Role of radiotherapy in the management of malignant airway obstruction

Short-course Radiotherapy for Airway Stenting in Malignant Airway Obstruction: A Case Report and Literature Review

Background

Malignant airway obstruction (MAO) secondary to tumor growth occurs in nearly a third of patients with lung cancer and portends a very poor prognosis if untreated. Treatment options include bronchoscopic intervention with tumor debulking, stent placement, endobronchial brachytherapy, or palliative radiotherapy.

Case Report

This is a report of a 74-year-old woman with a medical history of metastatic lung adenocarcinoma, hospitalized for dyspnea, hemoptysis, and chest pain with a radiographic finding of MAO on chest X-ray and computed tomography. Patient underwent radiation with a total dose of 13 Gy in two once-weekly fractions of 6.5 Gy per fraction. Three days after the end of radiation treatment, chest X-ray showed a completely right lung re-expansion without atelectasis. Two weeks after radiotherapy treatment, the patient was discharged from hospital without pulmonary symptoms.

Conclusion

A different fractionation with a lower equivalent dose in 2 Gy fraction compared to literature data showed efficacy in resolving MAO with excellent local control in the first three months of follow-up.

External Beam Radiotherapy for Malignant Central Airway Obstruction in a Remote Rural Patient: A Case Study

Introduction

Malignant central airway obstruction (MCAO) is a challenging therapeutic scenario, caused by tumour burden which limits airflow within the large airways. Squamous cell carcinoma (SCC) of the lung accounts for 50% of MCAO seen in the setting of non-small cell lung cancer. Here, we present the challenging case of a 63-year-old Indigenous Australian Female rom a remote rural community with background history of metastatic SCC of presumed pulmonary origin, who presented with a 1-week history of dyspnoea, stridor, and hoarse voice.

Case Presentation

A CT chest and neck demonstrated a superior mediastinal mass compressing the trachea to a narrowest diameter of 3 mm. The patient was stabilised in her local health centre, then transferred to our tertiary care facility for further evaluation and management. This stenotic lesion was not amenable to bronchoscopic or surgical intervention but was instead treated successfully with a short course of external beam radiotherapy, to total dose of 25Gy delivered over 10 fractions. The patient had almost complete resolution of respiratory symptoms with no significant radiotherapy related toxicity.

Conclusion

Here, we discuss a challenging case of MCAO in a remote rural Australian patient and demonstrate the utility of external beam radiotherapy in this setting. We also discuss aspects of cancer related healthcare disparities which exist for Indigenous Australians. In doing so, we wish to highlight the need for improved cancer healthcare for such communities.

Computed tomography-guided interstitial implantation of I (125) radioactive seeds in the treatment of hilar airway stenosis caused by non-small cell lung cancer

BACKGROUND

Airway stenosis secondary to non-small cell lung cancer (NSCLC) is one of the severe complications that can lead to life-threatening outcomes.

OBJECTIVE

To investigate the clinical utility of computed tomography (CT)-guided interstitial implantation of radioactive I-125 seeds in the treatment of hilar airway stenosis caused by NSCLC.

METHODS

The cases of hilar airway stenosis caused by NSCLC in our hospital from 2017 to 2022 were collected and divided into observation and control groups. Both groups underwent conventional lung cancer treatment, and the observation group was treated with CT-guided interstitial implantation of radioactive I-125 seeds. The mean tumor diameter, hilar airway stenosis, and obstructive pneumonia scores at 3 months after treatment were compared between the two groups.

RESULTS

After 3 months of treatment, the mean tumor diameter (28.8 ± 9.3 mm vs 49.33 ± 16.75 mm, P < 0.001), hilar airway stenosis (20.55 ± 30.36% vs 84.85 ± 26.19%, P < 0.001), and obstructive pneumonia score (2.19 ± 1.41 vs 3.48 ± 1.12, P < 0.001) of the observation group were significantly lower than those of the control group.

CONCLUSION

CT-guided interstitial implantation of I (125) radioactive seeds in the treatment of hilar airway stenosis caused by NSCLC can effectively reduce the tumor volume, relieve airway stenosis, and alleviate the associated obstructive pneumonia and has a certain value of application in the clinic.

A Retrospective Study of Patients Undergoing Palliative Radiotherapy for Airway Obstruction due to Lung Cancer

BACKGROUND/AIM

In advanced stage lung cancer, bulky tumors can cause serious symptoms such as malignant airway obstruction (MAO). Prompt response to airway obstruction might be essential to improve quality of life and prolong life expectancy. Palliative external beam radiotherapy (EBRT) is a less invasive and highly safe treatment method that can alleviate symptoms and at the same time treat lung cancer. However, there are few reports on the results of palliative radiotherapy performed for improving airway obstruction and obstructive pneumonia. Therefore, this study retrospectively examined the effectiveness of palliative radiotherapy.

PATIENTS AND METHODS

We reviewed 38 lung cancer patients with MAO who underwent EBRT. Patients were treated with a median dose of 37.5 Gy (range=30-40 Gy) in 10-20 fractions. Whether a patient was a responder or non-responder was assessed by whether the bronchus that was obstructed before EBRT reopened or improvement of obstructive pneumonia was observed on follow-up chest X-ray or computed tomography after EBRT.

RESULTS

The median survival time was 135 days (range=31-469 days) for the responders to EBRT and 45 days (range=23-355 days) for non-responders; this difference was statistically significant (p=0.03). One-year overall survival rate was 18.5% and 0% for the responders to EBRT and non-responders, respectively.

CONCLUSION

Palliative EBRT might be an important option for non-curative lung cancer patients with MAO.

Clinical Radiobiology for Radiation Oncology

This chapter is focused on radiobiological aspects at the molecular, cellular, and tissue level which are relevant for the clinical use of ionizing radiation (IR) in cancer therapy. For radiation oncology, it is critical to find a balance, i.e., the therapeutic window, between the probability of tumor control and the probability of side effects caused by radiation injury to the healthy tissues and organs. An overview is given about modern precision radiotherapy (RT) techniques, which allow optimal sparing of healthy tissues. Biological factors determining the width of the therapeutic window are explained. The role of the six typical radiobiological phenomena determining the response of both malignant and normal tissues in the clinic, the 6R’s, which are Reoxygenation, Redistribution, Repopulation, Repair, Radiosensitivity, and Reactivation of the immune system, is discussed. Information is provided on tumor characteristics, for example, tumor type, growth kinetics, hypoxia, aberrant molecular signaling pathways, cancer stem cells and their impact on the response to RT. The role of the tumor microenvironment and microbiota is described and the effects of radiation on the immune system including the abscopal effect phenomenon are outlined. A summary is given on tumor diagnosis, response prediction via biomarkers, genetics, and radiomics, and ways to selectively enhance the RT response in tumors. Furthermore, we describe acute and late normal tissue reactions following exposure to radiation: cellular aspects, tissue kinetics, latency periods, permanent or transient injury, and histopathology. Details are also given on the differential effect on tumor and late responding healthy tissues following fractionated and low dose rate irradiation as well as the effect of whole-body exposure.

First-In-Human Computer-Optimized Endobronchial Ultrasound-Guided Interstitial Photodynamic Therapy for Patients With Extrabronchial or Endobronchial Obstructing Malignancies

Objective

Patients with inoperable extrabronchial or endobronchial tumors who are not candidates for curative radiotherapy have dire prognoses with no effective long-term treatment options. To reveal that our computer-optimized interstitial photodynamic therapy (I-PDT) is safe and potentially effective in the treatment of patients with inoperable extra or endobronchial malignancies inducing central airway obstructions.

Methods

High-spatial resolution computer simulations were used to personalize the light dose rate and dose for each tumor. Endobronchial ultrasound with a transbronchial needle was used to place the optical fibers within the tumor according to an individualized plan. The primary and secondary end points were safety and overall survival, respectively. An exploratory end point evaluated changes in immune markers.

Results

Eight patients received I-PDT with planning, and five of these received additional external beam PDT. Two additional patients received external beam PDT. The treatment was declared safe. Three of 10 patients are alive at 26.3, 12, and 8.3 months, respectively, after I-PDT. The treatments were able to deliver a prescribed light dose rate and dose to 87% to 100% and 18% to 92% of the tumor volumes, respectively. A marked increase in the proportion of monocytic myeloid-derived suppressor cells expressing programmed death-ligand 1 was measured in four of seven patients.

Conclusions

Image-guided light dosimetry for I-PDT with linear endobronchial ultrasound transbronchial needle is safe and potentially beneficial in increasing overall survival of patients. I-PDT has a positive effect on the immune response including an increase in the proportion of programmed death-ligand 1-expressing monocytic myeloid-derived suppressor cells.

International consensus on radiotherapy in metastatic non-small cell lung cancer

BACKGROUND

Lung cancer is the leading cause of cancer-related death worldwide, with non-small cell lung cancer (NSCLC) accounting for most cases. While radiotherapy has historically served as a palliative modality in metastatic NSCLC, considerable advances in its technology and the continuous development of cutting-edge therapeutic agents, such as targeted therapy and immune checkpoint inhibitors (ICIs), are increasing its role in the multi-disciplinary management of the disease.

METHODS

International radiotherapy experts were convened to consider and reach consensuses on the clinical utilities of radiotherapy in metastatic NSCLC, with the aim to provide patient-focused, up to date, evidence-based, recommendations to assist cancer specialists in the management of patients with metastatic NSCLC worldwide.

RESULTS

Timely radiotherapy can offer rapid symptom alleviation and allow subsequent aggressive treatment approaches in patients with heavy tumor burden and/or oncologic emergencies. In addition, appropriate incorporation of radiotherapy as concurrent, consolidation, or salvage therapy makes it possible to achieve long-term survival, or even cure, for patients with oligo-metastatic disease. Cranial radiotherapy plays an important role in the management of brain metastasis, potentially augmenting the response and prolonging survival associated with targeted agents and ICIs. However, key questions remain, such as the appropriate choice of radiation techniques, optimal sequence of systemic therapies and radiotherapy, and optimal patient selection for such combination strategies. Although a strong rationale for combining radiotherapy and ICIs exists, its optimal parameters in this setting remain to be established.

CONCLUSIONS

In the modern era, radiotherapy serves not only as a palliative tool in metastatic NSCLC, but also plays active roles in patients with oligo-focal disease, CNS metastasis and receiving ICIs.

Malignant Central Airway Obstruction: What's New?

Malignant central airway obstruction (MCAO) is a debilitating and life-limiting complication that occurs in an unfortunately large number of individuals with advanced intrathoracic cancer. Although the management of MCAO is multimodal and interdisciplinary, the task of providing patients with prompt palliation falls increasingly on the shoulders of interventional pulmonologists. While a variety of tools and techniques are available for the management of malignant obstructive lesions, advancements and evolution in this therapeutic venue have been somewhat sluggish and limited when compared with other branches of interventional pulmonary medicine (e.g., the early diagnosis of peripheral lung nodules). Indeed, one pragmatic, albeit somewhat uncharitable, reading of this article's title might suggest a wry smile and shug of the shoulders as to imply that relatively little has changed in recent years. That said, the spectrum of interventions for MCAO continues to expand, even if at a less impressive clip. Herein, we present on MCAO and its endoscopic and nonendoscopic management-that which is old, that which is new, and that which is still on the horizon.

A narrative review of evolving roles of radiotherapy in advanced non-small cell lung cancer: from palliative care to active player

Radiotherapy, along with other loco-regional interventions, is conventionally utilized as a palliative approach to alleviate symptoms and mitigate oncological emergencies in advanced non-small cell lung cancer (NSCLC). Thanks to the ongoing improvement of medical treatments in the last decade, such as targeted therapy and immunotherapy, the survival of patients with advanced NSCLC has been considerably prolonged, making it feasible and clinically beneficial for radiotherapy to play a more active role in highly selected subpopulations. In this review, we will focus on the evolving roles of radiotherapy in advanced NSCLC. First of all, among patients who are initially unable to tolerate aggressive treatment due to severe symptoms caused by metastases and/or tumor emergencies, timely radiotherapy could significantly improve their performance status (PS) and general condition, thus giving them a chance for intensive treatment and prolonged survival. The efficacy, potential candidates, and optimal dose-fractionation regimens of radiotherapy in this clinical scenario will be discussed. Additionally, radiotherapy can play a curative role as a concurrent therapy, consolidation therapy, and salvage therapy for patients with oligo-metastatic, oligo-residual, and oligo-progressive disease, respectively. Accumulating evidence from recent clinical trials, basic research, and translational investigations regarding the potentially curative roles of radiotherapy in NSCLC patients with oligo-metastatic disease will be summarized. Moreover, with the advent of various small molecular tyrosine kinase inhibitors (TKIs), the treatment efficacy and overall survival of oncogene-addicted NSCLC with brain metastases have been significantly improved, and the clinical value and optimal timing of cranial radiotherapy have become topics of much debate. Finally, synergistic antitumor interactions between radiotherapy and immunotherapy have been repeatedly demonstrated. Thus, the immune sensitizing role of radiotherapy in advanced NSCLC is also highlighted in this review.