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R P Baum

Publications and source records attributed to R P Baum.

At least 19 recordsLinked to original sources
PubMed2007

Are radiogallium-labelled DOTA-conjugated somatostatin analogues superior to those labelled with other radiometals?

PURPOSE: Gallium-68 is a metallic positron emitter with a half-life of 68 min that is ideal for the in vivo use of small molecules, such as [68Ga-DOTA,Tyr3]octreotide, in the diagnostic imaging of somatostatin receptor-positive tumours. In preclinical studies it has shown a striking superiority over its 111In-labelled congener. The purpose of this study was to evaluate whether third-generation somatostatin-based, radiogallium-labelled peptides show the same superiority. METHODS: Peptides were synthesised on solid phase. The receptor affinity was determined by in vitro receptor autoradiography. The internalisation rate was studied in AR4-2J and hsst-HEK-transfected cell lines. The pharmacokinetics was studied in a rat xenograft tumour model, AR4-2J. RESULTS: All peptides showed high affinities on hsst2, with the highest affinity for the Ga(III)-complexed peptides. On hsst3 the situation was reversed, with a trend towards lower affinity of the Ga(III) peptides. A significantly increased internalisation rate was found in sst2-expressing cells for all 67Ga-labelled peptides. Internalisation into HEK-sst3 was usually faster for the 111In-labelled peptides. No internalisation was found into sst5. Biodistribution studies employing [67Ga-DOTA,1-Nal3]octreotide in comparison to [111In-DOTA,1-Nal3]octreotide and [67Ga-DOTA,Tyr3]octreotide showed a significantly higher and receptor-mediated uptake of the two 67Ga-labelled peptides in the tumour and somatostatin receptor-positive tissues. A patient study illustrated the potential advantage of a broad receptor subtype profile radiopeptide over a high-affinity sst2-selective radiopeptide. CONCLUSION: This study demonstrates that 67/68Ga-DOTA-octapeptides show distinctly better preclinical, pharmacological performances than the 111In-labelled peptides, especially on sst2-expressing cells and the corresponding animal models. They may be excellent candidates for further development for clinical studies.

Animals↗
PubMed2005

[Correlation of histologic results with PET findings for tumor regression and survival in locally advanced non-small cell lung cancer after neoadjuvant treatment].

UNLABELLED: CT cannot provide useful information in a timely manner after neoadjuvant treatment. To evaluate the role of (18)F FDG PET after neoadjuvant chemoradiation for early therapy response and its effect on survival as compared to histopathologic tumor response, findings in 32 patients were analyzed prospectively in an ongoing multicenter trial (LUCAS-MD). INCLUSION CRITERIA: histologically confirmed NSCLC stage IIIA/IIIB. Neoadjuvant treatment: 2-3 cycles with paclitaxel/carboplatin and a block of chemoradiation followed by surgery. Pretherapeutic staging: PET scan in addition to a spiral CT and/or MRI. Second PET scan after completion of neoadjuvant therapy prior to surgery. Documentation of lymph node involvement. Assessment of SUV and the metabolic tumor index for primary tumor and metastatic lymph nodes. Image fusion of PET with CT data followed by molecular radiation treatment planning. Evaluation of histologic regression grade and correlation with PET for primary tumor and each lymph node location. All patients (10/32) with complete response in lymph node metastases detected by PET prior to surgery, had no vital tumor cells (i.e. histologic regression grade/RG III, sensitivity 100%). In primary tumors showing complete response, the RG was IIb or III, in one patient IIa (false negative in PET). False positive findings in PET are due to inflammation (5 patients, histologically confirmed). Univariate analyses: actuarial tumor-specific survival for complete metabolic remission vs. incomplete remission after 24 months: 76 vs. 20% (p=0,0079); for RG III/IIb vs. RG IIa/I after 24 months: 63 vs. 36% (p=0,0123).(18)F FDG PET precedes CT in measuring the tumor response and may predict (long term) therapeutic outcome in stage III NSCLC. Histologic regression grade correlates well with metabolic remission as detected by PET.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Position of nuclear medicine modalities in the diagnostic workup of cancer patients: lung cancer.

This review summarizes the current literature and tries to define the status of nuclear medicine in the clinical workup of lung cancer patients. Nuclear medicine procedures and positron emission tomography (PET) with the EMEA-approved radiopharmaceutical fluorodeo-xyglucose (FDG) are indicated for the characterization of lung lesions; the nodal staging of non-small cell lung cancer (NSCLC); the detection of distant metastases; and for the diagnosis of recurrent disease. Recent studies have shown the clinical efficacy of nuclear medicine and especially of FDG-PET in the workup of lung cancer patients and its significant impact on patients' management. Conventional nuclear medicine procedures are established for the pre-therapeutic assessment of pulmonary perfusion and function (lung perfusion and ventilation scintigraphy) and for the detection of bone metastases (skeletal scintigraphy). In studies in thousands of patients, FDG-PET has been proved to be the most accurate non-invasive diagnostic test for the characterization of lung nodules and masses. It can be recommended at least for patients with increased risk at surgery. FDG-PET should be applied in candidates for surgery of lung cancer, as mediastinoscopy may be omitted if PET shows no metastases in the mediastinum, and because FDG-PET avoids futile surgery by a more accurate selection of patients, especially by the detection of unexpected distant metastases. In candidates for thoracic radiotherapy, FDG-PET can help to exclude extrathoracic disease which needs systemic treatment and to better define the target volume for radiation therapy. The time has come for FDG-PET to find its place in new guidelines for the workup of lung cancer patients.

Bone Neoplasms↗
PubMed2001

[Pilot study with the monoclonal antibody IOR-C5 as a potential agent of radioimmunoscintigraphy in colorectal cancer].

UNLABELLED: IOR C-5 is a G1 immunoglobulin type intact murine monoclonal antibody (MAb) that was developed in the Center of Molecular Immunology in Havana City, Cuba. In immunohistochemical studies, this demonstrated a significant affinity for the epithelial tissues so that it was used in a pilot clinical study to perform a radioimmunoscintigraphy of the colorectal primary tumors and their locoregional recurrences. It was labeled with 99mTc using the Schwarz method, with a > 95% performance. Planar images of the chest, abdomen and pelvis were performed at 10 minutes, 4-6 hours and 18-24 hours post-injection in the anterior and posterior projections and the SPECT was performed 4-6 hours and 18-24 hours post-injection of 1.85 GBq 99mTC. This study has aimed to verify in vivo the capacity of ior-C5 MAb to accumulate in the malignant colorectal lesions. ior-C5 accumulated in 5 out of the 7 patients who were studied and who were suffering from colorectal cancer or in whom there was suspicion of recurrence. There was a negative case of primary tumors, which was an adenocarcinoma in situ in a tubular-papillary adenoma. The second case with a negative radioimmunoscintigraphy was a true negative case. CONCLUSIONS: It can be concluded that even though the number of patients is quite low, ior-C5 fulfilled the expectations of recognizing the epitope expressed in colorectal tumors in an in vivo human environment.

Adenocarcinoma↗
PubMed2001

Induction of CA125-specific B and T cell responses in patients injected with MAb-B43.13--evidence for antibody-mediated antigen-processing and presentation of CA125 in vivo.

The murine monoclonal anti-CA125 antibody MAb-B43.13 has previously been administered as an immunoscintigraphic agent in order to monitor recurrence of ovarian cancer in patients, and a long-term follow-up demonstrated a survival benefit for these patients. The clinical benefit was initially attributed to the activation of the idiotypic network. The objective of this study was to investigate the role of CA125-MAb-B43.13 immune complex formation on the induction of CA125-specific immune responses. Analysis of patient serum samples from pharmacokinetic studies demonstrated that the antibody forms immune complexes with CA125 in circulation within 30 minutes of injection. Induction of humoral and cellular anti-CA125 responses correlated with the amount of circulating CA125 antigen present at time of antibody injection. Subsequent to the injection of MAb-B43.13, the patients generated anti-CA125 antibodies that were directed against various epitopes on the antigen and were not restricted to the specific epitope recognized by MAb-B43.13. The generation of CA125-specific B and T cell responses after MAb-B43.13 injection correlated with improved survival. The influence of circulating CA125 for the induction of CA125-specific immune responses and the multi-epitopic nature of the human anti-CA125 antibodies suggest that the majority of these antibodies were not induced via the idiotypic network but by the autologous antigen itself. Since antibody and T cell responses to CA125 were not present before injection of MAb-B43.13, it is hypothesized that complex formation of MAb-B43.13 with circulating antigen triggers the induction of CA125-specific immune responses.

Adenocarcinoma↗
PubMed2001

Evaluation of therapy response in breast and ovarian cancer patients by positron emission tomography (PET).

Positron emission tomography (PET) has the potential to contribute significantly to treatment planning and to the evaluation of response to therapy in patients with cancer. For disease recurrence PET imaging provides information non-invasively. The final goal is to biologically characterize an individual patient's tumor and to predict the response to treatment at the earliest possible time. Since the development of neoadjuvant chemotherapy, PET has been proved to be the most sensitive and accurate imaging technique for early therapy response evaluation of breast tumors. Quantitative and/or semi-quantitative PET studies yield valuable information in breast cancer regarding prognosis and response to chemohormontherapy in a timely fashion. In ovarian cancer, up to now only few studies have been performed applying PET techniques for the evaluation of treatment response. These preliminary studies indicate that serial assessment of tumor metabolism by FDG-PET early during effective chemotherapy may predict subsequent response to such therapy. PET studies can be repeated without any side-effects and with low radiation exposure and results can be directly correlated with clinical laboratory data and histology. The role of PET in the context of patient management and the cost-effectiveness of this approach needs further evaluation. Therapy monitoring by PET could help to optimize neoadjuvant therapy protocols and to avoid ineffective preoperative therapy in non-responders, but this has to be proven in a larger number of patients and in different neoadjuvant settings such as chemotherapy, radiation therapy, hormone therapy or a combination of these.

Breast Neoplasms↗
PubMed2000

Staging of the neck in patients with oral cavity squamous cell carcinomas: a prospective comparison of PET, ultrasound, CT and MRI.

BACKGROUND: The choice of treatment in patients with oral malignancies depends on accurate pretreatment staging and particularly the detection of lymph node involvement. Therefore staging of the neck should be as accurate as possible. PATIENTS: One hundred and six patients with histologically proven squamous cell carcinoma of the oral cavity. STUDY DESIGN: In a prospective study, PET using fluoro-desoxy-glucose (18F-FDG), ultrasound, CT and MRI of head and neck were compared with the postoperative histologic tissue evaluation. Two thousand one hundred and ninety-six neck lymph nodes of 106 patients were investigated. In all patients the tumour was resected and a lymph node dissection was performed. RESULTS: The diagnostic procedures showed the following results when compared with the histological findings: PET: sensitivity 70%, specificity 82%, accuracy 75%; Ultrasound: 84%, 68%, 76%; CT: 66%, 74%, 70%; MRI: 64%, 69% 66%. Thus PET showed the highest specificity while ultrasound had the highest sensitivity compared with the other staging procedures. A nonsignificant correlation was found between the size of a lymph node metastasis and the ability to detect it. In 10 patients, second primary tumours or distant metastases were detected by PET only. CONCLUSION: Due to the high number of small lymph node metastases from oral cavity carcinoma, the non-invasive neck staging methods are limited to a maximum accuracy of 76%. Elective neck treatment should be mandatory for all patients with squamous cell carcinoma of the oral cavity.

Adult↗
PubMed2000

Intraoperative use of gamma-detecting probes to localize neuroendocrine tumors.

Neuroendocrine tumors are characterized by the expression of different peptides and biogenic amines. These rare tumors tend to grow slowly and are notoriously difficult to localize, at least in the early stages. Surgical removal is the only definitive therapeutic option for neuroendocrine tumors and relief from hyperfunctional status. The effectiveness of surgical treatment is invariably dependent upon the complete surgical excision of all tumor tissue, because microscopic and occult disease not readily seen by the surgeon may remain in situ, leading to shortened survival. Therefore, pre- and intraoperative localization of the primary as well as of metastatic tumors is of utmost importance. Radioguided surgery (RGS) is an intraoperative technique that enables the surgeon to localize radiolabelled tissue based on the characteristics of the various tissues. Concerning gastroenteropancreatic tumors (GEP), intraoperative gamma probe examination is able to reveal small tumor sites accumulating (111In-DTPA-D-Phe1)-pentetreotide more efficiently (> 90%) than somatostatin receptor scintigraphy (68%-77%), because lesions with a size smaller than 5 mm in greatest dimension could be identified. Furthermore, RGS identified 57% more lesions when compared to the "palpating finger" of the surgeon. In medullary thyroid cancer (MTC), surgical removal of the tumor is the first and most efficient treatment of the disease. Persistent or increasing serum calcitonin and carcinoembryonic antigen (CEA) levels imply tumor recurrence after thyroid ablation. For imaging recurrent MTC many radiopharmaceuticals have been used to visualize tumor sites, but none of them has shown excellent sensitivity. Preoperative somatostatin receptor scintigraphy and intraoperative RGS in patients with recurrent MTC demonstrate only part of the tumor sites and cannot visualize small tumor sites (less than 10 mm). In comparison, RGS using 99mTc(V)-DMSA detects metastases with a size of 5 mm in diameter, whereas the "palpating finger" of the surgeon localized metastases with a size of more than 1 cm in diameter. In patients with recurrent MTC, intraoperative gamma probe examination is able to localize over 30% more tumor lesions when compared with conventional preoperative imaging modalities and surgical findings. MIBG scintigraphy is the most sensitive technique for the detection and staging of neuroblastoma (sensitivity 92%; specificity nearly 100%). Intraoperative RGS with iodine labelled MIBG has been developed to improve the definition of tumor limits or to localize small, nonpalpable tumors. Comparison of 123I- and 125I-labelled MIBG revealed a sensitivity of 91% and 92%, respectively; the specificity of 125I (85%) was significantly higher than that of 123I (55%). In addition to scintigraphy of the adrenal glands by precusors of adrenal hormones, imaging with a radiolabelled somatostatin analogue is possible; however, (111In-DTPA-D-Phe1)-pentetreotide is not specific for any adrenal disease or function and the relatively high radioligand accumulation in the kidneys limited the use for detection of tumors in the area of the adrenal glands.

Endocrine Gland Neoplasms↗
PubMed1999

Immunoscintigraphy of xenotransplanted hepatoblastoma with iodine 131-labeled anti-alpha-fetoprotein monoclonal antibody.

BACKGROUND/PURPOSE: Hepatoblastoma (HB) is the most common primary malignant liver tumor affecting infants and young children. The alpha-fetoprotein level is elevated in 95% of all children with hepatoblastoma. Therefore, it is of interest to assess targeting of the HB marker alpha-fetoprotein by antibody imaging. In this pilot study, the authors investigated the radioimmunoscintigraphy of xenotransplanted HB in nude mice utilizing an anti-alpha-fetoprotein antibody. METHODS: HB cell suspensions from tumors of 3 children were transplanted subcutaneously into nude mice NMRI (nu/nu). A total of 200 microg of intact anti-alpha-fetoprotein antibody was injected intravenously into 8 animals from each HB. Before injection, the monoclonal antibody was labeled with iodine (I) 131 (specific activity of 75 MBq/mg, labeling yield of 95%) using the conventional iodogen method. Planar scintigraphic images of anesthetized mice in posterior views were acquired with a gamma camera immediately after injection, and after 1, 2, 3, 7, and 14 days. The biodistribution data were obtained by killing and dissecting animals, and the activity in the tissues was measured in a gamma counter. The alpha-fetoprotein levels in the animals' sera were recorded 15 days after imaging and were compared with the control group. RESULTS: A total of 66% of the hepatoblastomas could be detected by scintigraphy. Within 24 hours, the mean specific tumor uptake in nude mice hepatoblastomas with a volume of over 1,000 mm3, was 14% per injected dose (+/-3.9%). The biological half-life of the labeled antibody complex in the tumor was 3.86 (+/-0.84) days. Thyroid uptake of free I-131 was 2.85% per injected dose (+/-1.5%) reflecting the deiodination of the labeled antibody complex. CONCLUSIONS: The results show the possibility of imaging xenotransplanted hepatoblastoma with 131I-labeled anti-alpha-fetoprotein and may, in the future, determine tumor recurrence and extension, and thereby improve the prognosis of advanced HBs.

Animals↗
PubMed1999

Immunoscintigraphy with 99Tcm-labelled monoclonal anti-CEA BW 431/26 antibodies in patients with suspected recurrent and metastatic colorectal carcinoma: two-year follow-up.

The aim of this study was to evaluate immunoscintigraphy with BW 431/26 anti-CEA antibody in the follow-up of 15 patients with colorectal carcinoma. A whole-body scan followed by SPET imaging of the abdomen and pelvis was performed 4-6 and 20-24 h after the intravenous infusion of 0.6-1.0 mg of intact anti-CEA monoclonal BW 431/26 antibody labelled with 814-1110 MBq of 99Tcm. The HAMA response and serum CEA levels were determined. Immunoscintigraphic findings were verified by biopsy, radiologically and/or by 2 year follow-up. On an individual patient basis, immunoscintigraphy demonstrated an overall sensitivity of 83%, specificity of 100%, accuracy of 87%, positive predictive value of 100% and negative predictive value of 60%. Better results were achieved in the pelvic region than in the liver or in the extra-hepatic abdominal region. We evaluated 40 lesions; on an individual lesion basis, immuno-scintigraphy gave a sensitivity of 80% and an accuracy of 80%. SPET images detected significantly more lesions than whole-body planar images (P < 0.05). SPET at 20-24 h detected significantly more 'hot' lesions than at 4-6 h (P < 0.01). No correlation between CEA serum levels and immunoscintigraphy was observed (r = 0.376, P > 0.05). One of nine patients (11%) developed HAMA after immunoscintigraphy. We conclude that immunoscintigraphy with BW 431/26 antibody appears able to differentiate between tumour recurrence and scar tissue, and to evaluate liver metastases of colorectal carcinoma. Serum CEA levels appear not to influence the result of immunoscintigraphy and the HAMA response is minimal. A delayed SPET scan should be part of an immunoscintigraphic imaging protocol when 99Tcm-labelled BW 431/26 monoclonal antibody is used.

Abdomen↗
PubMed1999

Fluorine-18 FDG positron emission tomography for imaging of hepatocellular carcinoma.

OBJECTIVE: The detection of increased fluorine-18 fluorodeoxyglucose (18F-FDG) uptake by positron emission tomography (PET) is based on the enhanced glucose metabolism of tumor cells. Because the detection and staging of hepatocellular carcinoma (HCC) in patients with liver cirrhosis can be difficult, we prospectively evaluated the sensitivity of 18F-FDG PET in 14 consecutive patients with HCC. METHODS: Whole body and regional 18F-FDG PET of the liver were obtained. The results were compared with ultrasonography, contrast-enhanced, helical CT, histological grading, p53 protein expression of HCC, and serum alpha-fetoprotein (AFP) level. RESULTS: In 7 patients PET demonstrated increased tumor 18F-FDG uptake, whereas HCC was not distinguishable from nonmalignant liver tissue in 7 other patients. Hepatic lesions were detected by ultrasonography in all patients, whereas only 11 of 14 HCCs could be identified by CT. In 3 patients extrahepatic spread was demonstrated by 18F-FDG PET. Patients with increased tumor 18F-FDG uptake had significantly larger hepatic lesions and higher serum AFP levels than those with normal 18F-FDG uptake. Lesions could be visualized by 18F-FDG PET in 7 of 8 patients with moderately or poorly differentiated HCC, whereas none of the six well-differentiated tumors was detected. Two patients with strong p53 expression demonstrated increased tumor 18F-FDG uptake and extrahepatic metastases. CONCLUSIONS: The sensitivity of 18F-FDG PET for the imaging of HCC is low. Nevertheless, in patients with moderately or poorly differentiated HCC, tumors >5 cm, or with markedly elevated AFP levels 18F-FDG PET may contribute to an effective noninvasive staging.

Adult↗
PubMed1999

Positron emission tomography (PET) for staging and evaluation of response to treatment in patients with Hodgkin's disease.

Forty two examinations utilizing F-18 FDG-PET were performed in 23 patients with Hodgkin's disease to study for involved lymphoma regions and compared to conventional staging procedures. Twenty stagings were performed at diagnosis of untreated Hodgkin's disease or at first relapse, and 22 restagings during and after chemoradiotherapy. At diagnosis in 5 of 20 patients PET and other procedures revealed different extranodal manifestations and in 3 patients established different clinical staging. PET seemed to be accurate in the assessment of lymphoma involvement in nodal sites. During follow up, in 10 out of 22 investigations different results and discrepancy were recorded, mostly due to the different extent of F-18-FDG metabolism in residual masses in lymphatic tissues compared to CT, X-ray or ultrasonography. The results indicate that PET may have advantages in the assessment of remissions in nodal sites. Less conclusive results were observed with regard to extranodal involvement or inflammatory disease. In conclusion PET may be sufficient for the staging of the majority of patients with Hodgkin's disease and particularly for assessing remission status in nodal sites, but PET may have disadvantages in the evaluation of extranodal lymphoma and inflammatory disease.

Adolescent↗
PubMed1999

[Radioimmunoscintigraphy of colorectal cancer using the anti-CEA monoclonal antibody BW 431/26. Final results].

The anti-carcinoembryonic antigen (CEA) antibody, BW 431/26 (Scintimun CEA, Behringwerke, Marburg, Germany ) labeled with technetium pertechnectate (99mTc), is an intact immunoglobulin G1, monoclonal antibody that has been used to image colorectal cancer. Planar and SPECT images of chest, abdomen and pelvis were performed at 10 minutes, 4-6 and 18-24 hours after the intravenous antibody injection. 44 patients were studied and the pathological antibody concentration localization by radioimmunoimaging (RI) were correlated with surgical, clinical and other imaging modality findings to validate the RI. The RI was positive in 29 patients and negative in the other 15 patients. The CEA and CA 19.9 were elevated in the serum of some patients with primary tumors or recurrence. The HAMA were determined in all the patients before and after the RI.

Adult↗
PubMed1999

Bone marrow immunoscintigraphy for the detection of skeletal metastases in patients with breast cancer.

In this study, we evaluated the efficacy of bone marrow immunoscintigraphy (BMIS) for the detection of skeletal metastases in 23 patients with histologically confirmed breast cancer. All patients underwent whole-body BMIS 3-6 h after the intravenous injection of 0.20-0.33 mg of the intact anti-NCA 95 MAb BW 250/183 labelled with 259-555 MBq 99Tcm and a whole-body 99Tcm-MDP bone scan. In four patients, BMIS SPET of the lumbar spine was also performed. Serum alkaline phosphatase was determined in all patients and the level of human anti-mouse antibody (HAMA) in 16. Final diagnosis was confirmed by radiology and 2 years follow-up. Compared with the 99Tcm-MDP bone scan, BMIS demonstrated better specificity (88% vs 75%) and a better positive predictive value (92% vs 85%). There were no significant differences between BMIS and the bone scan in the detection of skeletal metastases (P > 0.05). In one patient with normal planar BMIS of the lumbar spine, SPET disclosed a metastatic lesion in the bone marrow. The correlation coefficient between BMIS and bone scan and between BMIS and serum alkaline phosphatase was r = 0.688 and r = 0.483 respectively. One patient developed a minor HAMA response after BMIS. Patients with diffuse increased activity of the skull on the bone scan had a significantly higher skull to whole body ratio on BMIS (P < 0.01). Thus BMIS can improve the specificity and positive predictive value of bone scanning in the detection of skeletal metastases, with a low HAMA response. Diffuse increased activity of the skull on bone scans could be explained by bone marrow extension. SPET scanning of the spine may improve the sensitivity of BMIS.

Adult↗
PubMed1998

Primary staging and follow-up of high risk melanoma patients with whole-body 18F-fluorodeoxyglucose positron emission tomography: results of a prospective study of 100 patients.

BACKGROUND: Positron emission tomography (PET) has been retrospectively reported to be a sensitive method for detecting malignant melanoma metastases. METHODS: One hundred consecutive patients with high risk melanoma (tumor thickness > 1.5 mm) were prospectively evaluated (52 at primary diagnosis, comprising Group A, and 48 during follow-up, comprising Group B) by whole-body PET and conventional diagnostics (CD). RESULTS: In Group A, the sensitivity of PET was 100% and the specificity was 94%, whereas CD did not identify any of the 9 lymph node metastases and demonstrated a lower specificity (80%). In Group B, 121 lesions were detected, 111 by PET and 69 by conventional imaging. On the basis of patients, the sensitivity, specificity, and accuracy of PET were 100%, 95.5%, and 97.9%, respectively (91.8%, 94.4%, and 92.1%, respectively, on the basis of single metastases). Prospectively, CD did not identify all patients with progression (sensitivity, 84.6%) and detected significantly fewer metastases (sensitivity, 57.5%) with much lower specificity (68.2% on the basis of patients, 45% on the basis of single lesions); therefore, the accuracy of CD was 77.1% on the basis of patients and only 55.7% on the basis of single metastases. Results also depended on specific sites: while PET yielded a higher sensitivity in detecting cervical metastases (100% vs. 66.6%) and abdominal metastases (100% vs. 26.6%), computed tomography proved to be superior in detecting small lung metastases (87% vs. 69.6%). CONCLUSIONS: PET is a highly sensitive and specific technique for melanoma staging. With the exception of the brain, one single whole-body 18F-fluorodeoxyglucose-PET scan could replace the standard battery of imaging tests currently performed on high risk melanoma patients.

Adult↗
PubMed1998

[Value of 18F fluorodeoxyglucose positron emission tomography in radiotherapy planning of head-neck tumors].

PURPOSE: An individualized radiation treatment planning in patients with head and neck tumors requires an exact definition of tumorspread. Despite of high reliability of methods like computed tomography, sonography or magnetic resonance imaging used in daily routine, the correct diagnosis of lymphonodal tumor infiltration is often not possible. In a prospective trial, we examined whether an additional FDG-PET gives a relevant gain of information for radiation treatment planning. PATIENTS AND METHODS: We studied data of 34 patients with histologically confirmed squamous cell carcinoma of the head and neck who received a FDG-PET prior to treatment planning additionally to conventional staging procedures. The extent of changes of treatment strategy or target volume due to additional FDG-PET findings were analyzed. RESULTS: In 9/22 of patients with primary tumors and in 7/12 of patients with recurrent disease, FDG-PET detected additional tumor manifestations. In all cases, changes of treatment strategy or target volume were necessary. Regarding patients with primary tumors, the percentage of treatment modifications was highest in patients with large tumors (T3 and T4) and patients with advanced lymph node involvement (N2 and N3). CONCLUSIONS: Especially in patients with recurrent disease and patients with advanced tumor stages, FDG-PET is able to give clinically relevant information compared to conventional staging procedures. Therefore, in these group of patients a FDG-PET study prior to radiotherapy planning should be considered.

Adult↗
PubMed1998

Prospective comparison of 18F-FDG PET with conventional imaging modalities (CT, MRI, US) in lymph node staging of head and neck cancer.

The aims of this study were to investigate the detection of cervical lymph node metastases of head and neck cancer by positron emission tomographic (PET) imaging with fluorine-18 fluorodeoxyglucose (FDG) and to perform a prospective comparison with computed tomography (CT), magnetic resonance imaging (MRI), sonographic and histopathological findings. Sixty patients with histologically proven squamous cell carcinoma were studied by PET imaging before surgery. Preoperative endoscopy (including biopsy), CT, MRI and sonography of the cervical region were performed in all patients within 2 weeks preceding 18F-FDG whole-body PET. FDG PET images were analysed visually and quantitatively for objective assessment of regional tracer uptake. Histopathology of the resected neck specimens revealed a total of 1284 lymph nodes, 117 of which showed metastatic involvement. Based on histopathological findings, FDG PET correctly identified lymph node metastases with a sensitivity of 90% and a specificity of 94% (P<10(-6)). CT and MRI visualized histologically proven lymph node metastases with a sensitivity of 82% (specificity 85%) and 80% (specificity 79%), respectively (P<10(-6)). Sonography revealed a sensitivity of 72% (P<10(-6)). The comparison of 18F-FDG PET with conventional imaging modalities demonstrated statistically significant correlations (PET vs CT, P = 0.017; PET vs MRI, P = 0.012; PET vs sonography, P = 0.0001). Quantitative analysis of FDG uptake in lymph node metastases using body weight-based standardized uptake values (SUVBW) showed no significant correlation between FDG uptake (3.7+/-2.0) and histological grading of tumour-involved lymph nodes (P = 0.9). Interestingly, benign lymph nodes had increased FDG uptake as a result of inflammatory reactions (SUVBW-range: 2-15.8). This prospective, histopathologically controlled study confirms FDG PET as the procedure with the highest sensitivity and specificity for detecting lymph node metastases of head and neck cancer and has become a routine method in our University Medical Center. Furthermore, the optimal diagnostic modality may be a fusion image showing the increased metabolism of the tumour and the anatomical localization.

Carcinoma, Squamous Cell↗