered high risk based on the primary tumor site and extent of nodal involvement, were treated to 51 Gy in 30 fractions in LENI plans using a simultaneous integrated boost approach.

RESULTS

All planning objectives for PTVs and OARs were achieved for both IFI and LENI plans. LENI resulted in significantly higher esophagus Dmean (15.3 vs. 22.5 Gy, p < 0.01), spinal cord Dmax (34.9 vs. 42.4 Gy, p = 0.02) and lung Dmean (13.5 vs. 15.9 Gy, p = 0.02), V20 (23.0 vs. 27.9%, p = 0.03), and V5 (52.6 vs. 59.4%, p = 0.02). No differences were observed in heart parameters. On average, only 32.2% of the high-risk nodal volume received an incidental dose of 51 Gy when untargeted in IFI plans.

CONCLUSION

The addition of LENI to VMAT plans for LA-NSCLC is feasible, with only modestly increased doses to OARs and marginal expected increase in associated toxicity.

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

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

Involved field radiotherapy (IFRT) versus elective nodal irradiation (ENI) for locally advanced non-small cell lung cancer: a meta-analysis of incidence of elective nodal failure (ENF)

Background and purpose

The use of involved field radiotherapy (IFRT) has generated concern about the increasing incidence of elective nodal failure (ENF) in contrast to elective nodal irradiation (ENI). This meta-analysis aimed to provide more reliable and up-to-date evidence on the incidence of ENF between IFRT and ENI.

Materials and methods

We searched three databases for eligible studies where locally advanced non-small cell lung cancer (NSCLC) patients received IFRT or ENI. Outcome of interest was the incidence of ENF. The fixed-effects model was used to pool outcomes across the studies.

Results

There were 3 RCTs and 3 cohort studies included with low risk of bias. There was no significant difference in incidence of ENF between IFRT and ENI either among RCTs (RR = 1.38, 95 % CI: 0.59–3.25, p = 0.46) or among cohort studies (RR = 0.99, 95 % CI: 0.46–2.10, p = 0.97). There was also no significant difference in incidence of ENF between IFRT and ENI when RCTs and cohort studies were combined (RR = 1.15, 95 % CI: 0.65–2.01, p = 0.64). I² of test for heterogeneity was 0 %.

Conclusion

This meta-analysis provides more reliable and stable evidence that there is no significant difference in incidence of ENF between IFRT and ENI.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-016-0698-3) contains supplementary material, which is available to authorized users.

Acute radiation esophagitis caused by high-dose involved field radiotherapy with concurrent cisplatin and vinorelbine for stage III non-small cell lung cancer

Purpose of this study is to obtain dose-volume histogram (DVH) predictors and threshold values for radiation esophagitis caused by high-dose involved field radiotherapy (IFRT) with concurrent chemotherapy in patients with stage III non-small cell lung cancer (NSCLC). Thirty-two patients treated by 66 Gy/33 Fr, 72 Gy/36 Fr, and 78 Gy/39 Fr thoracic radiotherapy without elective nodal irradiation plus concurrent cisplatin and vinorelvine were reviewed. Acute radiation esophagitis was evaluated according to common terminology criteria for adverse events version 4.0, and correlations between grade 2 or worse radiation esophagitis and DVH parameters were investigated. Grade 0-1, 2, 3, and 4-5 of radiation esophagitis were seen in 11 (34.4%), 20 (62.5%), 1 (3.1%), and 0 (0%) of the patients, respectively. Multivariate analysis revealed that whole esophagus V35 is a predictor of radiation esophagitis (OR = 0.74 [95%CI; 0.60-0.91], p = 0.006). There is a significant difference (38.4% vs. 89.4%, p = 0.027) in the cumulative rates of acute esophagitis according to V35 values of more than 20% versus less. As compared with other factors concerning patient and tumor and treatment factors, V35 ≤ 20% of the esophagus was an independent predictor (HR 5 0.29 [95%CI; 0.09-0.85], p 5 0.025). In conclusion, whole esophagus V35 < 20% is proposed in high-dose IFRT with concurrent chemotherapy for stage III NSCLC patients.

Multidisciplinary approach in stage III non-small-cell lung cancer: standard of care and open questions

Lung cancer is the most frequent cause of cancer death worldwide and its global incidence has been steadily increasing during recent decades. A third of patients with newly diagnosed non-small-cell lung cancer (NSCLC) present with locally advanced disease. There is not a single widely accepted standard of care for these patients because of the wide spectrum of presentation of the disease. Although feasible and safe in experienced hands, evidence that surgical resection after induction treatment improves overall survival (OS) is lacking. For resectable or potentially resectable stage III, the findings of two phase III trials suggest that surgical resection should not be considered a standard of care but rather reserved for selected patients after critical multidisciplinary assessment, in whom surgery improves survival after downstaging if pneumonectomy can be avoided or in some T4N0-1 resectable tumours. For unresectable stage III NSCLC the standard of care is a combination of chemotherapy and radiotherapy. In those patients with good performance status and minimal weight loss, the concurrent approach has resulted in a statistically significant improvement in OS rates compared with a sequential approach in randomised clinical trials, although several questions remain unresolved.

Final results of the randomized phase III CHARTWEL-trial (ARO 97-1) comparing hyperfractionated-accelerated versus conventionally fractionated radiotherapy in non-small cell lung cancer (NSCLC)

BACKGROUND

Continuous hyperfractionated accelerated radiotherapy (CHART) counteracts repopulation and may significantly improve outcome of patients with non-small-cell lung cancer (NSCLC). Nevertheless high local failure rates call for radiation dose escalation. We report here the final results of the multicentric CHARTWEL trial (CHART weekend less, ARO 97-1).

PATIENTS AND METHODS

Four hundred and six patients with NSCLC were stratified according to stage, histology, neoadjuvant chemotherapy and centre and were randomized to receive 3D-planned radiotherapy to 60Gy/40 fractions/2.5weeks (CHARTWEL) or 66Gy/33 fractions/6.5weeks (conventional fractionation, CF).

RESULTS

Overall survival (OS, primary endpoint) at 2, 3 and 5yr was not significantly different after CHARTWEL (31%, 22% and 11%) versus CF (32%, 18% and 7%; HR 0.92, 95% CI 0.75-1.13, p=0.43). Also local tumour control rates and distant metastases did not significantly differ. Acute dysphagia and radiological pneumonitis were more pronounced after CHARTWEL, without differences in clinical signs of pneumopathy. Exploratory analysis revealed a significant trend for improved LC after CHARTWEL versus CF with increasing UICC, T or N stage (p=0.006-0.025) and after neoadjuvant chemotherapy (HR 0.48, 0.26-0.89, p=0.019).

CONCLUSIONS

Overall, outcome after CHARTWEL or CF was not different. The lower total dose in the CHARTWEL arm was compensated by the shorter overall treatment time, confirming a time factor for NSCLC. The higher efficacy of CHARTWEL versus CF in advanced stages and after chemotherapy provides a basis for further trials on treatment intensification for locally advanced NSCLC.

The analysis of prognostic factors affecting post-radiation acute reaction after conformal radiotherapy for non-small cell lung cancer

INTRODUCTION

The aim was to evaluate the risk of acute side effects in the lung after 3-dimensional conformal radiotherapy (3D-CRT) in patients treated for non-small cell lung cancer (NSCLC). An attempt was made to single out clinical factors and factors related to treatment technique which may induce acute post-radiation pneumonitis.

MATERIAL AND METHODS

The analysis concerned 34 consecutive patients who underwent radical radiation therapy for NSCLC. Intensity of early toxicity was evaluated using modified RTOG/EORTC toxicity score. The endpoint for this analysis was the occurrence of radiation pneumonitis of grade 2 or higher. Factors related to treatment techniques were included in the statistical analysis.

RESULTS

Fifty-three percent of patients included in the study suffered from acute post-radiation pneumonitis. The results of the study revealed the existence of lung tissue sensitivity to low doses of ionizing radiation. The multivariate analysis showed that total lung volume receiving a low dose of 10 Gy increased the risk of post-radiation pneumonitis (p = 0.01).

CONCLUSIONS

Acute post-radiation pneumonitis was a relevant clinical problem in patients who underwent radical radiotherapy for non-small cell lung cancer. The lung volume receiving a dose of 10 Gy was the most important dosimetric factor which influenced the post-radiation acute pneumonitis.