Tumor debulking by radiofrequency ablation in hypertrophic pulmonary osteoarthropathy associated with pulmonary carcinoma

Lung radiofrequency and microwave ablation: a review of indications, techniques and post-procedural imaging appearances

Lung ablation can be used to treat both primary and secondary thoracic malignancies. Evidence to support its use, particularly for metastases from colonic primary tumours, is now strong, with survival data in selected cases approaching that seen after surgery. Because of this, the use of ablative techniques (particularly thermal ablation) is growing and the Royal College of Radiologists predict that the number of patients who could benefit from such treatment may reach in excess of 5000 per year in the UK. Treatment is often limited to larger regional centres, and general radiologists often have limited awareness of the current indications and the techniques involved. Furthermore, radiologists without any prior experience are frequently expected to interpret post-treatment imaging, often performed in the context of acute complications, which have occurred after discharge. This review aims to provide an overview of the current indications for pulmonary ablation, together with the techniques involved and the range of post-procedural appearances.

Hypertrophic pulmonary osteoarthropathy with primary lung cancer

Hypertrophic pulmonary osteoarthropathy (HPO) is a rare paraneoplastic syndrome that is frequently associated with lung cancer; however, the incidence of clinically apparent HPO is not well known. The clinical data of 6,151 patients with advanced lung cancer between January 1996 and December 2008 were retrospectively analyzed in Zhejiang Cancer Hospital (Hangzhou, China). Data pertaining to the presentation of HPO, diagnosis, treatment, pathology, follow-up and clinical course were documented. HPO was confirmed using bone scintigraphy by the identification of symmetrical, abnormally high uptake in the joints, and/or long bones with digital clubbing in the extremities as well as joint pain. The clinical characteristics were investigated based on clinical and pathological records. The patients were presenting with lung cancer for the first time and had not received treatment. Among the 6,151 lung cancer patients, 115 (1.87%) demonstrated an abnormally high uptake on bone scintigraphy and digital clubbing in the extremities combined with joint pain. A total of 109 patients received surgery or chemotherapy treatment and 92 exhibited improved symptoms. The improvement rate of HPO was lower in the non-surgery compared with the surgery patients (77.4 vs. 91.1%; P=0.049). Bone scintigraphy was repeated in 85 patients within 3-6 months, and the HPO symptoms improved in 70 patients. The present retrospective study indicated that 1.87% of patients with lung cancer showed characteristics that were identified as HPO. The majority of the patient symptoms and the bone scintigram of HPO improved as a result of treatment.

Review of current therapies for secondary hypertrophic pulmonary osteoarthropathy

Hypertrophic osteoarthropathy (HOA) is a disabling condition that may occur secondarily to primary lung cancer. It is characterized by digital clubbing, arthralgia/arthritis, and periostosis of the tubular bones. The pain associated with HOA can be disabling and often refractory to conventional analgesics. We performed a comprehensive review of the literature using the PubMed database on treatment modalities available for HOA. We found 52 relevant articles-40 case reports, six case series, two review papers, and four combined case series and review papers. There were no randomized controlled trials reported. We then classified treatments used for HOA into two categories: (1) treatment of primary cause (i.e., resection of tumor, chemotherapy, radiotherapy, treatment of infection, etc.) and (2) symptomatic treatments (i.e., bisphosphonates, octreotide, NSAIDs, vagotomy, etc.). Subsequently, we summarized the main findings for each treatment. Although the clinical diagnosis of HOA has existed for over 100 years, the pathogenesis mechanism has not yet been elucidated, and treatment options for this condition remain experimental. Primary treatment is the most widely reported modality to be efficacious. In cases which primary therapy is not possible, several symptomatic treatment modalities are suggested, with various degree of success. Further research is needed to clarify the pathophysiological mechanism of HOA as to appropriately direct therapy.

Image-guided radiofrequency ablation (RFA) of spinal tumors

PURPOSE

To evaluate retrospectively the efficacy and safety of radiofrequency ablation (RFA) in patients with spinal tumors.

MATERIALS AND METHODS

Forty-one patients (25 men, 16 women; age range, 46-82 years) with nonresectable primary or secondary tumor involvement of the spine unresponsive to chemo- and radiotherapy received RFA treatment. Two radiofrequency ablation systems, one with a cool-tip electrode and one with an expandable electrode catheter, were used. Both systems work impedance controlled with a power output of 150- 200 W. Each coagulation cycle lasted 12-15 min depending on tumor impedance. Several single RFA cycles of 15 min each were used for overlapping RFAs in tumors with diameters of more than 3 cm. Temperature was kept between 50 degrees C and 120 degrees C and was chosen according to spinal cord distance and patient heat tolerance during the ablation. Multi-slice computed tomography (CT) combined with C-arm fluoroscopy guided the intervention. Efficacy outcomes were assessed after about 6 weeks, 6 months, and more than 6 months using standardized questionnaires and indices regarding tumor pain, pain disability, functional activities, quality of life, neurological status, and tumor progression.

RESULTS

RFA significantly reduced tumor-induced pain within 6 weeks, improved daily activities, and maintained quality of life. Mean time to tumor progression was 730+/-54 days (Kaplan-Meier estimate). No RFA-associated complications were reported.

CONCLUSION

RFA of primary and secondary spinal tumors, which were unresponsive to chemo- and radiotherapy and prone to progression, is a safe, resource-saving, and highly effective percutaneous technique in patients with nonresectable spinal tumors.

Radiofrequency ablation of primary and metastatic lung tumors: preliminary experience with a single center device

BACKGROUND

This study aimed to assess the feasibility and short-term results for percutaneous radiofrequency ablation in the treatment of primary and secondary lung tumors.

METHODS

Between May 2003 and July 2004, 15 patients (mean age, 64.9 years; range, 51-80 years) with 18 pulmonary lesions (9 primitive non-small cell lung cancers and 9 metastases) underwent the ablation procedure. All the patients had absolute contraindications to the surgery. The procedure was performed under computed tomography (CT) guidance with anesthesiologic assistance using a coaxial Le Veen needle electrode. The results were evaluated by postprocedural CT scan, and then by clinical and laboratory examination and CT scan 1, 3, 6, 9, and 12 months after the treatment.

RESULTS

A complete ablation was obtained for 16 of 18 lesions (88.9%), and a partial ablation was achieved for the remaining 2 lesions (central tumors). In terms of complications, there were five cases of pneumothorax (2 resolved spontaneously and 3 were drained through a coaxial needle), four middle pleural reactions, and one hemothorax that required draining surgically. Follow-up evaluation was performed for 16 of 18 lesions. Stability was observed in one of two central tumors that received partial ablation. The remaining 15 tumors that received a complete ablation were followed up for a mean of 5 months (range, 1-12 months). All 15 lesions appeared to be hypodense at the CT examination. Dimension reduction with progressive fibrotic scar formation was observed in seven of seven lesions during a follow-up period of 6 months or more. A recurrence at the site of the treatment for two of three lesions was observed during a 12-month follow-up period. One of these received a second radiofrequency ablation. Five patients experienced systemic disease progression. In four of these five patients, this progression was not associated with recurrence at the site of the treatment.

CONCLUSION

Radiofrequency ablation seems to be possible for "nonsurgical" patients with primary and secondary lung tumors. Good results in terms of local tumor control were observed during short-term follow-up evaluation.

Percutaneous CT-guided radiofrequency ablation of pulmonary malignant tumors: preliminary report

OBJECTIVE

Radiofrequency ablation (RFA) is frequently used for hepatic malignant tumors, but few reports discuss its use for lung tumors. We report our pilot clinical study with RFA for the treatment of pulmonary malignant tumors.

PATIENTS AND METHODS

Five patients with histologically-proven malignant primary and three metastatic lung tumors underwent a total of 11 RFA procedures. RFA was performed in two patients as palliative therapy to shrink the tumors and in six as radical therapy. All RFA was performed by the percutaneous CT-guided approach.

RESULTS

Three tumors were completely ablated by one procedure. Contrast CT revealed cyst cavity formation or scar formation at these three tumors. Gd contrast-enhanced MRI revealed cystic lesions with ringlike enhancement or scar formation. Partial ablation after the first procedure was noted in six tumors including the two palliative cases. RF ablation was well tolerated in all patients. Intraprocedural complications included six cases of pneumothorax (one patient required chest tube placement), six cases of pleural effusion (two patients required chest tube placement), one case of pneumonia (improved immediately with antibiotics), three cases of bloody sputum (mild), and six cases of chest pain (all cases after the procedure).

CONCLUSIONS

This pilot clinical study demonstrates that CT-guided RFA is a relatively safe and effective treatment option for malignant lung tumors. Additional trials are needed to determine the safety, efficacy, and optimal indications of RFA.

Surgical aspects in the treatment of lung cancer

PURPOSE OF REVIEW

The treatment of lung cancer has been most successful when surgery is involved. This review is a succinct overview of lung cancer treatment from the thoracic surgeon's perspective over the past 2 years.

RECENT FINDINGS

Starting with the evidence-based guidelines developed by the American College of Chest Physicians, the main themes in the literature are a multimodality approach and the miniaturization of surgical approaches. Palliative procedures, staging, and extension of surgery to patients previously thought inoperable are other subjects covered.

SUMMARY

We are standing on the verge of having a definitive answer to the 20-year-old question whether adjuvant or neoadjuvant chemotherapy benefits patients with early-stage non-small cell lung cancer. Sufficient data will be available shortly to determine whether minimally invasive surgical approaches yield similar long-term outcomes as traditional approaches.

Percutaneous radiofrequency ablation of lung tumors in a large animal model

PURPOSE

Percutaneous radiofrequency ablation (RFA) is accepted therapy for liver tumors in the appropriate clinical setting, but its use in lung neoplasms remains investigational. We undertook this study to evaluate the feasibility and immediate effectiveness of RFA for treatment of both solitary pulmonary nodules and clusters of lung tumors in a large animal model.

MATERIALS AND METHODS

Percutaneous RFA of 14 lung tumors in five dogs was performed under CT guidance. Animals were euthanatized 8-48 hours after the procedure. The lungs and adjacent structures were harvested for gross and histopathologic evaluation.

RESULTS

Five solitary pulmonary nodules (range, 17-26 mm) and three clusters of three nodules each (range, 7-17 mm per nodule) were treated with RFA. All ablations were technically successful. Perilesional ground-glass opacity and small asymptomatic pneumothoraces (n = 4) were visualized during the RFA sessions. One dog developed a large pneumothorax treated with tube thoracostomy but was euthanatized 8 hours post-RFA for persistent pneumothorax and continued breathing difficulty. Follow-up CT 48 hours post-RFA revealed opacification of the whole lung segment. Gross and histopathologic evaluation showed complete thermal coagulation necrosis of all treated lesions without evidence of any viable tumor. The region of thermal coagulation necrosis typically extended to the lung surface. Small regions of pulmonary hemorrhage and congestion often surrounded the areas of coagulation necrosis.

CONCLUSIONS

RFA can be used to treat both solitary pulmonary nodules and clusters of tumor nodules in the canine lung tumor model. This model may be useful for development of specific RFA protocols for human lung tumors.