High Dose Rate Brachytherapy for Nonmalignant Airway Obstruction

Therapeutic and prophylactic effects of radiation therapy in the management of recurrent granulation tissue induced tracheal stenosis: a review on the role of Endobronchial brachytherapy and external beam radiation therapy

PURPOSE

Granulation tissue-induced tracheal stenosis (mainly secondary to intubation or lung transplantation) is one of the most common etiologies of benign airway obstructions. Recurrence rates after standard treatment options (surgical resection and/or endobronchial interventions) can inadvertently worsen the stricture through the stimulation of more granulation tissue generation (via increased fibroblast activity and roliferation). Low-dose radiotherapy could be a promising tool to prevent granulation tissue formation after surgery and/or endobronchial interventions regarding its established role in the treatment of keloids or hypertrophic scars, two benign diseases with similar a pathophysiology to tracheal stenosis. This study reviews case reports and small series that used endobronchial brachytherapy (EBBT) or external beam radiotherapy (EBRT) for the management of refractory granulation tissue-induced tracheal stenosis after surgery and/or endobronchial interventions.

METHODS AND MATERIALS

Case reports and series (published up to October 2022) that reported outcomes of patients with recurrent granulation tissue-induced tracheal stenosis (after surgery and/or endobronchial interventions) treated by EBBT or EBRT (in definitive or prophylactic settings) were eligible.

RESULTS

Sixteen studies (EBBT: nine studies including 69 patients, EBRT: seven studies including 32 patients) were reviewed. The pooled success rate across all studies was 74% and 97% for EBBT and EBRT, respectively.

CONCLUSIONS

Radiation therapy appears to be effective in the management of selected patients with recurrent/refractory tracheal stenosis. Response to this treatment is usually good, but further studies with a larger number of patients and long-term followup are necessary to determine the optimal technique, dose, and timing of radiation therapy, late complications, the durability of response, and criteria for patient selection.

Systematic review of brachytherapy for symptom palliation

PURPOSE

Brachytherapy is most often applied in the curative or salvage setting, but many forms of brachytherapy can be helpful for symptom palliation. Declining utilization is seen, for multiple reasons, such as lack of awareness, insufficient expertise, or poor access to equipment. High level evidence for many types of palliative brachytherapy has been lacking. The objective of the current study was to review the evidence for utilization and efficacy of brachytherapy to palliate symptoms from cancer.

MATERIALS AND METHODS

We performed a systematic search in EMBASE and MEDLINE for English-language articles published from January 1980 to May 2022 that described brachytherapy used for a palliative indication in adults with a diagnosis of cancer (any subtype) and at least one symptom related outcome. Individual case reports and conference abstracts were excluded. All publications were independently screened by two investigators for eligibility.

RESULTS

The initial search identified 3637 abstracts of which 129 were selected for in-depth review. The number of studies (total number of patients) included in the final analysis varied widely by tumor site with the majority (68.2%) involving either lung or esophageal cancer. Despite a limited number of prospective trials that assessed the efficacy of brachytherapy for symptom management, there was a positive effect on palliation of symptoms across all tumor types. There was no clear trend in the number of publications over time. The most commonly cited symptom indications for palliation by brachytherapy were dysphagia, dyspnea, pain and bleeding.

CONCLUSIONS

Brachytherapy can provide palliation for patients with advanced cancer, across different tumor sites and clinical scenarios. However, high level evidence in the literature to support palliative applications of brachytherapy is lacking or limited for many tumor sites. There appears to be a strong publication bias towards positive studies in favor of brachytherapy. Beyond anecdotal reports and individual practices, outcomes research can further our understanding of the role of brachytherapy in palliating advanced cancers of all types, and should be encouraged.

Endobronchial brachytherapy-A novel approach for the management of airway amyloidosis

PURPOSE

Airway amyloidosis is an uncommon condition and may have variable clinical course. There is no proven systemic therapy, and the management mainly relies on local invasive treatments. Several reports have found external beam radiotherapy to produce durable responses. The optimal dose and fractionation has not been determined. Endobronchial brachytherapy (EBB) has never been reported to affect this disease.

METHODS

The study includes a retrospective chart review of all patients with airway amyloidosis treated with EBB at the Davidoff Cancer Center. Data include symptoms, radiotherapy method and dose, treatment outcomes, and toxicities.

RESULTS

Three patients were included. Patients were either symptomatic with extensive airway involvement or have undergone multiple local procedures with rapid recurrence of the amyloid deposits. Two patients had upper and 1 patient had lower airway involvement. Two were treated with external beam radiotherapy and EBB and 1 was treated with EBB only. All patients achieved rapid improvement of symptoms with visible improvement in followup bronchoscopies. EBB doses ranged from 7.5 to 10 Gy. Of the seven lesions treated with EBB, only one lesion recurred 6 months from treatment. No major toxicities were reported.

CONCLUSIONS

EBB is effective and safe for the management of airway amyloidosis and can offer long-term control. This is the first report of EBB for this indication. EBB should be further explored as means of minimizing the irradiated lung volume.

Endobronchial brachytherapy provides excellent long-term control of recurrent granulation tissue after tracheal stenosis

PURPOSE

To review the experience of using endobronchial brachytherapy (EBB) as a treatment for recurrent tracheal granulation tissue.

METHODS AND MATERIALS

Patients referred for EBB at the Rabin Medical Center for benign stenosis were reviewed with institutional review board approval. Patients underwent bronchoscopic resection of granulation tissue followed by insertion of self-expanding metallic stents. After stenting, repeat laser resection was done at least 1 week before brachytherapy. After CT simulation, patients had three-dimensional brachytherapy treatment planning. A single 10-Gy dose was prescribed to 1.0cm from the source and treatment was delivered using high-dose-rate afterloader with (192)Ir source. Patients were followedup with bronchoscopy every 3 months after the completion of therapy.

RESULTS

From November 2001 to January 2009, 29 patients were treated with EBB to prevent granulation tissue reformation. Median age was 70 years and 55% of patients were male. Ninety percent of patients were treated to the trachea and the remaining patients had stenoses in the main stem bronchi. The primary cause of stenosis was prolonged mechanical ventilation (76%). The median time from stent placement to brachytherapy was 69 days. Median active length of treatment was 7cm. With a median followup of 36 months, 66% (19 of 29) of patients remained free of granulation tissue. Forty-eight percent of patients have died, with all except 1 patient dying of their underlying condition. A single patient experienced death from tracheoesophageal fistula.

CONCLUSION

EBB is an effective and safe treatment to prevent recurrent granulation tissue formation after endobronchial resection and should be considered in patients who are unable to undergo surgical resection.

Flexible bronchoscopic management of benign tracheal stenosis: long term follow-up of 115 patients

Background

Management of benign tracheal stenosis (BTS) varies with the type and extent of the disease and influenced by the patient's age and general health status, hence we sought to investigate the long-term outcome of patients with BTS that underwent minimally invasive bronchoscopic treatment.

Methods

Patients with symptomatic BTS were treated with flexible bronchoscopy therapeutic modalities that included the following: balloon dilatation, laser photo-resection, self-expanding metal stent placement, and High-dose rate endobronchial brachytherapy used in cases of refractory stent-related granulation tissue formation.

Results

A total of 115 patients with BTS and various cardiac and respiratory co-morbidities with a mean age of 61 (range 40-88) were treated between January 2001 and January 2009. The underlining etiologies for BTS were post - endotracheal intubation (N = 76) post-tracheostomy (N = 30), Wegener's granulomatosis (N = 2), sarcoidosis (N = 2), amyloidosis (N = 2) and idiopathic BTS (N = 3). The modalities used were: balloon dilatation and laser treatment (N = 98). Stent was placed in 33 patients of whom 28 also underwent brachytherapy. Complications were minor and mostly included granulation tissue formation. The overall success rate was 87%. Over a median follow-up of 51 months (range 10-100 months), 30 patients (26%) died, mostly due to exacerbation of their underlying conditions.

Conclusions

BTS in elderly patients with co-morbidities can be safely and effectively treated by flexible bronchoscopic treatment modalities. The use of HDR brachytherapy to treat granulation tissue formation following successful airway restoration is promising.

Liquid (188)Re-filled balloon dilation for the treatment of refractory benign airway strictures: preliminary experience

PURPOSE

To present the preliminary results of beta irradiation with use of liquid rhenium 188 ((188)Re)-filled balloon dilation in the treatment of refractory benign airway strictures.

MATERIALS AND METHODS

Ten sessions of beta irradiation by using liquid (188)Re-filled balloon dilation were prospectively performed in nine patients with refractory bronchial strictures between 2003 and 2006. Indications for treatment were dyspnea caused by repeat stricture or no response to previous treatment (ie, balloon dilation and/or temporary stent placement or laser therapy) in seven patients and dyspnea caused by exuberant granulation tissue formation at the distal end of the placed stent in two. To assess the treatment efficacy, the authors calculated and compared the mean intervals of interventional treatments before and after dilation with (188)Re and mercaptoacetyltriglycine (MAG(3))-filled balloons.

RESULTS

Liquid (188)Re-filled balloon dilation was successfully performed in all nine patients, with no procedure-related complications. Immediately after the procedure, all patients showed resolution of their dyspnea. Five patients remained asymptomatic at 5-25-month follow-up. Four patients experienced dyspnea caused by recurrent stricture 1-10 months after dilation. The mean intervals between interventional treatments increased significantly from 3.1 months +/- 2.1 before (188)Re-MAG(3)-filled balloon dilation to 10.8 months +/- 8.8 after (188)Re-MAG(3)-filled balloon dilation in all nine patients (Wilcoxon signed rank test, P = .025).

CONCLUSIONS

beta irradiation with liquid (188)Re-filled balloon dilation can be safely used for refractory benign airway strictures. A large study with longer follow-up is needed to draw a definite conclusion.

High-Dose-Rate Endobronchial Brachytherapy for Recurrent Airway Obstruction From Hyperplastic Granulation Tissue

PURPOSE

Benign endobronchial granulation tissue causes airway obstruction in up to 20% of patients after lung transplantation or stent placement. High-dose-rate endobronchial brachytherapy (HDR-EB) has been successful in some cases refractory to standard bronchoscopic interventions.

METHODS AND MATERIALS

Between September 2004 and May 2005, 8 patients with refractory benign airway obstruction were treated with HDR-EB, using one to two fractions of Ir-192 prescribed to 7.1 Gy at a radius of 1 cm. Charts were retrospectively reviewed to evaluate subjective clinical response, forced expiratory volume in 1 second (FEV(1)), and frequency of therapeutic bronchoscopies over 6-month periods before and after HDR-EB.

RESULTS

The median follow-up was 14.6 months, and median survival was 10.5 months. The mean number of bronchoscopic interventions improved from 3.1 procedures in the 6-month pretreatment period to 1.8 after HDR-EB. Mean FEV(1) improved from 36% predicted to 46% predicted. Six patients had a good-to-excellent subjective early response, but only one maintained this response beyond 6 months, and this was the only patient treated with HDR-EB within 24 h from the most recent bronchoscopic intervention. Five patients have expired from causes related to their chronic pulmonary disease, including one from hemoptysis resulting from a bronchoarterial fistula.

CONCLUSION

High-dose-rate-EB may be an effective treatment for select patients with refractory hyperplastic granulation tissue causing recurrent airway stenosis. Performing HDR-EB within 24-48 h after excision of obstructive granulation tissue could further improve outcomes. Careful patient selection is important to maximize therapeutic benefit and minimize toxicity. The optimal patient population, dose, and timing of HDR-EB should be investigated prospectively.

Removal of Covered Self-Expandable Metallic Airway Stents in Benign Disorders

STUDY OBJECTIVES

To describe the technique and outcome of removal of self-expandable metallic airway stents (SEMAS) in a series of patients who underwent stenting for benign airway stenoses.

DESIGN AND SETTING

A retrospective cohort analysis of patients with benign airway disorders treated with SEMAS between 1997 and 2003, who presented with an indication for stent removal in a tertiary-care hospital, and referral interventional pulmonology clinic.

PATIENTS AND METHODS

During the study period, 49 SEMAS were inserted in 39 patients for treatment of benign airway disorders. Ten of these 39 patients (25.6%), bearing 12 covered stents, presented with an indication for stent removal. Data of these cases were extracted from electronic files kept in our institution archive.

RESULTS

Indications for stent removal included excessive or recurrent granuloma formation (five cases), recurrence of stenosis after stent failure (one case), stent fracture (two cases), and accomplishment of treatment (two cases). In all of these cases, covered versions of SEMAS had been placed either in the trachea or in a main bronchus. In contrast to many previous reports, these stents proved to be absolutely retrievable even if some difficulties were encountered. In all cases, however, removal was successful without major complications. All patients resumed normal spontaneous ventilation postoperatively, and follow-up was uneventful. Average duration of stenting before removal was 16.2 +/- 17.5 months (+/- SD) [range, 1 to 60 months].

CONCLUSIONS

We conclude that although placement of SEMAS is assumed to be permanent in patients with benign airway disorders, an indication for stent removal is often observed (25.6% in our series). The covered SEMAS can be effectively and safely removed if needed without major sequelae. Nevertheless, new technical improvements in metallic stent design and materials may help reinforce the concept of a retrievable metallic airway stent, which may offer significant clinical advantages.

Central Airway Obstruction

Central airway obstruction is a problem facing all medical and surgical subspecialists caring for patients with chest diseases. The incidence of this disorder appears to be rising because of the epidemic of lung cancer; however, benign causes of central airway obstruction are being seen more frequently as well. The morbidity is significant and if left untreated, death from suffocation is a frequent outcome. Management of these patients is difficult, but therapeutic and diagnostic tools are now available that are beneficial to most patients and almost all airway obstruction can be relieved expeditiously. This review examines current approaches in the workup and treatment of patients suffering from airway impairment. Although large, randomized, comparative studies are not available, data show significant improvement in patient outcomes and quality of life with treatment of central airway obstruction. Clearly, more studies assessing the relative utility of specific airway interventions and their impact on morbidity and mortality are needed. Currently, the most comprehensive approach can be offered at centers with expertise in the management of complex airway disorders and availability of all endoscopic and surgical options.