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Biomedical subjects

Khaldoun Kerrou

Publications and source records attributed to Khaldoun Kerrou.

At least 19 recordsLinked to original sources

PET/CT in patients with hepatocellular carcinoma using [(18)F]fluorocholine: preliminary comparison with [(18)F]FDG PET/CT.

PURPOSE: The diagnostic accuracy of [(18)F]fluorodeoxyglucose (FDG) PET is insufficient to characterise hepatocellular carcinoma (HCC) in liver masses and to diagnose all cases of recurrent HCC. HCC has been reported to take up [(11)C]acetate, but routine use of this tracer is difficult. Choline is another tracer of lipid metabolism, present in large amounts in HCC. In a proof-of-concept study, we evaluated [(18)F]fluorocholine (FCH) uptake by HCC and compared FCH PET/CT with FDG PET/CT. METHODS: Twelve patients with newly diagnosed (n=8) or recurrent HCC (n=4) were prospectively enrolled. HCC was assessed by histology in eight cases and by American Association for the Study of Liver Diseases (AASLD) criteria in four cases. All patients underwent whole-body PET/CT 10 min after injection of 4 MBq/kg FCH. Within 1 week, 9 of the 12 patients also underwent whole-body FDG PET/CT 1 h after injection of 5 MBq/kg FDG. RESULTS: The per-patient analysis showed a detection rate of 12/12 using FCH PET/CT for both newly diagnosed and recurrent HCC. The median signal to noise ratio was 1.5+/-0.38. There was a trend towards a higher FCH SUV(max) in well-differentiated HCC (15.6+/-7.9 vs 11.9+/-0.9, NS). Of the nine patients who underwent FCH and FDG PET/CT, all nine were positive with FCH whereas only five were positive with FDG. CONCLUSION: FCH provides a high detection rate for HCC, making it potentially useful in the initial evaluation of HCC or in the detection of recurrent disease. The favourable result of this proof-of-concept study opens the way to a phase III prospective study.

Carcinoma, Hepatocellular↗

[FDG PET and its impact on patient's management in oncology].

FDG, a radioactive glucose analog for PET imaging, requires some precautions: it should be used only in patients with glycemia < 7mmol/L, fasting for at least 6 h but well hydrated, and after pregnancy is ruled out. FDG-PET has many indications in oncology. Its clinical utility has been documented in some circumstances, listed as routine indications in the European Principal Characteristics Summary and the French Standards, Options, and Recommendations. The European "Points to Consider" define as a principal criterion of clinical utility the impact of the imaging results on patient management. The original results presented here evaluate the clinical impact of FDG-PET among patients at Tenon Hospital by the rate of modifications in patient' management, determined with the same questionnaire as that used in two California studies of 2044 patients. Our response rate was lower than in our previous retrospective study in 2000 (34% versus 73%), probably because a prospective evaluation requires more work by the referring physician (who had to respond to two separate letters). On the other hand, the modification rate rose significantly (54% versus 46%, p<0.001), especially for colorectal cancer (58% versus 44%, p<0.02). The California studies had similar response rates (31%-48%, depending on the indication). Their modification rates were also similar, although higher for lymphoma (68%), colorectal (65%) and breast (58%) cancers.

Decision Making↗

[PET and malignant cerebral tumors].

Normal biodistribution of FDG includes intense physiologic uptake in the brain, which consumes glucose. The high background therefore makes it difficult to detect the foci taking up glucose, which correspond to malignant lesions. FDG PET is nevertheless clinically useful for detecting high-grade gliomas, cerebral lymphomas and, in some cases, unexpected brain metastases in whole-body PET examinations. As an adjunct to CT and MRI, FDG-PET can make stereotactic radiosurgery more precise in targeting primary or secondary brain cancers and can differentiate necrotic fibrosis from viable cancer tissue during follow-up in cases of abnormal or equivocal MRI results. When available, methionine-(11C) PET delineates low grade gliomas accurately. Several fluorine (18F)-labeled radiopharmaceuticals have been proposed in this setting, with FET and FDOPA apparently the most effective. Four original clinical cases illustrating performances of FET and FDOPA PET in this setting are presented.

Brain Neoplasms↗

[PET in head and neck cancers].

FDG PET is useful when cancer in the head or neck (except for tumors of the salivary glands, which cannot be characterized accurately) is diagnosed or suspected but not confirmed by biopsy. It can, for example, find evidence of suspicious lymph nodes in clinically N0 necks, detect foci suggestive of distant metastases or second cancers, and provide useful prognostic information. Because it can be very difficult to identify anatomical structures and landmarks on PET images in the head and neck region, PET/CT fusion is very helpful in this area. In early assessment of chemotherapy, the absence of a significant reduction in FDG uptake after one or two cycles predicts lack of efficacy and thus indicates the need to modify the regimen. Conversely, the disappearance of FDG foci indicates effective treatment and good prognosis but cannot rule out the persistence of any malignant tissue at the end of treatment, especially neoadjuvant. Diagnostic impact is probably greatest in monitoring for recurrence and restaging known recurrence: FDG PET should be performed - perhaps routinely - early enough that curative options are still open, but long enough after the end of treatment to avoid false positive results from inflammation. The strategy and timing of FDG PET during follow-up should be determined in more detail in the future, as should the role (if any) of fluorotyrosine (FET) PET in squamous cell carcinoma.

Antineoplastic Agents↗

[FDG-PET in localization of cancers of unknown primary origin].

FDG-PET can be successful in localizing the primary cancer when a metastasis is discovered but no primary tumor can be identified (cancer of unknown primary, or CUP) by physical examination, laboratory testing (for tumor markers, for example) or conventional imaging. The greatest number of PET studies in CUP concern secondary lesions in cervical lymph nodes, and PET is an established clinical use (highest ranking, 1A) according to the 3rd German Consensus Conference and an "option" in the French Standards, Options, and Recommendations. Success rates range from 30% to 50% in most studies using PET; a higher rate was reported recently with PET/CT. FDG-PET should be performed sufficiently early in cases of neurological paraneoplastic syndrome, because established lesions become irreversible. Identification of the antibody present helps to specify the organ and FDG-PET can then localize the lesion; together these techniques make it possible to perform curative surgery even when the primary tumor is not visible. The success rate is somewhat lower than in cases of metastasis, around 35%. The clinical utility of PET in other paraneoplastic syndromes has not yet been sufficiently studied, but these conditions are rare. It is precisely in cases with a kind of 'orphan' indication that FDG PET should be considered, as an effective "problem solver".

Fluorodeoxyglucose F18↗

[PET in thyroid cancers].

FDG PET can detect thyroid cancer in patients referred for exploration of a different cancer. Because of its lack of specificity, however, this modality is not indicated for examination of thyroid nodules: ultrasonography and fine needle biopsy with cytology allow histological diagnosis, which can be completed by iodine-123 scintigraphy when an autonomous nodule is suspected. No information is currently available about the utility of FDG PET in preoperative staging. In follow-up of patients undergoing thyroidectomy for adenocarcinoma, FDG PET is useful for detecting recurrence in cases where serum thyroglobulin levels rise and iodine-131 scintigraphy is negative: surgical resection may be appropriate. Nonetheless FDG PET should be performed more widely and earlier: the initial presence of foci positive for FDG is a major predictor of shorter survival, and most cancer lesions take up either iodine or FDG. In follow-up of medullary carcinoma, FDG PET detects residual tissue better than any other scintigraphic procedures, especially when serum levels of CEA (carcinoembryonic antigen) are rising rapidly. FDOPA PET seems to have better sensitivity than FDG-PET and may be useful in occult recurrence, as three case reports indicate.

Adenocarcinoma↗

[PET in primary pulmonary or pleural cancer].

In our hospital as in many others, primary lung cancer is the most frequent indication for FDG PET. Studies have assessed the clinical utility of this imaging modality in characterizing solitary pulmonary nodules or masses, initial staging, defining tumor volume in radiotherapy and searching for recurrence of or restaging non-small cell carcinoma; studies are currently underway to evaluate its use in early assessment of chemotherapy response. Small cell lung cancer has a high FDG uptake and PET/CT can be useful for rapid staging. False negative results may be due to pure bronchioloalveolar carcinomas and endocrine tumors. FDG-PET will certainly play a more important role in the diagnosis and follow-up of pleural cancers in the future. An unexpected positive FDG PET focus should be considered as a warning, but histological proof should precede any irrevocable decisions.

Diagnosis, Differential↗

Can fluorodihydroxyphenylalanine PET replace somatostatin receptor scintigraphy in patients with digestive endocrine tumors?

UNLABELLED: The aim of this study was to evaluate whether (18)F-fluorodihydroxyphenylalanine ((18)F-FDOPA) PET is accurate for the diagnosis and follow-up of any type of well-differentiated digestive endocrine tumor and to assess its performance compared with standard somatostatin receptor scintigraphy (SRS) using (111)In-pentetreotide. METHODS: We reviewed the results of 33 evaluable (18)F-FDOPA PET and (111)In-pentetreotide SRS examinations performed between March 2002 and September 2005 in 30 patients referred for documented well-differentiated digestive endocrine tumor. RESULTS: The sensitivity and accuracy of (18)F-FDOPA PET were significantly better for carcinoid tumors (defined according to the World Health Organization 2000 classification) (n = 19) than for noncarcinoid tumors (n = 14)-that is, 93% versus 25% for sensitivity (P < 0.01) and 89% versus 36% for accuracy (P < 0.01), respectively. In contrast, the performances of (111)In-pentetreotide SRS did not differ according to the carcinoid or noncarcinoid type of the primary endocrine tumor-that is, 81% versus 75% for sensitivity and 79% versus 71% for accuracy, respectively. In carcinoid tumors, comparison between (18)F-FDOPA PET and (111)In-pentetreotide SRS showed that (18)F-FDOPA PET more accurately evaluated the extent of disease than (111)In-pentetreotide SRS. (111)In-Pentetreotide SRS did not reveal any additional lesions in any case. Conversely, in noncarcinoid tumors, the extent of the disease was more accurately evaluated in all cases by (111)In-pentetreotide SRS than by (18)F-FDOPA PET. CONCLUSION: This preliminary study emphasizes the importance of a precise histologic characterization of well-differentiated digestive endocrine tumor to select the best radiopharmaceutical. (18)F-FDOPA PET appears to be useful in carcinoid tumors and could become the first-line scintigraphic imaging modality for these tumors, but (111)In-pentetreotide SRS appeared to be a better first-line scintigraphic imaging modality for noncarcinoid digestive tumors.

Adult↗

Laparoscopic resection of occult metastasis using the combination of FDG-positron emission tomography/computed tomography image fusion with intraoperative probe guidance in a woman with recurrent ovarian cancer.

BACKGROUND: Positron emission tomography and computed tomography (PET/CT) have a potential role in detecting and locating recurrent ovarian cancer. Precise tumor location during surgical treatment is often difficult, owing to limited tumor size and post-surgical anatomic modifications. The surgical gamma probe, which has become increasing popular in recent years with the development of sentinel node mapping, may improve tumor detection and facilitate resection of occult metastases. CASE REPORT: We describe the first case of laparoscopic resection of occult metastasis using the combination of FDG-PET/CT image fusion with intraoperative FDG-sensitive probing in a patient with recurrent ovarian cancer. CONCLUSION: FDG-sensitive probe combined with preoperative PET/CT image fusion can help to detect occult metastasis and guide laparoscopic excision.

Combined Modality Therapy↗

Endometriosis with FDG uptake on PET.

BACKGROUND: The value of [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) uptake in endometriosis has not yet been extensively reported. CASE REPORT: A 32-year-old woman was examined to find an explanation for right pelvic pain associated with right subcostal pain. A computerised tomography (CT) scan was compatible with a haemangioma or a focus of endometriosis in the liver. Transvaginal sonography and magnetic resonance imaging (MRI) showed a complex ovarian cyst on the left. Blood CA125 levels were elevated. FDG-PET revealed a focus of uptake in the right paravesical area. Laparoscopy showed a left endometrioma associated with diffuse inflammatory pelvic adhesions. After surgery and 3 months GnRH agonist treatment the pain had disappeared and neither MRI nor FDG-PET showed any pelvic abnormality. The patient subsequently presented with dyspareunia and rectal pain resulting from a right uterosacral nodule and a rectal nodule. These were resected laparoscopically. After a 1-year follow-up, the patient is doing well. CONCLUSION: Endometriosis can give rise to false-positive results on FDG-PET. However, the FDG uptake in this particular case of endometriosis seems to have been due to inflammation rather than to a cyst. This report highlights the relationship between some of the biological features of endometriosis and some observed in neoplastic lesions.

Abdominal Pain↗

Contralateral axillary sentinel lymph node drainage in breast cancer: a case report.

BACKGROUND: Since the introduction of sentinel node (SN) mapping in breast cancer, extra-axillary lymph node sites of breast tumor drainage are discovered in about one-quarter of cases, especially after intraparenchymal injection. In most such cases, an ipsilateral axillary SN is associated with an extra-axillary SN. Non visualization of ipsilateral axillary SN and extra-axillary SN drainage are often associated with an increased risk of axillary involvement. CASE: We report a case of contralateral axillary SN drainage on lymphoscintigraphy in a breast cancer patient with a history of bilateral reduction mammoplasty and no ipsilateral axillary lymph node involvement.

Aged↗

[18F]FDG in recurrent breast cancer: diagnostic performances, clinical impact and relevance of induced changes in management.

Prognosis and management of patients with recurrent breast cancer depend on the spread of the disease. The aim of this study was to evaluate the performance of fluorine-18 fluorodeoxyglucose gamma camera positron emission tomography (FDG-GPET) in detecting breast cancer recurrence, its clinical impact and the relevance of induced changes in management. Patients (n = 134) with suspicion of recurrence either clinically or on conventional imaging (suspected recurrence: SR) or with an isolated increase in tumour marker levels (occult recurrence: OR) underwent FDG-GPET on a coincidence gamma camera. The reference standard for evaluation of accuracy, either histology (n = 26) or follow-up for 1 year (n = 49), was available in 75 (56%) patients. A questionnaire was sent to the referring clinician to evaluate the impact of FDG on management. Responses were obtained for 75 patients. Information regarding both approaches was available for 46 patients (46/134 = 34%). At the patient level, the sensitivity of FDG-GPET was 84%, significantly higher than the 63% sensitivity for conventional modalities, and the specificity was 78% versus 61%. The values for FDG-GPET were 81% and 86% respectively in the SR group and 90% and 73% respectively in the OR group, without any significant difference between these settings. The rate of change in management was 44% overall, 43% in the SR group and 45% in the OR group. Within the two groups, intermodality (major) changes were more frequent than intramodality (minor) changes. In the 46 patients for whom both approaches were available, 93% of management modifications were relevant (validated by biopsy or clinical follow-up). The results of this retrospective study show that FDG-GPET has an important role to play in patient management by confirming and evaluating the extent of recurrence or by localising occult recurrence.

Adult↗

Detection of recurrent colorectal carcinoma by 18F-FDG: comparison of the clinical performances of FDG PET and FDG CDET.

OBJECTIVES: To assess the clinical performance of fluorodeoxyglucose positron emission tomography (FDG PET) using either a coincidence (CDET) gamma camera or PET equipment with Nal crystals for the detection of recurrences of colorectal cancer. METHODS: From July 1997 to December 1999, 290 examinations were performed in 244 patients using a CDET gamma camera (2-dimensional system with 19 mm thick crystals). Additionally, from January 2000 to July 2002, 354 examinations were performed in 303 patients using PET (3-dimensional system with Nal crystals). RESULTS: Four hundred and seventy-three of the 644 examinations performed were evaluable on the basis of histological data (202 examinations) or more than 6 months of follow-up (273 examinations). The performances of the two systems were equivalent on a patient basis (sensitivity, specificity and accuracy of dedicated PET was 92%, 84% and 90%, respectively; and sensitivity, specificity and accuracy of CDET was 90%, 94% and 91%, respectively). On a site basis, a highly significant reduction in sensitivity was observed for lesions < or = 10 mm vs. > 10 mm with both PET and the CDET gamma camera, but no difference was observed between PET and CDET according to the size of the lesions. CONCLUSION: For detection of recurrent colorectal carcinoma, a 2-D coincidence gamma camera with 19 mm thick crystals and optimized acquisition and reconstruction parameters provides similar results in terms of accuracy, both per patient and per site, to those of an Nal PET camera.

Adult↗

[Sentinel lymph node biopsy in cervical and endometrial cancers: a feasibility study].

The sentinel lymph node (SLN) biopsy has been proposed for the cancers of the uterus in order to optimize the diagnosis of lymphatic metastases and micrometastases in early stage tumors. Patients with early invasive cervical (n = 8) or endometrial (n = 15) cancers were enrolled. A lymphoscintigraphy was carried out before the intervention. Intraoperative SLN identification was performed with blue dye combined to a handheld gamma probe detection. Non-sentinel pelvic nodes were separately cleared out. SLNs were examined with frozen sections, permanent sections with hematoxylin-eosin staining and further serial sections with immunohistochemistry if negative. Six cervical cancer patients and 13 endometrial cancer patients had a positive lymphoscintigraphy, showing in 5 patients extra-iliac SLN(s). The intraoperative detection was successful in 6 cervical cancer patients and 14 endometrial cancer patients. The higher detection rate was obtained with the isotopic method. Most of the SLNs were ilio-obturator. Four endometrial cancer patients had a lymphatic spread, only involving the SLN in each case. No false negative SLN has been noted. SLN biopsy appears feasible in cervical and endometrial cancers. This procedure could improve the lymphatic evaluation of these cancers.

Adult↗

Positron emission tomography with [(18)F]FDOPA and [(18)F]FDG in the imaging of small cell lung carcinoma: preliminary results.

Small cell lung carcinomas (SCLC) express neuroendocrine markers, and dihydroxyphenylalanine (DOPA) is known to accumulate in neuroendocrine tumours. This study was performed with the aim of evaluating the uptake of 3,4-dihydroxy-6-(18)F-fluoro-phenylalanine ([(18)F]FDOPA) by SCLC, based on comparison with the results of fluorine-18 fluorodeoxyglucose ([(18)F]FDG) positron emission tomography (PET) and standard imaging procedures. [(18)F]FDG PET and [(18)F]FDOPA PET were performed on four patients with newly diagnosed SCLC. There was agreement between the results of [(18)F]FDOPA PET and [(18)F]FDG PET in four tumoural sites out of 11, whereas [(18)F]FDG PET and standard imaging procedures were in full agreement. A semi-quantitative analysis based on standardised uptake values (SUVs) was performed in order to compare [(18)F]FDG and [(18)F]FDOPA tumour uptake. The median [(18)F]FDG SUV(max) was 5.9 (with a 95% confidence interval from 4.4 to 9.2), while the median [(18)F]FDOPA SUV(max) was 1.9 (with a 95% confidence interval from 1.6 to 3.8). The difference between [(18)F]FDG SUV(max) and [(18)F]FDOPA SUV(max) was significant ( P<0.01). [(18)F]FDOPA PET appeared less sensitive than [(18)F]FDG PET and standard imaging procedures in the staging of SCLC. No clear relation between [(18)F]FDOPA uptake and positivity of neuroendocrine markers on immunohistochemistry emerged from these preliminary results; however, since [(18)F]FDOPA uptake may reflect better differentiation of the tumour, and possibly a better prognosis, this point warrants clarification in a larger study.

Adult↗