Cryotherapy in early superficial bronchogenic carcinoma

[EBUS-guided cryobiopsy in the diagnosis of mediastinal lesions - step by step]

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the gold standard in the diagnosis of mediastinal and hilar lesions. For certain purposes, such as the diagnosis and subtyping of lymphoproliferative disorders or molecular pathology, a larger amount of intact sample material is required. EBUS cryobiopsy is a new and efficient tool for this purpose. As it is a new approach, there is still no standardised workflow. In this review, we present the procedure step by step as it is performed at the Ruhrlandklinik in Essen.

Cryoablation and immunity in non-small cell lung cancer: a new era of cryo-immunotherapy

Despite remarkable advances in tumor response and patient survival in the past decade, systemic immunotherapies for lung cancer result in an objective response in only around half of patients treated. On the basis of this limitation, combination strategies are being investigated to improve response rates. Cryoablation has been proposed as one such technique to induce immunogenic cell death and synergize with systemic immunotherapies, including immune checkpoint inhibitors. Cryoablation has been traditionally delivered percutaneously with imaging guidance although recent technological advances allow for bronchoscopic delivery. Herein, we review the pre-clinical and clinical evidence for the use of cryoablation in non-small cell lung cancer and potential induction of anti-tumor immunity. We highlight ongoing studies involving this approach and propose areas of future investigation.

[Transbronchial lung cryobiopsy in interstitial lung diseases]

In some cases of interstitial lung disease (ILD), clinical and biological findings associated with CT scan pattern during multidisciplinary discussion (MDD) fail to yield a confident diagnosis. In these cases, histology may be necessary. Transbronchial lung cryobiopsy (TBLC) is a bronchoscopic procedure that has been developed in recent years and currently contributes to diagnostic work-up in patients with ILD. TBLC provides tissue samples for histological analysis with an acceptable risk of complications, consisting mainly in pneumothorax or bleeding. In addition to higher diagnostic yield than conventional forceps biopsies, the procedure shows a better safety profile than surgical biopsies. The indication to perform TBLC is decided during a 1st MDD and during a 2nd MDD, results can provide a diagnostic yield approximating 80%. TBLC appears to be an attractive, minimally invasive technique to be proposed as a first-line procedure in selected patients in experienced centers, while surgical lung biopsy may be considered as a second-line solution.

Applications of cryobiopsy in airway, pleural, and parenchymal disease

INTRODUCTION

:Cryobiopsy is a novel diagnostic technique for thoracic diseases which has been extensively investigated over the past 20 years. It was originally proposed for the diagnosis of endobronchial lesions and diffuse parenchymal lung disease due to limitations of conventional sampling techniques including small size and presence of artifacts.

AREAS COVERED

:We will review recent evidence related to the expanding use of cryobiopsy in thoracic diseases. To identify references, the MEDLINE database was searched from database inception until May 2022 for case series, cohort studies, randomized controlled trials, systematic reviews and meta-analyses related to cryobiopsy.

EXPERT OPINION

Cryobiopsy has expanding applications in the field of thoracic diseases. Evidence to support transbronchial cryobiopsy as an alternative to surgical lung biopsy is increasing and was recently endorsed as a conditional recommendation by the latest American Thoracic Society guideline update for Idiopathic Pulmonary Fibrosis. Developments in technology and technique, in particular the availability of a 1.1 mm flexible cryoprobe, have extended applications to pulmonary diseases, including diagnosis of interstitial lung diseases, peripheral pulmonary lesions, and lung transplant rejection.

Treatment of Pulmonary Carcinoid Tumors With Bronchoscopic Cryotherapy: A 28-Year Single-center Experience

BACKGROUND

Pulmonary carcinoids are rare tumors originating from neuroendocrine cells in the lungs. Because of their potentially infiltrative nature, surgical resection remains the treatment of choice. However, not all patients with technically resectable disease will be able to undergo surgery, primarily because of poor lung function or medical co-morbidities. Centrally located, intraluminal tumors have been reported to be amenable to bronchoscopic treatment. We specifically examined the role of cryotherapy in the treatment of bronchial carcinoid tumors.

METHODS

Sixty-three patients (52.38% female) who underwent a combined total of 243 cryotherapy procedures for treatment of bronchial carcinoid between 1992 and 2020 in our institution were included in the study. Following discussion in multidisciplinary meetings, patients were considered for first-line cryotherapy when lung resection was deemed not possible or when they had rejected surgery.

RESULTS

Cryotherapy resulted in complete remission in 21 (33.33%) patients with maximum tumor diameter less than 20 mm (mean: 11.08 mm, 95% confidence interval: 8.76-13.40), and allowed 22 (34.92%) patients with larger lesions (mean: 24.04 mm, 95% confidence interval: 18.78-29.30) to proceed with parenchymal sparing resections. Marked symptomatic relief (P<0.001) was reported by 58 (92.06%) patients. The median follow-up was 33 months (range: 0 to 243 mo). One (1.59%) patient was diagnosed with recurrence in a contralateral lobe 3 years after surgery and was treated with radiofrequency ablation.

CONCLUSIONS

In the absence of a definitive randomized controlled trial comparing bronchoscopic treatment with surgical resection, we provide evidence on the safety and efficacy of cryotherapy and encourage wider adoption of this inexpensive and minimally invasive technique for treatment of bronchial carcinoids.

Bronchoscopic diagnosis and treatment of endobronchial carcinoid: case report and review of the literature

Carcinoid tumours are rare neuroendocrine neoplasms that mostly occur in younger adults with low tendencies to metastasise. Based on their histological characteristics, they are divided into typical and atypical subtypes. The most common presenting symptoms are due to central airway obstruction. The first step in the diagnostic assessment should be a computed tomography (CT) scan, as it provides information both for local tumour extent and lymph node involvement. Bronchoscopy is the main tool for histological confirmation, evaluation of bronchial wall invasion and removal of endobronchial manifestation with subsequent resolution of atelectasis. Endobronchial ultrasound may be necessary to rule out lymph node metastasis. Somatostatin receptor scintigraphy in combination with CT can rule out further metastatic disease.Surgical resection using parenchyma-sparing techniques remains the gold standard for treatment. For selected patients, endobronchial therapy could be an alternative for minimal invasiveness. Long-term follow-up is suggested due to the high likelihood of recurrence.Here, we describe our clinical experience in a 35-year-old male patient who originally presented with haemoptysis and a central polypoid tumour in the left main bronchus revealed by a CT scan. The histological characteristics were indicative of a typical carcinoid. The patient was treated using an endobronchial approach only. No complications and no recurrences have been observed in a follow-up of 2 years.

Feasibility study of cryobiopsy for practical pathological diagnosis of primary lung cancer including immunohistochemical assessment

BACKGROUND

Precision medicine in non-small cell lung cancer requires attainment of a sufficient amount of high-quality tumor tissue. Transbronchial cryobiopsy has emerged as a new diagnostic method for non-neoplastic lung disease with a better potential to assess morphology compared with conventional methods. However, the influence of cryobiopsy on specimen quality, particularly detection of protein expression, is unknown. We performed a comparative immunohistochemical study in specimens obtained by cryobiopsy versus conventional sampling to evaluate the feasibility of cryobiopsy for lung cancer diagnosis.

METHODS

Pairs of artificial biopsy specimens, collected using a cryoprobe or conventional scalpel, were obtained from 43 surgically resected primary lung tumors. Formalin-fixed, paraffin-embedded blocks were prepared in an ISO15189-certified laboratory. Immunohistochemical staining of thyroid transcription factor-1, p40, Ki67 and programmed death-ligand 1 (22C3) was performed. The H-scores for thyroid transcription factor-1 and p40, labeling index for Ki67 and tumor proportion score for programmed death-ligand 1 were assessed. Pearson's correlation coefficients between two sampling types were calculated.

RESULTS

The thyroid transcription factor-1 and p40 H-scores showed perfect correlations between the cryobiopsy and conventional scalpel-obtained specimens (R2 = 0.977 and 0.996, respectively). Ki67 labeling index and PD-L1 tumor proportion score also showed strong correlations between the two sample types (R2 = 0.896 and 0.851, respectively). Five cases (11.6%) exhibited differences in tumor proportion score category between sample types, potentially because of intratumoral heterogeneity.

CONCLUSIONS

Immunohistochemical expression of certain tumor markers showed a high concordance between cryobiopsy and conventional scalpel sampling. Cryobiopsy is feasible for pathological diagnostics including PD-L1 evaluation.

An Open-label, Single-arm Study of CRYO2 for Debulking at the Site of Central Airway Obstruction or Stenosis

BACKGROUND

An open-label, single-arm study was conducted to assess the safety of a cryosurgery unit named CRYO2 for debulking at the site of obstruction or stenosis.

PATIENTS AND METHODS

In order to treat central airway tumor-related stenosis, debulking at the stenotic site of the airway was performed using CRYO2 under general or local anesthesia. The primary endpoint was the incidence of moderate to massive hemorrhage.

RESULTS

Incidence of moderate to massive hemorrhage during surgery was 3.8% (1/26) (95% confidence interval(CI)=0.1-19.6%). Technical success was 96.2% (25/26), with a 95% confidence interval of 80.4-99.9%.

CONCLUSION

CRYO2 for debulking at the site of obstruction or stenosis can be performed safely.

Role of bronchoscopy in management of central squamous cell lung carcinoma in situ

Squamous cell carcinoma in situ (SCIS) is the pre-invasive stage of squamous cell carcinoma. Early detection and management of SCIS can prevent further progression. Although surgery and external beam radiation therapy are treatment options for SCIS, smaller lesions can be easily managed by bronchoscopic modalities like photodynamic therapy (PDT), cryotherapy, mechanical debulking with biopsy forceps, electrocautery and argon plasma coagulation (APC). Endobronchial brachytherapy (EBBT) and lasers may be judiciously utilized in selected cases. Although, previous studies of treatment modalities may have inadvertently included cases of invasive carcinomas, the advent of new technologies like radial probe endobronchial ultrasound (RP-EBUS) and optical coherence tomography (OCT) can help accurately determine the of depth of invasion. Superficial extent can also be better demarcated with techniques like auto-fluorescence bronchoscopy and narrow band imaging (NBI). New drugs for PDT with deeper penetration and less phototoxicity are being developed. These advances hopefully will allow us to perform superior clinical trials in future and improve our understanding of diagnosis and management of SCIS.

Experimental study for evaluation of a low-cost spray cryotherapy system

Objective

To evaluate the feasibility and applicability of a low-cost cryotherapy system.

Methods

Experimental study with 25kg Landrace pigs submitted to a longitudinal cervico-thoraco-abdominal incision for exposure of the trachea, thorax and abdomen. The tissues were frozen by continuous spray application at different periods of time (5, 10 and 15 seconds). Spray cryotherapy was performed using a fluorinated gas (tetrafluorethane) delivered at - 47°C temperature (DermaFreeze^®, Emdutos; ANVISA registration 80409950001; price R$ 394,00). via an adapted, disposable 1.8mm cholangiography catheter (Olympus; price R$ 280,00). The specimens were resected for histopathological analysis.

Results

Thirty samples were obtained from ten different organs and divided according to spray cryotherapy application time. System activation for 5, 10 or 15 seconds led to consumption of 14g, 27g and 40g of gas respectively (average gas consumption, 2.7g/s using a 1.8mm catheter). The system comprising a spray tube and catheter proved user-friendly and effective, with constant gas dispersion and adequate tissue freezing. In spite of effective freezing, microscopy failed to reveal tissue changes. This may have reflected methodological constraints precluding evaluation at tissue damage peak time (48 hours).

Conclusion

The low-cost spray cryotherapy system proved feasible and safe.

Interstitial lung disease: the diagnostic role of bronchoscopy

Interstitial lung diseases (ILDs) form one of the most fascinating fields in pulmonary medicine. They also pose one of the greatest challenges for accurate diagnosis and proper treatment. Even within the recommended and warranted multidisciplinary approach, differentiating between one disease and another may lead to frustration, especially when proper lung tissue is not available for adequate pathological review. A surgical lung biopsy (SLB) might render enough tissue for histopathology, but this could come at the expense of high morbidity and even mortality, as in the case of usual interstitial pneumonia (UIP). Could bronchoscopy and its various techniques offer a safer and higher yield alternative? Since the very late 19th century, efforts have been made to better examine the airways, obtain tissue and treat various conditions. This resulted in the successive emergence of bronchoalveolar lavage (BAL), endobronchial and transbronchial forceps biopsies, until recently when transbronchial cryobiopsy surfaced as a nascent technique with much promise. The use of endobronchial ultrasound revolutionized the diagnosis and staging of lung cancer, while adding to the yield of other conditions such as sarcoidosis. Ongoing research, efforts and studies have continuously scrutinized the roles of various techniques in the approach to ILDs. For example, BAL seems to serve mostly to eliminate infection as an etiology or a complicating factor in the acute worsening of a fibrotic lung disease, while a predominant cellular component might be diagnostic, such as eosinophilia in eosinophilic lung disease, or lymphocytosis in hypersensitivity pneumonitis (HP). On the other hand, endobronchial biopsy's (EBB) role appears limited to sarcoidosis. As for transbronchial biopsy by forceps, the small sample size and related artifact appear to be limiting factors in making an accurate diagnosis. Recently, however, the use of cryotherapy via employing a cryoprobe in obtaining transbronchial lung biopsies is unfolding into a refined interventional method which might transform indefinitely our approach to the pathological diagnosis of the various ILDs.

[Endoscopic interventions in pulmonology]

Bronchoscopy plays a significant role in the diagnosis and treatment of pulmonary diseases. Hemoptysis, or central airway obstruction, is a common indication for interventional bronchoscopy. In addition, the treatment of early lung cancer is the domain of bronchoscopy in inoperable patients. In recent years, endoscopic techniques have also been established as new therapeutic options in advanced chronic obstructive pulmonary disease and uncontrolled bronchial asthma.

Techniques of endoscopic airway tumor treatment

Interventional bronchoscopy has a predominant role in the management of both early and advanced-stage airway tumors. Given the very poor prognosis of lung cancer, there is a need for new tools to improve early detection and bronchoscopic treatment of endo-bronchial precancerous lesions. In more advanced stages, interventional bronchoscopy plays an important role, as nearly a third of lung cancers lead to proximal airway obstruction. This will cause great discomfort or even life-threatening symptoms related to local extension, such as dyspnea, post-obstructive pneumonia, and hemoptysis. Surgery for very locally advanced disease is only effective for a limited number of patients and the effects of conventional antitumor therapies, like radiation therapy or chemotherapy, are inconstant and are too delayed in a palliative context. In this review, we aim to provide pulmonologists with an exhaustive technical overview of (I) the bronchoscopic management of benign endobronchial lesions; (II) the bronchoscopic management of malignant tumors, including the curative treatment of localized lesions and palliative management of malignant proximal airway stenosis; and (III) descriptions of the emerging endoscopic techniques used to treat peripheral lung tumors.

Intra-patient comparison of parietal pleural biopsies by rigid forceps, flexible forceps and cryoprobe obtained during medical thoracoscopy: a prospective series of 80 cases with pleural effusion

BACKGROUND

There is only few data available on the use of cryotechnique during medical thoracoscopy.

METHODS

Medical thoracoscopy was performed in consecutive patients with pleural effusion. Prospectively, biopsies were taken by rigid forceps, flexible forceps and cryoprobe. Specimen size, depth and diagnostic yield were compared.

RESULTS

80 Patients were included. 408 biopsies were taken (205 rigid biopsies, 104 flexible biopsies, 99 cryobiopsies). Mean surface area of rigid biopsies was 22.6 ± 20.4 mm(2) (flexible biopsies: 7.1 ± 9.3 mm(2), cryobiopsies: 14.4 ± 12.8 mm(2)). Rigid biopsies were significantly larger than cryobiopsies (p < 0.001) and flexible biopsies (p < 0.001), crybiopsies were significantly larger than flexible biopsies (p < 0.01). A deep biopsy containing fatty tissue was harvested in 63 % of rigid biopsies (cryobiopsy: 49.5 % flexible biopsy: 39.5 %). In 79/80 cases (98.7 % 95 % CI cannot be calculated) a diagnosis was obtained by rigid biopsy (cryobiopsy: 73/80 cases (91.3 % 95 % CI 86.0 - 96.5 %), flexible biopsy: 74/80 cases (92.5 % 95 % CI 88.6 - 97.4 %)). Diagnostic yield achieved with cryobiopsies was inferior to the yield of rigid biopsies (Difference: 12.7 %), but non-inferior to flexible biopsies (Difference: 6.5 %).

CONCLUSION

Cryobiopsies in medical thoracoscopy are safe with high diagnostic yield, non-inferior to flexible biopsies with increased tissue quantity and quality. Cryotechnique can develop an important role in medical thoracoscopy in the near future when rigid thoracoscopy is not available.

Cryosurgery for Tumors — A Clinical Overview

Cryosurgery, a method of treating disease by the production of freezing temperatures in the tissue, is a useful technique for the treatment of tumors. When the modern era of cryosurgery began in the mid 1960's, the technique was used only for tumors easily accessible by direct observation or via endoscopy, such as those of the skin, oral cavity, and prostate gland. In general, the technique had limited usefulness in the next two decades. However, with the advent of intraoperative ultrasound as a method of monitoring the process of freezing and with the development of more effective cryosurgical apparatus, the cryosurgical treatment of tumors of the viscera and other deep tissues became practical in the 1990's. This review assesses the present day status of cryosurgery in the management of diverse tumors.

From electrocautery, balloon dilatation, neodymium-doped:yttrium-aluminum-garnet (Nd:YAG) laser to argon plasma coagulation and cryotherapy

Over the past decade, there has been significant advancement in the development/application of therapeutics in thoracic diseases. Ablation methods using heat or cold energy in the airway is safe and effective for treating complex airway disorders including malignant and non-malignant central airway obstruction (CAO) without limiting the impact of future definitive therapy. Timely and efficient use of endobronchial ablative therapies combined with mechanical debridement or stent placement results in immediate relief of dyspnea for CAO. Therapeutic modalities reviewed in this article including electrocautery, balloon dilation (BD), neodymium-doped:yttrium-aluminum-garnet (Nd:YAG) laser, argon plasma coagulation (APC), and cryotherapy are often combined to achieve the desired results. This review aims to provide a clinically oriented review of these technologies in the modern era of interventional pulmonology (IP).

Cryo-recanalization in a case of carcinoid tumor - An interesting case report

The term “cryotherapy” comes from the Greek cryo (κρύο) meaning cold, and therapy (θεραπεία) meaning cure. Cryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. Carcinoid tumors of the lung are a fascinating but uncommon group of pulmonary neoplasms. In the past, these tumors were grouped with benign or less aggressive malignant pulmonary tumors, namely bronchial adenomas. Recent studies have revealed that carcinoid lung tumors are the most indolent form of a spectrum of bronchopulmonary neuroendocrine tumors that, at its extreme, include small cell carcinoma of the lung as its most malignant member. They commonly present as endobronchial obstructions, and if complete, can be life-threatening and require immediate intervention.[1] Recently, we have treated a patient of carcinoid tumor of lung who was managed with cryo-recanalization with excellent response.

Bronchoscopic management of malignant airway obstruction

Approximately one-third of patients with lung cancer will develop airway obstruction and many cancers lead to airway obstruction through meta stases. The treatment of malignant airway obstruction is often a multimodality approach and is usually performed for palliation of symptoms in advanced lung cancer. Removal of airway obstruction is associated with improvement in symptoms, quality of life, and lung function. Patient selection should exclude patients with short life expectancy, limited symptoms, and an inability to visualize beyond the obstruction. This review outlines both the immediate and delayed bronchoscopic effect options for the removal of airway obstruction and preservation of airway patency with endobronchial stenting.

Diaphragmatic hernia after lung percutaneous radiofrequency ablation: incidence and risk factors

PURPOSE

To evaluate diaphragmatic hernias (DH) after percutaneous radiofrequency ablation (PRFA) for basal lung nodules and to detect risk factors.

MATERIALS AND METHODS

Between January 2009 and December 2012, the presence of DH was retrospectively recorded in all of the patients who underwent PRFA with multitine expandable electrodes for ablation of nodules in the lower lobe. All nodules were classified into three groups according to the location of the tines after deployment relative to the diaphragm: In group 1, the tines were at a distance of >1 cm from the diaphragm; in group 2, at least one tine was in contact with the diaphragm without perforation; and in group 3, at least one tine was perforating the diaphragm.

RESULTS

We recorded 4 cases of DH (3 on the left side, 1 on the right side) in 156 patients (2.3% of procedures). The delay of onset was 7.8 months. DH occurred in groups 2 (n = 1) and 3 (n = 3). Only the 3 cases that occurred on the left side were symptomatic (2 intussusceptions and 1 gastroesophageal reflux) and were surgically repaired. The electrode was positioned in the center of the diaphragm in all cases.

CONCLUSION

The central position of the electrode and the contact of at least one tine with the diaphragm after deployment seem to be a risk factor to develop DH.

Diagnosis and treatment of bronchial intraepithelial neoplasia and early lung cancer of the central airways: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Bronchial intraepithelial lesions may be precursors of central airway lung carcinomas. Identification and early treatment of these preinvasive lesions might prevent progression to invasive carcinoma.

METHODS

We systematically reviewed the literature to develop evidence-based recommendations regarding the diagnosis and treatment of intraepithelial lesions.

RESULTS

The risk and timeline for progression of bronchial intraepithelial lesions to carcinoma in situ (CIS) or invasive carcinoma are not well understood. Multiple studies show that autofluorescence bronchoscopy (AFB) is more sensitive that white light bronchoscopy (WLB) to identify these lesions. In patients with severe dysplasia or CIS in sputum cytology who have chest imaging studies showing no localizing abnormality, we suggest use of WLB; AFB may be used as an adjunct when available. Patients with known severe dysplasia or CIS of central airways should be followed with WLB or AFB, when available. WLB or AFB is also suggested for patients with early lung cancer who will undergo resection for delineation of tumor margins and assessment of synchronous lesions. However, AFB is not recommended prior to endobronchial therapy for CIS or early central lung cancer. Several endobronchial techniques are recommended for the treatment of patients with superficial limited mucosal lung cancer who are not candidates for resection.

CONCLUSION

Additional information is needed about the natural history and rate of progression of preinvasive central airway lesions. Patients with severe dysplasia or CIS may be treated endobronchially; however, it remains unclear if these therapies are associated with improved patient outcomes.

Detection and minimally invasive treatment of early squamous lung cancer

Non-small cell lung cancer (NSCLC) is the most common cause of cancer deaths worldwide. The majority of patents presenting with NSCLC have advanced disease, which precludes curative treatment. Early detection and treatment might result in the identification of more patients with early central lung cancer and improve survival. In addition, the study of early lung cancer improves understanding of lung carcinogenesis and might also reveal new treatment targets for advanced lung cancer. Bronchoscopic investigation of the central airways can reveal both early central lung cancer in situ (stage 0) and other preinvasive lesions such as dysplasia. In the current review we discuss the detection of early squamous lung cancer, the natural history of preinvasive lesions and whether biomarkers can be used to predict progression to cancer. Finally we will review the staging and management of preinvasive lung cancer lesions and the different therapeutic modalities that are available.

Successful treatment of a tracheal squamous cell carcinoma with a combination of cryoablation and photodynamic therapy

Malignant tumors of the trachea are rare, and account for less than 0.1% of all malignancies. Because there are no guidelines based on randomized clinical trials, the choice of treatment modalities and optimal sequences have not yet been established. In most cases of malignant airway obstruction, a single modality is chosen as the treatment of choice for management, but complete ablation becomes increasingly problematic with minimal residual lesions that require additional treatment. There were few case reports of the combined use of cryoablation and photodynamic therapy to treat tracheal cancer. Therefore, we present our experience of successful tracheal cancer treatment using this combination therapy. A bronchoscopic complete regression was obtained using these two modalities, and the procedures proved to be a safe and effective treatment option based on a one-year follow-up.

Preinvasive lesions of the bronchus

It has been proposed that invasive carcinoma of the bronchus develops through a transition from preinvasive lesions to overt malignancy. Newer diagnostic technologies have provided a more sensitive way to diagnose preinvasive lesions and a better understanding of the prevalence of such lesions. The natural history of preinvasive lesions has not been well defined; however, there is evidence that high-grade lesions are at a higher risk of progression to carcinoma. Molecular alterations have been described in preinvasive lesions and may help better predict which lesions will progress. Several noninvasive techniques are available for the treatment of high-grade lesions.

CT-guided conformal cryoablation for peripheral NSCLC: initial experience

PURPOSE

To study the feasibility of CT-guided and monitored percutaneous conformal cryoablation of Non-Small Cell Lung Cancer for patients who are not suitable for surgical resection.

MATERIALS AND METHOD

CT-guided percutaneous conformal cryoablation was performed on 46 patients with peripheral Non-Small Cell Lung Cancer. Patients with tumor sizes less than 3 cm in diameter were treated with double-needle clamping cryoablation, while the patients with 3-5 cm tumor sizes were treated with multiple-needle conformal cryoablation. CT was used to monitor the extent of cryoablation during the procedures. At month 1, 3, 6, 12, and 24 post-procedure, enhanced CT scans and/or PET-CT scans were performed to evaluate the impact of the therapy.

RESULTS

The average tumor CT values were 32±10 HU and -21±8 HU before and after cryoablation, respectively. The largest diameters of the lesions at month 1, 3, 6, 12, and 24 post-procedure were 2.63±0.56 cm, 1.93±0.51 cm, 1.55±0.39 cm, 1.43±0.40 cm, and 1.38±0.38 cm, respectively, in patients with tumor diameter less than 3 cm, and 3.63±0.39 cm, 2.98±0.31 cm, 2.62±0.32 cm, 2.54±0.34 cm, and 2.56±0.37 cm respectively in patients with the tumor diameters between 3 and 5 cm. At the 24th month, there were 36 cases of complete response (83.7%), 7 cases of partial response (16.3%), and no cases of stable disease or progressive disease. 3 patients died due to multiple metastases.

CONCLUSION

CT-guided percutaneous conformal cryoablation is a safe, effective, and minimally invasive therapeutic method for peripheral lung cancer.

Percutaneous cryoablation as a salvage therapy for local recurrence of lung cancer

A 66-year-old male was diagnosed with inoperable non-small cell lung cancer, and underwent chemoradiotherapy, to which he achieved a partial response. During subsequent follow-up, positron emission tomography showed a fluorodeoxyglucose uptake lesion within the primary tumor, without evidence of metastatic foci elsewhere in the body. As local disease progression was most suspected, cryoablation was performed for the lesion with high fluorodeoxyglucose uptake. After treatment, there has been no evidence of recurrence for 12 months. Herein, we present a case of percutaneous cryoablation as a salvage therapy for recurrent lung cancer after chemoradiotherapy.

Optical detection of preneoplastic lesions of the central airways

Current routine diagnosis of premalignant lesions of the central airways is hampered due to a limited sensitivity (white light bronchoscopy) and resolution (computer tomography (CT), positron emission tomography (PET)) of currently used techniques. To improve the detection of these subtle mucosal abnormalities, novel optical imaging bronchoscopic techniques have been developed over the past decade. In this review we highlight the technological developments in the field of endoscopic imaging, and describe their advantages and disadvantages in clinical use.

A case of typical pulmonary carcinoid tumor treated with bronchoscopic therapy followed by lobectomy

Carcinoid bronchopulmonary tumors represent approximately 25% of all carcinoid tumors and 1%-2% of all lung neoplasms. The most common symptoms are: persistent cough, asthma-like wheezing, chest pain, dyspnea, hemoptysis and obstructive pneumonitis. We present a case of a young adult diagnosed with a typical carcinoid tumor. The diagnosis was established on the basis of imaging examination and bronchoscopic biopsy. The patient was treated with bronchoscopic electrocautery therapy to relieve the obstructed airway, followed by surgical lobectomy in order to entirely remove the exophytic damage. This approach was not only a palliative management to bronchial obstruction but also avoided pneumonectomy. Recent studies support the use of such interventional resection methods, as they may result in a more conservative surgical resection.

Percutaneous cryoablation of pulmonary metastases from colorectal cancer

OBJECTIVE

To evaluate the safety and efficacy of cryoablation for metastatic lung tumors from colorectal cancer.

METHODS

The procedures were performed on 24 patients (36-82 years of age, with a median age of 62; 17 male patients, 7 female patients) for 55 metastatic tumors in the lung, during 30 sessions. The procedural safety, local progression free interval, and overall survival were assessed by follow-up computed tomographic scanning performed every 3-4 months.

RESULTS

The major complications were pneumothorax, 19 sessions (63%), pleural effusion, 21 sessions (70%), transient and self-limiting hemoptysis, 13 sessions (43%) and tract seeding, 1 session (3%). The 1- and 3-year local progression free intervals were 90.8% and 59%, respectively. The 3-years local progression free intervals of tumors ≤15 mm in diameter was 79.8% and that of tumors >15 mm was 28.6% (p = 0.001; log-rank test). The 1- and 3-year overall survival rates were 91% and 59.6%, respectively.

CONCLUSION

The results indicated that percutaneous cryoablation is a feasible treatment option. The local progression free interval was satisfactory at least for tumors that were ≤15 mm in diameter.

Endoscopic cryotherapy of lung and bronchial tumors: a systematic review

BACKGROUND/AIMS

We made a systematic review and evaluation of endoscopic cryotherapy of endobronchial tumors, investigating safety and efficacy.

METHODS

Qualified studies regarding endoscopic cryotherapy of lung tumors were systemically evaluated using available databases according to predefined criteria.

RESULTS

In total, 16 publications were included in the final assessment. A narrative synthesis was performed because a formal meta-analysis was not viable due to the lack of controlled studies and study heterogeneity. Overall success rates for significant recanalization of the obstruction were approximately 80%, although they varied, depending on disease status in the patient population. Complications from the procedure developed in 0-11.1% of cases, most of which were minor and controlled by conservative management. Although limited data were available on comprehensive functional assessment, some studies showed that respiratory symptoms, pulmonary function tests, and performance status were significantly improved.

CONCLUSIONS

Endoscopic cryotherapy was found to be a safe and useful procedure in the management of endobronchial tumors although its efficacy and appropriate indications have yet to be determined in well-designed controlled studies.

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.

Preinvasive lesions of the bronchus

Preinvasive lesions are considered the precursors of squamous cell carcinoma of the bronchus. Treatment at the preinvasive stage, before the potential for metastasis, may improve survival from squamous cell carcinoma. An understanding of the natural history and outcome of preinvasive lesions is essential for the accurate interpretation studies of their treatment, and decisions regarding the management of individual lesions. The natural history of preinvasive lesions has only been reported in a small number of highly selected patients and uses different inclusion criteria, treatment criteria. and time-periods of follow-up, making it difficult to draw definitive conclusions. High-grade preinvasive lesions carry a risk of progression to carcinoma but most patients have multiple lesions and a significant probability of developing new lesions over time. Distinguishing lesions with malignant potential, the targets for therapy, from those that will regress or remain indolent is difficult. The American College of Chest Physicians guidelines recommend bronchoscopic follow-up of severe dysplasia and carcinoma-in situ. This review of the evidence regarding the natural history and outcome of preinvasive lesions supports this view, but also shows that further studies in individuals at risk for lung cancer are necessary before guidelines for the management of preinvasive lesions can be developed.

Experimental study on biopsy sampling using new flexible cryoprobes: influence of activation time, probe size, tissue consistency, and contact pressure of the probe on the size of the biopsy specimen

Cryoextraction is a procedure for recanalization of obstructed airways caused by exophytic growing tumors. Biopsy samples obtained with this method can be used for histological diagnosis. The objective of this study was to evaluate the parameters influencing the size of cryobiopsies in an in vitro animal model. New flexible cryoprobes with different diameters were used to extract biopsies from lung tissue. These biopsies were compared with forceps biopsy (gold standard) in terms of the biopsy size. Tissue dependency of the biopsy size was analyzed by comparing biopsies taken from the lung, the liver, and gastric mucosa. The effect of contact pressure exerted by the tip of the cryoprobe on the tissue was analyzed on liver tissue separately. Biopsy size was estimated by measuring the weight and the diameter. Weight and diameter of cryobiopsies correlated positively with longer activation times and larger diameters of the cryoprobe. The weight of the biopsies was tissue dependent: lung < liver < stomach. Only little tissue dependency was found for the biopsy diameter. The biopsy size increased when the probe was pressed on the tissue during cooling. Cryobiopsies can be taken from different tissue types with flexible cryoprobes. The size of the samples depends on tissue type, probe diameter, application time, and pressure exerted by the probe on the tissue. Even the cryoprobe with the smallest diameter can provide larger biopsies than a forceps biopsy in lung. It can be expected that the same parameters influence the sample size of biopsies in vivo.

Endoscopic cryotherapy for the management of gastric antral vascular ectasia

BACKGROUND

Gastric antral vascular ectasia (GAVE) is an uncommon but clinically significant cause of chronic GI bleeding.

OBJECTIVE

To assess the efficacy and safety of cryotherapy for endoscopic treatment of GAVE.

DESIGN

Patients received 3 sessions of endoscopic cryotherapy at 3-week to 6-week intervals and had a follow-up endoscopy 4 weeks thereafter. They were followed prospectively in terms of clinical and endoscopic response.

SETTING

Tertiary-care center, between October 2004 and April 2006.

PATIENTS

The patients were 43 to 89 years of age, with a diagnosis of GAVE and documented iron deficiency anemia. Eight patients had a history of overt GI bleeding. Eight patients (67%) had previously been treated with argon plasma coagulation (APC) (median 6 sessions, range 1-10 sessions) and failed to respond or had a recurrence.

RESULTS

Twelve patients were enrolled. Six patients (50%) had a complete response, and 6 patients had a partial response. The mean number of units of blood transfused in the period of 3 months before cryotherapy and during the period of follow-up of 3 months was 4.6 and 1.7 units, respectively. An increased mean Hb level, from 9.9 to 11.3 g/dL, was noted. The average duration of the cryotherapy was 5 minutes (range 1-15 minutes). In 32 of 36 cryotherapy treatment sessions performed (89%), it was technically possible to treat more than 90% of GAVE lesions. There were no immediate cryotherapy-related complications, and none of the patients required admission after the procedure.

LIMITATIONS

A pilot study from a single center.

CONCLUSIONS

Endoscopic cryotherapy is a safe and effective treatment for GAVE. It appears to be effective, even for GAVE refractory to APC therapy. Optimal cryogen, delivery device, and treatment protocols are yet to be determined.