Low dose rate versus high dose rate intraluminal brachytherapy for malignant endobronchial tumors

Bronchoscopy in lung cancer: appraisal of current technology and for the future

Bronchoscopy in the new millennium spells an exciting time for the pulmonologist, which likens to Alice peering through the looking glass into a wonderland of miniaturized probes, optics, and technology that are advancing at a maddening pace. Although scientists continue to push the envelope using nanotechnology that may facilitate further miniaturization of probes to allow imaging at the cellular or molecular level, it is opportune to evaluate the strengths and weaknesses of available technologies and bronchoscopic techniques for the diagnosis and staging of lung cancer, in its early detection and palliation. We appraise current technologies and what they hold for the future.

Brachytherapy for advanced prostate cancer bleeding

Advanced prostate cancer patients frequently deal with intractable prostatic bleeding which is a difficult problem to manage. Intraurethral high-dose rate (HDR) brachytherapy may palliate this condition. Advanced prostate cancer patients with intractable prostatic bleeding were offered brachytherapy with Iridium-192 using a Micro-selectron HDR machine. During a 5-year period, analysis was performed in 23 patients with a median age and Gleason score of 78 years and 9, respectively. Following brachytherapy, haematuria resolved in 19 of the 23 patients and was recurrence free at 6 months. Intraurethral HDR brachytherapy is a potentially effective modality for treating haematuria in patients with advanced prostate cancer.

State of the art: interventional pulmonology

Interventional pulmonology (IP) provides comprehensive care to patients with structural airway disorders and pleural diseases. A growing armamentarium of diagnostic and therapeutic tools has expanded the interventional pulmonologist's ability to care for pulmonary patients with complex abnormalities, often in concert and close collaboration with physicians in other specialties, such as thoracic surgery. Innovative technologies promise to have an impact on diseases and clinical entities not traditionally treated by invasive pulmonary interventions, such as asthma, COPD, and the solitary pulmonary nodule. Training, credentialing, reimbursement, and scientific validation remain key necessities for the continued growth of IP, and require a concerted effort by chest physicians and their professional organizations.

Endobronchial Brachytherapy: An Effective Option for Palliation of Malignant Bronchial Obstruction

Symptoms resulting from tumors extending to the endobronchial wall are common in patients with lung cancer and significantly impact quality of life. A number of treatment options are available for palliation, including endobronchial brachytherapy, stent placement, laser photoresection, external-beam radiation therapy, and photodynamic therapy. This review will focus on the methodology and role of endobronchial brachytherapy while discussing benefits of other treatment options as additions or alternatives to brachytherapy.

Continuing evidence for poorer treatment outcomes for single male patients: Retreatment data from RTOG 97-14

PURPOSE

The specific aim of this study was to evaluate outcome differences by gender and partner status for patients treated on Radiation Therapy Oncology Group (RTOG) protocol 97-14.

METHODS AND MATERIALS

RTOG 97-14 randomized patients with metastatic breast or prostate cancer to bone to receive 8 Gy in 1 fraction or 30 Gy in 10 fractions. Retreatment rates and overall survival were made based upon gender, marital status, and Karnofsky Performance Status (KPS). The cumulative incidence method was used to estimate retreatment time at 36 months from enrollment, and Gray's test was used to test for treatment differences within the same groupings. Marital status, gender, KPS, and treatment were variables tested in a univariate Cox model evaluating the time to retreatment.

RESULTS

Married men and women and single women receiving 30 Gy had significantly longer time to retreatment, p = 0.0067, p = 0.0052, and p = 0.0009 respectively. We failed to show a difference in retreatment rates over time in single men receiving either 30 Gy or 8 Gy. Univariate analysis of the entire group determined patients receiving 30 Gy in 10 fractions significantly less likely to receive retreatment, p < 0.0001, with a trend toward single patients less likely to be re-treated, p = 0.07.

CONCLUSION

Non-disease-related variables, such as social support, might influence the results of clinical trials with subjective endpoints such as retreatment rates. The statistically nonsignificant difference in the 36-month retreatment rates observed in single male patients receiving 8 Gy may be a result of inadequate social support systems in place to facilitate additional care. Patients receiving 8 Gy in a single fraction had significantly higher retreatment rates compared with patients receiving 30 Gy in 10 fractions.

Palliative radiation therapy in oncology

Palliative radiation therapy is considered when the incurable cancer patient has symptoms specifically related to a malignancy that may be relieved by localized treatment of the primary tumor or metastatic lesions. Developing a treatment plan with radiation in the palliative setting may be more difficult than the curative setting, where there are clear guidelines for many situations. Radiation therapy has been used successfully in the management of a variety of pain syndromes. Radiation also has proven effective in the management of other tumor-related symptoms, including bleeding, neurologic compromise, dysphagia, and airway obstruction. Palliative radiation can be delivered using a variety of techniques: external beam radiation therapy, intraluminal brachytherapy (radioactive seed delivery), and systemic radionucleotides.

Palliative radiation therapy

Radiation is an effective modality to aid in symptom management of patients with metastatic disease. The type and duration of treatment depends on the Karnofsky performance status (KPS) of the patient and type and status of the cancer. Abbreviated treatment regimens may be favored in this patient population. They provide quick palliation without the patient and family spending significant time traveling back and forth to the treatment center. Hypofractionated regimens have been found effective in relieving pain from metastatic bone disease, relieving obstruction from locally advanced lung cancer, bleeding from gynecologic cancers, and hematuria from advanced bladder cancer. More aggressive regimens such as whole-brain radiation therapy (WBRT) and stereotactic radiosurgery may be appropriate for select patients with a good KPS. Radiation has also been found to be effective in palliating recurrent cancer that has already received definitive radiation.

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.

Therapeutic bronchoscopy in lung cancer. Laser therapy, electrocautery, brachytherapy, stents, and photodynamic therapy

Therapeutic bronchoscopic techniques such as LPR, EC, brachytherapy, stents, and PDT are effective tools in the palliation and local control of lung cancer. Palliation of malignant tracheobronchial obstruction by LPR, stents, brachytherapy, PDT, or a combination thereof results in relief of dyspnea, hemoptysis, and postobstructive pneumonia. Importantly, it avoids intubation in patients with respiratory distress and facilitates the weaning of patients from MV. In the exciting field of lung cancer screening and treatment of early lung cancer, PDT, brachytherapy, EC, and LPR may represent treatment alternatives to surgical resection, especially in a select group of patients with high surgical risk or favorable endobronchial lesions. Clinicians await the results of future studies, which will (1) better define the impact of each treatment modality on patient care in terms of cost, survival, and improvement in quality of life, and (2) determine the optimal combination therapy relative to bronchoscopic and conventional treatment for effective palliation and cure of lung cancer.

Intraluminal Brachytherapy for Malignant Endobronchial Tumors: An Update on Low-Dose Rate Versus High-Dose Rate Radiation Therapy

Although the evolution from low-dose rate (LDR) to high-dose rate (HDR) brachytherapy for malignant endobronchial tumors was presumably based on economy, patient convenience, and radiation protection, our experience with both modalities permits assessment of the pros and cons of each technique. In November 1991, our HDR remote afterloading brachytherapy unit became operational. By that time, we had treated 110 patients (group 1) with malignant endobronchial obstruction with LDR brachytherapy. Since then, all patients have been treated with HDR brachytherapy. The outcome of our first 110 patients (group 2) treated with HDR brachytherapy is presented in this communication, using group 1 as the historic control group. In group 1, patients were treated with 1 or 2 sessions of 30-60 Gy, each calculated at a 1-cm radius. In group 2, patients received 3 or 4 weekly treatments of 7 Gy, each calculated at a 1-cm radius. The majority of patients in each group had previously received a full course of external beam irradiation, and a history of laser bronchoscopy was also similar for the 2 groups. Differences in bronchoscopic response rate (82% vs. 96%, respectively) and complications (3.6% vs. 2.7%, respectively) were statistically insignificant between the LDR group and the HDR group. We believe HDR brachytherapy is the state-of-the-art modality in intraluminal therapy for endobronchial malignancies.

The role of brachytherapy for palliation

The goal of palliative radiation is to alleviate symptoms in a short amount of time and maintain an optimal functional and quality-of-life level while minimizing toxicity and patient inconvenience. Despite advances in multimodality antineoplastic therapies, failure to control the tumor at its primary site frustratingly remains the predominant source of morbidity and mortality in many patients with cancer. Escalation of doses of radiation using external beam irradiation has been shown to improve local tumor control, but limits are imposed by the tolerance of normal surrounding structures. The highly conformal nature of brachytherapy enables the radiation oncologist to accomplish safe escalation of radiation doses to the tumor while minimizing doses to normal surrounding structures. Thus, by enhancing the potential for local control, brachytherapy used alone or as a supplement to external beam radiation therapy retains a significant and important role in achieving the goals of palliation. Proper patient selection, excellent technique, and adherence to implant rules will minimize the risk of complications. The advantages realized with the use of brachytherapy include good patient tolerance, short treatment time, and high rates of sustained palliation. This article reviews various aspects of palliative brachytherapy, including patient selection criteria, implant techniques, treatment planning, dose and fractionation schedules, results, and complications of treatment. Tumors of the head and neck, trachea and bronchi, esophagus, biliary tract, and brain, all in which local failure represents the predominant cause of morbidity and mortality, are highlighted.

Massive haemoptysis after radiotherapy in inoperable non-small cell lung carcinoma: is endobronchial brachytherapy really a risk factor?

BACKGROUND AND PURPOSE

This retrospective study was conducted to investigate whether endobronchial brachytherapy (EBB) is a risk factor for massive haemoptysis in patients primarily treated by a combination of EBB and external irradiation (XRT) for NSCLC.

MATERIALS AND METHODS

The records of 938 patients with inoperable NSCLC who were treated with XRT and/or EBB were reviewed. The patients were divided into five groups as follows: group XRT, treated by XRT alone (n = 421); group XRTelig, treated by XRT but eligible for EBB (n = 419); group XRTEBB, primarily treated with EBB+XRT (n = 62); group EBBrec, treated by EBB for recurrence after XRT (n = 23); and group EBB, treated by EBB alone (n = 13). EBB was delivered using HDR. Patients with bronchoscopy-proven endobronchial tumour in the proximal airways, i.e. the trachea, the main bronchus or lobar bronchus were considered eligible for EBB.

RESULTS

One hundred one out of 938 patients (10.8%) died from massive haemoptysis. The incidence was 4.3% in group XRT, 13.1% in group XRTelig and 25.4% in group XRTEBB. The differences between groups XRT and XRTelig as well as between groups XRTelig and XRTEBB were statistically significant (P<0.01). The incidence of massive haemoptysis depended significantly on the fraction size of brachytherapy. When two fractions of 7.5 Gy or a single fraction of 10 Gy were used, 11.1% of the patients died from massive haemoptysis. However, when a single dose of 15 Gy was used, 47.8% died from massive haemoptysis. In the multivariate analysis, a single dose of 15 Gy EBB was the most important prognostic factor for massive haemoptysis.

CONCLUSION

XRT+EBB as primary treatment for NSCLC does not lead to a higher risk of massive haemoptysis as compared to XRT alone when fraction sizes for EBB of 7.5 or 10 Gy are used. However, the risk of massive haemoptysis increases dramatically when a fraction size of 15 Gy is used.

Brachytherapy in lung cancer

Brachytherapy, the direct application of a radioactive isotope into the tumor bed, delivers a high dose to the tumor as compared to the surrounding normal tissue. Interstitial brachytherapy, the placement of the isotope into a tumor bed where no lumen exists, has been described but is utilized infrequently in clinical practice. Endobronchial brachytherapy, the placement of the source within the airway lumen, as a boost to conventional external beam radiation has not yet demonstrated improved local tumor control or overall survival as compared to external beam alone in the definitive treatment of inoperable lung cancer. In the palliative setting, brachytherapy can provide prompt relief of obstructive symptoms and hemoptysis in the majority of patients.