A method for selective endobronchial and endotracheal irradiation

Imaging of therapeutic airway interventions in thoracic oncology

Tracheobronchial obstruction, haemoptysis, and airway fistulas caused by airway involvement by primary or metastatic malignancies may result in dyspnoea, wheezing, stridor, hypoxaemia, and obstructive atelectasis or pneumonia, and can lead to life-threatening respiratory failure if untreated. Complex minimally invasive endobronchial interventions are being used increasingly to treat cancer patients with tracheobronchial conditions with curative or, most often, palliative intent, to improve symptoms and quality of life. The selection of the appropriate treatment strategy depends on multiple factors, including tumour characteristics, whether the lesion is predominately endobronchial, shows extrinsic compression, or a combination of both, the patient's clinical status, the urgency of the clinical scenario, physician expertise, and availability of tools. Pre-procedure multidetector computed tomography (MDCT) imaging can aid in the most appropriate selection of bronchoscopic treatment. Follow-up imaging is invaluable for the early recognition and management of any potential complication. This article reviews the most commonly used endobronchial procedures in the oncological setting and illustrates the role of MDCT in planning, assisting, and follow-up of endobronchial therapeutic procedures.

[Recurrent adenoid cystic carcinoma. Review based on a case report]

The adenoid cystic carcinoma is a malignant epithelial glandular type neoplasia, occurring frequently in the salivary and mammary glands, and rarely in the lung, and is responsible for 0.2% of lung tumours. These tumours present a slow growth and prolonged clinical course, and are characterised by their infiltrative nature and tendency towards late local recurrence. The authors present a case of a woman with adenoid cystic lung carcinoma diagnosed after investigation of a lung nodule, submitted to surgical resection with curative intention, whose follow -up identified late recurrence, 9 years after surgery. The present case emphasises the need for a prolonged surveillance, due to the potential late recurrence of this kind of tumour. The article reviews clinical and pathological features of lung adenoid cystic carcinoma, as well as therapeutic options, namely for prevention of recurrence.

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.

The role of radiation therapy and chemotherapy in the management of airway tumors other than small-cell carcinoma and non-small-cell carcinoma

In rare pulmonary tumors, the choice of local and systemic therapy is frequently dictated by the histologic cell type and (generally) by extrapolation from the existing therapeutic literature for that cell type's more common presentation; however, this approach might change. We are in the midst of a new biological and technological era in how approach and treat cancer. In a phase I trial for non-small-cell lung cancer, Hayman et al safely treated with radiation doses as high as 102.9 Gy (to limited volumes) using three-dimensional, conformal radiation [100]. Such techniques facilitate radiation dose escalation for thoracic neoplasms while minimizing normal tissue toxicity, potentially enhancing the therapeutic ratio. Furthermore, the entire human genome has been sequenced recently, and scientists are now in the process of discovering the functions of previously unknown sequences and their protein products. DNA microarrays can be used to analyze small tissue samples for the presence of gene variations or mutations (genotyping), performing the equivalent of several thousand "Southern blot" experiments in only a few days. In the future, patients might receive individually tailored therapy based upon unique molecular-genetic alterations of the tumor.

Contemporary role of modern brachytherapy techniques in the management of malignant thoracic tumors

Sole brachytherapy for carcinoma of the lung is most often performed using high-dose-rate (HDR) remote afterloading equipment, which delivers the treatment within the tracheobronchial tree in an outpatient setting. It provides excellent, rapid palliation in advanced stages, and can also be used selectively for curative intent in early stages. In better-performance patients, fractionated external beam radiation therapy (EBRT) is preferred to brachytherapy as an initial treatment because it appears to provide a modest gain in survival, and more sustained palliation. In patients with centrally located tumors and limited extent of disease, the combination of external and endoluminal irradiation enables curative treatment options. Intraoperative brachytherapy may complement standard adjuvant treatment in incompletely resected, unresectable, or medically inoperable patients, and has the potential to improve local control in selected cases. Due to the rarity of the disease, the role of endoluminal brachytherapy in the treatment regimen of tracheal neoplasms is not yet clearly defined. The risk of fatal bleeding after endoluminal brachytherapy appears to be correlated with tumor localization and fraction size, but in the majority of cases fatal bleeds are caused by progression of local disease. The use of a distanceable applicator provides a central positioning of the source, prevents the delivery of high-contact doses to the mucosa, and may reduce toxicity. The standard technique for interstitial brachytherapy after breast-conserving surgery and adjuvant EBRT is the use of low-dose-rate (LDR) brachytherapy, but it may also be applied by means of pulsed-dose-rate (PDR) or HDR techniques. Prospective trials comparing different boost techniques and indications are needed to define more precisely the subgroup of patients who are most suitable for interstitial brachytherapy. Reirradiation of chest wall local recurrences using brachytherapy molds is effective and provides a high local control rate with acceptable toxicity.

HDR-brachytherapy boost for residual tumour after external beam radiotherapy in patients with tracheal malignancies

Seven inoperable patients with tracheal neoplasms received a high dose rate (HDR) brachytherapy boost (median 15 Gy, single dose 3-5 Gy) for residual tumour after external beam radiotherapy (median 50 Gy, 5 x 2 Gy/week). The median actuarial survival was 34.3 months. The 1-, 2- and 3-year actuarial survival rates were 85.7%, 85.7% and 32%. Local control was obtained in 5/7 patients. Late toxicity occurred in three patients (stenosis n = 2, hemorrhage n = 1). Our data indicate, that a HDR brachytherapy boost is effective and feasible.

Results of treating primary tumors of the trachea with radiotherapy

PURPOSE

To report the efficacy of treatment and to identify prognostic factors that were predictive of survival in primary tumors of the trachea treated with radiotherapy.

METHODS AND MATERIALS

The medical records of patients treated at the Peter MacCallum Cancer Institute in the period 1962 to 1995 were reviewed. Forty-two patients were eligible for the study and were treated with radiotherapy. Squamous cell carcinoma (SCC) was the commonest subtype and patients generally presented with long-standing respiratory symptoms. Eleven patients were planned for treatment with at least 50 Gy to the primary, while the rest were treated with lower doses.

RESULTS

The estimated median survival for all patients was 5.7 months, with 13% surviving at 2 years. Univariate analysis revealed performance status, weight loss, and lymph node or distant metastatic involvement as significant prognostic factors. Patients planned for treatment with at least 50 Gy survived longer than patients treated with less than 50 Gy, but this was probably due to selection of patients with better prognostic factors for higher dose treatment.

Role of radiation therapy in the treatment of primary tracheal carcinoma

PURPOSE

The objective of this work is to investigate the role of radiation therapy in the treatment of primary tracheal carcinoma.

METHODS AND MATERIALS

From 1963 to 1993, 106 patients presenting with a tracheal carcinoma received a radiation course as part of their treatment in three institutions. Eighty-four patients were treated with megavoltage radiation only, receiving doses ranging from 30 to 70 Gy, with a median dose of 56 Gy. Five patients received high-dose-rate (HDR) brachytherapy, five patients underwent a surgical procedure, and eight received chemotherapy.

RESULTS

With a mean follow-up of 141 months, the overall 1-, 2-, and 5-year survival rates are 46%, 21%, and 8%, respectively. Prognostic factors included tumor size (less than 3 cm), performance status, and total radiation dose: the 5-year survival rate dropped from 12% for patients receiving doses greater than 56 Gy to 5% for lower doses. Performance status and radiation doses are the only independent significant factors in multivariate analysis; these results must however be analyzed with precaution in this retrospective study.

CONCLUSIONS

Radiation is a good alternative to surgery for primary tracheal cancer. A review of the literature and our current results allow us to recommend a radiation dose greater than 60 Gy for primary irradiation. Collaborative studies are warranted to (1) determine the optimal radiation dose for definitive irradiation, (2) define the potential role of radiation after complete and partial surgery, (3) determine the role and optimal treatment scheme for HDR brachytherapy, (4) describe and record the late effects, (5) establish the potential benefit of chemoradiation.

Management of Tracheal Neoplasms

Patients with tracheal involvement from primary or secondary neoplasms usually present with relatively nonspecific symptoms of cough, wheeze, and shortness of breath. Prompt diagnosis often requires a high index of suspicion. Tomography or computed tomography of the chest will often confirm the presence of a tracheal lesion. A detailed rigid bronchoscopic assessment by an experienced thoracic surgeon is essential for establishing the extent of tracheal involvement. Although advanced tumor stage often precludes surgical resection, the application of current operative techniques allows a significant number of tracheal tumors to be completely excised and primarily reconstructed. Adjuvant radiotherapy is often employed with surgical resection to improve local control and enhance the potential for cure.

Treatment of primary neoplasms of the trachea. The role of radiation therapy

BACKGROUND

Primary tracheal tumors are a rare malignancy. Before 1960, most patients had a biopsy, followed by external orthovoltage irradiation or radon seed implantation. Advances in surgery and in radiation therapy during the past three decades have allowed more patients to undergo definitive treatment.

METHODS

Between 1957 and 1988, 22 patients with primary tracheal malignancy were treated with curative intent at The University of Texas M.D. Anderson Cancer Center. Five patients underwent primary surgical resection (Group 1), 5 patients had surgical resection and adjuvant irradiation (Group 2), and 12 patients had primary irradiation (Group 3).

RESULTS

Median survival times were 26 months for all patients; 16 months for Group 1; 61 months for Group 2; and 26 months for Group 3. Local control was attained in 1 of 5 patients in Group 1, 4 of 5 patients in Group 2, and 4 of 12 patients in Group 3. Among those treated with primary radiation therapy, local control was attained by three of four patients who received 60 Gy or higher and one of eight patients who received less than 60 Gy. Results of chi-square test (P = 0.03) were statistically significant. Severe complications, including treatment-related deaths, occurred in 2 of 5 patients in Group 1, 2 of 5 patients in Group 2, and 3 of 12 patients in Group 3.

CONCLUSION

Radiation therapy has a role in the treatment of patients with tracheal malignancy, either as postoperative adjuvant therapy or as sole therapy for those who refuse surgery or have medically inoperable disease. Alternative methods for increasing the local administration of radiation therapy, such as endotracheal brachytherapy, should be investigated for improvement in local control.

Treatment of primary tracheal carcinoma in Finland in 1967-1985

The treatment results of all the 95 primary tracheal carcinomas recorded by the Finnish Cancer Registry in 1967-1985 are evaluated. Six of the 95 patients were treated by surgery, 60 received radiotherapy and 29 were left untreated or received only palliative endoscopic or cytostatic therapy. The prognosis of the disease was poor. Among the 44 squamous cell carcinoma patients treated by radiotherapy, the median survival time after the diagnosis was 8 months (range 1-81 months). Complete response to radiotherapy was a favourable prognostic sign; after complete response the survival rates at 1, 2 and 5 years were 45%, 18% and 9% respectively. Patients with adenocystic carcinoma had the best prognosis.

Radiotherapy for primary carcinoma of the trachea

Between 1940 and 1985, 24 cases of primary carcinoma of the trachea were registered at the London Regional Cancer Centre. The most common presenting symptoms were hoarseness, haemoptysis and cough. Twenty patients had epidermoid carcinoma and four had adenoid cystic carcinoma. Because of different clinical behaviours, the two histologies were separately analyzed. Of the 20 patients with epidermoid carcinoma, 19 received radiotherapy as primary treatment and one patient did not receive radiotherapy because of advanced disease. Radiation doses ranged from 4000 to 6000 cGy and most patients had megavoltage irradiation. Treatment result was disappointing. Only one patient remained disease-free at 15-month follow-up and all other patients had persistent or recurrent tracheal tumour. Median survival for all 20 patients was 5 months (range 1 to 19 months). Of the four patients with adenoid cystic carcinoma, two had primary surgery and postoperative radiotherapy and two had primary radiotherapy. Two patients died of disease, at 5 months and 8 years from diagnosis. Two surviving patients had 15-month follow-up: one had persistent disease and the other was free from recurrence. In this study, radiotherapy within the range of doses given was found to be an ineffective primary treatment for tracheal carcinoma.

Combined laser therapy and endobronchial radiotherapy for unresectable lung carcinoma with bronchial obstruction

Over a 4 year period, we refined a protocol for treatment of airway obstruction due to recurrent lung carcinoma. Patients undergo bronchoscopy with the Nd:YAG laser available on standby. If bronchial obstruction is found to be due to extrinsic compression, an endobronchial catheter is inserted for iridium 192 brachytherapy, treating a cylindrical volume 7.5 to 15 mm in radius. If an endobronchial lesion is found, the presence of complete versus partial bronchial obstruction determines the course of treatment. Total airway obstruction is treated with the laser until a channel is created and then an endobronchial catheter is placed for adjuvant endobronchial radiotherapy to treat a cylindrical volume 5 mm in radius. Partial airway obstruction is treated with an endobronchial catheter and radiotherapy alone. Segmental obstruction is also treated with a distally placed endobronchial catheter instead of the laser. Using this protocol, we hope to minimize risk to the patient by restricting the use of the laser with its inherent higher potential rate of complications to cases of total obstruction. In addition, we expect to prolong the duration of palliation with endobronchial radiotherapy. The laser is an excellent tool to reopen occluded bronchi, but it is relatively ineffective in producing long-term tumor control. Instead, we have found that placement of a temporary transtracheal endobronchial catheter for radiotherapy is a simple, low-risk procedure that can be safely performed even in critically ill patients. The endobronchial catheter can provide good to excellent long-term palliation for patients with both partially and totally obstructed endobronchial lesions or malignant extrinsic compression of major airways.

Management of malignant airway obstruction: clinical and dosimetric considerations using an iridium-192 afterloading technique in conjunction with the neodymium-YAG laser

Fourteen patients with malignant airway obstruction have had 21 placements of a flexible nylon catheter for afterloading Iridium-192 using the flexible fiberoptic bronchoscope. Prescribed therapy was completed in 13 patients (18 courses). All patients had prior full-dose external irradiation, and no effective surgical or chemotherapeutic options remained. While many have had a trial of neodymium-YAG (yttrium-aluminum-garnet) laser therapy alone, eight patients received laser treatment one to three weeks prior to planned brachytherapy to provide immediate relief of symptoms and/or facilitate access and safe catheter placement. Most patients (64%) had recurrent squamous cell lung cancer. A dose of 3000 cGy is currently specified to 5 mm and 10 mm in the bronchus and trachea, respectively. Nine of the 13 treated patients have had follow-up bronchoscopy at approximately three months post-treatment with improvement documented in seven and progression in two patients. One patient was clinically improved without follow-up bronchoscopy, and three patients have had insufficient follow-up. A single patient treated with laser and 6000 rad at 5 mm developed a bronchoesophageal fistula. No other complication has been observed. The technique is simple and safe with the use of laser therapy when needed and appears to offer effective palliation in most patients even when standard therapy is exhausted.