| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Eur J Cardiothorac Surg 2002;21:611-615
© 2002 Elsevier Science NL
Royal Prince Alfred Hospital, Sydney, NSW, Australia
Received 10 October 2000; received in revised form 6 December 2001; accepted 3 January 2002.
* Corresponding author. Department of Cardio-thoracic Surgery, Plymouth Hospital, Plymouth PL6 8DH, UK. Tel.: +44-1752-763-833
e-mail: malcolm.dalrymple-hay{at}virgin.net
 |
Abstract |
|---|
 Top Abstract 1. Introduction2. Patients and methods3. Results4. DiscussionAppendix A. Conference...References |
|---|
Key Words: Pulmonary metastatic melanoma • Positron emission tomography scanning • Metastectomy
|
1. Introduction |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix A. Conference...References |
|---|
The principal difficulty in assessing these patients is ensuring there is no extra pulmonary disease. Whole body fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) has a high sensitivity and specificity in staging newly diagnosed and recurrent malignant melanoma. In several studies PET has been shown to detect more lesions than CT leading to alterations in both tumour stage and clinical management [2–5] however this is not a universal finding [6,7]. It is proven that changes in glucose uptake can be visualized before anatomical changes [8].
We have performed a retrospective review of the impact of preoperative PET on the treatment of patients with pulmonary metastatic melanoma. Survival is compared in patients who underwent pulmonary metastectomy staged with conventional radiology and PET.
|
2. Patients and methods |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix A. Conference...References |
|---|
In all cases the disease was thought to be isolated to the lung. A postero-lateral thoracotomy with surgically stapled wedge resection of all radiological and palpable nodes was the procedure of choice. All patients had histological confirmation of pulmonary metastatic melanoma.
There was no significant difference in number of patients with lymphatic involvement or in the number of metastases resected in each group. There was also no significant difference in time from excision of primary and detection of metastasis between the two groups (PET 63 months, CT 83 months – P=0.30).
Survival was obtained from existing records and by telephone contact with the relevant practices. Survival totals 238 patient years and was 100% complete.
2.1. Statistical analysis
The preoperative performance of a PET scan has been used to divide the patients into two groups.
Statistical analysis was performed according to standard statistical protocols incorporated in the SAS statistical package JMP (SAS Institute, Cary, NC, USA). Survival was analyzed using Kaplan–Meier curves [9]. Survival between groups was compared using Log rank tests.
|
3. Results |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix A. Conference...References |
|---|
One patient died within 30 days. Survival (±SE) including early mortality at 1, 3, 5, and 7 years was 68% (±4.5) (n=67), 36.6% (±5.2) (n=27), 22.1% (±4.8) (n=15) and 13.5% (±4.2) (n=7), respectively (Fig. 1) .
|
|
|
|
|
|
4. Discussion |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix A. Conference...References |
|---|
It has previously been shown that staging melanoma with whole body PET detects more extensive metastatic disease than conventional imaging [3,10,11] and that changes in the management of cutaneous and metastatic melanoma occur as a result of PET scanning [4,5,12]. This however is the first time that the use of PET has been shown to be associated with a survival benefit.
There were no changes in the treatment of pulmonary metastatic melanoma in the study period thus we believe this improved survival reflects the superiority of PET at detecting metastases compared to conventional radiology. Patients deemed suitable for pulmonary metastectomy have by definition metastatic disease limited to the lung. A normal preoperative PET scan increases the probability that any patient is truly free of extrathoracic disease at the time of metastectomy, this increased sensitivity is significant enough to be associated with improved survival.
Survival is similar beyond 5 years because these patients had no extrathoracic disease at metastectomy and thus survival is similar independent of the type of preoperative imaging.
Aside from increased survival, there is an additional benefit that may result from a preoperative PET scan. Patients with a normal CT but a positive PET are spared an unnecessary thoracotomy [12,13].
Further improvements in the preoperative detection of extrathoracic disease are however required; those patients who died of metastatic melanoma following pulmonary metastectomy must have had micrometastases at the time of metastectomy.
5. Conclusion
Preoperative whole body PET scanning is a useful investigation in the management of patients with pulmonary metastatic melanoma. Firstly, it results in less unnecessary thoracotomies and secondly compared to conventional radiological investigation a normal PET scan is associated with increased survival.
|
Footnotes |
|---|
|
Appendix A. Conference discussion |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix A. Conference...References |
|---|
Dr Dalrymple-Hay: Survival following resection of pulmonary metastasis for melanoma has been documented as poor. However, 22% survival at 5 years is valuable to one in five in whom you have resected the metastasis.
Dr A. Bamousa (Riyadh, Saudi Arabia): PET scan can give you a false positive in patients with TB and with patients with other kinds of malignancies. So how can you differentiate by PET scan that those are melanomas?
Dr Dalrymple-Hay: Firstly you have to involve your radiologists closely, and clearly if you are worried that you have a false positive, then further investigation is necessary. As you accumulate experience with the nuclear radiologists, these problems decrease.
Dr Bamousa: What is the false negative and the false positive in your PET scan?
Dr Dalrymple-Hay: I don't have the data for that in terms of who then subsequently had an MR or CT.
Dr D. Van Raemdonck (Leuven, Belgium): I want to ask you about your current practice at the moment. Now that you have PET scan, have you stopped doing CT scans for these lesions, or are you combining both investigations?
Dr Dalrymple-Hay: They are proceeding directly to PET scan now.
Dr Van Raemdonck: We know that these melanomas often metastasize to the brain and we also know that PET scan is useless for the brain. So are you still doing CT scans of the brain?
Dr Dalrymple-Hay: They would only do a CT scan of the brain if the patient was symptomatic.
Dr W. Klepetko (Vienna, Austria): I'm sorry, I cannot follow your conclusion. I assume that the patients who had a PET scan were operated in a much later period of time than the others. Maybe there have been differences in other treatment forms during that period of time.
Dr Dalrymple-Hay: You are correct to assume that the PET scanning group is a more recent group than the other group, but there has been no difference in treatment in terms of adjuvant therapy for those who were included in the analysis.
Dr Klepetko: Can you give us some information as to in how many patients PET scanning really led you to detect additional nodes in those patients as compared to conventional CT staging?
Dr Dalrymple-Hay: There is a group of 6 within the analysis who without the PET scan would have undergone an unnecessary thoracotomy because they had extra pulmonary disease that wasn't detected by conventional radiological investigation. The difficulty is that sometimes you don't scan the correct area for example. If somebody has a metastasis in their scaphoid but no symptoms, if you were merely to do a CT scan of their chest and head, you would miss that, but if they have no symptoms, there is no reason to give everybody a full radiological investigation of their whole body.
Dr Klepetko: And how often do you perform PET scan in your patients after melanoma? Do you repeat that?
Dr Dalrymple-Hay: Do we do a postoperative PET scan?
Dr Klepetko: No. During the surveillance, if you have a patient with melanoma who you are following up, do you repeat it after surgery again?
Dr Dalrymple-Hay: No. The patients who come to us with melanoma already have the diagnosis. They are followed up by the melanoma clinic, where the numbers are huge compared to what we get sent. The ones that get sent to us are those who have presumed isolated pulmonary disease, and we would then perform the PET scan, or indeed they now perform the PET scan before sending them to us.
Dr Klepetko: What is the limit of nodes which you accept for surgery?
Dr Dalrymple-Hay: I think that would depend on the age and clinical condition, but there is no definitive number in which we wouldn't operate.
Dr A. Lerut (Leuven, Belgium): Maybe I missed it, but what type of CT scanner are you using and what is the distance between two slices? Is it 1, 0.5 cm? I think that makes a lot of difference.
Dr Dalrymple-Hay: It's a spiral CT. I think it varies on the radiological technique from 1984 onwards, but at the moment it would be 0.5 cm.
Dr Lerut: I think that plays a role in your historical group where you will might have missed a number of nodules.
Dr Dalrymple-Hay: Although nodules are missed on CT they are palpable and all palpable ones are removed.
Dr Lerut: It depends on the accuracy of your radiologist to a certain extent.
Dr Dalrymple-Hay: It depends on close liaison between radiologist and surgeon.
Dr T. Dosios (Athens, Greece): Do you biopsy the lesion? When PET scan shows that there is a lesion, do you biopsy these areas, or do you consider every such lesion as a positive? This question is similar to the previous one.
Dr Dalrymple-Hay: If somebody has extra pulmonary disease preoperatively that is positive on the PET scan, do we biopsy it, is that what you're asking me?
Dr Dosios: Yes.
Dr Dalrymple-Hay: Yes.
Dr Dosios: Always?
Dr Dalrymple-Hay: Well, it would depend on how many lesions they have got, but I think you have to confirm the histological diagnosis, yes.
Dr J.-F. Velly (Pessac, France): In terms of policy, if the PET scan appeared to detect metastases out of the lung, if those metastases are resectable, what would you do as a surgeon, because we are more and more required to resect all of what is resectable in this metastatic of melanoma; for example, in the bone or in the sternum. So do you think that the metastases out of the lung have not to be operated on, or do you try with other surgical teams to remove all the diseases, when possible?
Dr Dalrymple-Hay: I can't answer that question fully. In my experience while I worked in Australia I didn't see patients who had extra pulmonary disease undergoing two procedures, i.e. resection of some peripheral metastasis and metastasis within the lung, and there is little in the literature on whether this has been shown to be of benefit or not.
Dr Velly: I know that sternal and finger metastases have been resected with some benefit for the patients. So PET scanning would enlarge detection but not focus the surgery only to the lung.
|
References |
|---|
|
TopAbstract1. Introduction2. Patients and methods3. Results4. DiscussionAppendix A. Conference...References |
|---|
This article has been cited by other articles:
|
|
 |
|
  D. Fuster, S. Chiang, G. Johnson, L. M. Schuchter, H. Zhuang, and A. Alavi Is 18F-FDG PET More Accurate Than Standard Diagnostic Procedures in the Detection of Suspected Recurrent Melanoma? J. Nucl. Med., August 1, 2004; 45(8): 1323 - 1327. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
