Georges Baillet

Effect of 18F-FDG PET/CT Imaging in Patients With Clinical Stage II and III Breast Cancer

PURPOSE To investigate the potential effect of using (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in the initial assessment of patients with clinical Stage II or III breast cancer. METHODS AND MATERIALS During 14 consecutive months, 39 patients (40 tumors) who presented with Stage II or III breast cancer on the basis of a routine extension assessment were prospectively included in this study. PET/CT was performed in addition to the initial assessment. RESULTS In 3 cases, PET/CT showed extra-axillary lymph node involvement that had not been demonstrated with conventional techniques. Two of these patients had hypermetabolic lymph nodes in the subpectoral and infraclavicular regions, and the third had a hypermetabolic internal mammary node. PET/CT showed distant uptake in 4 women. Of these 4 women, 1 had pleural involvement and 3 had bone metastasis. Overall, of the 39 women, the PET/CT results modified the initial stage in 7 (18%). The modified staging altered the treatment plan for 5 patients (13%). It led to radiotherapy in 4 patients (bone metastasis, pleural lesion, subpectoral lymph nodes, and internal mammary nodes) and excision of, and radiotherapy to, the infraclavicular lymph nodes in 1 patient. CONCLUSIONS PET/CT can provide information on extra-axillary lymph node involvement and can uncover occult distant metastases in a significant percentage of patients. Therefore, initial PET/CT could enable better treatment planning for patients with Stage II and III breast cancer.

18F-FDG PET/CT Imaging for an Early Assessment of Response to Sunitinib in Metastatic Renal Carcinoma: Preliminary Study

PURPOSE Sunitinib is a new standard for the treatment of metastatic renal-cell carcinoma (RCC). We evaluated the accuracy of 18-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in assessing early response to this antiangiogenic drug, which cannot be obtained with conventional CT. PROCEDURES Patients had an FDG-PET/CT at baseline and another one for follow-up at the end of the first cycle (at day 42). For each examination, all lesions were registered and the maximum standardized uptake value (SUV(max)) was measured. The metabolic response on PET at day 42 was assessed, using European Organization for Research and Treatment of Cancer criteria. Morphologic response on CT at day 84 (after two cycles), using Response Evaluation Criteria in Solid Tumors criteria, was used as the reference standard. The long-term outcome was assessed by the progression-free survival. RESULTS Twelve (12) patients who completed at least two cycles of sunitinib were assessed. The SUV(max) for the lesions with the highest uptake ranged between 2.9 and 11.8 for the 12 patients (mean = 6.3). Early PET/CT findings, after one cycle of sunitinib, were consistent with later CT results in 9 patients of 11 assessable patients: 1 patient progressed on PET and CT, 7 patients had stable disease, and 1 had a partial response. The other 2 patients had a metabolic partial response on PET and stable disease on CT. However, 1 patient achieved a partial response later in follow-up, suggesting that metabolic early changes are an indication of sunitinib activity. CONCLUSION FDG-PET/CT seems to be an interesting tool for the early evaluation of response to sunitinib in metastatic RCC. Larger studies are needed to confirm these preliminary results and establish a prognostic value for PET/CT.

18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in AIDS-Related Burkitt Lymphoma

This study aims to describe 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) findings in patients with AIDS-related Burkitt lymphoma, at various times of treatment, and to define its utility for a better patient management. We retrospectively studied 13 consecutive HIV-positive patients with Burkitt lymphoma who underwent one or more PET/CT. In 5 of 5 patients imaged before treatment, PET/CT confirmed all involved sites detected at conventional work-up and demonstrated additional sites in 4 of 5 patients. Lymph node involvement, which is known to be uncommon in endemic or sporadic Burkitt lymphoma, was present in 54% of patients. Additionally, in 3 patients, Burkitt lymphoma was predominantly located in parotid lymph nodes, which is also an unusual finding. A negative scan was encountered in 3 of 10 patients imaged during treatment and in 1 of 4 patients imaged after treatment completion and was always associated with lasting complete remission. Presence of residual area of uptake was related to both favorable and unfavorable outcome whether performed during treatment (5/7 and 2/7, respectively) or after (1/3 and 2/3, respectively). Areas of increased uptake could be observed in lung (4 cases) or esophagus (3 cases), and were clinically related to pneumonia or esophagitis. We recommend PET/CT for accurate initial staging of patients with AIDS-related Burkitt lymphoma. PET/CT is also useful to monitor treatment response, as regression of initial disease can be early observed. Furthermore, PET/CT appears to have prognostic value, as a negative scan was always associated with a favorable outcome.

Hepatosplenic candidiasis imaged with F-18 FDG PET/CT.

We report a case of hepatosplenic candidiasis imaged with F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). A 22-year-old man receiving treatment for acute myeloid leukemia presented with fever. Hepatosplenic candidiasis was diagnosed based on the presence of hepatosplenic micro abscesses on CT. Fever persisted in spite of fluconazole treatment. F-18 FDG PET/CT scan was performed to rule out persistent hepatosplenic infection or other organ involvement. PET showed multiple intense uptake foci throughout the liver and spleen. The fungicidal drug was changed. The patient improved. We conclude that it would be interesting to investigate the use of F-18 FDG PET/CT in the work-up of systemic candidiasis.

Should FDG PET/CT be used for the initial staging of breast cancer?

Previous studies have pointed to the suboptimal sensitivity of F-FDG PET in assessing axillary lymph node status in breast cancer patients [1, 2]. In this issue of The European Journal of Nuclear Medicine and Molecular Imaging, Heusner and colleagues from the University Hospital of Essen bring further evidence to this statement. The study shows that contrast-enhanced full-dose FDG PET/CT is also not able to replace the sentinel lymph node biopsy technique (SLNB) or axillary lymph node dissection (ALND) for axillary staging [3]. The authors retrospectively examined the data of 61 consecutive women with histopathologically confirmed breast cancer who had received an i.v. contrastenhanced whole-body FDG PET/CT. Twenty-four patients (39%) had preoperative clinical stage T1 [4], while the others had larger tumours. In all patients, the ipsilateral axilla was assessed for lymph node metastases either with SLNB, ALND or both. Of the 61 patients, 24 had axillary lymph node metastases. The sensitivity of FDG PET/CT on a patient basis was 58% [3]. The ten axillary fossae which were falsely negative on FDG PET/CT contained 1.8 lymph node metastases on average (range: 1–4). In one case, a 2.4 cm invaded lymph node immediately adjacent to the primary tumour was overlooked by FDG PET/CT because of mistaking it as a part of the primary tumour. In the other missed cases, the size of the metastatic deposits ranged from 0.8 to 6 mm. FDG findings in the axillary fossae came out to be false-positive in three patients. The positive predictive value was 82% (14/17). The authors conclude that FDG PET/CT cannot replace invasive approaches for axillary staging in breast cancer patients but may be helpful as a pre-test for the triage to SLNB versus ALND.

Extraskeletal accumulation of Tc-99m HMDP in a tuberculous cold abscess.

A large and well-delineated area of increased uptake of Tc-99m HMDP in extraskeletal tissue is presented. This well-delineated scintigraphic lesion includes an extremely avid upper portion conforming to the right gluteal region, lateral to the iliac bone. The lower portion of the lesion spreads down to the lower two-thirds of the right femur as a lower, but still higher uptake compared to skeletal tissue. The final diagnosis of this lesion was a tuberculous cold abscess that was drained, and the therapy with a combination of three drugs was started.

Effect of variation in relaxation parameter value on LOR-RAMLA reconstruction of 18F-FDG PET studies.

PurposeWe tested the impact of different values of the relaxation parameter lambda (λ) on contrast and noise in line-of-response row-action maximum likelihood algorithm (LOR-RAMLA) in 18F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) imaging. MethodsPhantom studies were performed on a Gemini XL PET/CT scanner. The NEMA/IEC (National Electrical Manufacturers Association/International Electro technical Commission) torso phantom was used and acquisition data were reconstructed with λ values ranging from 0.025 to 0.1. Quality of the reconstructed images was evaluated by contrast recovery coefficients and background variability values according to the NEMA NU 2-2001 procedures. ResultsContrast recovery coefficients and background variability increased significantly when λ increased. The best noise-versus-resolution trade-off was obtained with λ in the 0.04–0.06 range. For LOR-RAMLA reconstruction, the manufacturer allows a possible λ choice from 0.025 to 0.1. We would not advise too small (0.025) or too large (0.1) λ values which result in too smooth or too noisy images. ConclusionWe determined optimal λ values in LOR-RAMLA on a Gemini XL PET/CT scanner. Caution is needed when using λ values out of that range.

Slow Dynamic Lymphoscintigraphy Is Not a Reliable Predictor of Sentinel-Node Negativity in Cutaneous Melanoma

We reviewed data from 160 consecutive patients (89 M/71 F; 53.5 [range, 9-88] years) who had under-gone lymphoscintigraphy and sentinel lymph node biopsy (SNB) in our hospital for histologically proven cutaneous malignant melanoma (CMM) (located on the upper limb: 33; lower limb: 57; trunk: 44; and head and neck: 26 patients), with a Breslow index > 1 mm and without clinical or radiologic evidence of metastatic spread. Colloidal (99m)Tc-rhenium sulfide (36-76 MBq) was injected intradermally in the four quadrants around the tumorectomy scar, followed by dynamic acquisition and static imaging. SN(s) were identified in 157 patients (overall identification rate, 98%). Fast (< 20 minutes), intermediate (20-30 minutes), or slow (> 30 minutes) lymphatic drainage was observed, respectively, in 122 (78%), 24 (15%), or 11 (7%) cases. Overall malignancy rate was 15%, respectively found in 19 (16%), 2 (8%), and 2 (18 %) patients with fast, intermediate, or slow drainage. No statistical difference between SN-positivity rates of patients with fast (19/122 = 16%) versus intermediate or slow drainage (4/35 = 11.4%) was observed (p = 0.69). Therefore, lymphoscintigraphic SN appearance time in CMM patients is unable both to predict SN metastasis and spare them from undergoing SN excision.

Tc-99m HMDP imaging of a large chondrosarcoma of the knee

After multiple myeloma and osteogenic sarcoma, chondosarcoma is the third most common skeletal malignancy with known characteristics of cortical destruction and tumor necrosis. The median patient age is 45 years old. A large chondrosarcoma of the left knee in a 22-year-old man was identified on Tc-99m HMDP imaging.

Apport de l’imagerie au 18FDG dans la prise en charge du cancer du testicule

Resume Les cles du pronostic Le bilan d’extension initial et le diagnostic precoce des recidives conditionnent le pronostic et le traitement du cancer du testicule. Le bilan initial Il est difficile car les techniques traditionnelles n’identifient pas certaines localisations ganglionnaires. En outre, ces techniques sont peu specifiques car l’augmentation de taille d’un ganglion n’est pas synonyme d’envahissement. L’utilisation de la tomographie par emission de positons au 18FDG dans le bilan d’extension augmente l’exactitude diagnostique. Masses residuelles et recidives La persistance d’une masse ou une augmentation de son volume malgre une reponse favorable a la chimiotherapie pose un probleme particulier. Plusieurs etudes successives montrent l’interet de l’imagerie par 18FDG dans la caracterisation des masses residuelles. Dans le suivi des patients, l’imagerie par 18FDG du corps entier permet d’eviter la multiplication des examens et peut detecter les recidives avec une valeur diagnostique plus elevee que les autres modalites d’investigation.