Is there any improvement in clinical staging with 18F-FDG PET/CT compared to surgical staging in cases of lung cancer?

OBJECTIVE

¹⁸F-Fluorine fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) imaging is considered the standard imaging modality for patients with non-small cell lung carcinoma. The aim of this study was to compare clinical staging (cTNM) performed with ¹⁸F-FDG PET/CT and surgical staging (sTNM) in patients with non-small cell carcinoma treated with surgery.

MATERIAL AND METHODS

We performed a retrospective analysis of 99 surgical patients with non-small cell carcinoma who underwent ¹⁸F-FDG PET/CT examination. Semiquantitative measures were calculated from the primary lesions and mediastinal lymph nodes. Findings of cTNM were compared with final surgical-pathological evaluation. Subjects were divided into two groups as postsurgical cTNM changed and cTNM unchanged. Patients in the cTNM changed group were further classified as postsurgical upstaged (US) and downstaged (DS). Results of the US patients were compared with the results of the remaining patients consisting of cTNM unchanged and DS to evaluate the predictable roles of semiquantitative parameters for postsurgical upstaging. To determine mediastinal tumoral involvement, cut-off values were obtained from calculated semiquantitative results of FDG uptakes in lymph nodes. A p value<0.05 was considered statistically significant.

RESULTS

Subjects were aged 40-82 years with a mean age of 64.78±8.70 years. Classification agreement was observed in 43 patients (43%) and in 57%, postsurgical stage migration was seen. Concurrence of cTNM and sTNM was more pronounced in the T1 and N0 subsets which were 84% and 74%, respectively. The lowest concurrence was observed in N1 classification followed by T4 and N2 (1%, 50% and 58%, respectively). Change in T staging occurred in 20 of 56 (36%), in N staging 22 of 56 (39%) and change in T and N in 14 patients (25%). Distribution of US and DS patients in the cTNM changed group was 43% (24 of 56) and 57% (32 of 56), respectively. Results of semiquantitative measures were significantly higher in US patients than the results of the group consisting of DS patients and cTNM unchanged patients, for all parameters. Cut-off value calculated from mediastinal uptakes was most specific for metastases in MTV (metabolic tumor volume) with an acceptable sensitivity (90% and 67%, respectively).

CONCLUSIONS

The concordance between cTNM and sTNM was better in staging T category compared to N stations. Semiquantitative measures of primary tumor may play a role in predicting postsurgical upstaging. Taking MTV into consideration in the mediastinal region may be more valuable than other parameters in the assessment of nodal involvement.

Relationship between primary tumour 18F-FDG uptake and immunohistochemical and clinical prognostic parameters in breast carcinoma

OBJECTIVE

The objective of this study was to investigate the relationship between level of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) accumulation in primary breast tumour assessed by positron emission tomography/computed tomography (PET/CT) and histopathological and clinical prognostic factors.

MATERIAL AND METHODS

A retrospective analysis was performed using the medical records of 58 female patients (age range: 31-86 years, mean age: 56) with biopsy of proven breast carcinoma, and who had undergone ¹⁸F-FDG PET/CT examination before chemotherapy/surgery. The ¹⁸F-FDG uptake of breast tumours was calculated as tumour to background ratio (TBR), which was compared with histopathological and clinical prognostic parameters.

RESULTS

The histology of the breast tumour in the 58 patients was ductal type in 52 (90%), lobular in 4 (7%), and mucinous in 2 (3%). Tumour size was ≤ 2cm in 31 (53%) patients, and>2cm in 27 (47%). The levels of TBRs were not significantly different between the patients groups with tumours of 2cm or less and greater than 2cm (P=0.131). No significant difference between levels of TBR was observed neither with regards to axillary lymph node involvement (P=0.065) nor in terms of distant metastases (p=0.123). No statistically significant difference was found in levels of TBRs between patients with c-erbB-2 receptor positive and negative ones (P=0.107). Progesterone receptor (PR) expression was observed in 33 patients (57%), and 25 patients (43%) were PR negative. As regards progesterone receptor status, a statistically significant difference was observed in mean TBR levels between patients with and without progesterone receptor expression (P=0.020). Oestrogen receptor expression was positive in 41 (71%) patients, and negative in 17 (29%) patients. The difference in the levels of TBRs between patients with and without oestrogen receptor expression was at the level of significancy (P=0.050).

CONCLUSIONS

It is concluded that ¹⁸F-FDG uptake correlates with progesterone negativity of the tumour. However, a significant association with clinical prognostic parameters and level of ¹⁸F-FDG uptake levels could not be demonstrated.

A case of hypercalcaemic crisis secondary to coexistence of primary hyperparathyroidism and Graves' disease

A 46 year-old female patient presented to the hospital with ongoing and progressively increasing fatigue, severe nausea and vomiting, loss of appetite, constipation, palpitations and somnolence. Laboratory evaluation revealed a severe hypercalcaemia and overt hyperthyroidism. She was diagnosed with primary hyperparathyroidism accompanied by Graves' disease. The patient underwent total thyroidectomy and right inferior parathyroid gland adenoma excision on the 24th day of her admission to the hospital after calcium levels and free thyroid hormone levels were brought to normal ranges. We suggest that a possibility of simultaneous thyrotoxicosis and primary hyperparathyroidism in cases presenting with a hypercalcaemic crisis should be considered.

Incidental pheochromocytoma in a patient with nasopharyngeal carcinoma

Because the adrenal glands are common locations for metastases, pheochromocytoma is frequently misdiagnosed as adrenal metastasis in patients with a history of cancer. An incidental adrenal mass was detected during an abdominal computed tomography (CT) scan performed to stage the nasopharyngeal carcinoma in a 35-year-old male patient. The features of an adrenal mass on the CT, magnetic resonance imaging (MRI), and fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) were thought to show adrenal metastasis. However, the patient did not complain about flushing, palpitation, headache or excessive sweating. His blood pressure was 132/74 mmHg, and his pulse rate was 82 bpm. A pheochromocytoma was found during a biochemical diagnosis that evaluated the catecholamine in urine collected over a 24-hour period. The urine had elevated urinary adrenaline, metanephrine, and vanillylmandelic. An I123 MIBG scan showed avid tracer uptake in the right adrenal mass with no evidence of abnormal uptake elsewhere. A right adrenalectomy operation was performed and a diagnosis of pheochromocytoma was confirmed histopathologically. Incidental adrenal masses detected in the presence history of cancer should always be subjected to hormonal evaluation. Although patients may be asymptomatic, the probability of incidental pheochromocytoma should not be ignored.

Splenic and multiple abdominal metastases of endometrial carcinoma detected with FDG-PET/CT

A 58 year old female was referred for FDG-PET/CT for restaging of endometrial adenocarcinoma. For evaluation of treatment, no metastases were detected on FDG-PET/CT which was performed 18 months later after the surgery. During follow-up, FDG-PET/CT was performed 6 months later than the previous FDG-PET/CT for restaging. A lesion with increased metabolic activity (SUV max: 10.21) was detected at spleen which was not seen on previous FDG-PET/CT scan. The lesion was consistent with metastasis of endometrial carcinoma. Splenic metastasis of endometrial carcinoma is extremely rare. There are only 13 cases of splenic metastasis from endometrial carcinoma that reported in the literature before. There is only one splenic metastasis of endometrial carcinoma case reported in the literature which is imaged with FDG-PET. To best of our knowledge this is the first report of solitary splenic metastasis of endometrial carcinoma that is imaged with FDG-PET/CT.

Evaluation of cardiovascular complications with 99mTc tetrofosmin gated myocardial perfusion scintigraphy in patients with thalassemia major

OBJECTIVE

Iron overload limits the life expectancy of thalassaemic patients by causing cardiac toxicity. Iron also plays a catalytic role in the pathogenesis of atherosclerosis. The aim of this study was to evaluate the role of (99m)Tc Tetrofosmin gated myocardial perfusion scintigraphy (GMPS) in the detection of cardiac dysfunction in patients with thalassemia major.

MATERIALS AND METHODS

Forty two patients with homozygous beta-thalassemia were enrolled in the study. Myocardial perfusion and wall motion were analysed in all patients (mean age 17 +/- 5.28) and 34 age-matched controls using GMPS. Clinical data, liver function tests, hemoglobin, ferritin, low density lipoprotein (LDL) and cholesterol levels, and the total number and frequency of transfusions were collected from patient records.

RESULTS

97.6 % and 78.5 % of patients had normal myocardial perfusion and wall motion respectively. Nine out of 42 thalassaemic patients had abnormal left ventricular wall motion; half of these had septal hypokinesia. No significant correlation was found between the total number of transfusions, serum ferritin levels and left ventricular ejection fraction (p = 0.442 and p = 1.00, respectively). Echocardiography revealed systolic dysfunction in 5 out of 9 patients with wall motion abnormality. LDL was normal in 38 out of 42 patients and cholesterol levels were normal in 37 out of 42 patients.

CONCLUSIONS

Regional wall motion abnormalities can be seen in patients with thalassemia major. This early damage is frequently located in the septum and can be detected by GMPS. Serum ferritin levels and the number of blood transfusions are inadequate as predictors of myocardial dysfunction.

The additional diagnostic value of a single-session combined scintigraphic and ultrasonographic examination in patients with thyroid and parathyroid diseases

AIM

The aim of this study was to investigate the diagnostic efficacy and the clinical impact of scintigraphy combined with ultrasonography (USG) in the management of thyroid and parathyroid disorders in a large series of patients.

METHODS

A total of 387 consecutive patients referred to the Nuclear Medicine Department of Hacettepe University in the period from January to September 2007 for investigating a thyroid (N. 339 patients: 232 females and 107 males, mean age+/-SD=48.9+/-13.6 years) or a parathyroid disease (N. 48 patients: 34 females and 14 males, mean age+/-SD=47.4+/-9.6 years) were prospectively evaluated, systematically performing both scintigraphy and USG in a single-day session. All the examinations were independently reviewed by two nuclear medicine physicians; in cases of discrepancy (3%) a final diagnosis was reached by consensus. For thyroid pathologies, USG results were considered to provide additional diagnostic information over scintigraphy: 1) if more nodules were identified; 2) if an irregular hyperactive area at scintigraphy suspicious for the presence of a nodule was clearly characterized at USG; 3) if a nodule missed at scintigraphy because of small size (<1 cm) was well depicted at USG, thus allowing an USG-guided fine needle aspiration cytology (FNAC) to reach a final diagnosis. For parathyroid pathologies, USG was considered to provide additional diagnostic information over scintigraphy if a low intensity radiotracer retention from the parathyroid suspected of being a parathyroid enlargement was clearly depicted at USG. In thyroid diseases, scintigraphy was considered to provide additional diagnostic information over USG, if the functional status of a diffuse or uni- or multi-nodular goiter were clearly defined at scintigraphy. In parathyroid diseases, scintigraphy was considered to provide additional diagnostic information over USG, if the differential diagnosis between a lymph node or a muscle or a vessel depicted at USG was clearly defined as a parathyroid enlargement at scintigraphy. Lastly, the clinical impact of the single-day combined scintigraphic/USG protocol was evaluated.

RESULTS

USG. In the thyroid diseases group, USG was particularly useful: 1) to detect additional nodules in glands with suppressed thyroid tissue; 2) to disclose small thyroid nodules (<1 cm) in which it was possible to perform a USG-FNAC. In the parathyroid diseases group, USG was particularly useful for the detection of parathyroid enlargements not visualized at scintigraphy because characterized by a rapid wash-out of the radiotracer and thus by a low radioactivity intensity in the delayed scintigraphic images. Scintigraphy. In the thyroid diseases group, scintigraphy was particularly useful: 1) to diagnose a diffuse hyperfunctioning thyroid gland, and to differentiate in multinodular goiters the hyper- from the hypo-functioning nodules. In the hyperparathyroid diseases group, scintigraphy was particular useful in making a differential diagnosis between a true parathyroid enlargement vs. a lymph node or a muscle or a vessel as depicted at USG, and in cases with deeply or ectopically-positioned parathyroid glands. Combined imaging approach. Combined interpretation provided additional benefit in 225 of 339 patients (64.4%). Overall, using the combined scintigraphic/USG single-day protocol, in the thyroid diseases group the therapeutic strategy (drug therapy vs radioiodine therapy vs surgery) was changed in 176/225 patients (78.2%, P<0.001 by chi(2) of Pearson), and in the parathyroid disease group the therapeutic strategy (medical therapy vs surgery) was changed in 18/48 patients (37.5%, P<0.01 by chi2 test of Pearson).

CONCLUSION

In agreement with some previous published experiences, the combined single-day scintigraphic/USG protocol systematically adopted in a large series of consecutive patients with thyroid and parathyroid diseases, enrolled in a limited period of time, proved to significantly increase the global diagnostic accuracy and to change the therapeutic strategy in more than two third of patients with a thyroid disease and in more than one third of patients with a parathyroid disease.