Clinical application of [18F]FDG PET/CT in follicular lymphoma

The objective of the present paper was to review the clinical application of [¹⁸F]FDG PET/CT in follicular lymphoma (FL). Once it was clear that, despite it is characterized as indolent, this type of lymphoma usually shows a high [¹⁸F]FDG avidity, PET/CT became more important and it's now considered the standard technique in staging, re-staging and response evaluation. Many studies have shown its impact on the management of patients (as it can change the stage in a significant proportion of cases and lead to treatment modifications), its superiority over CT (mainly because it's able to distinguish fibrosis in residual masses from viable tumor) and its prognostic value. The latter was initially associated only to the degree of metabolic response, which has proved to be a strong and independent predictive factor in terms of disease-free survival (DFS) and overall survival (OS). Thus, a negative PET/CT scan could be considered a guarantee in high-tumor-burden follicular lymphoma patients. However, semiquantitative parameters such as metabolic tumor volume or total lesion glycolysis, may also provide useful information and help us to identify patients with poor prognosis, guiding a risk-adjusted management and follow-up.

18F-FDG PET/CT in locally advanced cervical cancer: A review

Cervical cancer is the second most common gynecological cancer worldwide. In locally advanced cervical cancer, ¹⁸F-FDG PET/CT has become important in the initial staging, particularly in the detection of nodal and distant metastasis, aspects with treatment implications and prognostic value. The aims of this study were to review the role of ¹⁸F-FDG PET/CT in uterine cervical cancer, according to the guidelines of the main scientific institutions (FIGO, NCCN, SEGO, SEOM, ESGO, and ESMO) and its diagnostic accuracy compared to conventional radiological techniques, as well as to review the acquisition protocol and its utility in radiotherapy planning, response assessment and detection of recurrence.

Radium-223 in the treatment of bone metastasis in patients with castration-resistant prostate cancer. Review and procedure

Bone metastatic disease is the main cause of morbidity / mortality in patients with prostate cancer, presenting frequently as bone pain, pathological fractures or spinal cord compression, which requires early and timely therapy. Although, for the moment, the therapeutic window for its use has not been definitively established, radium-223 (²²³Ra), an alpha particle emitter, has proved to be an effective therapeutic tool, pre or post-chemotherapy, in patients with castration-resistant prostate cancer with symptomatic bone metastases and absence of visceral metastases, significantly modifying the prognosis of the disease. It is therefore imperative to define the ideal scenarios and the correct protocol for the use of this therapy and thus offer the greatest possible clinical benefit to the patient.

[Meta-analysis of the diagnostic performance of 18F-FDG PET in renal cell carcinoma]

AIM

Renal cell carcinoma is the most frequent solid kidney tumor. At present, PET is not the imaging test of choice, the helical CT being the best method to assess these patients. The aim of the study was to perform a meta-analysis of the literature to evaluate the performance and accuracy of 18F-FDG PET in the detection of primary disease, recurrence and metastasis of renal cell carcinoma.

MATERIALS AND METHODS

A systematic search was done of the available literature in primary and secondary databases published until October 2004 indexed in MEDLINE and CANCERLIT. Exclusion/inclusion criteria were applied. Their quality was evaluated using the Flynn criteria and joint estimators of sensitivity (S), specificity (Sp), likelihood ratios (LR), diagnostic odds ratio (DOR) and summary ROC (SROC) curve were obtained. The presence of the threshold effect was evaluated and the summary ROC (SROC) curve was calculated.

RESULTS

Seven out of 46 studies fulfilled the inclusion criteria and were analyzed. Three studies evaluated the use of 18F-FDG PET in the differential diagnosis of renal masses. Two studies analyzed restaging and two analyzed the role of 18F-FDG PET in the detection of metastatic disease. All the selected studies were classified according to Flynn's criteria. We found the highest S in restaging with S 0.87 (95 % CI, 0.75-0.95) and in metastases detection with S 0.72 (95 % CI, 0.56-0.85) as well as the high Sp in differential diagnosis of renal masses.

CONCLUSIONS

The results of this meta-analysis suggest that 18F-FDG PET can be useful in restaging and detection of metastatic disease, based on its acceptable S and Sp. However, the performance of 18F-FDG PET in the detection of primary disease is limited, but this may improve with the new PET/CT systems.

Recurrencia de un carcinoma gástrico de células en anillo de sello demostrada por PET-FDG

OBJECTIVE

To present the case report of a patient with undifferentiated and diffuse signet-ring cell gastric carcinoma in which FDG-PET evidenced recurrent disease.

MATERIALS AND METHODS

The patient was diagnosed of a stage III gastric carcinoma in 1994 and was treated with a subtotal gastrectomy. In February 2003, recurrent disease was detected in mediastinal and left supraclavicular lymph nodes. The patient was treated with chemotherapy and radiotherapy, reaching a complete response. After 6 months free of disease, he presented an elevation of the tumor markers with negative results in conventional imaging methods (upper digestive endoscopy, bone scintigraphy, and CT). An FDG-PET scan was performed to rule out recurrent disease.

RESULTS

FDG-PET detected pathologic findings suggestive of malignant disease in right supraclavicular and mediastinal lymph nodes. These findings were confirmed by clinical follow-up and with another CT scan performed 4 months later.

CONCLUSIONS

In this case report we stress the importance of early recurrence by FDG-PET in a non-intestinal gastric carcinoma. This is of interest given the greater difficulty to detect mucous secreting and/or producing carcinomas with the PET-FDG.

Meta-análisis de la eficacia diagnóstica de la PET-FDG en pacientes con sospecha de recurrencia por cáncer de ovario

AIM

The aim of this paper was to perform a meta-analysis of the literature to evaluate the accuracy of FDG-PET in recurrence detection in patients with ovarian cancer.

METHODS

The search strategy consisted in identifying papers published between November 1972 and October 2003 indexed in MEDLINE and CANCERLITE. Inclusion criteria were publications that evaluated recurrence with FDG-PET in patients with ovarian carcinoma. Exclusion criteria were duplicated papers or those outdated by subsequent ones. The statistical analysis included 95 % confidence intervals (CI) of sensitivity (S), specificity (Sp) and natural logarithm of the odds ratio (Ln OR).

RESULTS

Seventeen publications fulfilled the inclusion criteria and were analyzed. The S and Sp were 0.94 (95% CI, 0.93-0.96) and 0.65 (95% CI, 0.46-0.85), respectively. The Ln OR presented global homogeneity and significant values in > 75% of the studies.

CONCLUSION

According to our meta-analysis, FDG-PET has high S and intermediate Sp, with few false negative results. These preliminary findings suggest that FDG-PET may be an effective means of identifying patients with recurrent ovarian cancer.

Impacto de la tomografía por emisión de positrones mediante 18-Fluoro-2-Desoxi-D-Glucosa (PET-FDG) en el manejo terapéutico de pacientes con recurrencia secundaria a cáncer de ovario

AIM

Recurrent ovarian cancer is a major problem and an accurate diagnosis can often change patients' management. This study aimed to assess the impact on management of FDG-PET in recurrent ovarian cancer.

MATERIAL AND METHODS

Forty-three patients in whom FDG-PET scan was performed due to suspected recurrent ovarian cancer were included. FDG-PET results were confirmed by histopathology and clinical follow-up of at least 12 months. To assess impact on management the treatment plan based on conventional imaging methods was compared with the treatment plan based on inclusion of PET findings, classifying FDG-PET impact on management as high, medium, low or no impact. Management changes, when present, were classified as intermodality or intramodality.

RESULTS

FDG-PET had a high impact on therapeutic management in 28 patients (65.1 %), medium impact in 2 patients (4.6 %), low impact in 9 patients (20.9 %), and no impact in 4 patients (9.3 %). FDG-PET induced an intermodality change in management in 27 patients (62,8 %); intramodality changes were induced in 3 patients (7 %). Finally, it produced no treatment changes in 13 patients (30.2 %).

CONCLUSION

FDG-PET supplied additional information when compared to conventional diagnostic procedures and allowed adequate management changes in most patients.

Hipercaptación esplénica secundaria a factor estimulador de colonias granulocitarias (G-CSF) en el estudio PET-FDG

We present the case of an 11 year-old Caucasian girl who presented chest pain of 12 weeks evolution, with no other symptoms and a negative physical examination. Lactate dehydrogenase levels were increased to 797 U/l, whereas beta-2-microglobulin (BM2) levels were normal. The thoracic CT showed a bulky mediastinal mass that occupied the pretracheal, paratracheal and right prevascular regions. The gallium scintigraphy showed high uptake in the mediastinic region; the bone scintigraphy was negative. Biopsy of the mediastinal mass revealed the presence of diffuse large B-cell non-Hodgkin's lymphoma. Treatment included 4 cycles of chemotherapy followed by 7 days of subcutaneous granulocyte colony-stimulating factor (G-CSF, Lenogastrim) at a dose of 5 mg/Kg/day. Following treatment, a CT scan was performed to evaluate response, finding a calcification of the mass without significant reduction of the overall size. Because CT was inconclusive in the assessment of response to therapy, a 18F-FDG PET scan was performed. The 18F-FDG PET scan did not show any pathological uptake in the mediastinum but revealed a splenic and bone marrow diffusely increased 18F-FDG uptake. The differential diagnosis included a secondary effect induced by G-CSF therapy as one of the main possibilities, but other possibilities such as a malignant infiltration by lymphoma could not be discarded. Therefore, a second 18F-FDG PET scan was performed 3 months later. This study showed no pathological findings, with a normal 18F-FDG uptake in the spleen and bone marrow. Thus, the benign and reactive nature of the splenic and bone marrow 18F-FDG increased uptake found in the previous study was confirmed. We consider that the stimulating effect that G-CSF therapy has on the spleen and bone marrow must be taken into account when performing a 18F-FDG PET scan, as it can be an important source of false-positive results.