Prevalence of occult metastatic disease in patients undergoing 18F-FDG PET for primary diagnosis or staging of lung carcinoma and solitary pulmonary nodules

BACKGROUND

Accurate staging of lung cancer is essential in determining the most appropriate management plan, as detection of occult metastasis can significantly alter management.

AIMS

The aims of this study are to determine the prevalence of occult metastasis in patients undergoing 2-(18)F-fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography (PET) for evaluation of suspected/proven lung carcinoma and correlate pre-PET TNM stage with prevalence of metastasis.

METHODS

FDG-PET, which identified patients with metastasis on institutional database, was re-evaluated by a nuclear medicine physician blinded to clinical information. The confidence level of metastasis was scored on a 5-point scale, with a score of >/=4 considered positive.

RESULTS

There were 67 of 645 (10%) patients identified with suspected occult metastasis on FDG-PET. Twelve patients scoring </=3 were excluded. Prevalence of occult metastasis was 10/156 (6%) in solitary pulmonary nodules (SPN); 22/319 (7%) and 23/170 (14%) in proven and suspected lung cancer, respectively. Positive predictive value of FDG-PET for metastasis was 8/10 (80%) in solitary pulmonary nodules, 14/20 (70%) and 17/21 (81%) in proven and suspected lung cancer, respectively. (18)F-FDG-avid lesions classified as false positives were patients with cholelithiasis, rib fractures and those with equivocal/negative bone scans or computed tomography on follow up. There was a higher incidence of true positive occult metastasis in patients in all stages of disease, particularly stage III disease.

CONCLUSION

(18)F-FDG PET is predictive for occult metastatic disease in patients with solitary pulmonary nodules and proven or suspected lung cancer and is more likely to be present in all stages, particularly in stage III. PET findings should be actively pursued with correlative investigation to identify benign pathology in patients who remain candidates for curative treatment.

Video-assisted thoracoscopic thymectomy for myasthenia gravis

BACKGROUND

Thymectomy is an effective, but radical therapy for myasthenia. Video-assisted thoracic surgery (VATS) may allow a minimally invasive alternative to the standard sternotomy approach.

AIMS

To audit prospectively the outcome of VATS thymectomy for myasthenia gravis in a unit specializing in advanced VATS techniques.

METHODS

Twenty-six patients underwent VATS thymectomy between 1997 and 2001. Most underwent preoperative plasma exchange therapy. Seventeen women and nine men with a median age of 36 years (range 17-71 years) had a right-sided VATS approach to remove all anterior mediastinal fat and thymic tissue.

RESULTS

There was no perioperative mortality and all procedures were concluded successfully, with one patient requiring sternotomy. Twenty-five patients were extubated in theatre and one patient required 17 h of assisted ventilation. The other significant complication was a diathermy injury to the phrenic nerve, which recovered. Median postoperative stay was 4 days (range 2-6 days), with median postoperative chest drainage for 2 days (range 1-3 days). Three patients had progression of disease postoperatively. The remainder were asymptomatic (7), improved (14) or stable (2).

CONCLUSION

In a dedicated unit with neurological and intensive care support, VATS thymectomy is a safe, effective method of obtaining remission or improvement in myasthenia gravis (MG). While achieving the same surgical goal, this approach offers advantages of improved cosmesis, shorter recovery time and minimal chest wall disruption over the gold standard of sternotomy. Better patient acceptance of this minimally invasive technique may result in wider application of the benefits of thymectomy in MG.

F-18 fluorodeoxyglucose positron emission tomography in the non-invasive staging of non-small cell lung cancer

OBJECTIVE

Positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG), a glucose analogue, as a metabolic tumour marker, has been proposed for the non-invasive staging of oncological disease. Tumours demonstrate increased glycolytic activity and thereby, FDG PET can differentiate benign from malignant lesions. To determine its role in the mediastinal staging of patients with suspected non-small cell lung cancer, a prospective study of FDG PET and computed tomography (CT) compared to surgery and pathology was performed. The analysis group consists of 50 patients, 37 men and 13 women, mean age 64 years (range, 41-78 years).

METHODS

A nuclear physician, blind to the clinical and CT data, graded the FDG PET studies qualitatively on a five-point scale, based on the intensity of glucose uptake, for the presence of mediastinal nodal tumour involvement. Scores of four or greater were considered positive for tumour. An experienced radiologist interpreted the patients' CT scans blind to the other data. The CT criterion for tumour involvement was a nodal long axis diameter of 10 mm or greater. All patients underwent either thoracotomy or mediastinoscopy to obtain surgical specimens. The PET, CT, surgery and pathology were mapped according to the American Thoracic Society nodal classification resulting in 201 nodal stations evaluated. The imaging studies were analysed for N2 or N3 tumour involvement compared to histology or dissection of nodal stations.

RESULTS

All patients had proven non-small cell lung carcinoma. PET excluded tumour in 175 of 181 nodal stations (specificity 97%) compared to 162 of 181 (specificity 90%) by CT. PET correctly identified 16 of 20 (sensitivity 80%) nodal stations with tumour compared to 13 of 20 by CT (sensitivity 65%). Overall, PET correctly staged 191 of 201 nodal stations (accuracy 95%) compared to 175 of 201 by CT (accuracy 87%). By the McNemar test, PET was significantly more specific than CT in excluding nodal tumour involvement (X2 = 5.5, P < 0.05).

CONCLUSIONS

FDG PET is more specific than computed tomography in the non-invasive mediastinal staging of non-small cell lung cancer and has an important clinical role in the pre-operative staging of lung cancer patients.

VATS plication of diaphragmatic eventration

Diaphragmatic eventration in the adult may be associated with dyspnoea. Video-assisted thoracoscopic surgery (VATS) techniques have been applied to the plication of diaphragmatic eventration in three adult patients. Symptoms and spirometry improved in all patients. Ventilation and perfusion of the affected lung was also improved.

The contribution of 18F-fluoro-2-deoxy-glucose positron emission tomographic imaging to radiotherapy planning in lung cancer

A retrospective analysis was performed to determine whether coronal thoracic [18F]fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) scans, if viewed at the time of radiotherapy (RT) planning, would have influenced the anterior-posterior (AP) RT volumes that were administered to a group of unoperated lung cancer patients. Viewing of PET and diagnostic images enabled a qualitative assessment of whether abnormal thoracic PET activity was present in areas regarded as normal by diagnostic imaging; this would, therefore, have influenced the RT volume if done prospectively. Additionally a method of graphical co-registration was devised to quantitate the adequacy of coverage of each patient's abnormal PET activity by his/her actual RT field. Of 15 patients analyzed, 26.7% (four patients) would have had their RT volume influenced by PET findings, highlighting the potential value of PET in treatment planning.

Mucin 1 antigens in the serum and bronchial lavage fluid of patients with lung cancer

BACKGROUND

Lung cancer (LC) is the most common fatal malignancy, but there are no useful tumor markers for diagnosis or monitoring. Mucin 1 has an established role as a marker in other malignancies, but has undergone limited assessment in LC.

METHODS

Serum from 86 patients with LC and 24 with benign pulmonary disease (BPD), and bronchial lavage fluid from 55 LC patients and 21 BPD patients were tested using the Mucin 1 assays mammary serum antigen (MSA) and cancer-associated serum antigen (CASA).

RESULTS

For LC, serum CASA achieved sensitivity of 57%, specificity of 93% relative to normals, and 63% specificity relative to BPD. For MSA the same parameters were 19%, 95%, and 92%. Serum CASA levels were significantly higher in LC patients compared with BPD (P = 0.024) but there was no difference for MSA (P = 0.635). CASA showed excellent correlation with tumor stage and in patients with changing status of disease, while MSA did not. By contrast there was no difference in bronchial lavage fluid tumor marker levels from LC and BPD patients (CASA, P = 0.87; MSA, P = 0.89).

CONCLUSIONS

In a small series serum CASA appears to be a useful agent in detecting LC because it is elevated in all types and stages of LC, and its level correlates with stage and progress of disease. Some patients with BPD have elevated levels suggesting a greater value for monitoring rather than diagnosis. Both serum MSA testing and measurements of either marker in bronchial lavage fluid are of no value.

Dentures: difficult oesophageal foreign bodies

Oesophageal foreign bodies occur commonly, but dentures are swallowed infrequently. Two cases are reported that demonstrate the difficulties in the localization and retrieval of ingested dentures, because they are radiolucent and have an awkward shape. Early rigid oesophagoscopy is recommended as the most appropriate investigation and method of removal.

Craniotomy and thoracotomy for non-small cell carcinoma of the lung with cerebral metastasis

Twenty patients with non-small cell carcinoma of the lung who had cerebral metastasis, were treated by craniotomy and thoracotomy. Eighteen of these patients had a solitary metastasis and all were treated as curable. Ten patients presented with synchronous lung and brain disease. Of the remaining 10, nine initially presented with the lung tumour, which was treated first. There was a zero operative mortality rate and median survival was 12 months with reasonable quality of life for this time.

Bronchogenic cyst: a cause of pulmonary artery obstruction and breathlessness

A young woman presenting with breathlessness and a normal chest roentgenogram was found to have unilateral absent lung perfusion on an isotope scan. This was due to a bronchogenic cyst obstructing the right pulmonary artery. This is a rare cause of unilateral absence of lung perfusion and an unusual mode of presentation of a bronchogenic cyst.

Concomitant coronary revascularization and resection of lung cancer

As age and smoking are common risk factors, patients with lung cancer frequently have coexistent ischaemic heart disease. Ignoring the coronary disease results in an unacceptable operative mortality, whilst sequential coronary grafting and lung resection may prejudice the results of the resection. A series of 10 patients underwent combined coronary revascularization (average 2.9 grafts per patient) and lung resection for carcinoma (seven lobectomies, one bilobectomy, one sleeve lobectomy, and one pneumonectomy). The majority of patients had unstable angina, triple vessel or left main coronary artery stenosis and poorly staged tumours. There was no operative mortality and the average hospital stay was 20 days. Half the patients had significant peri-operative morbidity; seven are alive and well at between 12 and 38 months follow-up; but three have died of recurrent carcinoma (one with associated sepsis) at 3, 8, and 13 months. Combined coronary revascularization and lung resection can be safely performed in selected patients. The early morbidity is mainly related to the cardiac procedure and impaired respiratory function preoperatively, but the long-term results are dependent upon the control of the lung carcinoma.

Endosurgical treatment for spontaneous pneumothorax

When spontaneous pneumothorax is recurrent or persistent, an open pleurodesis with excision or ligation of the bullae is the procedure of choice but can lead to significant morbidity. Thorascopic surgery for the management of spontaneous pneumothorax was first introduced in 1937 but this has become a useful technique only since the introduction of video-controlled thorascopic surgery and the availability of suitable endothoracic instrumentation. A review was made of nine patients having endosurgery for recurrent (six) or persistent (three) pneumothorax. At surgery the bullae were ligated with an endoloop (four) or excluded with an endostapler (five). Pleurodesis was obtained by a combination of strip pleurectomy, diathermy and installation of an alcohol iodine solution. The early results are similar to those following an open operation with considerably reduced hospital stay and morbidity.

Subxiphoid partial pericardiectomy with or without sclerosant instillation in the treatment of symptomatic pericardial effusions in patients with malignancy

Twenty-two patients with malignant pericardial effusions were treated with subxiphoid partial pericardiectomy between 1984 and 1989. Thirteen patients also had a sclerosing agent instilled intrapericardially. Tamponade was relieved by pericardiocentesis before administration of general anesthesia. In 18 patients (82%), the effusions were controlled for longer than 30 days, and two patients died before 30 days without effusion. There were two recurrences at 1.5 and 7 months. There was one death due to hemorrhage from a laceration in a heavily infiltrated pericardium, and one patient had persistent dyspnea after the procedure. Complications included transient atrial arrhythmias (two patients), chest pain after sclerosant instillation (three patients), and fever greater than 37.5 degrees C after sclerosant (five patients). The survival range was 0.1 to 18 months (median, 5 months). Subxiphoid partial pericardiectomy with or without intrapericardial sclerosant is a safe and efficacious treatment for malignant pericardial effusions.

Bronchoscopic use of the neodymium-yttrium-aluminium-garnet laser for lesions of the trachea and bronchus

The neodymium-yttrium-aluminium-garnet laser has proved to be a useful therapeutic tool for the management of endobronchial lesions. Between October 1, 1986 and October 31, 1987, 31 patients received 41 laser treatments at the Peter MacCallum Cancer Institute mainly for bronchial obstruction, haemoptysis or persistent cough. Good symptomatic relief was obtained in the majority of patients with no operative mortality and a moderate morbidity. When the endobronchial lesion is malignant, concurrent radiotherapy is needed to prevent the early recurrence of the cancer.

Maximum likelihood estimation of genetic parameters of HLA-linked diseases using data from families of various sizes

This paper is concerned with estimating parameters associated with HLA-linked diseases. We consider a single disease locus closely linked to HLA, allowing a disease and a normal allele. The parameters to be estimated are the penetrances of the genotypes at the disease locus, the population frequency of the disease allele, and the distance of the disease locus from HLA. The presently used method of estimation uses HLA-sharing information from affected sib-pairs. The method proposed here generalizes the previous approach, using data from all sibs (affected or unaffected) in a family of any size. It allows immediate generalizations to the use of information on parental affectedness status and population prevalence.

The surgical management of total atrioventricular canal lesions

Between 1969 and 1976 sixteen children have had surgery for total atrioventricular canal lesions at the Royal Children's Hospital, Melbourne. Twelve infants had palliative banding of the main pulmonary artery to control heart failure and prevent the development of pulmonary hypertension, with two hospital deaths (17%) and one late death. One other patient has been lost to follow-up and may also have died. Nine patients have undergone complete repair, with three hospital deaths (33%), and one later death at reoperation for residual mitral incompetence. Five of these had previously had banding of the main pulmonary artery, and the mortality has occurred exclusively in this group. The techniques of repair are discussed, and reasons advanced in favour of early primary repair of the defect in preference to palliative banding and later secondary repair.

Surgical "correction" of transposition of the great arteries: a review of 100 consecutive cases

A review has been made of 100 patients having repair of transposition of the great arteries during a six-year period. The overall hospital mortality was 12%. In uncomplicated cases with an intact ventricular septum it was 7%. Late complications have presented a significant problem and include caval inflow stenosis, pulmonary venous obstruction, dysrhythmias and tricuspid incompetence. The changes in operative techniques to overcome them are discussed.

Massive pulmonary arteriovenous fistula in the newborn

Although pulmonary arteriovenous fistula as a cause of cyanosis is well recognized, most of the reported cases occur in older children and adults, and its importance as a correctable lesion in the newborn is often overlooked. The details of two babies who presented with cyanosis in the first few days of life are presented to emphasize that this eminently treatable lesion may need to be managed as an emergency.

Tetralogy of Fallot. Risk factors associated with complete repair

Ninety-six consecutive total repairs of the tetralogy of Fallot are reviewed. There was an overall hospital mortality of 8-3 per cent and a total incidence of low output cardiac failure of 18-8 per cent, and this was the principal cause of death and the most important source of postoperative morbidity. In 49 cases there had been a previous palliative shunt procedure and there was a strikingly lower mortality and a highly significant lower morbidity in this group. Other factors which correlated in a positive fashion with increased mortality and morbidity were chronic hypoxia (as evidenced by polycythaemia), age below 5 years, severe postoperative right ventricular hypertension, and (to a lesser extent) extensive right ventricular outflow tract reconstruction. Data are presented to support the hypothesis that a palliative shunt procedure should be considered in the severely polycythaemic child with a surgically 'unfavourable' right ventricular outflow. This policy carries a low early mortality in our hands (5-4%), and is associated with a low mortality (3-9%) at a subsequent repair. This compares with a mortality of 12-8 per cent for primary repair, and the incidence of low output cardiac failure is five times as high in the primary repair as compared to the previously shunted group.

An evaluation of Potts' aortopulmonary shunt for palliation of cyanotic heart disease

The results of 28 Potts' aortopulmonary shunts created for the relief of cyanotic heart disease are reviewed in this study. The shunt gave excellent symptomatic relief, but the incidence of immediate and late complications is high. Regular follow-up of patients is mandatory to detect evidence of increasing pulmonary vascular disease and to under take corrective surgery whenever feasible before its occurrence. Although Potts' anastomosis has been largely replaced by alternative shunt procedures, there may still be a place for its application in selected situations. Only a few problems were encountered at the time of closure of the shunt in 11 patients during corrective surgery using a transpulmonary technique and hypothermia with circulatory arrest.

The management of aortopulmonary window: advantages of transaortic closure with a dacron patch

Since 1970, 7 patients varying in age between 1 month and 3 years have had successful correction of an aortopulmonary septal defect. Three of these patients had associated cardiac lesions which were repaired at the same time. Extracorporeal circulation was used in 3 patients and profound hypothermia with limited extracorporeal circulation in 4. In 5 patients the defect was closed with a Dacron patch through a transaortic approach. The advantages of this method are discussed.

The management of infants for cardiac surgery under deep hypothermia

Deep hypothermia is now employed for open heart surgery in infants. The method of surface cooling infants to 25° C and then by-pass cooling down to 15–20° C prior to exsanguination is described. This provides a still heart and ideal operating conditions. The infants are re-warmed on by-pass. Some of the physiological effects of hypothermia and the methods employed to counteract these are discussed. The aims are to reduce temperature gradients, improve cerebral oxygen supply, avoid arrhythmias and secure haemostasis.

The experience in 33 operations is outlined. Seventeen patients were under one year of age.

The fate of preserved homograft pericardium and autogenous pericardium within the heart

Animal experiments were performed to assess the usefulness of preserved homograft pericardium for intracardiac surgery, with particular reference to the problem of homograft mitral valve papillary muscle fixation. The fate of fresh autogenous pericardium was also studied. Both homograft and autogenous pericardium were destroyed and replaced by fibrous tissue. This reaction was faster when the pericardium was in direct contact with the blood stream and slower when it was buried within the myocardium. As homograft pericardium provided a more intense fibrous reaction than autogenous pericardium, it was considered to be very suitable for papillary muscle fixation and less suitable for other intracardiac procedures. The technique used for attaching the papillary muscle of a homograft mitral valve is briefly described.