Impact of FDG-PET/CT for the Detection of Unknown Primary Tumours in Patients with Cervical Lymph Node Metastases

Objective: Because the detection of the primary tumour is of importance to optimize the patient’s management and allows a targeted therapy, the performance of hybrid positron emission tomography–computed tomography (PET/CT) using fluorodeoxyglucose (FDG) in the detection of primary tumors and unrecognized metastases with cervical lymph node metastases were evaluated in a retrospective study. Material and Methods: Twenty patients with cervical lymph node metastases of unknown primary tumors underwent staging with FDG-PET/CT. All underwent head and neck examinations, computed tomography (CT), and/or magnetic resonance imaging (MRI), panendoscopies, and biopsies of head and neck mucosal sites. The diagnostic accuracy of FDG-PET/CT in detecting primary tumors was compared with that of histopathology and clinical follow-up. The ability of FDG-PET/CT to detect distant metastases was also tested. Results: PET/CT was positive with an increased FDG uptake suggesting the potential primary site in 45% of patients (9/20). PET/CT findings were true positive in 7, true negative in 10, false positive in 2, and false negative in 1 patients, resulting in a sensitivity of 87%, a specificity of 83%, an accuracy of 85%, a positive predictive value of 77% and a negative predictive value of 90%. Also, PET/CT showed distant metastases in seven patients. Conclusion: FDG-PET/CT can be successfully used for the identification of the primary site and distant metastases in patients with cervical lymph node metastases from an unknown primary cancer. (MIRT 2012;21:63-68

Clinically Occult Pituitary Adenoma Can Appear as a Hypermetabolic Lesion on Whole Body FDG PET Imaging in a Patient with Lymphoma

We report a case with Non-Hodgkin Lymphoma with a focus of intense hypermetabolism in the sellar region in the primary staging and posttreatment whole body F-18 FDG PET. Further evaluation with magnetic resonance imaging after posttreatment FDG PET revealed a pituitary adenoma. Endocrinologic workup was normal consistent with nonfunctioning pituitary adenoma and endocrinologists decided to follow up the patient by yearly magnetic resonance imaging. This case demonstrates a nonfunctioning pituitary adenoma by whole body FDG PET and emphasizes the importance of pursuing incidental findings detected in the sella on PET imaging

Diferansiye Tiroit Karsinomunda Rekürrens Sıklığı ve Klinik İzlemde Tanısal İyot-131 Sintigrafisinin Önemi

Objective: Differentiated thyroid cancers (DTC) are tumors with good prognosis. However, local recurrence or distant metastasis can be observed. In our study, we aimed to investigate the incidence of recurrence and the importance of diagnostic iodine-131 whole body scan (WBS) in clinical follow-up in patients with DTC. Methods: The clinical data of 217 patients with DTC who were followed-up more than 3 years were reviewed retrospectively. The incidence of recurrence was investigated in a group of patients who had radioactive iodine (RAI) treatment and showed no sign of residual thyroid tissue or metastasis with diagnostic WBS that was performed at 6-12 months after therapy and had a thyroglobulin (Tg) level lower than 2 ng/dl. Results: At the time of diagnosis, ten cases had thyroid capsule invasion, 25 cases had extra-thyroid soft tissue invasion, 11 patients showed lymph node metastasis and four patients had distant organ metastasis. One hundred forty-five patients had RAI treatment at ablation dose (75-100 mCi), whereas 35 patients had RAI treatment at metastasis dose (150-200 mCi). Thirty-seven patients with papillary microcarcinoma did not receive RAI treatment. In 12 (%7.5) of the 160 patients who were considered as ;quot;successful ablation;quot;, a recurrence was identified. Recurrence was detected by diagnostic WBS in all cases and stimulated Tg level was ;lt;2 ng/dL with the exception of the two cases who had distant metastasis. Conclusion: Identification of pathological findings with WBS in patients who developed local recurrence in the absence of elevated Tg highlights the importance of diagnostic WBS in clinical follow-up.Amaç: Diferansiye tiroit karsinomları (DTK) iyi prognoza sahip tümörlerdir. Ancak lokal rekürrens ve uzak metastaz izlenebilmektedir. Çalışmamızda DTK'lı olgularda rekürrens sıklığının ve tanısal iyot-131 (I-131) tüm vücut tarama sintigrafisinin klinik izlemdeki öneminin araştırılması amaçlandı.Yöntem: İzlem süresi 3 yılın üzerinde olan iki yüz on yedi DTK'lı olgunun klinik verileri retrospektif olarak incelendi. Radyoiyot (RAI) tedavisi alan hastalardan tedavi sonrası 6. ay-1. yıl tanısal I-131 tarama sintigrafisinde rezidüel tiroit dokusu ve metastaza ait bulgu saptanmayan, tiroglobulin (Tg) düzeyi 2 ng/dl'nin altında olan grupta rekürrens sıklığı araştırıldı. Bulgular: Tanı anında on olguda tiroit kapsülü, 25 olguda ekstratiroidal yumuşak doku invazyonu, 11 hastada lenf nodu metastazı ve dört hastada uzak metastaz mevcuttu. Yüz kırk beş olgu ablasyon dozunda (75-100 mCi), 35 olgu metastaz dozunda (150-200 mCi) RAI tedavisi almıştı. Papiller mikrokarsinom tanılı 37 hasta ise RAI tedavisi almamıştı. Tedavi başarısına karar verilen 160 hastanın 12'sinde rekürren hastalık saptandı (%7,5). Olguların tümünde rekürrens I-131 tarama sintigrafisi ile saptanmış olup uzak metastazı olan iki hasta dışında stimüle Tg değerleri 2 ng/dL idi. Sonuç: Lokal rekürrens gelişen tüm olgularda stimüle Tg yüksekliği olmaksızın I-131 tarama sintigrafisi ile patolojik bulguların saptanması klinik izlemde tanısal I-131 taramanın önemini vurgulamaktadır

Akciğer kanserlerinin tanı ve evrelemesinde pozitron emisyon tomografisinin tanısal değeri

Noninvasive diagnostic methods have an important role in the diagnosis and staging of lung cancers. In recent years, positron emission tomography (PET) was introduced for use in the differentiation of malignant and benign lesions, and also in staging cancers. OBJECTIVE: A retrospective study was designed with the aim of examining the role of PET in the diagnosis and staging of lung cancers. MATERIALS-METHODS: A total of 52 patients including 41 males and 11 females who were assessed with an initial diagnosis of lung cancer between April 2003 and September 2004 were analyzed. FINDINGS: The mean age was 59.5 (;plusmn;12.4) years. Forty two (88%) of the patients were found to smoke. Forty three of the patients had been diagnosed as having non-small cell lung cancer, 7 were found to have benign pathology, and 2 had been diagnosed as having small cell lung cancer. In PET analysis, involvements above the value of 2.5 SVU were accepted as being pathologic. Overall assessment of the lesions which were detected after PET revealed a sensitivity and specificity of 95.4% and 87.5%, respectively. In addition, the possitive predictive value was found as 97.6 whereas the negative predictive value was 77.7%. CONCLUSION: In selected cases, PET is a useful method fort he diagnosis and staging of lung cancer.Akciğer kanserlerinin tanı ve evrelemesinde noninvaziv tanı yöntemleri önemli bir yer tutmaktadır. Son yıllarda lezyonların malign-benign ayrımının yapılmasında ve kanserlerin evrelendirmesinde tümör dokusunun aşırı glukoz alması esasına dayanan pozitron emisyon tomografisi (PET) kullanılmaya başlanmıştır. AMAÇ: PET'in akciğer kanseri tanı ve evrelemesindeki rolünü araştırmak amacıyla retrospektif bir çalışma planlanmıştır. GEREÇ-YÖNTEM: Nisan 2003 ile Eylül 2004 tarihleri arasında akciğer kanseri ön tanısıyla değerlendirilen ve PET uygulanan 41 erkek 11 kadın olmak üzere toplam 52 hasta incelemeye alınmıştır. BULGULAR: Yaş ortalaması 59.5 (±12.4) olan hastalardan 42'sinin (%88.8) sigara içtikleri belirlenmiştir. Hastalardan 43'ünün küçük hücreli dışı akciğer karsinomu, 7 hastanın benign patoloji, 2 hastanın ise küçük hücreli akciğer karsinomu tanısı aldıkları görülmüştür. PET tetkikinde 2.5 SVU değerinin üzerindeki tutulumlar patolojik olarak kabul edilmiştir. PET yapıldıktan sonra saptanan tüm lezyonlar birlikte değerlendirildiğinde duyarlılık % 95.4, özgüllük ise % 87.5 olarak saptanmış, ayrıca pozitif prediktif değerinin % 97.6, negatif prediktif değerinin ise % 77.7 olduğu görülmüştür. SONUÇ: PET akciğer kanserinin tanı ve evrelemesinde seçilmiş olgularda uygulanabilecek bir yöntemdir