CT for detection of malignant posterior intercostal lymph nodes in patients undergoing pre-operative staging for malignant pleural mesothelioma

INTRODUCTION

Recent evidence suggests that patients with malignant pleural mesothelioma (MPM) undergoing extended pleurectomy/decortication (eP/D) with metastasis to the posterior intercostal lymph nodes (PILN) have a worse prognosis. In this study, we determine if MPM PILN metastasis can be reliably detected on computed tomography (CT).

MATERIALS AND METHODS

Preoperative staging CT exams were reviewed for the presence of PILN in MPM patients undergoing eP/D between 2007-2013 with surgical sampling of their PILN. CT images were reviewed by two thoracic radiologists blinded to clinical records, including operative pathology reports. The number and short axis size of PILN were recorded and correlated with surgical pathology. Statistical analysis examined the value of preoperative CT to detect metastatic PILN.

RESULTS

Of 36 patients that underwent eP/D with PILN sampling had preoperative CT images for review. At surgery, 22 of these patients had metastatic PILN and 14 had benign PILN. The positive and negative predictive values for one or more nodes seen on preoperative CT were 60 % and 38 % respectively. The number of PILN on preoperative CT did not predict metastasis (p = 0.40) with an average of 2 PILN seen, regardless of PILN pathology. The average nodal short axis size was 4.6 mm and 4.8 mm for benign and malignant PILN, respectively, and PILN short axis size did not predict metastasis (p = 0.39). There was little inter-observer variability between the size and number of nodes detected by each radiologist.

CONCLUSIONS

CT does not reliably identify metastatic PILN on preoperative CT for patients with MPM undergoing extended pleurectomy/decortication.

A multicenter pilot study of a bronchial valve for the treatment of severe emphysema

BACKGROUND

Chronic obstructive pulmonary disease (COPD) affects millions of people and has limited treatment options. Surgical treatments for severe COPD with emphysema are effective for highly selected patients. A minimally invasive method for treating emphysema could decrease morbidity and increase acceptance by patients.

OBJECTIVE

To study the safety and effectiveness of the IBV(R) Valve for the treatment of severe emphysema.

METHODS

A multicenter study treated 91 patients with severe obstruction, hyperinflation and upper lobe (UL)-predominant emphysema with 609 bronchial valves placed bilaterally into ULs.

RESULTS

Valves were placed in desired airways with 99.7% technical success and no migration or erosion. There were no procedure-related deaths and 30-day morbidity and mortality were 5.5 and 1.1%, respectively. Pneumothorax was the most frequent serious device-related complication and primarily occurred when all segments of a lobe, especially the left UL, were occluded. Highly significant health-related quality of life (HRQL) improvement (-8.2 +/- 16.2, mean +/- SD change at 6 months) was observed. HRQL improvement was associated with a decreased volume (mean -294 +/- 427 ml, p = 0.007) in the treated lobes without visible atelectasis. FEV(1), exercise tests, and total lung volume were not changed but there was a proportional shift, a redirection of inspired volume to the untreated lobes. Combined with perfusion scan changes, this suggests that there is improved ventilation and perfusion matching in non-UL lung parenchyma.

CONCLUSION

Bronchial valve treatment of emphysema has multiple mechanisms of action and acceptable safety, and significantly improves quality of life for the majority of patients.

Phase 1/2 trial of autologous tumor mixed with an allogeneic GVAX vaccine in advanced-stage non-small-cell lung cancer

Tumor vaccines composed of autologous tumor cells genetically modified to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF) (GVAX) have demonstrated clinical activity in advanced-stage non-small-cell lung cancer (NSCLC). In an effort to remove the requirement for genetic transduction of individual tumors, we developed a 'bystander' GVAX platform composed of autologous tumor cells mixed with an allogeneic GM-CSF-secreting cell line. We conducted a phase I/II trial of this vaccine (3-12 biweekly vaccinations) in advanced-stage NSCLC. Tumors were harvested from 86 patients, tumor cell processing was successful in 76, and 49 proceeded to vaccination. The most common toxicity was local vaccine injection site reactions. Serum GM-CSF pharmacokinetics were consistent with secretion of GM-CSF from vaccine cells for up to 4 days with associated transient leukocytosis confirming the bioactivity of vaccine-secreted GM-CSF. Evidence of vaccine-induced immune activation was demonstrated; however, objective tumor responses were not seen. Compared with autologous GVAX vaccines prepared by transduction of individual tumors with an adenoviral GM-CSF vector, vaccine GM-CSF secretion was approximately 25-fold higher with the bystander GVAX vaccine used in this trial. However, the frequency of vaccine site reactions, tumor response, time to disease progression, and survival were all less favorable in the current study.

Current treatment options and biology of peritoneal mesothelioma: meeting summary of the first NIH peritoneal mesothelioma conference

Peritoneal mesothelioma is a rare cancer of the peritoneum with about 250 new cases diagnosed each year in the United States. It is the second most common site for mesothelioma development and accounts for 10-20% of all mesotheliomas diagnosed in the United States. A meeting sponsored by the NIH Office of Rare Diseases was held in Bethesda, Maryland on September 13 and 14, 2004. The objective of this meeting was to review the epidemiology, biology and current surgical and medical management of peritoneal mesothelioma. In addition, the meeting also discussed clinical and pre-clinical evaluation of novel treatments for mesothelioma as well as ongoing laboratory research to better understand this disease. This report summarizes the proceedings of the meeting as well as directions for future clinical and basic research.

Prognostic value of FDG PET imaging in malignant pleural mesothelioma

Despite several attempts at treating malignant pleural mesothelioma with various modalities, mortality remains high, with median survival between 12 and 18 mo. This disease may have a highly variable clinical course, with occasional long-term survivors. The purpose of this study was to assess whether tumor metabolic activity, as assessed by fluorodeoxyglucose (FDG) PET imaging, correlates inversely with survival.

METHODS

Twenty-eight patients with suspected mesothelioma underwent FDG PET scanning between September 1995 and May 1997. A diagnosis of mesothelioma was confirmed in 22. Fully corrected scans with attenuation correction of the entire chest were available in 17 patients with sufficient follow-up for survival analysis. Standardized uptake values (SUVs) were determined from the most active tumor site in each patient.

RESULTS

Seven patients died during follow-up, at a median period of 5.3 mo after FDG PET scanning. Follow-up information was available on the remaining 10 patients for a median period of 15.6 mo after the PET study. The mean SUV of the deceased patients was 6.6+/-2.9, compared with 3.2+/-1.6 among the combined survivors. The deceased patients had tumor SUVs that were highly correlated with duration of survival after the PET study (r = 0.87, P < 0.05). The cumulative survival estimate by the Kaplan-Meier product limit method was 0.17 at 12 mo for the patients with tumor SUVs greater than the median value and 0.86 for those with lower SUVs. The survival distribution of the high SUV group showed significantly shorter survivals compared with the low SUV group (P < 0.01).

CONCLUSION

Patients with highly active mesotheliomas on FDG PET imaging have a poor prognosis. High FDG uptake in these tumors indicates shorter patient survival.

Metabolic imaging of malignant pleural mesothelioma with fluorodeoxyglucose positron emission tomography

BACKGROUND

The diagnosis of malignant mesothelioma is a challenging medical problem. CT often cannot differentiate between benign diffuse pleural thickening and malignant mesothelioma, while thoracentesis and CT-guided biopsies are insensitive. We have assessed the value of positron emission tomography (PET) with 2-fluoro-2-deoxy-D-glucose (FDG) in the evaluation of malignant mesothelioma.

METHODS

Twenty-eight consecutive patients referred for the evaluation of suspected malignant mesothelioma were evaluated by FDG-PET imaging. Measured attenuation correction was performed in 26 of 28 cases for quantitation with the standardized uptake value (SUV) method. The results of PET imaging were compared with those of video-assisted thoracoscopy or surgical biopsies.

RESULTS

Surgical biopsy specimens confirmed the presence of malignant disease in 24 patients and demonstrated benign processes in the remaining four. The uptake of FDG was significantly higher in malignant than in benign lesions (SUV=4.9+/-2.9 and SUV=1.4+/-0.6, respectively; p<0.0001). With a SUV cutoff of 2.0 to differentiate between malignant and benign disease, a sensitivity of 91% and a specificity of 100% could be achieved, although the activity in some epithelial mesotheliomas tended to be close to this threshold. FDG-PET images provided excellent delineation of the active tumor sites. Hypermetabolic lymph node involvement was noted on FDG-PET images in 12 patients, 9 of which appeared normal on CT scans. Histologic examination in six patients confirmed malignant nodal disease in five cases and indicated granulomatous lymphadenitis in one.

CONCLUSION

In this highly selected population, FDG-PET imaging was a sensitive method to identify malignant mesothelioma and determine the extent of the disease process.