Mediastinoskopi: Küçük Hücreli Dışı Akciğer Kanseri N-Evrelemesinde Hala Geçerli Mi Yoksa Değersiz Bir Yöntem Midir?

Öz

Mediastinal lenf nodu metastazı, küçük hücreli dışı akciğer kanserinin tedavisinde ve prognozunda önemli bir faktördür. Mediastinal lenf nodu metastazının tespiti için en sık kullanılan pozitron emisyon tomografi (PET) ile mediastinoskopinin karşılaştırılması yapıldı. PET’in mediastinal lenf nodu metastazının saptanmasında altın standart olarak kullanılan mediastinoskopiye alternatif bir yöntem olup olmadığı araştırıldı. Kliniğimizde 2012 ile 2017 yılları arasında küçük hücreli dışı akciğer kanseri tanısı alan 102 hasta çalışmaya dahil edildi. Bu hastalardan alınan toplam 277 lenf nodu biyopsileri histopatolojik sonuçları ve pozitron emisyon tomografisindeki tutulumları ile karşılaştırıldı. PET’in negatif öngörücülük değeri %82,7, pozitif öngörücülük değeri ise %69,5, duyarlılığı %66,6 iken özgüllüğü %84,5 olarak saptandı. Sadece mediastinoskopi yapılan ve frozen sonucunda tutulum saptanmayan hastalarda torakotomi ile yapılan lenf nodu diseksiyon sonuçları hastalar incelendiğinde mediastinoskopinin negatif öngörücülük değeri %97 olarak saptandı.PET’de tutulumu olmayan; 1 santimetreden küçük 46 adet istasyon ve 1 santimetreden büyük 19 adet olmak üzere toplam 65 istasyon örneklendi. Bu lenf nodlarının histopatolojik evrelemesinde metastaz saptanmadı. PET’inde mediastinal lenf nodlarında tutulum olmayan hastalarda invaziv mediastinal lenf nodu örneklemesinin gerekli değildir. Ancak gereksiz torakotomilerden korumak için, PET’de mediastinal lenf nodlarının tutulumunun, malignite eşiğinin altında olsa bile invaziv mediastinal lenf nodu örneklemesinin yapılması gerekmektedir

Anahtar Kelimeler

• Lenf nodu,mediastinal,mediastinoskopi,pozitron emisyon tomografisi

Mediastinoscopy: A Depreciated or Still Viable Method For N-Staging of Non-Small Cell Lung Cancer?

Öz

This study compares the two most frequently used methods, combined positron emission tomography-computed tomography (PET/CT) and mediastinoscopy, in detecting mediastinal lymph node metastases. It has been investigated whether PET/CT can be used as an alternative method to mediastinoscopy which is considered the gold standard in detecting mediastinal lymph node metastasis. Mediastinal lymph node metastasis is an important factor in treatment and prognosis of non-small cell lung cancer. A total of 102 patients diagnosed with non-small cell lung cancer by our clinic between 2012 and 2017, were enrolled in the study. In total 277 lymph nodes were compared with respect to their histopathologic results and their involvement in positron emission tomography. Specificity value of PET/CT was detected as 84.5% while its negative predictive value, positive predictive value and sensitivity were 82.7%, 69.5% and 66.6%, respectively. In patients who underwent only mediastinoscopy and whose frozen section samples did not demonstrate any metastatic involvement, when histopathological results of lymph node dissection performed by thoracotomy were analyzed, the negative predictive value of mediastinoscopy was calculated as 97%. In total 65 stations including 46 stations smaller than 1 centimeter and 19 stations larger than 1 centimeter, which did not demonstrate any uptake in PET/CT, were sampled. No metastasis was detected in histopathologic staging of these lymph nodes. For patients who do not demonstrate any uptake in mediastinal lymph nodes on PET/CT, invasive lymph node sampling is redundant. However, with the aim of avoiding unnecessary thoracotomies, invasive lymph node sampling is required, even though mediastinal lymph node uptake detected with PET/CT is below the threshold of malignancy.

Anahtar Kelimeler

• Lymph node,mediastinal,mediastinoscopy,positron emission tomography

Kaynakça

1. 1. Yıldız O, Cangır AK, Kılıç D, et al. Importance of SUVmax threshold in positron emission tomography-computed tomography assessment of mediastinal and hilar lymph nodes in non-small cell lung cancer. Turk Gogus Kalp Dama 2016;24(2):333-9
2. 2. Metin M, Çıtak N, Büyükkale S, et al. Akciğer kanserinin mediastinal evrelemesinde mediastinoskopinin etkinliği yıllar geçtikçe artmakta mıdır? Turk Gogus Kalp Dama 2015;23(3):499-506
3. 3. Kandemir Z, Şentürk A, Özdemir E, et al. The Evaluation Of Hypermetabolic Mediastinal–Hilar Lymph Nodes Determined By Pet/Ct İn Pulmonary And Extrapulmonary Malignancies: Correlation With Ebus-Tbna Turk J Med Sci 2015;45:1234-42
4. 4. Öneş T, Erdil TY. Toraks Malignitelerinin Evreleme Ve Yeniden Evrelemesinde Pet Uygulamaları. Toraks Cerrahisi Bülteni 2015; 6: 180-91
5. 5. Erdoğan Y, Özyürek BA, Özmen Ö, et al. The Evaluation of FDG PET/CT Scan Findings in Patients with Organizing Pneumonia Mimicking Lung Cancer. Molecular Imaging and Radionuclide Therapy 2015;24(2): 60-65
6. 6. Shingyoji M, Nakajima T, Yoshino M, et al. Endobronchial Ultrasonography for Positron Emission Tomography and Computed Tomography–Negative Lymph Node Staging in Non-Small Cell Lung Cancer. Ann Thorac Surg 2014;98:1762–8.
7. 7. Perigaud C, Bridji B, Roussel JC, et al. Prospective preoperative mediastinal lymph node staging by integrated positron emission tomography–computerised tomography in patients with non-small-cell lung cancer. European Journal of Cardio-Thoracic Surgery,2009;36:731-6
8. 8. Bury T, Dowlati A, Paulus P, et al. Whole-body 18FDG positron emission tomography in the staging of non-small cell lung cancer. Eur Respir J 1997;10:2529-34.

9. 9. Lee BE, Redwine J, Foster C, et al. Mediastinoscopy might not be necessary in patients with non-small cell lung cancer with mediastinal lymph nodes having a maximum standardized uptake value of less than 5.3. J Thorac Cardiovasc Surg 2008;135:615-9.
10. 10. Perigaud C, Bridji B, Roussel JCet al. Prospective preoperative mediastinal lymph node staging by integrated positron emission tomography-computerised tomography in patients with non-small-cell lung cancer. Eur J Cardiothorac Surg 2009;36:731-6.
11. 11. Nelson E, Pape C, Jørgensen OD, Olsen KE, Licht PB. Mediastinal staging for lung cancer: the influence of biopsy volume. Eur J Cardiothorac Surg 2010;37:26-9.
12. 12. Lemaire A, Nikolic I, Petersen T, et al. Nine-year single center experience with cervical mediastinoscopy: complications and false negative rate. Ann Thorac Surg 2006;82:1185-9.
13. 13. Detterbeck FC, Jantz MA, Wallace M, Vansteenkiste J, Silvestri GA. Invasive mediastinal staging of lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition). Chest 2007;132:202-220.
14. 14. Billé A, Pelosi E, Skanjeti A, et al. Preoperative intrathoracic lymph node staging in patients with non-small-cell lung cancer: accuracy of integrated positron emission tomography and computed tomography. Eur J Cardiothorac Surg 2009;36:440-5.
15. 15. Al-Sarraf N, Aziz R, Gately K, et al. Pattern and predictors of occult mediastinal lymph node involvement in non-small cell lung cancer patients with negative mediastinal uptake on positron emission tomography. Eur J Cardiothorac Surg 2008;33:104-9.