GİRİŞ ve AMAÇ: Serum kalsitonin yüksekliği bulunan medüller tiroid kanseri (MTK) tanılı hastalarda rekürrensin saptanmasında 18F-FDOPA PET/BT’nin performansının değerlendirilmesi
YÖNTEM ve GEREÇLER: Primer MTK cerrahisi sonrasında yüksek kalsitonin düzeyi olan ve 18F-FDOPA PET/BT uygulanmış olan hastalar çalışmaya dahil edildi. Ek olarak, eğer varsa 18F-FDG PET/BT ve 68Ga - DOTATATE PET/BT bulguları da retrospektif olarak değerlendirildi.18F-FDOPA PET/BT’nin duyarlılığı ve tanısal performansı araştırıldı.
BULGULAR: Toplam 14 hasta (9K, 5E, median yaş: 45) analize dahil edildi. Üç hastada MENIIA, 1 hastada MEN IB sendromu, 10 hastada sporadik medüller tiroid kanseri mevcuttu. Hastaların medyan kalsitonin seviyeleri 757.5 (min-maks: 28.5-7911) pg/mL bulundu. 18F-FDOPA PET/BT görüntülemesinden önce 9 hastaya boyun ultrasonu, 5 hastaya kontrastlı boyun BT uygulanmıştı. 18F-FDOPA PET/BT’de 3 hastada tiroid yatağında nüks, 5 hastada lenf nodu metastazı ve 2 hastada uzak metastaz saptandı. Rekürren veya metastatik lezyonlarda median SUVmax: 6.4 (min-maks: 1.9-18.4) olarak hesaplandı. Rekürren hastalığın saptanmasında 18F-FDOPA PET/BT’nin duyarlılığı %64 bulundu. 18F-FDOPA PET/BT’den önceki 3 ay içerisinde 8 hastanın 68Ga - DOTATATE, 7 hastanın 18F-FDG PET/BT görüntülemeleri mevcuttu. 18F-FDOPA PET/BT, negatif 18F-FDG PET/BT’si olan 5 hastanın 4’ünde ve negatif 68Ga - DOTATATE PET/BT’si olan 5 hastanın 2’sinde rekürren hastalığı gösterdi.
TARTIŞMA ve SONUÇ: 18F-FDOPA PET/BT, MTK için primer cerrahi sonrası yüksek kalsitonin düzeyi bulunan hastaların yaklaşık 2/3’ünde rekürrens saptayabilir. Tiroid medüller karsinomunun değişken diferansiyasyon derecesi, farklı reseptör durumu ve klinik davranışına bağlı olarak, her üç radyofarmasötik de hasta yönetiminde faydalı olabilir ve birbirine tamamlayıcıdır.

INTRODUCTION: To evaluate the diagnostic performance of 18F-FDOPA PET/CT in the detection of medullary thyroid carcinoma (MTC) recurrence in patients with elevated calcitonin levels
METHODS: The patients who had undergone 18F-FDOPA PET/CT imaging for elevated calcitonin levels after primary surgery of MTC were included to the study. Additionally, if available 18F-FDG PET/CT and 68Ga - DOTATATE PET/CT images of the patients were evaluated retrospectively. Sensitivity and diagnostic performance of 18F-DOPA PET/CT was investigated.
RESULTS: A total of 14 patients (9F and 5M; median age: 45) were included to the analysis. Three patients had MEN IIA syndrome and 1 patient had MEN IIB syndrome, 10 patients had diagnosis of sporadic MTC. Median calcitonin levels of patients were calculated as 757.5 (min-max: 28.5-7911) pg/mL. Nine patients and 5 patients had undergone ultrasound and contrast-enhanced computed tomography (ceCT) of the neck respectively, before 18F-FDOPA PET/CT imaging. 18F-FDOPA PET/CT revealed pathological uptake in the thyroid bed, lymph nodes and distant organs in three, five and two patients respectively. Median SUVmax for the recurrent or metastatic lesions were calculated as 6.4 (min-max: 1.9-18.4). Sensitivity of 18F-FDOPA PET/CT in the detection of recurrent disease was calculated as 64%. Eight patients had 68Ga - DOTATATE PET/CT and 7 of them had 18F-FDG PET/CT within 3 months period before 18F-FDOPA PET/CT. 18F-FDOPA PET/CT revealed recurrent disease in 4 of the 5 and 2 of the 5 patients who had negative 18F-FDG PET/CT and negative 68Ga - DOTATATE PET/CT, respectively.
DISCUSSION AND CONCLUSION: 18F-FDOPA PET/CT can detect recurrence in about two third of the patients with elevated calcitonin levels after primary surgery for MTC. Due to variable differentiation degree, different receptor status and clinical behavior of medullary thyroid carcinoma, all three radiopharmaceuticals can be beneficial and are complementary to each other in patient management.

GİRİŞ ve AMAÇ: Cerrahi olarak tedavi edilen akciğer kanserli hastaların düzenli takibi, lokal nüks ve uzak metastaz saptanmasında oldukça önemlidir. Postoperatif takipler toraks BT ve gerekirse PET-BT ile yapılır. Bazen hemostaz sağlamak için ameliyat sırasında kullanılan materyallere bağlı inflamatuar doku reaksiyonları görüntüleme modalitelerinde tümör nüksü görünümüne neden olabilir. Bu çalışmada intraoperatif kullanılan oksitlenmiş rejenere selülozun (ORS), PET-BT’ de yalancı tümör nüksüne neden olabileceğini göstermeyi amaçladık.
YÖNTEM ve GEREÇLER: Akciğer kanseri cerrahisi sonrası lokal tümör nüksü gelişen hastaların kayıtları geriye dönük olarak incelendi. Dahil edilme kriterleri, PET-BT'de lokal kanser nüksü varlığı, cerrahi notlarda ORS kullanımının belirtilmesi ve tümörün nüks bölgesinin histopatolojik tanısının yabancı cisim reaksiyonu olarak bildirilmesiydi. Hastalara ait yaş, cinsiyet, yapılan cerrahi, adjuvan tedavi durumu, rezolüsyon durumu ve ORC süresi ve PET-BT'deki 18-F FDG standart uptake değeri verileri toplandı.
BULGULAR: Kriterleri karşılayan 11 hasta (1 kadın, 10 erkek) çalışmaya dahil edildi. Ortanca yaş 64 idi. Tüm hastaların histopatolojik raporları yabancı cisim reaksiyonu olarak rapor edildi. Ameliyattan sonra PET-BT pozitifliğinin ortanca tespit süresi 139 gündü (Dağılım: 52–208 gün). Kontrol radyolojik incelemelerinde 8 hastada (%72.7) tümör görünümü düzeldi ve ortanca iyileşme süresi 334 gündü (Dağılım: 222-762 gün). PET-BT'de lezyonların ortanca maksimum standart tutulum değeri 6,2 (Dağılım: 1,7-11) idi.

TARTIŞMA ve SONUÇ: Cerrahi olarak tedavi edilen akciğer kanserli hastaların takibinde tümör nüksünden şüphelenildiğinde, gereksiz operasyon ve tedavileri önlemek için histopatolojik doğrulama gereklidir.

INTRODUCTION: Regular follow-up of patients with lung cancer treated surgically is crucial to detect local recurrence or distant metastasis of the tumor. Postoperative follow-ups are performed with thorax CT and, if necessary, PET-CT. Sometimes, inflammatory tissue reactions due to the materials used during the surgery for hemostasis may cause the appearance of tumor recurrence in imaging modalities. In this study, we presented oxidized regenerated cellulose (ORC) used intraoperatively may cause false tumor recurrence on PET-CT.
METHODS: The records of patients who had local tumor recurrence after lung cancer surgery was reviewed retrospectively. Inclusion criteria were presence of local recurrence of cancer on PET-CT, specification of using ORC in the surgical notes, and histopathological diagnosis of recurrence site of tumor was reported as foreign body reaction. Data of patients were collected according to age, gender, surgery performed, adjuvant therapy status, resolution status and time ORC, and standard uptake value of 18-F FDG on PET-CT.
RESULTS: Eleven patients (1 female, 10 males) who met the criteria were included in the study. The median age was 64. Histopathological results of all patients were reported as foreign body reactions. The median detection time of PET-CT positivity after surgery was 139 days (range: 52–208 days). False tumor recurrence was resolved in 8 patients (72.7%) in their control radiological examinations and median resolution time was 334 days (range: 222–762 days). Median SUV-max of the lesions was 6.2 (1.7–11) on the PET-CT.
DISCUSSION AND CONCLUSION: ORC used intraoperatively in patients undergoing surgery for lung cancer may cause false tumor recurrence in imaging modalities in postsurgical follow-ups. When tumor recurrence is suspected in the follow-up of these patients, histopathological confirmation is necessary to prevent unnecessary operations and treatments.

INTRODUCTION: To compare vaccinated-side axillary lymph node uptake on 18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) after coronavirus disease 2019 (COVID-19) and influenza vaccination.
METHODS: We retrospectively analyzed 177 patients who underwent 18F-FDG PET/CT after COVID-19 or influenza vaccination. We compared the uptake of the vaccinated-side axillary lymph nodes of 109 COVID-19 vaccinated patients with those of 68 influenza vaccinated patients. We also compared the uptake between 66 patients who received the first COVID-19 vaccination with 43 who received the second COVID-19 vaccination.
RESULTS: 18F-FDG-avid axillary lymph nodes on the vaccinated side were significantly more frequently observed in the COVID-19 group (45%) than in the influenza group (19%) (p<0.001). When the interval between vaccination to PET/CT was within 7 days, there was no significant difference in the frequency of 18F-FDG-avid vaccinated-side axillary lymph nodes between the groups (COVID-19 group: 41% vs. influenza group: 45%, p=0.724). When the interval was over 7 days, 18F-FDG-avid lymph nodes were much more frequent in the COVID-19 group (47%) than in the influenza group (7%) (p<0.001). Comparing the first and second COVID-19 groups, 18F-FDG-avid lymph nodes were more frequent in the second vaccination group than in the first vaccination group, but the difference was not significant.
DISCUSSION AND CONCLUSION: 18F-FDG-avid vaccinated-side axillary lymph nodes were more frequently observed in the COVID-19 group than in the influenza group. In the case of the COVID-19 vaccine, a delay of 18F-FDG PET/CT examination is recommended by a longer interval from vaccination than in the influenza vaccine.

GİRİŞ ve AMAÇ: Oligometastazlar, tümörün sınırlı metastatik kapasitesini ifade etmekte olp hastalığın yavaş biyolojisine sekonder gelişebildikleri düşünülmektedir. Bu çalışma, prostat kanserinde (PK) prostat bölgesi ve metastatik lezyonların Flor-18 florodeoksiglukoz (FDG) ve Galyum-68 (Ga-68) prostat spesifik membran antijeni (PSMA) tutulumunun semikantitatif ölçümlerinin oligometastatik (OM) ve multimetastatik (MM) hastalık arasında farklı olup olmadığını araştırmak için tasarlanmıştır.
YÖNTEM ve GEREÇLER: Ekim 2012-Şubat 2020 tarihleri arasında pozitron emisyon tomografisi/bilgisayarlı tomografi (PET/BT) incelemesi yapılan PK'li hastaların verileri retrospektif olarak incelendi. Sonuç raporları metastatik hastalık ile uyumlu olan hastalar seçildi. Hastalar MM veya OM hastalığı olanlar olarak iki gruba ayrıldı. İlgi alanı, görsel olarak en yüksek radyofarmasötik tutulumu gösteren metastatik lezyondan ve prostat bölgesinden çizilerek maksimum standartlaştırılmış tutulum değerleri (STDmaks) hesaplandı. OM ve MM’li hastalarda prostat bölgesi ve metastatik lezyonların medyan STDmaks değerleri karşılaştırıldı.
BULGULAR: Yaş ortalaması 71.46 ± 9.26 olan, 47-90 yaş aralığında toplam 145 hasta değerlendirildi. 145 hastanın 59'una FDG PET/BT uygulandı; kalan 86 hastaya Ga-68 PSMA PET/BT incelemesi yapıldı. 145 hastanın 37'si OM, 108 hasta MM hasta grubundaydı. FDG uygulanmış OM ve MM hastalığı olan hastalarda metastatik lezyonların medyan STDmaks değeri sırasıyla 5.60 (aralık: 1.72-17.40) ve 9.51 (aralık: 4.13-56.01) olarak hesaplandı. Ga-68 PSMA grubundaki OM ve MM hastalığı olanlarda hesaplanan metastatik lezyondan hesaplanan medyan STDmaks değerleri sırasıyla 13.44 ve 29.84 olarak bulundu. FDG ve Ga-68 PSMA gruplarında OM ve MM hastalığı olan hastaların metastatik lezyonlarının medyan STDmaks değerleri istatistiksel olarak anlamlı fark gözlenirken (p< 0.05), prostat bölgesinden hesaplanan medyan STDmaks değerleri FDG grubunda sırasıyla 7.83 ve 12.29; Ga-68 PSMA grubunda ise 26.23 ve 26.74 olarak bulundu ve aralarında istatistiksel olarak fark saptanmadı (p> 0.05).
TARTIŞMA ve SONUÇ: Prostat kanserinde metastatik lezyonların STDmaks değerleri MM hastalarda OM hastalardan anlamlı olarak daha yüksek olup bu sonuç, OM ve MM yayılım gösteren tümörlerin agresiflik açısından farklı biyolojik içeriklerinden kaynaklanıyor olabilir.

INTRODUCTION: Oligometastases may generate secondary to indolent tumor biology. In this study we investigated whether semiquantitative measures of Fluorine-18 fluorodeoxyglucose (FDG) and Gallium-68 (Ga-68) prostate-specific membrane antigen (PSMA) uptake of metastatic lesions and prostatic site are different between oligometastatic (OM) and multimetastatic (MM) disease of prostate carcinoma (PC).
METHODS: Patients with PC, who underwent positron emission tomography/computed tomography (PET/CT) from October 2012 to February 2020 were retrospectively reviewed. Patients, whose reports were consistent with metastatic diseases were selected. Patients classified as with MM or OM disease. Maximum standardized uptake values (SUVmax) were calculated from metastatic lesions and the prostatic site. The median of the SUVmax results between patients with OM and MM disease were compared.
RESULTS: Totally 145 patients with a mean age of 71.46 ± 9.26, were evaluated. In 59 of 145 patients FDG PET/CT was performed; 86 patients had gone through Ga-68 PSMA PET/CT. Thirty-seven of 145 patients were OM whereas 108 patients were MM. The median of the SUVmax of metastatic lesions in patients with OM and MM disease in the FDG group were 5.60 and 9.51, respectively. The results of calculated median SUVmax values in OM and MM disease in the Ga-68 PSMA group were 13.44 and 29.84, respectively. Significant difference was observed in median SUVmax results of metastatic lesions between OM and MM disease (p< 0.05). Median values of SUVmax calculated from prostatic site in OM and MM disease were 7.83 and 12.29 respectively in FDG; 26.23 and 26.74 in the Ga-68 PSMA group. No significant difference was found in SUVmax results of prostatic site between OM and MM disease (p>0.05).
DISCUSSION AND CONCLUSION: SUVmax results of metastatic lesions are significantly higher in patients with MM than in patients with OM disease in patients with prostate carcinoma which may be secondary to their different biological content in terms of aggressiveness.

GİRİŞ ve AMAÇ: F-18 Florodeoksiglukoz-pozitron emisyon tomografisi/bilgisayarlı tomografi (F-18 FDG-PET/BT), pankreas kanserinde yararlı bir evreleme yöntemidir. Pankreas adenokarsinomunun prognozu, tümör evresi ve rezektabl durumdan etkilenir. Primer tümörün maksimum standartlaştırılmış alım değeri (SUVmax), metabolik tümör hacmi (MTV) ve toplam lezyon glikolizisi (TLG), pankreas kanserinde prognostik parametrelerle ilişkili olduğu gösterilmiştir. Bu çalışma, pankreas kanserli hastaların F-18 FDG-PET/BT bulgularınının prognostik faktörler ve sağkalım ile arasındaki ilişkiyi araştırmayı amaçlamıştır.
YÖNTEM ve GEREÇLER: 2015-2022 yılları arasında bölümümüze evreleme için sevk edilen pankreas adenokarsinomu tanılı hastalar retrospektif olarak değerlendirildi. FDG enjeksiyonundan 1 saat sonra baş-uyluk ortası PET/BT görüntüleri elde edildi. PET/BT görüntüleme sonrası opere edilen 39 hastanın demografik bilgileri, sağ kalım süreleri, klinik ve patolojik bulguları toplandı. Primer tümöre ait MTV, SUVmax, arka plan SUVmax ve TLG verileri ölçülerek hesaplamalar yapıldı.
BULGULAR: Yaş ortalaması 66.62 ± 9.60 yıl olan 39 hastanın (24 kadın ve 15 erkek) görüntüleri değerlendirildi. Pankreas dokusunda primer tümörün ortalama SUVmax, MTV %40 ve TLG'si sırasıyla 6.28 ± 2.33, 19.33 ± 9.77 ve 66.56 ± 45.99 idi. Hastalık teşhisi sonrası ortalama sağkalım 18.97 ± 11.47 (2-55) ay olarak bulundu. Çalışmamız sırasında ölen hastalarda MTV ve TLG anlamlı olarak daha yüksekti. SUVmax'ın mortalite üzerinde önemli bir etkisi olduğu saptandı.
TARTIŞMA ve SONUÇ: Preoperatif olarak elde edilen metabolik F-18 FDG-PET/BT parametreleri olan SUVmax, MTV ve TLG rezektabl pankreas kanserinin prognozunu öngörmede ve takipte yardımcı olabilir. Ek olarak, tümör derecesi ve perinöral invazyon da genel sağkalımı önemli ölçüde etkilediği çalışmamızda anlaşılmıştır.

INTRODUCTION: F-18 Fluorodeoxyglucose-positron emission tomography/computed tomography (F-18 FDG-PET/CT) was a useful staging method in pancreatic cancer. The prognosis of pancreatic adenocarcinoma is affected by tumor stage and resectable state. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of primary tumor are correlated with prognostic parameters in pancreatic cancer. This study aimed to correlate F-18 FDG-PET/CT findings with prognostic factors and survival of patients with pancreatic cancer.
METHODS: Patients with pancreatic adenocarcinoma referred to our department between 2015 and 2022 for staging were retrospectively evaluated. Head to mid-thigh PET/CT images were obtained 1 h after FDG injection. Demographic data, survival, and clinical and pathological findings of 39 patients, who underwent surgery after PET/CT imaging, were collected. All primary MTV, SUVmax, background SUVmax, and TLG data have been measured.
RESULTS: The images of 39 patients, (24 women and 15 men) with mean age of 66.62 ± 9.60 years, were evaluated. Mean SUVmax, MTV 40%, and TLG of primary tumor in pancreatic tissue were 6.28 ± 2.33, 19.33 ± 9.77, and 66.56 ± 45.99, respectively. The average survival after disease diagnosis was 18.97 ± 11.47 (2–55) months. MTV and TLG were significantly higher in patients who have died during our study. SUVmax has a significant effect on mortality.
DISCUSSION AND CONCLUSION: F-18 FDG-PET/CT metabolic parameters of SUVmax, MTV, and TLG could be helpful in understanding the prognosis of pancreatic cancer preoperatively and follow-up in patients with resectable tumors. Additionally, tumor grade and perineural invasion significantly affect overall survival.

INTRODUCTION: Attenuation correction (AC) using transmission scanning like CT is the standard method to increase the accuracy of cardiac SPECT images. Recently developed dedicated cardiac SPECT do not support CT and thus, scans on these systems are vulnerable to attenuation artifacts. This study aimed to present a new method for generating attenuation map directly from emission data by segmentation of precisely nonrigid registration XCAT-digital phantom with cardiac SPECT image.
METHODS: In-house developed nonrigid registration algorithm automatically aligns the XCAT- phantom with cardiac SPECT image to precisely segment the contour of organs. Pre-defined attenuation coefficients for given photon energies were assigned to generate attenuation maps. The CT-based attenuation maps were used for validation with which cardiac SPECT/CT data of 38 patients were included. Segmental myocardial counts of a 17-segment model from these databases were compared on the basis of the paired t-test.
RESULTS: The mean, and STD (standard deviation) of the MSE (mean square error) and SSIM (structural similarity index) measure of female stress phase between proposed attenuation maps and the CT attenuation maps were 6.99 ± 1.23% and 92 ± 2.0%, of the male stress were 6.87 ± 3.8% and 96 ± 1.0%. ProAC and CTAC average myocardial perfusion count were significantly higher than that in non-AC in the mid- inferior, mid-lateral, basal-inferior and lateral regions (P<0.001).
DISCUSSION AND CONCLUSION: The proposed attenuation maps showed good agreement with the CT-based attenuation map. Therefore, it is feasible to enable AC for dedicated cardiac SPECT or SPECT standalone scanner.

A 66- year old man known case of metastatic castration resistant prostate cancer underwent successful 6 cycles treatment with 177Lu-PSMA. On the last post therapy whole body scan a new lesion in the skull was noted, suspected for disease progression. One week later, the patient complained from weakness of left upper extremity and brain MRI revealed a brain tumor, confirmed as glioblastoma pathologically.

Total tiroidektomi yapılan 50 yaşındaki erkek hastada histopatolojik incelemede tümör boyutu 4,5 cm olan papiller tiroid karsinomu saptandı. Hasta radyoiyot tedavisi için nükleer tıp kliniğine yönlendirildi. Tedavi öncesi tiroglobulin düzeyi 495 ug/L olduğundan düşük doz (185 MBq) I-131 taraması yapıldı. İlk evreleme sırasında I-131 tüm vücut taraması ve SPECT/BT görüntülemede çoklu karaciğer metastazlarına ek olarak sakrum ve sağ 7. kostada kemik metastazları saptandı. Klinik ve Radyoiyot tedavi yanıtı 18F-FDG ve 68Ga-FAPI-04 PET/BT ile değerlendirilen multipl metastatik papiller tiroid karsinomu olgusu sunulmuştur.

A 50-year-old man undergone total thyroidectomy and histopathology revealed papillary thyroid carcinoma with a tumor size of 4.5 cm. Patient was referred to nuclear medicine clinic for radioiodine theraphy. Since the thyroglobulin level before the treatment was 495 ug/L, low-dose (185 MBq) I-131 scan was performed. In addition to multiple liver metastases, bone metastases were detected in the sacrum and right 7th rib in I-131 whole body scanning and SPECT/CT imaging at the time of initial staging. We present a case of multiple metastatic papillary thyroid carcinoma whose radioiodine treatment response and clinical outcome was evaluated with 18F-FDG and 68Ga-FAPI-04 PET/CT.

A 70-year-old man with a tumor in the nasal and paranasal space, was pathologically diagnosed with an alveolar rhabdomyosarcoma, with right cervical lymph node metastasis. Magnetic resonance imaging revealed a primary tumor in the nasal and paranasal sinuses, with associated intracranial infiltration. 11C-methionine positron emission tomography/computed tomography (PET/CT) revealed increased uptake in the primary tumor and right cervical lymph node metastasis. 18F-fluorodeoxyglucose PET/CT also revealed increased uptake in the primary tumor and right cervical lymph node. However, the physiological brain uptake overlapped with the primary tumor uptake. Our case suggests the usefulness of 11C-methionine PET/CT for accurately assessing the extent of alveolar rhabdomyosarcoma, especially in cases with intracranial infiltration or those approximating the brain.

Yazarlar 75 yaşında prostat adenokarsinom Gleason skor 3+4 (pT2N0Mx) tanılı erkek hastanın çekilen tüm vücut kemik sintigrafisinde(TVKS) sağ paryetotemporal kortekse uyan alanda izlenen Tc-99m metilen difosfonat (MDP) tutulumunu sunmaktadır. Hastanın TVKS’den 4 ay önce çekilen Ga-68 prostat spesifik membran antijeni (PSMA) PET/BT’de rezidü veya metastaz saptanmamıştı. Prostat spesifik antijen (PSA) düzeyi ölçülebilir aralığın altında olan hastaya, önceki TVKS’de saptanan şüpheli bulguların aydınlatılması amacıyla yeniden evreleme amaçlı TVKS çekilmişti. Güncel TVKS’de sağ kranial bölgede saptanan Tc-99m MDP tutulumunu aydınlatmak için yapılan single-photon emission computed tomography (SPECT) görüntülemede sağ paryetotemporal bölgede heterojen Tc-99m MDP birikimi, sfenoid kemikte fokal tutulum ve lomber alt vertebralarda nospesifik tutulum izlendi. İki yıl önce hipofiz tümörüne yönelik transfenoidal cerrahi ve yakın tarihli serebrovasküler olay öyküsü mevcuttu. Diffüzyon ağırlıklı kranial manyetik rezonans (MR) görüntülerinde sağ paryetotemporal bölgede kortikal-subkortikal alanda akut iskemi ile uyumlu yamasal difüzyon kısıtlılığı alanı saptandı. Sağ paryetotemporal bölgede izlenen heterojen Tc99m-MDP tututlumu yakın tarihli iskemik serebrovasküler olaya ve sekonder vasküler-doku değişikliğine bağlı distrofik kalsifikasyona ikincil nitelikte değerlendirildi.

The authors present Tc-99m methylene diphosphonate (MDP) uptake in the right parietotemporal area at whole-body bone scan (WBBS) in a 75 years male patient with prostate adenocarcinoma Gleason score 3+4 (pT2N0Mx). The patient had no residual or metastatic disease in Ga-68 prostate specific membrane antigen (PSMA) PET/CT at the prostate cancer diagnosis four months before WBBS. The patient had undetectable prostate specific antigen (PSA) levels and underwent WBBS to restage prostate cancer due to equivocal findings in previous WBBS. Current WBBS planar views revealed heterogenous Tc-99m MDP uptake in the right parietotemporal area and sphenoid bone in addition to equivocal uptake on lower lumbar vertebrae. Single-photon emission computed tomography (SPECT) study to identify the MDP-avid lesion on the right cranial area revealed heterogenous Tc-99m MDP uptake in the right parietotemporal area and sphenoid bone. He had a history of transsphenoidal surgery for a hypophyseal tumor two years ago and a recent cerebrovascular event (CVE). Diffusion-weighted magnetic resonance imaging (MRI) revealed a cortical-subcortical patchy area of restricted diffusion in the parietotemporal region compatible with acute ischemia. Heterogeneous Tc-99m MDP uptake in the right parietotemporal area attributed to recent CVE and secondary vascular-tissue change-related dystrophic calcification.

Lenfomatoid granülomatozis, çoğunlukla akciğer, daha az sıklıkla deri, böbrek ve merkezi sinir sistemi tutulumu ile giden, nadir görülen ekstranodal Epstein-Barr virüsü ilişkili B hücreli lenfoproliferatif bir hastalıktır. Burada, primer immün yetmezlikli, biyopsi ile pulmoner grade-3 lenfomatoid granülomatozis tanısı almış pediatrik bir vaka sunulmaktadır. F-18 FDG PET/BT görüntülemesi, santral kesimde hava bronkogramları ve kavitasyonlar içeren ve FDG tutulumu gösteren pulmoner kitleler göstermiştir. Kesin tanı biyopsiye bağlı olsa da F-18 FDG PET/BT tetkiki hastalık yaygınlığının ve tedaviye yanıtın değerlendirilmesinde yardımcı bir görüntüleme yöntemidir.

Lymphomatoid granulomatosis is a rare extranodal Epstein-Barr virus-driven B-cell lymphoproliferative disease, involving predominantly lung, less often skin, kidney, and central nervous system. Herein, we present a pediatric case with primary immunodeficiency, diagnosed with pathologically proven pulmonary grade-III lymphomatoid granulomatosis. F-18 FDG PET/CT imaging demonstrated FDG avid pulmonary masses with central air-bronchograms and cavitations. Though the definitive diagnosis depends on biopsy, F-18 FDG PET/CT serves as a complementary imaging tool to evaluate the extent of the disease and response to treatment.

A 59-year-old man, previously submitted to anterior resection due to rectal cancer, underwent a contrast enhanced CT (ce-CT) for restaging before eventual chemotherapy. Since ce-CT showed a moderate enlargement of descending colonic lumen, in spite of lack of symptoms, a positron emission computed tomography (PET/CT) with 18F-fluorodeoxyglucose (18F-FDG) was carried out. 18F-FDG PET/CT demonstrated highly increased tracer incorporation along colon walls. Two days after the PET/CT examination, complaints of diarrhea and abdominal pain began. Clostridioides difficile stool test resulted positive, thus he started antibiotic therapy without benefit. Since follow-up ce-CT demonstrated a megacolon condition, he was submitted to hemicolectomy. Histology revealed a diffuse condition of pseudomembranous colitis (PMC). This case highlights the potential of 18F-FDG PET/CT for the detection of PMC morphological and functional features also in pre-symptomatic patients.

62 yaşında hasta timik kitle nedeniyle kliniğimize başvurdu. Yapılan FDG-PET/BT’de anterior mediasten yumuşak doku kitlesine ek olarak sağ akciğerde hipermetabolik nodüler lezyon izlendi. Akciğer rezeksiyon sonrasında pulmoner dev hücreli karsinom tanısı aldı. Takip FDG-PET/BT’sinde beyin, sağ postauriküler, bilateral adrenal, mide, pankreas, pelvik yumuşak doku, mezenterik, sol femur ve bilateral akciğer parankiminde multipl patolojik aktiviteli lezyon gözlendi. Bunlardan sağ frontal, pelvik kitle ve postauriküler yerleşimli lezyonların histopatolojisi metastatik olarak sonuçlandı.

A 62 years old man referred to our clinic due to suspicion of thymic mass. Hypermetabolic nodular lesion in the right lung upper lobe was seen in FDG-PET/CT in addition to the mass in the anterior mediastinum which was found to without malignancy. Patient underwent wedge resection and final diagnosis was pulmonary giant cell carcinoma. In follow-up FDG-PET/CT multiple lesions with pathological activity were observed in cerebrum, right postauricular region, bilateral adrenal, stomach, pancreas, pelvic soft tissue, mesenteric, left femur and bilateral lung parenchyma 6 months after. The pathology results of the right frontal, pelvic mass and the postauricular region were metastasis.

Subcutaneous panniculitis like T-cell lymphoma (SPTCL) is a very rare disorder. Patients usually present with multiple subcutaneous nodules on the extremities without visceral disease. Dissemination to extra-cutaneous sites is unusual. Only a few cases of SPTCL have been reported in the literature describing the findings of F-18 FDG PET. Here, we represent an interesting and unusual case of diffuse subcutaneous panniculitis-like T-cell lymphoma with snow Leopard skin appearance on 18F-FDG PET-CT.

Pulmonary intimal sarcoma (PAS) is a highly aggressive malignant mesenchymal tumour affecting the central pulmonary arteries. Similar clinical presentation and indeterminate laboratory parameters often result in misdiagnosis of this condition as pulmonary thromboembolism, which is a relatively common disease. Certain imaging features can however allow differentiation between these two diagnoses. We present one such case of pulmonary intimal sarcoma that was initially treated as pulmonary embolism; and briefly review the relevant imaging characteristics to avoid overlooking PAS especially in patients with an atypical clinical history for thromboembolism.

Sağ memede kitle saptanan meme kanseri ön tanılı 40 yaşında kadın hasta, lezyonun metabolik karakterizasyonu ve hastalığın evrelenmesi amacıyla 18F-FDG PET/BT ünitesine başvurdu. Hastanın ateş, kilo kaybı veya gece terlemesi yoktu. 18F-FDG PET/BT görüntülemesinde sağ meme üst dış kadranda artmış 18F-FDG tutulumu gösteren solid bir kitle lezyonu ile; sağ aksillada artmış 18F-FDG tutulumu gösteren lenf nodları izlenmiş olup ön planda primer meme kanseri ve aksiller lenf nodlarında metastaz şüphesi uyandırmıştır. Tüm vücudun geri kalan kısımlarında herhangi bir patolojik 18F-FDG tutulumu yoktu. Lezyonun eksizyonel biyopsi histopatolojisinde diffüz büyük B hücreli Non-Hodgkin lenfoma saptandı.

A 40 year old woman with palpable mass lesion in her right breast suggested as breast cancer was admitted to 18F-FDG PET/CT unit for the metabolic characterisation of the lesion and for the staging of the disease. Patient had no fever and no evidence of weight loss or night sweats. 18F-FDG PET/CT revealed an isolated solid mass lesion with increased 18F-FDG uptake in the upper outer quadrant of the right breast and increased 18F-FDG uptake in the lymph nodes of right axilla suspected as primary breast cancer and its local lymph node metastasis. There was no other pathological 18F-FDG uptake in whole body. Excisional biyopsy histopathology revealed diffuse large B-cell Non-Hodgkin lymphoma.

İnternal herniasyon karın içi cerrahi ve malignite öyküsü olan hastalarda daha sık görülür. Biz bu vaka sunumunda, yedi yıl önce rektal adenokarsinom tanısı almış, cerrahi ve pelvik radyoterapi öyküsü olan 58 yaşında erkek hastayı sunduk. Hastada rutin takiplerde çekilen abdomen bilgisayarlı tomografi (BT)’ de karın ön duvarında serozal implant şüphesi olan lezyon saptandı. Nüks şüphesiyle çekilen 18F-florodeoksiglukoz pozitron emisyon tomografi/bilgisayarlı tomografi (18F-FDG PET/BT) ile BT' de implant olarak değerlendirilen lezyonun, spontan redüksiyon yapan internal herniasyon olduğu sonucuna varıldı. Kanser hastalarında FDG PET/BT görüntüleme bu hastalarda nüks şüphesinin aydınlatılmasında önemlidir ve onkoloji pratiğinde hastaların seyrine ışık tutar.

Internal herniation may be seen more frequently in patients with intra-abdominal surgery and malignancy history. We presented a 58-year-old male patient diagnosed with rectal adenocarcinoma seven years ago with a history of surgery and pelvic radiotherapy. When the abdominal computerized tomography (CT) image was taken during routine oncology follow-up, a lesion mimicking a serosal implant on the anterior abdominal wall was detected. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging was performed with the suspicion of recurrence. It was concluded that the lesion, which was evaluated as an implant in abdominal CT with FDG PET/CT imaging, was a spontaneously reducing internal herniation. FDG PET/CT imaging in cancer patients is crucial in illuminating the suspicion of recurrent lesions of these patients and sheds light on the course of the patients in oncology practice.

Sistemik juvenil idiyopatik artrit (sJIA), ilk semptomu genellikle ateş olan önemli bir otoinflamatuar hastalık olup tanı ve tedavi geciktiğinde makrofaj aktivasyon sendromu gibi hayatı tehdit eden durumlar gelişebilir. sJIA, diğer ateşli hastalıklardan ayıran spesifik testi olmayan bir dışlama tanısıdır. Ateş, döküntü, artralji ile başvuran 12 yaşındaki bir kız çocuğunda sJIA'nın pozitron emisyon tomografi / bilgisayarlı tomografi (PET/BT) bulgularını sunuyoruz. Nedeni bilinmeyen ateş etiyolojisini araştırmak için yapılan FDG-PET/BT'de dalak, kemik iliği ve lenf düğümlerinde florodeoksiglukoz (FDG) tutulumu gözlendi. Yoğun FDG tutulumu olan sol servikal lenf düğümünden lenfoma şüphesiyle yapılan eksizyonel biyopsi sonucu reaktif hiperplazi olarak rapor edildi. PET/BT, nedeni bilinmeyen ateşi olan hastalar için alternatif bir tanı yöntemidir. Bu olgu sunumunda, sJIA'lı hastalarda, lenfoproliferatif hastalık düşünülmesine yol açabilecek yoğun florodeoksiglukoz tutan lenf nodları olabileceğini, dalak ve kemik iliği tutulumu nedeniyle PET/BT bulgularının lenfoma ile örtüşebileceğini vurgulamaktayız.

Systemic juvenile idiopathic arthritis (sJIA) is an important autoinflammatory disease whose first symptom is usually fever, and life-threatening conditions such as macrophage activation syndrome can develop when diagnosis and treatment is delayed. sJIA is an exclusion diagnosis and there is no specific test that distinguishes it from other febrile diseases. We report the positron emission tomography/computed tomography (PET/CT) findings of sJIA in a 12-year-old girl who presented with fever, rash, arthralgia. Fluorodeoxyglucose (FDG) uptake was observed in the spleen, bone marrow and lymph nodes in FDG-PET/CT performed to investigate the etiology of fever of unknown origin. The result of an excisional biopsy performed with suspicion of lymphoma from the left cervical lymph node with intense FDG uptake was reported as reactive hyperplasia. PET/CT is an alternative diagnostic method for patients with fever of unknown origin. In this case report, we emphasize that in patients with sJIA, there may be intense fluorodeoxyglucose-avid lymph nodes that may lead to the consideration of lymphoproliferative disease, and PET/CT findings along with spleen and bone marrow involvement may overlap with lymphoma.