Treatment of roentogenographically occult endobronchial carcinoma with external beam radiotherapy and intraluminal low dose rate brachytherapy

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.

Radiologically Occult Lung Cancer Curatively Treated with High-Dose Rate Endobronchial Brachytherapy

Most patients diagnosed with early-stage non-small cell lung cancer (NSCLC) can be easily cured with surgery or stereotactic body radiotherapy (SBRT). Modalities such as photodynamic therapy, cryotherapy, or laser therapy only offer temporary palliation. A 79-year-old gentleman with early-stage NSCLC who underwent a left lower lobe lobectomy in 2009 presented to us again in 2010 with hemoptysis. A friable ~5 cm tumor along the bifurcation of anterior and the posterior segment of the right upper lobe was noted on bronchoscopic examination, and biopsy confirmed this to be squamous cell carcinoma. Because of his previous surgery, the patient was not a candidate for another surgery. SBRT was not possible as the lesion could not be seen on radiologic imaging. The patient was, therefore, treated with curative intent high-dose rate endobronchial brachytherapy (HDR-EBBT) in 4 weekly sessions of 7 Gy per fraction delivered at a depth of 8 mm, covering ~5 cm tumor plus 1 cm margin proximally and distally. He tolerated the treatment well without any acute or late side effects and was followed every 3 months thereafter with bronchoscopy examinations for 6 months and subsequently with computerized tomography (CT) imaging. In July 2018, the patient started having episodes of hemoptysis and evaluation leads to diagnosis of a third primary lung cancer, which was successfully treated with SBRT with image-guided radiotherapy using a five-fraction regimen. The patient’s most recent CT from July 2019 showed no evidence of disease. We conclude that in patients with early-stage NSCLC, when surgery or SBRT is not feasible due to radiologic occult nature, HDR-EBBT can yield excellent long-term outcome.

Bronchial sleeve resection for early-stage squamous cell carcinoma

A 75-year-old man complained of sputum and was referred to our department. His sputum cytology was class III. Chest X-ray and computed tomography showed no abnormalities, but bronchoscopy revealed an elevated lesion in the membranous portion of the left main bronchus, which was pathologically diagnosed as squamous cell carcinoma in situ. Since bronchoscopy revealed no other lesions in the visible parts of the airway, it was considered to be a solitary, early lung cancer, and sleeve resection of the left main bronchus was performed. The postoperative pathological diagnosis was squamous cell carcinoma in situ, pTisN0M0, stage 0. In recent years, an increasing number of studies have reported photodynamic therapy and brachytherapy for the treatment of early lung cancer. However, aggressive bronchoplastic surgery with emphasis on curability should be considered for lesions that are deemed resectable based on their number and extent of invasion.

Long-term observation of 64 patients with roentgenographically occult lung cancer treated with external irradiation and intraluminal irradiation using low-dose-rate iridium

OBJECTIVE

Therapeutic results of intraluminal irradiation were analyzed in 64 patients with roentgenographically occult lung cancer (ROLC).

METHODS

The subjects were 64 patients who underwent intraluminal irradiation between 1987 and 2003. Radiotherapy was performed by combining external irradiation with intraluminal irradiation using low-dose-rate iridium (four 370-MBq wires) through a catheter with a spacer. The doses of radiation were 0-70 Gy (median value 46 Gy) by external irradiation and 10-60 Gy (median value 29.3 Gy) by intraluminal irradiation.

RESULTS

The therapeutic effect was CR in 63 patients and PR in 1 patient, and local recurrence was observed in a PR case and in seven of the 63 patients who showed CR. The 5-year overall and relapse-free survival rates were 56 (95% CI, 43-69%) and 55% (95% CI, 43-68%), respectively. Fatal pulmonary hemorrhage was observed in one case.

CONCLUSIONS

Considering the facts that ROLC often occurs as multiple cancers and that many patients with ROLC have reduced lung function, radiation therapy by a combination of intraluminal and external irradiation may replace surgery as the first choice for the treatment of this disease.

Toward endobronchial Ir-192 high-dose-rate brachytherapy therapeutic optimization

A number of patients with lung cancer receive either palliative or curative high-dose-rate (HDR) endobronchial brachytherapy. Up to a third of patients treated with endobronchial HDR die from hemoptysis. Rather than accept hemoptysis as an expected potential consequence of HDR, we have calculated the radial dose distribution for an Ir-192 HDR source, rigorously examined the dose and prescription points recommended by the American Brachytherapy Society (ABS), and performed a radiobiological-based analysis. The radial dose rate of a commercially available Ir-192 source was calculated with a Monte Carlo simulation. Based on the linear quadratic model, the estimated palliative, curative and blood vessel rupture radii from the center of an Ir-192 source were obtained for the ABS recommendations and a series of customized HDR prescriptions. The estimated radius at risk for blood vessel perforation for the ABS recommendations ranges from 7 to 9 mm. An optimized prescription may in some situations reduce this radius to 4 mm. The estimated blood perforation radius is generally smaller than the palliative radius. Optimized and individualized endobronchial HDR prescriptions are currently feasible based on our current understanding of tumor and normal tissue radiobiology. Individualized prescriptions could minimize complications such as fatal hemoptysis without sacrificing efficacy. Fiducial stents, HDR catheter centering or spacers and the use of CT imaging to better assess the relationship between the catheter and blood vessels promise to be useful strategies for increasing the therapeutic index of this treatment modality. Prospective trials employing treatment optimization algorithms are needed.

Endobronchial brachytherapy and optimization of local disease control in medically inoperable non-small cell lung carcinoma: a matched-pair analysis

PURPOSE

External beam radiation therapy (EBRT) alone for early stage, medically inoperable non-small cell lung cancer (MILC) can produce local disease control and sometimes cure. We have previously reported that higher EBRT doses result in improved disease control and, for patients with tumors > or =3.0 cm, improved survival. This report describes the impact of dose escalation with endobronchial brachytherapy boost during or following EBRT upon local disease control.

METHODS AND MATERIALS

Medical records of 404 patients with MILC treated with radiotherapy alone were reviewed. Thirty-nine patients received a planned endobronchial brachytherapy boost during or following a course of EBRT. A matched-pair analysis of disease control and survival was performed by matching each brachytherapy patient to 2 EBRT patients from a reference group of the remaining patients.

RESULTS

Endobronchial brachytherapy boost significantly improved local disease control over EBRT alone (58% vs. 32% at 5 years). The local control benefit for brachytherapy was found to be limited to patients with T(1-2) disease or tumors < or =5.0 cm. Among these patients treated with endobronchial boost, EBRT doses of > or =6500 cGy were necessary to optimize local disease control. No overall survival differences were observed at 3 years. Excess toxicity with brachytherapy was not observed.

CONCLUSION

Endobronchial brachytherapy boost enhances local disease control rates in MILC treated with EBRT. Local control outcome is optimized when radical EBRT doses are used in conjunction with brachytherapy.

Endobronchial phototoxicity of WST 09 (Tookad), a new fast-acting photosensitizer for photodynamic therapy: preclinical study in the pig

Photodynamic therapy (PDT) has been used for many years for both palliative and curative treatment of bronchial carcinomas. However, prolonged skin phototoxicity and reduced depth of penetration has limited the widespread use of PDT. We studied the endobronchial phototoxicity of a novel photosensitizer, WST 09 (Tookad). Fourteen pairs of Large White-Landrace male piglets were given intravenous WST 09 followed by laser light illumination of the left mainstem bronchus. Different settings for light dose (fluence), fluence rate (FR), drug dose (D) and drug-light interval (DLI) were applied to each pair. Bronchial toxicity was assessed with repeat bronchoscopic photographic evaluation as well as by pathologic examination following autopsy. Animals developed no toxicity, moderate toxicity or severe toxicity. Increased toxicity was seen with increasing D and fluence and decreasing DLI, whereas no increased toxicity was seen with higher FR. PDT-related histological changes in the normal bronchus confirm the vascular effect of WST 09. Depending on the parameter settings for fluence, D and DLI, the lesions ranged from focal intramucosal ischemia to transmural infarction with subsequent acute inflammation and fibrosis. Clinically feasible parameters for drug and light dosimetry were documented. These data will be important in determining safe starting doses for human phase I/II studies.

Diagnostic results before and after introduction of autofluorescence bronchoscopy in patients suspected of having lung cancer detected by sputum cytology in lung cancer mass screening

For the purpose of early detection, we have conducted population-based mass screening for lung cancer by sputum cytology since 1982. Although detection of lung cancer in its early stage is important for a good prognosis, it is often difficult to localize lesions in roentgenographically occult cancer. To clarify the role of autofluorescence bronchoscopy in localizing tumors in patients with roentgenographically occult cancer, we analyzed our diagnostic results. Fifty patients who had been detected by sputum cytology were screened by the light-induced fluorescence endoscope (LIFE)-Lung System from November 1997 to April 1999. We compared the results according to the screening methods: conventional bronchoscopy alone versus LIFE with conventional white-light bronchoscopy (November 1997 to April 1999). Twenty-eight cancerous lesions and 39 borderline lesions were detected by LIFE. Of the 39 borderline lesions, nine were detected only by LIFE. Multicentric lesions including cancer or dysplasia were also detected in 21 of the 50 patients by LIFE. The sensitivity by white-light bronchoscopy alone was 85.3%, whereas that of the LIFE-Lung System with white-light bronchoscopy was 94.1% (P=0.078). There were no cancerous lesions in the area observed as normal by LIFE. We also compared the diagnostic results of two localization methods: brushing of all bronchi (September 1986 to December 1990) and the LIFE-Lung System (November 1997 to April 1999). Although this was a historical comparison, the number of detected borderline lesions increased, which led to a high detection rate in patients with suspected-positive sputum (P=0.0006) by the LIFE-Lung System. In conclusion, the LIFE-Lung System is a safe and non-invasive system for detecting small intraepithelial lesions of the tracheobronchial tree. Autofluorescence bronchoscopy is more efficacious for localizing intraepithelial lesions and places fewer burdens on the patient than brushing of all bronchi.

Segmentectomy for roentgenographically occult bronchogenic squamous cell carcinoma

BACKGROUND

Roentgenographically occult bronchogenic squamous cell carcinomas (ROSCCs) are early squamous cell lung cancers of central type. Some of them cannot be treated with intrabronchial therapy. Although surgical treatment was performed for such tumors, it was unknown whether lobectomy was indispensable or not.

METHODS

The clinicopathologic information of the 58 patients who underwent segmentectomy for ROSCCs were collected from 16 hospitals and reviewed retrospectively, compared with 98 patients who underwent lobectomy for ROSCCs.

RESULTS

Five-year survival rate of the 58 patients based on lung cancer deaths was 96.8%, and 82.6% including all causes of death. The duration of chest tube drainage in the segmentectomy group was slightly longer than in the lobectomy group. Operative mortality and the frequency of postoperative complications were not statistically different in both groups. Postoperative/preoperative vital capacity and forced expiratory volume in 1 second were higher in the segmentectomy group.

CONCLUSIONS

These results suggest that segmentectomy may be an alternative for surgical therapy of carefully selected ROSCCs. More prospective studies are required to fully demonstrate clinical benefit.

External irradiation and intraluminal irradiation using middle-dose-rate iridium in patients with roentgenographically occult lung cancer

PURPOSE

Therapeutic results were analyzed in 39 patients with roentgenographically occult lung cancer (ROLC), and the significance and optimal dose of this therapy were evaluated.

METHODS AND MATERIALS

The subjects were 39 patients who underwent intraluminal irradiation between May 1987 and August 1999. Radiotherapy was performed by combining external irradiation with intraluminal irradiation using middle-dose-rate iridium (four 370-MBq wires) through a catheter with a spacer, which held the source in the center of the bronchus. The doses of radiation were 22-66 Gy (median value 45 Gy) by external irradiation and 10-46 Gy (median value 28 Gy) by intraluminal irradiation.

RESULTS

The therapeutic effect was CR in 38 patients and PR in 1, and local recurrence was observed in a PR case and 3 of the 38 patients who showed CR. The 3-year and 5-year relapse-free survival rates were both 87%. No severe radiation injury was observed.

CONCLUSIONS

Considering that ROLC often occurs as multiple cancers and that many patients with ROLC have reduced lung function, radiation therapy by a combination of intraluminal irradiation and external irradiation is expected to replace surgery as the first choice for the treatment of this disease in the twenty-first century.

The treatment results of 40 patients with localized endobronchial cancer with external beam irradiation and intraluminal irradiation using low dose rate (192)Ir thin wires with a new catheter

BACKGROUND AND PURPOSE

While bronchial intraluminal irradiation is valued highly as a useful palliative treatment for lung cancer, its role as a curative treatment is unclear. The treatment results of 40 localized enbobronchial tumors (including tracheal cancer) who underwent external beam irradiation (EBR) and intraluminal irradiation (IR) as a curative treatment is reported, and the role of combined EBR and IR as a curative potential treatment is examined.

MATERIALS AND METHODS

Forty patients, including 22 with roentgenographically occult lung cancer (ROLC), 14 (18 lesions) with postoperative recurrent lung cancer (PORLC) and four with tracheal cancer, who underwent EBR and IR from February 1987 to August 1996, were studied. IR was conducted using low dose rate (1.48 GBq) (192)Ir thin wires at a bronchial mucosal dose of 4-6 Gy per fraction, with a total dose of 10-57 Gy (median 28 Gy). All patients were also given combined external Linac X-ray irradiation for a total dose of 30-77 Gy (median 52 Gy).

RESULTS

As for the primary effect, complete response (CR) was obtained in all 22 ROLC cases; CR was obtained in 12 (16 lesions), partial response (PR) in one and minor response (MR) in one of the PORLC cases; and CR was obtained in three and PR in one of the tracheal cancer cases. The 3-year and 5-year local control rate by Kaplan-Meier method was 75 and 65%, respectively. Twenty-two patients survived for 3 years or longer. Complications included one case each of fatal tracheal hemorrhage, bronchial mucosal ulcer and bronchial stenosis.

CONCLUSIONS

Combined EBR and IR is useful as a curative potential treatment, and long-term survival can be expected in ROLC, tracheal cancer and a portion of PORLC cases.

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.

A CT-assisted method of dosimetry in brachytherapy of lung cancer. Rotterdam Oncological Thoracic Study Group

BACKGROUND

The toxicity of endobronchial brachytherapy (EB), in particular fatal haemoptysis and bronchial wall necrosis, has been correlated with the total dose, fraction size, volume encompassed by the 100% isodose, and a proximal tumor location. We describe a CT-based planning method which, by improving target volume definition and volumetric dose information, can improve the therapeutic ratio of EB.

MATERIALS AND METHODS

Sixteen CT-assisted EB procedures were performed in patients who were treated with palliative high-dose rate EB. The CT data were used to analyze applicator position in relation to anatomy. An example of a three-dimensional optimized treatment plan was generated and analyzed using different types of dose-volume histograms.

RESULTS

The procedure was well tolerated by patients and no post-procedure complications were observed. The bronchial applicator was eccentrically positioned at the level of the carina/mainstem bronchus in 12 (of 14) CT scans. A planning CT prior to EB was not found to be useful as the final target volume and/or the final applicator position were not reliably predicted before the therapeutic bronchoscopy. CT-scans performed with the applicator in situ allowed the bronchial segments in the target volume to be identified and enabled dose prescription to the bronchial mucosa.

CONCLUSIONS

CT-assisted EB is feasible and underlines the need for using centered applicators for proximally located tumors. By enabling accurate mucosal dose prescription, CT-assisted EB may reduce the toxicity of fractionated EB in the curative setting. However, faster on-line EB treatment planning is needed for the routine clinical application of this technique.

Mucosal dose prescription in endobronchial brachytherapy: a study based on CT-dosimetry

PURPOSE

To investigate the consequences of using different dose prescription methods for endobronchial brachytherapy (EB), both with and without the use of a centered applicator.

MATERIALS AND METHODS

A CT scan was performed during EB procedures in 13 patients after insertion of the lung applicator. A dosimetric analysis was subsequently performed in five of these patients using a 3D-brachytherapy treatment planning system (PLATO v13.3, Nucletron).

RESULTS

Dose prescription to the mucosa yields uniform dose distributions to the bronchial mucosa when a centrally positioned applicator is used. When non-centrally positioned applicators are used, mucosal dosing results in a significant underdosage to parts of the target volume. Due to the rapid dose fall-off in EB, dose prescription to the mucosa resulted in inadequate coverage of the outer portion of the bronchial wall and adjacent peribronchial space. When compared to mucosal dose prescription, prescription to the outer aspect of the bronchial wall appears to improve target coverage while limiting the hyperdose (i.e., 200%) volume. The diameters of the different bronchial segments, as determined by CT measurements in 13 patients, correlated well with calculated values based upon the tracheal diameter.

CONCLUSIONS

Mucosal dose prescription should only be used in combination with centered EB applicators. Given the rapid dose fall-off in EB mucosal dose prescription should be used with caution in curative treatments where EB, without additional external radiotherapy, is used as the sole treatment modality. In curative EB, both improved target coverage and a limited hyperdose volume can be achieved by dose prescription to the outer aspect of the bronchial wall.

Radiation therapy for roentogenographically occult lung cancer by external beam irradiation and endobronchial high dose rate brachytherapy

PURPOSE

We investigated the clinical usefulness of radiation therapy by external beam irradiation and endobronchial brachytherapy for the treatment of roentogenographically occult lung cancer.

PATIENTS AND METHODS

From 1995 to 1996, five patients were treated with radiation therapy. We analyzed their treatment outcomes. The follow-up period varied from 3.0 to 3.8 years or until death. External beam radiation (40 Gy/20 fractions/4 weeks) was delivered to the tumor site alone, and not prophylactically given to the mediastinum. Endobronchial brachytherapy using high dose rate iridium (Ir)-192 was concurrently administered principally to a total dose of 18 Gy on the bronchial mucosa in three weekly fractions of 6 Gy each.

RESULTS

Complete remission was obtained in all patients. Two patients died of intercurrent diseases at 12 and 21 months without any evidence of recurrence. The disease has been also controlled in the other three cases. With the above doses, three small tumors < 1 cm were controlled without adverse effect. In two tumors, the dose reference points were set 2-7 mm beneath the mucosa, and larger doses were administered by brachytherapy. An applicator acting as a spacer was not used in these cases. The tumors were controlled, although the irradiated bronchi showed severe stenosis in 6 months following the treatment. However, the patients were asymptomatic and did not need further intervention.

CONCLUSION

External beam irradiation combined with endobronchial brachytherapy was useful for the treatment of roentogenographically occult lung cancer as an alternative to surgery. Further investigation is needed to determine the optimal doses of radiation therapy.

Comparison of endoscopic features of early-stage squamous cell lung cancer and histological findings

Seventy cases with early-stage central-type squamous cell carcinoma were treated surgically between 1984 and 1993 in seven participating institutes. We classified endoscopic features of early-stage central-type squamous cell carcinoma into three types (hypertrophic type, nodular type and polypoid type). After surgery we investigated the relationship between endoscopic features and both the area of superficial extent and depth of carcinoma invasion based on histopathological investigations of the surgical specimens. In 66.7% of the hypertrophic type lesions cancer cells did not invade into the cartilaginous layer, and only 4.8% of this type showed tumour invasion beyond the bronchial cartilage. On the other hand, a few nodular and polypoid type cases showed in-situ carcinoma or carcinoma with invasion from the subepithelial layer to the muscle layer, and in approximately 20% the these types we observed carcinoma invasion beyond the cartilaginous layer, which was not suitable for photodynamic therapy. Also, concerning the greatest dimension 24 out of 35 lesions (68.6%) less than 10 mm in the greatest dimension were evaluated as either in-situ carcinoma or micro-invasive tumour within the muscle layer. The endoscopic features can provide a basis for the determination of therapeutic strategy in early-stage central-type lung cancer.

Brachytherapy in the treatment of thoracic tumors. Lung and esophageal

Brachytherapy for carcinoma of the lung is most often performed using HDR remote afterloading equipment which delivers the treatment within the tracheal-bronchial tree in an outpatient setting. It provides excellent palliation, rapidly, and can also be selectively used with for curative intent. Permanent implantation using iodine seeds at the time of surgery improves the local control rate for those patients. Esophageal brachytherapy is performed as an intraluminal technique, most often using HDR equipment in an outpatient setting, and is used for palliation as a single modality and as a boost following chemo/radiation for curative patients. In this latter situation, the more aggressive therapy provides significantly better palliation than is possible with single-modality therapy.

Cryotherapy, electrocautery, and brachytherapy

Since it was first used 70 years ago, brachytherapy has become an effective tool in the treatment with tracheal bronchial malignancy including primary and recurrent bronchogenic carcinoma and metastatic carcinoma. The technique has evolved from interstitial implantation of radioactive sources directly to the tumor using rigid bronchoscopy to intraluminal placement of a radioactive source into a polyethylene afterloading catheter placed using FB. Intraluminal brachytherapy is effective in palliating complications caused by malignant endobronchial tumors such as dyspnea, hemoptysis, intractable cough, atelectasis, and postobstructive pneumonia. Brachytherapy may be combined with external beam radiation, Nd:YAG laser therapy, and chemotherapy to enhance the palliative treatments of patients. The risk of severe complications from brachytherapy may be caused more by location of tumor being treated rather than those fractionations scheme. When tumor involves the mainstem bronchi and upper lobes, it seems prudent to obtain CT to exclude tumor invasion of the pulmonary arteries or considerable destruction of the bronchial wall and mediastinal invasion of the tumor. Patients with findings such as these should not be treated with endobronchial brachytherapy or treated with LDR brachytherapy. Brachytherapy is proved to be effective and a safe palliative treatment for endobronchial malignancies, but further investigations are necessary to determine the optimal dose scheme and its efficiency in bronchogenic carcinoma and combined with external beam radiation therapy or surgery or other endobronchial procedures such as Nd:YAG laser or cryotherapy.

A resected case of hilar type double primary lung cancer following endobronchial brachytherapy

A 61-year-old man with squamous cell carcinoma of the right B1 and the left second carina which extended to the left main bronchus, was treated with low dose rate brachytherapy bilaterally prior to resection. A complete response was gained at the right B1 and the left main bronchus, a resection of the left apical segment and the second carina was carried out with bronchoplastic procedures. The patient remains disease-free 2 years after the operation and maintains a good quality of life. In this case, the preoperative treatment with brachytherapy was effective.

Brachytherapy for non-small cell lung cancer and selected neoplasms of the chest

This article reviews the indications, techniques, and results of brachytherapy in the treatment of non-small cell lung cancer (NSCLC) and selected chest neoplasms. Various isotopes and techniques are used to place radioactive sources directly into a tumor, tumor bed, or the chest. Brachytherapy techniques can be tailored to the clinical situation and can be in the form of permanent interstitial volume or planar implants (radioactive sources permanently imbedded into the tumor or tumor bed) or in the form of temporary interstitial or endoluminal implants (where radioactive sources irradiate a tumor bed over a certain length of time and then are removed). These treatments can be delivered over a short interval (high-dose rate [HDR]) or over a more protracted time (low-dose rate). HDR treatments can be used intraoperatively to deliver a large dose of radiation to a determined target area with selective sparing of surrounding normal structures. Different methods of delivering HDR intraoperative radiation are under investigation. Most reports on brachytherapy for chest malignancies are retrospective and come from a few single institutions. Most of the published data relate to the treatment of NSCLC, but other intrathoracic malignancies, such as malignant pleural mesothelioma and malignant thymoma, have been treated with brachytherapy. To our knowledge, no major randomized trials accurately assess or confirm these retrospective studies yet, complicating the interpretation of these results. Nevertheless, brachytherapy is of value in selected situations and offers the clinician and the patient an innovative method of delivering conformal high-dose radiation to a defined target with preferential sparing of normal surrounding structures. With continued innovations in the development of radioactive isotopes, computerized treatment planning and targeting, and source delivery, brachytherapy should continue to offer an attractive alternative and complement to conventional treatment approaches, and may offer patients improved local control and survival.

Curative irradiation of limited endobronchial carcinomas with high-dose rate brachytherapy. Results of a pilot study

OBJECTIVES OF THE STUDY

Pilot study to assess high-dose rate (HDR) brachytherapy as sole treatment for limited endobronchial non-small cell lung carcinomas.

INCLUSION CRITERIA

Proximal non-small cell lung cancer in a not previously irradiated area, with a maximal diameter of 1 cm, no visible tumor on CT scan, lack of other treatment options in patients with severe, chronic respiratory failure, surgery, or external radiotherapy for a previous lung cancer.

TREATMENT PROTOCOL

Treatment was based on an escalating dose protocol. Patients received three to five fractions of 7 Gy prescribed at 10 mm from the center of the applicator, once a week.

RESULTS

Nineteen patients were included in this trial. The first two patients received three fractions of 7 Gy, the four next patients received four fractions, and the 13 remaining patients were treated with five fractions of 7 Gy. Two months after the end of the procedure, tumors in 15 of 18 evaluable patients (83%) were locally controlled with negative results of biopsies. At 1 year, local control was still obtained in 12 of 16 evaluable patients (75%). With a mean follow-up of 28-months, 1-year and 2-year actuarial survival rates were 78% and 58%, respectively, with a 28-month median survival. One patient with local control died from hemoptysis 12 months after treatment. Two patients suffered from severe necrosis of the bronchial wall; one of them died from hemoptysis.

CONCLUSIONS

HDR brachytherapy is an effective treatment for small endobronchial tumors. Late toxicity on the bronchial wall is still too high and was attributed mainly to contact between the catheter and the bronchial mucosa. Exclusive HDR brachytherapy should be restricted to carefully selected patients for whom there is no alternative curative treatment. New bronchial applicators and a lower dose per fraction may reduce the incidence and attenuate the severity of late complications.