Cancer Trials Ireland (ICORG) 06-34: A multi-centre clinical trial using three-dimensional conformal radiation therapy to reduce the toxicity of palliative radiation for lung cancer

A shift from simple to sophisticated: using intensity-modulated radiation therapy in conventional nonstereotactic palliative radiotherapy

PURPOSE OF REVIEW

The authors aimed to highlight trends in, and evidence underlying the use of highly conformal radiotherapy (RT) techniques in conventional nonstereotactic palliative RT. The authors reviewed palliative-intent and curative-intent studies relevant to the use of intensity-modulated radiation therapy (IMRT) for the delivery of nonstereotactic conventional regimens to the brain, head and neck, thorax, abdomen and pelvis, and bone metastases.

RECENT FINDINGS

The use of IMRT has become standard with certain indications for brain metastases such as hippocampus-avoiding/limiting whole brain RT. IMRT in the treatment of bone metastases is increasing at many institutions despite limited data comparing its effectiveness with that of fluoroscopy-based and three-dimensional conformal radiation therapy techniques. There is scant data describing the use of IMRT for palliation in other extracranial anatomic sites; guidance for its use in these settings must be gleaned almost exclusively from curative-intent randomized trials, consensus recommendations and contouring atlases.

SUMMARY

Consistent with historical technology shifts in RT practice, the uptake of highly conformal techniques such as IMRT for conventional palliative RT will likely outpace rigorous evaluations of their advantages and disadvantages relative to simpler techniques. Opportunities exist in virtually all anatomic sites for observational and randomized studies to evaluate the clinical impacts of these modern techniques in the palliative setting.

Use and Reporting of Patient-Reported Outcomes in Trials of Palliative Radiotherapy: A Systematic Review

IMPORTANCE

Approximately 50% of all patients with cancer have an indication for radiotherapy, and approximately 50% of radiotherapy is delivered with palliative intent, with the aim of alleviating symptoms. Symptoms are best assessed by patient-reported outcomes (PROs), yet their reliable interpretation requires adequate reporting in publications.

OBJECTIVE

To investigate the use and reporting of PROs in clinical trials of palliative radiotherapy.

EVIDENCE REVIEW

This preregistered systematic review searched PubMed/Medline, EMBASE, and the Cochrane Center Register of Controlled Trials for clinical trials of palliative radiotherapy published from 1990 to 2020. Key eligibility criteria were palliative setting, palliative radiotherapy as treatment modality, and clinical trial design (per National Institutes of Health definition). Two authors independently assessed eligibility. Trial characteristics were extracted and standard of PRO reporting was assessed in adherence to the Consolidated Standards of Reporting Trials (CONSORT) PRO extension. The association of the year of publication with the use of PROs was assessed by logistic regression. Factors associated with higher CONSORT-PRO adherence were analyzed by multiple regression. This study is reported following the PRISMA guidelines.

FINDINGS

Among 7377 records screened, 225 published clinical trials representing 24 281 patients were eligible. Of these, 45 trials (20%) used a PRO as a primary end point and 71 trials (31%) used a PRO as a secondary end point. The most prevalent PRO measures were the Numeric Rating Scale/Visual Analogue Scale (38 trials), European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire C30 (32 trials), and trial-specific unvalidated measures (25 trials). A more recent year of publication was significantly associated with a higher chance of PROs as a secondary end point (odds ratio [OR], 1.04 [95% CI, 1.00-1.07]; P = .03) but not as primary end point. Adherence to CONSORT-PRO was poor or moderate for most items. Mean (SD) adherence to the extension adherence score was 46.2% (19.6%) for trials with PROs as primary end point and 31.8% (19.8%) for trials with PROs as a secondary end point. PROs as a primary end point (regression coefficient, 9.755 [95% CI, 2.270-17.240]; P = .01), brachytherapy as radiotherapy modality (regression coefficient, 16.795 [95% CI, 5.840-27.751]; P = .003), and larger sample size (regression coefficient, 0.028 [95% CI, 0.006-0.049]; P = .01) were significantly associated with better PRO reporting per extension adherence score.

CONCLUSIONS AND RELEVANCE

In this systematic review of palliative radiotherapy trials, the use and reporting of PROs had room for improvement for future trials, preferably with PROs as a primary end point.

Palliative Radiation for Advanced Central Lung Tumors With Intentional Avoidance of the Esophagus (PROACTIVE): A Phase 3 Randomized Clinical Trial

Question

Can modern radiation techniques reduce the risk of radiation-associated esophageal adverse effects in patients with advanced lung cancer?

Findings

In this phase 3 randomized clinical trial of esophageal-sparing intensity-modulated radiotherapy (ES-IMRT) or standard palliative radiotherapy for 90 patients with stage III/IV incurable non–small cell lung cancer, ES-IMRT significantly reduced symptomatic esophagitis (24% [n = 11] vs 2% [n = 1]), but did not significantly improve esophageal-related quality of life.

Meaning

In this trial, the use of ES-IMRT did not definitively improve esophageal quality of life but reduced symptomatic esophagitis in patients with advanced lung cancer who were receiving palliative thoracic radiotherapy; this technique holds merit for translation into clinical practice.

Importance

Palliative thoracic radiotherapy (RT) can alleviate local symptoms associated with advanced non–small cell lung cancer (NSCLC), but esophagitis is a common treatment-related adverse event. Whether esophageal-sparing intensity-modulated RT (ES-IMRT) achieves a clinically relevant reduction in esophageal symptoms remains unclear.

Objective

To examine whether ES-IMRT achieves a clinically relevant reduction in esophageal symptoms compared with standard RT.

Design, Setting, and Participants

Palliative Radiation for Advanced Central Lung Tumors With Intentional Avoidance of the Esophagus (PROACTIVE) is a multicenter phase 3 randomized clinical trial that enrolled patients between June 24, 2016, and March 6, 2019. Data analysis was conducted from January 23, 2020, to October 22, 2021. Patients had up to 1 year of follow-up. Ninety patients at 6 tertiary academic cancer centers who had stage III/IV NSCLC and were eligible for palliative thoracic RT (20 Gy in 5 fractions or 30 Gy in 10 fractions) were included.

Interventions

Patients were randomized (1:1) to standard RT (control arm) or ES-IMRT. Target coverage was compromised to ensure the maximum esophagus dose was no more than 80% of the RT prescription dose.

Main Outcomes and Measures

The primary outcome was esophageal quality of life (QOL) 2 weeks post-RT, measured by the esophageal cancer subscale (ECS) of the Functional Assessment of Cancer Therapy: Esophagus questionnaire. Higher esophageal cancer subscale scores correspond with improved QOL, with a 2- to 3-point change considered clinically meaningful. Secondary outcomes included overall survival, toxic events, and other QOL metrics. Intention-to-treat analysis was used.

Results

Between June 24, 2016, and March 6, 2019, 90 patients were randomized to standard RT or ES-IMRT (median age at randomization, 72.0 years [IQR, 65.6-80.3]; 50 [56%] were female). Thirty-six patients (40%) received 20 Gy and 54 (60%) received 30 Gy. For the primary end point, the mean (SD) 2-week ECS score was 50.5 (10.2) in the control arm (95% CI, 47.2-53.8) and 54.3 (7.6) in the ES-IMRT arm (95% CI, 51.9-56.7) (P = .06). Symptomatic RT-associated esophagitis occurred in 24% (n = 11) of patients in the control arm vs 2% (n = 1) in the ES-IMRT arm (P = .002). In a post hoc subgroup analysis based on the stratification factor, reduction in esophagitis was most evident in patients receiving 30 Gy (30% [n = 8] vs 0%; P = .004). Overall survival was similar with standard RT (median, 8.6; 95% CI, 5.7-15.6 months) and ES-IMRT (median, 8.7; 95% CI, 5.1-10.2 months) (P = .62).

Conclusions and Relevance

In this phase 3 randomized clinical trial, ES-IMRT did not significantly improve esophageal QOL but significantly reduced the incidence of symptomatic esophagitis. Because post hoc analysis found that reduced esophagitis was most evident in patients receiving 30 Gy of RT, these findings suggest that ES-IMRT may be most beneficial when the prescription dose is higher (30 Gy).

Trial Registration

ClinicalTrials.gov Identifier: NCT02752126

An Institutional Audit of Maximum Heart Dose in Patients Treated With Palliative Radiotherapy for Non-small Cell Lung Cancer

BACKGROUND/AIM

Recent studies suggested that high unintended radiation doses to the heart may reduce survival of patients with non-small-cell lung cancer (NSCLC) irradiated with curative intent. In the palliative setting, limited information is available. Therefore, we analyzed a single-institution cohort of 165 patients.

PATIENTS AND METHODS

Patients in this retrospective study received palliative (chemo)radiotherapy (at least 30 Gy). Typical radiation doses were 10-13 fractions of 3 Gy and 15 fractions of 2.8 Gy. Heart dose constraints were not employed during treatment planning. The maximum dose to 1 cc of the heart was registered and converted into the equivalent dose in 2-Gy fractions (EQD2).

RESULTS

The median heart dose (maximum to 1 cc) was 26 Gy (range=11-42 Gy). This dose corresponded to 28-108% of the prescription dose. After conversion into EQD2, the median maximum heart dose to 1 cc was 26 Gy, range=10-58 Gy). Neither higher T-stage nor higher N-stage predicted for higher maximum heart EQD2. The maximum heart EQD2 was not associated with overall survival.

CONCLUSION

The current practice of focusing on sparing of lungs and esophagus appears acceptable in the context of palliative regimes. To further strengthen this strategy, additional studies looking at cardiac substructures and other dosimetric variables such as mean dose are warranted.

Palliative Thoracic Radiotherapy for Non-Small Cell Lung Cancer in Outpatients: Reasons for Unplanned Hospitalization and Its Impact on Survival

Background

The aims of the study were to examine the rates of and reasons for unplanned hospitalization after start of palliative radiotherapy or chemoradiation (CRT), and to study whether unplanned hospitalization deteriorates patients’ prognosis. In addition, risk factors were identified.

Methods

A retrospective review of 136 patients treated with palliative radiotherapy or CRT was performed. Inclusion criteria were prescribed total dose at least 30 Gy and outpatient at the start of treatment. Uni- and multivariate analyses were employed.

Results

Fifty-eight patients (43%) were hospitalized within 3 months from start of radiotherapy or CRT. Their median overall survival was 6.7 months as compared to 11.1 months in non-hospitalized patients (P = 0.09). The median length of hospitalization was 8 days (range 1 - 61). In patients with possibly treatment-related hospitalization (n = 32), median survival was 5.0 months, significantly shorter than the 11.1 months observed in the remaining patients (P = 0.006). In multivariate analysis, only one variable was significantly associated with higher risk of unplanned hospitalization: previous hospitalization in the last 4 weeks before commencing radiotherapy or CRT.

Conclusions

Unplanned hospitalization occurred frequently in a standard care setting without early involvement of a dedicated palliative team. Patients with preceding hospitalization might represent a group that is particularly vulnerable, thus qualifying for a targeted intervention aiming at continued outpatient care.

A systematic review and meta-analysis of treatment-related toxicities of curative and palliative radiation therapy in non-small cell lung cancer

Treatment-related toxicity is an important component in non-small cell lung cancer (NSCLC) management decision-making. Our aim was to evaluate and compare the toxicity rates of curative and palliative radiotherapy with and without chemotherapy. This meta-analysis provides better quantitative estimates of the toxicities compared to individual trials. A systematic review of randomised trials with > 50 unresectable NSCLC patients, treated with curative or palliative conventional radiotherapy (RT) with or without chemotherapy. Data was extracted for oesophagitis, pneumonitis, cardiac events, pulmonary fibrosis, myelopathy and neutropenia by any grade, grade ≥ 3 and treatment-related deaths. Mantel–Haenszel fixed-effect method was used to obtain pooled risk ratio. Forty-nine trials with 8609 evaluable patients were included. There was significantly less grade ≥ 3 acute oesophagitis (6.4 vs 22.2%, p < 0.0001) and any grade oesophagitis (70.4 vs 79.0%, p = 0.04) for sequential CRT compared to concurrent CRT, with no difference in pneumonitis (grade ≥ 3 or any grade), neutropenia (grade ≥ 3), cardiac events (grade ≥ 3) or treatment-related deaths. Although the rate of toxicity increased with intensification of treatment with RT, the only significant difference between treatment regimens was the rate of oesophagitis between the use of concurrent and sequential CRT. This can aid clinicians in radiotherapy decision making for NSCLC.

Early High-Grade Thoracic Toxicity After Palliative Radiotherapy for Non-Small Cell Lung Cancer

INTRODUCTION

Palliative radiotherapy or chemoradiotherapy (CRT) for non-small cell lung cancer (NSCLC) may cause thoracic toxicities due to the radiation dose delivered to the lungs, heart, and esophagus. We studied severe thoracic toxicities resulting in hospitalization or death during the acute and sub-acute phase, i.e., three months from commencing radiotherapy. In addition, risk factors were identified.  Methods: A retrospective review of 165 patients treated with three-dimensional conformal palliative radiotherapy or CRT was performed. The prescribed total dose was equivalent to at least 30 Gy in 10 fractions. Uni- and multivariate analyses were employed.

RESULTS

Twelve patients (7%) were hospitalized within three months from the start of radiotherapy or CRT. Six patients were hospitalized for esophagitis, three for dyspnea most likely caused by pneumonitis, and three for cardiac arrhythmia. Fatal toxicity was not observed. However, 19% of the 165 patients died from tumor-related causes during the time period of interest. In multivariate analysis, the only esophageal dose was significantly associated with the risk of hospitalization.  Conclusion: The safety profile of palliative radiotherapy or CRT in the acute and subacute phases was satisfactory. The hospitalization rate can be reduced by lowering the esophageal dose, as long as safe lung and heart doses can be maintained.

Risk factors for esophagitis after hypofractionated palliative (chemo) radiotherapy for non-small cell lung cancer

Introduction

Esophagitis influences quality of life and might cause treatment interruption and hospitalization. Previous studies of risk factors focused on curative treatment for non-small cell lung cancer (NSCLC), which often involves concomitant chemoradiation (CRT). Given the uncertainty around extrapolation of dose constraints, we analyzed risk factors in patients treated with hypofractionated palliative regimens.

Patients and methods

A retrospective review of 106 patients treated with palliative radiotherapy or CRT between 2009 and 2017 was performed. Inclusion criteria: prescribed total dose 30–54 Gy, dose per fraction 2.5–4 Gy, esophageal dose > 1 Gy. Uni- and multivariate analyses were performed in 97 eligible patients to identify predictive factors for acute esophagitis grade ≥ 1 (CTCAE 5.0).

Results

Forty percent of patients were treated with 15 fractions of 2.8 Gy (42 Gy) and 28% also received chemotherapy according to the CONRAD study regimen (induction and concomitant Carboplatin/Vinorelbine) published by the Norwegian Lung Cancer Group. Thirty-four percent were treated with 10 fractions of 3 Gy. Stage IV NSCLC was present in 47%. Esophagus Dmax was 39 Gy (population median) and Dmean 15 Gy. Overall 31% of patients developed esophagitis (26% grade 2–3, no grade 4–5). Several dosimetric parameters correlated with the risk of esophagitis (Dmax, Dmean, D5cc, V20, V30, V35, V40). Dmax outperformed other dosimetric variables in multivariate analysis. Furthermore, concomitant chemotherapy significantly increased the risk of esophagitis, while oral steroid medication reduced it. In patients with Dmax ≥40 Gy a reduced Dmean (≤20 Gy) was beneficial.

Conclusion

In order to reduce esophagitis after hypofractionated palliative treatment lower doses than those recommended in curative NSCLC settings are preferable. Besides esophageal dose, CRT is the main risk factor for esophagitis. Additional work is needed to confirm that steroids are able to modify the risk (or to rule out confounding effects of baseline variables not included in our database).