Brachytherapy in lung cancer

High-dose-rate brachytherapy for airway malignancy a single institution experience

PURPOSE

To evaluate clinical outcomes of endobronchial malignancy treated using high-dose-rate endobronchial brachytherapy (HDREB).

METHODS AND MATERIALS

A retrospective chart review was conducted for all patients treated with HDREB for malignant airway disease between 2010 and 2019 at a single institution. Most patients had a prescription of 14 Gy in two fractions given a week apart. The Wilcoxon signed rank test and paired samples t test were used to compare changes in mMRC dyspnea scale prior to and after brachytherapy at first followup appointment. Toxicity data were collected for dyspnea, hemoptysis, dysphagia, and cough.

RESULTS

A total of 58 patients were identified. Most (84.5%) had primary lung cancer with advanced cancers, stage III or IV (86%). Eight were treated while admitted in the ICU. Previous external beam radiotherapy (EBRT) was received by 52%. An improvement in dyspnea was seen in 72%, with an mMRC dyspnoea scale score improvement of 1.13 points (p < 0.001). Most (22, 88%) had an improvement in hemoptysis and 18 out of 37 (48.6%) had an improvement in cough. Grade four to five events occurred in 8 (13%) at the median time of 2.5 months from brachytherapy. Twenty-two patients (38%) had complete obstruction of the airway treated. Median progression free survival was 6.5 months and median survival was 10 months.

CONCLUSIONS

We report a significant symptomatic benefit among patients receiving brachytherapy with endobronchial malignancy, with rates of treatment related toxicities similar to prior studies. Our study identified new subgroups of patients, ICU patients & those with complete obstruction, who benefited from HDREB.

Dosimetry investigation of a prototype of 169Yb seed brachytherapy for use in circular stapler

This study aims to investigate dosimetry parameters for the new design of ¹⁶⁹Yb seed in the form of a surgical staple for circular staplers commonly used in the abdominal incision and the esophageal and gastric surgery, which facilitates the precise placement. This seed includes a titanium tube with the inner diameter and outer diameter 0.68 mm and 2.2 mm, respectively, and length of 0.8 mm. Both sides of the tube are closed by titanium wires with the thickness of 0.65 mm by the laser. Natural ytterbium oxide is used after the thermal neutron activation; it is necessary for cooling time of 40 days. The dosimetry parameters were calculated based on the TG-43U1 using Monte Carlo MCNP5 code. The experimental dosimetry was performed by EBT3 radiochromic film to determine 2D dosimetry at near distance of the source and validate the MC code. The dose rate constant of MC calculation was obtained at 1.39cGyh^-1U^-1 ± 4% with the difference of 5% compared to another study. The dose distribution was symmetrical along the Z-axis and Y-axis (around the seed) and there was a uniform activity inside the tube. The distinction of dose rate was not noticeable at the 90 and 270 degrees on the Z-axis, which indicated a slight effect on staple legs in the matter of delivery dose. However, to understand dose distribution and introduce this source in a pre-clinical study, 3D dosimetry as well as further studying the heterogeneous function is required.

Brachytherapy in the treatment of lung cancer - a valuable solution

The majority of patients with lung cancer are diagnosed with clinically advanced disease. Many of these patients have a short life expectancy and are treated with palliative aim. Because of uncontrolled local or recurrent disease, patients may have significant symptoms such as: cough, dyspnea, hemoptysis, obstructive pneumonia, or atelectasis. Brachytherapy is one of the most efficient methods in overcoming difficulties in breathing that is caused by endobronchial obstruction in palliative treatment of bronchus cancer. Efforts to relieve this obstructive process are worthwhile, because patients may experience improved quality of their life (QoL). Brachytherapy plays a limited but specific role in definitive treatment with curative intent in selected cases of early endobronchial disease as well as in the postoperative treatment of small residual peribronchial disease. Depending on the location of the lesion, in some cases brachytherapy is a treatment of choice. This option is fast, inexpensive, and easy to perform on an outpatient basis. Clinical indications, different techniques, results, and complications are presented in this work.

Definitive high-dose-rate endobronchial brachytherapy of bronchial stump for lung cancer after surgery

PURPOSE

The aim of this work was to evaluate outcomes after definitive high-dose-rate endobronchial brachytherapy (HDR-BT) for lung cancer.

METHODS AND MATERIAL

We treated 34 patients after surgery for lung cancer, without nodal or distant metastases, with HDR-BT. Two groups were analyzed, one with local recurrence in stump after prior surgery (n = 13) and a second with nonradical primary lobar resection found in histopathologically positive margins (n = 21). There were 27 men and 7 women with a median age of 57.4 years. Twenty-five patients received sole brachytherapy with 4 fractions of 7.5 Gy and 9 received combined treatment consisting of 2 fractions of 6 Gy (HDR-BT) and 50 Gy from external beam radiotherapy. Overall survival time (OS) and overall disease-free survival time (OFS) were compared with prognostic factors.

RESULTS

The complete local and radiologic response rate evaluated at the first month after HDR-BT was 73.5% (25/34). The partial response rate was 26.5%. OFS time in total group was 17.4 months; OS was 18.8 months. Differences were found in OS between both groups-primary tumor or recurrence (log-rank test, p = 0.048). Differences were not found according to gender (p = 0.36), clinical stage (p = 0.76), histopathology (p = 0.93), treatment dose (p = 0.45), sole or combined treatment (p = 0.16), or grade of remission in week 4 (p = 0.15).

CONCLUSIONS

HDR-BT of a stump recurrence or after nonradical resection leads to a long-term OS rate in patients with localized lung cancer and could be considered curative. We found no correlations between OS and chosen clinical data; adjuvant HDR-BT gave better results.

Second line palliative endobronchial radiotherapy with HDR Ir 192 in recurrent lung carcinoma

PURPOSE

To observe the efficiency of reirradiation with high dose rate intraluminal brachytherapy in symptomatic palliation of recurrent endobronchial tumors.

MATERIALS AND METHODS

Between January 1994 and June 1998, 21 patients diagnosed with recurrent endobronchial tumors following external beam radiotherapy were treated palliatively with high dose rate intraluminal irradiation at Hacettepe University Oncology Institute. A single fraction of 10 Gy was prescribed to the specified area in 9 patients and 15 Gy to 12.

RESULTS

Endobronchial treatment improved the performance and reduced symptomatology in 17 (81%) patients. Ten dyspneic patients (10/14, 71%) recovered clinically with an accompanying radiological downstaging. The median symptomatic palliation was 45 days (range, 0-9 months), and the overall median survival was 5.5 months (range, 4-12 months). The palliative intrabronchial brachytherapy was well tolerated, with the exception of in one patient with a fatal hemorrhage, and another with medically salvaged bronchospasm and intrabronchial edema.

CONCLUSION

Recurrent patients with a history of previous thoracic external beam irradiation can be effectively palliated with high dose rate endobronchial reirradiation if the symptoms are directly related to the endobronchial tumor.

Crosslinked chitosan implants as potential degradable devices for brachytherapy: in vitro and in vivo analysis

Compared with conventional external beam radiation, brachytherapy offers a superior therapeutic regimen. However, some major constraints are associated with its implementation, including the need of complicated procedures for device placement and removal. The purpose of this study was to examine whether crosslinked chitosan (Ct) implants could serve as potential biodegradable devices for brachytherapy. Ct was reacted with increasing amounts of glutaraldehyde to obtain hydrogels with different crosslinking densities, which were characterized chemically, thermally and mechanically. The effect of the dialysis medium conditions (ionic strength, osmolarity and pH) on the gel hydration and in vivo degradation was assessed. Two types of implants, slow and fast degrading gel (SDG and FDG, respectively), were prepared and implanted with or without Sudan Black (SB) in the rat. While SDG withstood for over a month, the FDG degraded within two weeks after implantation. The release kinetics of SB from the hydrogels verified their in vivo degradation properties. The incorporation of the radioactive compound (131)I-norcholesterol ((131)I-NC) into the SDG altered the degradation kinetics of the gel as reflected by the release kinetics of the radioactive marker. Eighty percent of (131)I-NC was released within a month after implantation, after which time, radioactivity was detected in the regional lymph nodes. Histological examination of the tissues surrounding the implants demonstrated negligible tissue response to the implants, when compared to biodegradable surgical sutures. It is concluded that hydrogels made of crosslinked Ct are potential novel, safe, degradable devices for brachytherapy.

High dose rate brachytherapy: its clinical applications and treatment guidelines

Brachytherapy has the advantage of delivering a high dose to the tumor while sparing the surrounding normal tissues. With proper case selection and delivery technique, high-dose-rate (HDR) brachytherapy has great promise, because it eliminates radiation exposure, allows short treatment times, and can be performed on an outpatient basis. Additionally, use of a single-stepping source, allows optimization of dose distribution by varying the dwell time at each dwell position. However, when HDR brachytherapy is used, the treatments must be executed carefully, because the short treatment times do not allow any time for correction of errors, and mistakes can result in harm to patients. Hence, it is very important that all personnel involved in HDR brachytherapy be well trained and be constantly alert. It is expected that the use of HDR brachytherapy will greatly expand over the next decade and that refinements will occur primarily in the integration of imaging (computed tomography, magnetic resonance imaging, intraoperative ultrasonography) and optimization of dose distribution. It is anticipated that better tumor localization and normal tissue definition will help to optimize dose distribution to the tumor and reduce normal tissue exposure. The development of well-controlled randomized trials addressing issues of efficacy, toxicity, quality of life, and costs-versus-benefits will ultimately define the role of HDR brachytherapy in the therapeutic armamentarium.

High-Dose-Rate Brachytherapy in Combination with Stenting Offers a Rapid and Statistically Significant Improvement in Quality of Life for Patients with Endobronchial Recurrence

Symptomatic endobronchial recurrence after treatment failure is common in advanced non-small cell lung cancer. Optimal palliation has yet to be defined. We examined the combination of near-simultaneous, high-dose-rate (HDR) brachytherapy with stenting in this cohort of patients. Informed consent for intervention was obtained for 10 patients experiencing severely symptomatic (hemoptysis and oxygen-dependent shortness of breath), biopsy-proven endobronchial recurrence. All patients (eight men, two women, aged 52-77 years) had failed to respond to chemoradiotherapy for stage IIIB non-small cell lung cancer. Intervention consisted of placement of a self-expanding metallic stent (Nitinol/Ultraflex stent, Boston Scientific Co., Natick, MA) into the obstructing region. During that same bronchoscopy, HDR catheters were introduced. A dose of 6 Gy at 0.5 cm from the catheter was then delivered via an HDR unit. Two additional HDR sessions followed at weekly intervals for a total dose of 18 Gy. Patients under went follow-up bronchoscopes 1 month after the last HDR and when clinically indicated. All patients completed the prescribed therapy. No morbidity was noted from bronchoscopy, HDR, or stenting. All patients had rapid relief of signs and symptoms. At 1 week after stenting/first HDR, a statistically significant improvement in Karnofsky status was noted. Pulmonary palliation was maintained for the duration of their survival. The radio-opaque stent also offered significant advantages for catheter placement and verification during the HDR procedure. Although this series is small, the beneficial outcome obtained deserves further evaluation.

Placement of 125I implants with the da Vinci robotic system after video-assisted thoracoscopic wedge resection: A feasibility study

PURPOSE

To evaluate the feasibility of using the da Vinci robotic system for radioactive seed placement in the wedge resection margin of pigs' lungs.

METHODS AND MATERIALS

Video-assisted thoracoscopic wedge resection was performed in the upper and lower lobes in pigs. Dummy (125)I seeds embedded in absorbable sutures were sewn into the resection margin with the aid of the da Vinci robotic system without complications. In the "loop technique," the seeds were placed in a cylindrical pattern; in the "longitudinal," they were above and lateral to the resection margin. Orthogonal radiographs were taken in the operating room. For dose calculation, Variseed 66.7 (Build 11312) software was used.

RESULTS

With looping seed placement, in the coronal view, the dose at 1 cm from the source was 97.0 Gy; in the lateral view it was 107.3 Gy. For longitudinal seed placement, the numbers were 89.5 Gy and 70.0 Gy, respectively.

CONCLUSION

Robotic technology allows direct placement of radioactive seeds into the resection margin by endoscopic surgery. It overcomes the technical difficulties of manipulating in the narrow chest cavity. With the advent of robotic technology, new options in the treatment of lung cancer, as well as other malignant tumors, will become available.

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.

Acute respiratory failure in critically ill patients with cancer. Diagnosis and management

Respiratory failure remains a common cause of admission to the ICU for patients with cancer, regardless of the nature of malignancy. The diagnosis and management of ARF in patients with cancer poses special challenges to the intensivist. Depending on the type of cancer, the degree of immunosuppression, underlying comorbidities, the modality of cancer treatment, progression or spread of underlying cancer, and disease- or therapy-associated complications are the most common causes of ARF in these patients. Despite significant advances in antineoplastic therapies and supportive management in the ICU, the mortality rate of patients with cancer with ARF remains high. Severity-of-illness scoring systems and mortality probability models, although useful in discriminating between survivors and nonsurvivors in large groups of critically ill patients, should not be used alone to justify reluctance in admitting individual patients with cancer with potentially reversible respiratory failure to the ICU. Close collaboration between oncologists and intensivists will ensure the establishment of clear goals and direction of treatment for every patient with cancer who requires mechanical ventilation.

Best supportive care in non-small cell lung cancer: is there a role for radiotherapy and chemotherapy?

Best Supportive Care (BSC) is the treatment of choice when cure is not achievable with anticancer treatments and involves management of disease-related symptoms. In the palliative treatment of non-small cell lung cancer (NSCLC) radiation therapy has for a long time been the cornerstone of symptom management, although the best schedule is still to be defined. Chemotherapy, on the other hand, has been excluded from classical definitions of BSC and has been reserved only for selected patient populations in which a survival benefit was demonstrated using cisplatin-based regimens. We reviewed randomized trials on both palliative radiotherapy and chemotherapy in order to assess the impact of anticancer treatments on quality of life in advanced NSCLC patients. While no randomized trials compared radiation therapy with a control arm not including it, several randomized trials assessed the use of different schedules. Hypofractionated schedules seem to have comparable palliative activity when compared with the standard fractionated regimens, at least in metastatic, poor-prognosis patients. In locally advanced, inoperable NSCLC higher radiation doses administered with conventional fractionation achieve better results in terms of local control and survival. The rate of palliation of local symptoms is high, being 60-80% for chest pain and hemoptysis, while breathlessness and cough are controlled at a somewhat lower rate (50-70%). General symptoms (fatigue, anorexia, and depression) are affected in a minority of patients. Chemotherapy was compared with BSC in several randomized trials, in some of which an analysis of the quality of life was included. Results are consistent in favor of its palliative role and, when local symptom control is assessed, rates of palliation seem similar to those achieved by radiation. Benefits apply to metastatic NSCLC patients with good performance status, low body weight loss, age below 70-75. However, some studies support the use of chemotherapy also in patients with poor prognostic features. A comparison in terms of quality of life and symptom palliation between different chemotherapy regimens is the object of few trials. Both chemotherapy and radiation have an important role in the palliative treatment of advanced NSCLC patients and should be included in BSC programs. Future randomized trials should assess the best way of combining these two approaches.

High-dose-rate endobronchial brachytherapy effectively palliates symptoms due to airway tumors: the 10-year M. D. Anderson cancer center experience

PURPOSE

To evaluate the toxicity and efficacy of Iridium-192 high-dose-rate (HDR) endobronchial brachytherapy (EBBT) for the palliation of symptoms caused by relapsed or persistent endobronchial tumors.

METHODS AND MATERIALS

We reviewed the treatment outcomes between 1988 and 1997 in 175 lung cancer patients who underwent HDR EBBT for recurrent or metastatic tumors at The University of Texas M. D. Anderson Cancer Center. One hundred sixty of these patients had previously received thoracic external-beam irradiation. This updated report includes 74 patients from a previous series. Most patients received 3,000-cGy EBBT delivered at a distance of 6 mm and divided into 2 fractions over 2 weeks. Subjective response was assessed by questionnaire at follow-up. Objective response was assessed by physical examination, bronchoscopy, and chest radiograph.

RESULTS

The median actuarial survival for the entire group was 6 months from the time of the first EBBT treatment session. Of the 115 patients (66%) who showed symptomatic improvement, 32% were much improved and 34% were slightly improved. Patients showing improvement survived for significantly longer than those who showed no change or worsening symptoms (7 vs. 4 months, p = 0.0032). Repeat bronchoscopy demonstrated a 78% overall objective response rate that correlated significantly with subjective response and symptom relief. Complications occurred in 19 patients (11% crude rate) with an actuarial complication rate of 13% at 1 year from the time of the first EBBT treatment session. The actuarial hazard for fatal hemoptysis due to EBBT was 5%.

CONCLUSION

HDR EBBT effectively palliates most patients' symptoms caused by endobronchial lesions. This relief correlates significantly with an overall survival benefit. Treatment complications appear to be few, even for patients who have received prior external-beam irradiation.

High-dose rate brachytherapy of bronchial cancer: treatment optimization using three schemes of therapy

PURPOSE

Our aim is to demonstrate that a fractionated high-dose rate endobronchial brachytherapy (HDRBT) treatment is tolerable for patients with advanced (IIIA-IIIB) non-small cell lung cancer and gives an improvement of symptoms. Patients and Methods. From January 1992 to July 1997, we treated 320 patients with external beam radiotherapy (EBRT) and concomitant HDRBT with Ir192. Eighty-four patients received 10 Gy in one fraction from January 1992 to March 1993 (Group A); 47 patients received two fractions of 7 Gy each from April 1993 to December 1993 (Group B), and 189 patients received three fractions of 5 Gy each from January 1994 to July 1997 (Group C).

RESULTS

Mean survival from diagnosis is 11.1 months and mean survival from last HDRBT is 9.7 months. The symptomatic response rate is 90% for dyspnea, 82% for cough, 94% for hemoptysis and 90% for obstructive pneumonia. Performance status was improved in 70% of patients. Follow-up is in the range of 5-36 months with 280/320 evaluable patients (87.5%) (40 patients were lost to follow-up). For the patients treated with three fractions of HDRBT plus EBRT, a smaller number of side effects occurred while relief from symptoms linked to bronchial obstruction and survival was similar for the three groups.

CONCLUSIONS

A three-fraction brachytherapy results in fewer side effects, such as bronchial fibrosis with or without stenosis, while survival and symptomatic relief are similar in the three groups treated.

Treatment of roentgenographically occult endobronchial carcinoma with external beam radiotherapy and intraluminal low-dose-rate brachytherapy: second report

PURPOSE

To evaluate the efficacy and toxicity of treatment with external beam radiotherapy and intraluminal low-dose-rate brachytherapy for roentgenographically occult endobronchial carcinoma (ROEC).

METHOD AND MATERIALS

A total of 79 lesions (71 cases) of ROEC were treated with external beam radiotherapy and intraluminal low-dose-rate brachytherapy from July 1991 to December 1998. Of these lesions, 68 (64 cases) were treated with our standard dose (external beam radiotherapy of 40 Gy and intraluminal low-dose-rate brachytherapy of 25 Gy) and are the subject of this report. All 64 patients were males, and their ages ranged from 55 to 80 (median, 68) years. The histologic diagnosis was squamous cell carcinoma in all patients.

RESULTS

In all cases, the scheduled treatment was carried out within 2 months. Follow-up period ranged from 4 to 91 (median, 44) months from the beginning of this treatment. Acute toxicity was tolerable. Grade 2 radiation pneumonitis was observed in 4 cases, and there was no case of greater than Grade 2 radiation fibrosis. Nineteen cases of bronchial stenosis and 23 cases of bronchial obstruction were observed on follow-up bronchoscopy. However, no Grade 2 or greater deterioration of respiratory function due to radiotherapy, prolonged symptoms, or fatal toxicity was observed. Nine patients suffered recurrence, 5 of whom were rescued by surgery and external beam radiotherapy, and 4 of whom died of disease. The 5-year cause-specific survival, overall-survival, and disease-free rate were 96.1%, 72.3%, and 87.3%, respectively.

CONCLUSION

Combined treatment with external beam radiotherapy and intraluminal low-dose-rate brachytherapy is effective and results in acceptable complications for ROEC.

The short and long term effects of intraoperative electron beam radiotherapy (IORT) on thoracic organs after pneumonectomy an experimental study in the canine model

PURPOSE

The tolerance of mediastinal structures and thoracic organs to intraoperative radiotherapy (IORT) was investigated in the canine model.

METHODS AND MATERIALS

Twenty-two adult beagles divided into three groups were subjected to a left pneumonectomy and IORT (10 MeV electrons) at doses of 20 Gy (n = 9), 25 Gy (n = 4), or 30 Gy (n = 9). Intraoperative electron beam radiotherapy was delivered through a 5 cm circular lucite cone encompassing a mediastinal field including the bronchial stump, aorta, esophagus, heart, phrenic nerve, contralateral hilar structures, and lung. Clinical monitoring was performed with regular chest X-ray, ECG, bronchoscopy, esofagoscopy, and fluoroscopy. From the different treatment dose groups, dogs were electively sacrificed at 1.5, 6, 12, and 72 months with complete autopsies.

RESULTS

There was no bronchial stump dehiscence or acute morbidity. Four dogs developed radiation induced esophagitis (18%), one in the 20 Gy IORT group (11%) and three in the 30 Gy IORT group (33%). There were six IORT related mortalities (27.5%), one esophagoaortic fistula (4.5%) and five bronchovascular fistulas (23%): two in the 20 Gy IORT group (22%), two in the 25 Gy IORT group (50%) and two in the 30 Gy IORT group (22%). Histopathological findings in uncomplicated follow-up showed marked myointimal fibrosis in the muscular arteries, submucosal fibrosis of the esophagus, and interstitial fibrosis of bronchial and lung tissue, especially in the higher dose group.

CONCLUSION

The mediastinal vascular, bronchial and esophageal structures are relatively sensitive to doses > 20Gy IORT. The IORT related morbidity found in this study may be lower when the current clinically used IORT doses of 10-15 Gy are applied. Further clinical application of IORT in the future treatment strategies for resectable nonsmall cell lung cancer may be worthwhile to investigate.

Percutaneous brachytherapy for small-sized non-small cell lung cancer

A patient with a small-sized pulmonary adenocarcinoma was successfully treated by percutaneous high dose rate interstitial brachytherapy alone. The patient, who had an adenocarcinoma with 12-mm diameter in the lingular lobe of left lung, was judged to be inoperable because of poor pulmonary function due to emphysema and extensive pleural adhesion. The tumor was punctured with a 21-gauge fine applicator needle followed by the introduction of an iridium 192 (192Ir) radioactive source through the applicator needle using a remote afterloader. The tumor was irradiated for 225.1 s in one fraction. The tumor was in the inside of the iso-dose line of 40 Gy. The delivered doses calculated at nine reference points, which were 12.5 mm distant from the center of the tumor, distributed between 19.225 and 32.169 Gy, with a mean of 24.8 Gy. No apparent side effect including pneumothorax and hemoptysis was observed. The tumor shrank and showed no increment of the size for about 2 years.