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A Daver

Publications and source records attributed to A Daver.

At least 19 recordsLinked to original sources

[Standards, options, and recommendation for external radiotherapy of prostatic cancer: evaluation of the effect of dosage].

CONTEXT: The "Standards, Options and Recommendations" (SOR) collaborative project was initiated in 1993 by the Federation of the French Cancer Centres (FNCLCC), with the 20 French Regional Cancer Centres, several French public university and general hospitals, as well as private clinics and medical speciality societies. Its main objective is the development of serviceable clinical practice guidelines in order to improve the quality of health care and the outcome of cancer patients. The methodology is based on a literature review, followed by critical appraisal by a multidisciplinary group of experts. Draft guidelines are produced, then validated by specialists in cancer care delivery. OBJECTIVES: Produce clinical practice guidelines for the radiotherapy of prostate cancer using the methodology developed by the Standards, Options and Recommendations project. METHODS: The FNCLCC and the French Urology Association (AFU) designated the multidisciplinary group of experts. Available data were collected by a search of Medline and lists selected by experts in the group. A first draft of the guidelines was written, they validated by independent reviewers. RESULTS: The main recommendations are: 1/ a minimal dose of 70 Gy must be used, whatever the prognostic factors; 2/ it appeared that patients with favourable prognostic indicators (stage T1-2, PSA < or = 10 micrograms/L and Gleason score < or = 6) do not benefit from a dose escalation effect for doses over 70-74 Gy; 3/ patients with intermediate prognosis are the ones who benefit most from the dose escalation effect over 74 Gy, provided they receive exclusive radiation therapy; 4/ whenever possible, patients should be included in controlled trials designed to assess the effects of dose escalation and hormonotherapy.

Humans↗

Thymidine kinase as a proliferative marker: clinical relevance in 1,692 primary breast cancer patients.

PURPOSE: To assess the prognostic value of thymidine kinase (TK), an enzyme involved in the DNA synthesis salvage pathway, relative to other prognostic factors in primary breast cancer. PATIENTS AND METHODS: This retrospective study involved 1,692 patients with operable breast cancer treated in six institutions (median follow-up, 82 months). Among the 857 node-negative patients, 135 received adjuvant chemotherapy (fluorouracil, doxorubicin, cyclophosphamide [FAC] or fluorouracil, etoposide, and cisplatin [FEC]). TK was assayed in cytosol with a quantitative radioenzymatic technique. Disease-specific survival (DSS), local recurrence-free interval (LRI), and distant-relapse-free interval (DRI) were investigated. RESULTS: High TK levels were associated with large tumor size, high histologic grade, and steroid hormone receptor negativity. Univariate analysis of the entire data set showed that high TK levels were related to shorter DSS (P < 10(-5)), LRI (P < 10(-3)), and DRI (P < 10(-5)). In time-dependent Cox models, high TK levels remained an independent predictor of the three outcomes, both in the overall population and in node-negative patients, although its prognostic value decreased over time. In node-negative patients, the introduction of an interaction term in multivariate analysis suggested that chemotherapy was more efficacious for patients who had tumors with high TK contents. In node-positive patients, high TK levels were related only to an increased risk of LRI. CONCLUSION: High TK values are an important risk factor in node-negative patients and seem to be associated with a beneficial effect of adjuvant FAC or FEC in patients who received adjuvant chemotherapy. The rationale of chemotherapy for patients with slowly proliferating tumors has to be discussed from a risk-benefit point of view.

Adult↗

[Standards, Options, and Recommendations for brachytherapy in patients with prostate cancer: efficacy and toxicity].

CONTEXT: The "Standards, Options and Recommendations" (SOR) collaborative project was initiated in 1993 by the Federation of the French Cancer Centres (FNCLCC), with the 20 French Regional Cancer Centres, several French public university and general hospitals, as well as private clinics and medical specialty societies. Its main objective is the development of serviceable clinical practice guidelines in order to improve the quality of health care and the outcome of cancer patients. The methodology is based on a literature review, followed by a critical appraisal by a multidisciplinary group of experts. Draft guidelines are produced, then validated by specialists in cancer care delivery. OBJECTIVES: Produce clinical practice guidelines for the brachytherapy of prostate cancer using the methodology developed by the Standards, Options and Recommendations project. METHODS: The FNCLCC and the French Urology Association (AFU) first designated the multidisciplinary group of experts. Available data were collected by a search of Medline and lists selected by experts in the group. A first draft of the guidelines was written, they validated by independent reviewers. RESULTS: The main recommendations are: 1/Brachytherapy with permanent seeds alone is a possible curative treatment for prostate cancer patients with the following prognosis factors: tumour stage T1 or T2a (TNM 1992), Gleason score < or = 6 and PSA < 10 micrograms/L. 2/Combined treatment with brachytherapy and hormonal therapy could be more efficient than brachytherapy alone for prostate cancer patients with Gleason score > 7 and/or PSA > 10.3/Combination of brachytherapy and external beam radiation therapy can be proposed to prostate cancer patients with intermediate prognosis. 4/Before and after seed implantation, risks of infection must be prevented by appropriate antibiotic therapy (recommendation). 5/Brachytherapy must not be performed within 2 months of transurethral prostate resection. 6/The height of the urethra receiving more than 200% of the prescribed dose must be reported. The portion of the rectum receiving 100 and 120% of the prescribed dose must be limited to 10 and 5 mm length, respectively.

Antineoplastic Agents, Hormonal↗

[Standards, options and recommendations for blood tumor markers in thyroid cancers].

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993, is a collaboration between the Federation of the French Cancer Centers (FNCLCC), the 20 French Cancer Centers and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcome for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary group of experts, with feedback from specialists in cancer care delivery. OBJECTIVES: To define, according to the definitions of the Standards, Options and Recommendations project, the characteristics of the main tumor markers in thyroid cancer and the potential role of these markers in the management of patients with this malignancy. METHODS: Data were identified by searching Medline and the personal reference lists of members of the expert groups. Once the guidelines were defined, the document was submitted for review to 55 independent reviewers, and to the medical committees of the 20 French Cancer Centers. RESULTS: The main recommendations are: 1) Thyroglobulin is a serum tumor marker for the monitoring of operated thyroid differentiated neoplasms (standard). 2) It is essential to know if the patient is under TSH stimulation or under thyroid suppression therapy to interpret thyroglobulin results (standard). 3) Thyroglobulin assay must be performed regularly during the monitoring of differentiated thyroid neoplasms (standard, level of evidence B2), should be coupled with the measurement of anti-thyroglobulin antibodies concentration using a sensitive method (standard, level of evidence B2). 4) Thyroglobulin assay should not be performed to detect or diagnose differentiated thyroid neoplasms (standard, level of evidence B2). 5) The methods used to assay thyroglobulin must have a limit of detection lower than 3 mug.l- 1 (standard, expert agreement). 6) Calcitonin is a marker for medullary thyroid cancer (standard). 7) Its assay, associated with RET gene study if indicated, enables medullary thyroid cancer to be diagnosed. 8) The pentagastrin test is essential to diagnose familial forms of medullary thyroid cancer. 9) All analyses for each patient must be performed in the same laboratory, using the same technique (standard, expert agreement). 10) Calcitonin and carcinoembryonic-antigen are serum markers for the monitoring of medullary thyroid cancer and allow the detection of recurrent disease (standard).

Antibodies, Neoplasm↗

[Standards, options and recommendations for tumor markers in colorectal cancer].

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993, is a collaboration between the French National Federation of Comprehensive Cancer Centers (FNCLCC), the 20 French Cancer Centers and specialists from French Public University or General Hospitals, and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcome of cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary group of experts, with feedback from specialists in cancer care delivery. OBJECTIVES: To define, according to the definitions of the Standards, Options and Recommendations project, the characteristics of the main tumor markers in colorectal cancer and their potential role in the management of patients with this malignancy. METHODS: Data were identified by searching Medline and the personal reference lists of members of the expert groups. Once the guidelines were defined, the document was submitted for review to 117 independent reviewers, and to the medical committees of the 20 French Cancer Centers. RESULTS: The main recommendations for the tumor markers in colorectal cancer are: 1) The carcinoembryonic antigen (CEA) is the reference serum marker (standard). 2) All the analyses for a given patient must be performed in the same laboratory, using the same technique (standard, expert agreement). 3) CEA or CA 19-9 should not be used for screening or diagnosis (standard, level of evidence B2). 4) High initial serum concentration of CEA is of bad predictive value (standard, level of evidence C). CEA is an independent prognostic factor of survival in colorectal cancers with lymph node metastases (standard, level of evidence B2). 5) CEA is the most sensitive biological parameter for the screening of hepatic metastases (standard, level of evidence B2). 6) CEA serum concentration before palliative chemotherapy is an independent prognostic factor of survival (standard, level of evidence B2). The combination of CEA assay with imagery techniques and clinical examination can help monitor the response to palliative chemotherapy (standard), in particular in non measurable disease (standard, expert agreement). 7) In 65% of the cases, CEA is the first indicator of relapse (standard, level of evidence B2). CEA is the choice marker for monitoring patients with colorectal cancer (standard, level of evidence B2). 8) A sustained biological follow-up including CEA assay can be used to predict the operability of recurring tumors (standard, level of evidence B2). Nevertheless, no survival advantage has been shown (standard).

Antigens, Tumor-Associated, Carbohydrate↗

Prognostic of DNA-synthesizing enzyme activities (thymidine kinase and thymidylate synthase) in 908 T1-T2, N0-N1, M0 breast cancers: a retrospective multicenter study.

Among the methodological approaches of tumor proliferation, thymidine kinase (TK) and thymidylate synthase (TS) assays take into account the specific pathways of pyrimidine synthesis. Studies pointing to a prognostic value of TK and TS in breast cancer involved small numbers of patients. We investigated the prognostic value of these enzymes and their combination in a large retrospective multicenter study. Nine hundred eight T1T2, N0N1, M0 primary breast cancer samples (median follow-up 68 months) were tested. TK and TS were measured in cytosols by using standardized radioenzymatic methods. Although a positive correlation was obtained between TK and TS (p<10(-5)), major discrepancies were observed in some tumors. High levels of both enzymes were associated with large tumor size, histological grade III and steroid receptor-negative tumors. Univariate analysis showed that TK, TS and their combination were predictive of poor metastasis-free (MFS) (p < 10(-4); p=0.004; p < 10(-4)) and disease-free survival (DFS) (p < 10(-4); p=0.007; p=0.0001). TK was selected as an independent factor for MFS in Cox analysis. It was the only variable selected in node-negative patients. Subgroups with specific outcomes, with possible therapeutic implications, were identified: a) in node-negative patients not receiving adjuvant treatment, TK values in the 4th quartile were associated with poor MFS (p=0.0002) and DFS (p=0.0005) as compared to the other quartiles; b) in node-positive patients receiving adjuvant chemotherapy, low levels of both TK and TS were associated with the highest survival rates (MFS: p=0.04; DFS: p=0. 03).

Adult↗

Comparison of the Bard Trak test with voided urine cytology in the diagnosis and follow-up of bladder tumors.

OBJECTIVES: To compare the results of the BTA Trak test with voided urine cytology (VUC) in the diagnosis and follow-up of bladder tumors. PATIENTS AND METHODS: Urine samples were obtained from 53 patients with bladder tumor (77 samples) and 53 patients treated for bladder tumor with no evidence of disease on the basis of cystoscopic evaluation (88 samples). Urine samples were collected prior to cystoscopy. The BTA assay was performed by the BTA Trak test according to the manufacturer's recommendations. A value >14 U/ml was considered abnormal. RESULTS: There was a statistically significant increase in median BTA value with increasing stage of tumor: 11.9, 57.9 and 391.0 U/ml respectively for stages pTa, pT1 and pT2/3 (p<0.0001, Kruskal-Wallis test). There was also a correlation between increasing grade and median BTA values measured at 6.9, 13.1 and 235.0 U/ml in grades 1, 2 and 3 tumors respectively (p<0.0001, Kruskall-Wallis test). The overall sensitivity of the BTA Trak test was 58.4% compared to 46.7% for VUC, a difference of 11.7%, which was statistically significant (McNemar test, p<0.005). The sensitivity of both tests combined was 63.6%. The specificity of the VUC (94.3%) was significantly higher than that of the BTA Traktrade mark (75.0%) (p<0.005, McNemar test). The accuracy of the Bard Trak test (67.3%) was similar to that of VUC (66.9%). CONCLUSION: The BTA Trak test is more sensitive than urinary cytology in the detection of bladder tumors but the improvement involved is insufficient to consider decreasing the frequency of endoscopic examinations in the follow-up of superficial bladder tumor.

Antigens, Neoplasm↗

[Is it possible to define a threshold for free PSA index that is useful in the daily practice of urology?].

OBJECTIVES: Retrospective evaluation of the use of the free PSA index before prostatic biopsies. MATERIAL AND METHODS: The authors retrospectively studied the values for total PSA, free PSA, and free PSA index (ratio of free PSA over total PSA expressed as a %) in men with a total PSA between 2 and 10 ng/ml, from a population of 391 men prior to prostatic biopsies. They also isolated a subgroup of patients in whom the free PSA index could have been used as a first-line marker to decide whether or not to perform prostatic biopsies. RESULTS: The mean values for total PSA, free PSA, and free PSA index were compared as a function of the diagnosis, age, and ultrasound prostatic volume. The yields of the various cut-off values for the free PSA index for PSA between 2 and 4 ng/ml, 4 and 10 ng/ml, and 2 and 10 ng/ml with a normal digital rectal examination are reported. Between 2 to 10 ng/ml, at a cut-off value of 30%, 94.1% of cancers would have been detected (sensitivity) and 22% of biopsies would have been avoided, 10 of which would have been useless, i.e. a 30.3% economy of useless biopsies not performed (specificity). At the cut-off value of 15%, less than half of cancers would have been detected (47.1%) and 90.9% of useless biopsies would have been avoided. Biases creating difficulties of interpretation were the assay kits, the reference population, age, storage of sera, and prostatic volume. CONCLUSION: The free PSA index would be a useful first-line parameter in only 12.7% of candidates for prostatic biopsies. The cut-off value of 30%, validated for our assay method, would be able to detect the majority of cancers in men aged 50 to 65 years, while avoiding biopsies in the third of men with no detectable cancer.

Aged↗

[Standards, Options and Recommendations (SOR) for tumor markers in breast cancer. SOR Working Group].

CONTEXT: The "Standards, Options and Recommendations" (SOR) project, started in 1993, is a collaboration between the Federation of the French Cancer Centres (FNCLCC), the 20 French Cancer Centres and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcome for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary group of experts, with feedback from specialists in cancer care delivery. OBJECTIVES: To define, according to the definitions of the Standards, Options and Recommendations project, the characteristics of various tumour markers in breast cancer and the potential role of these markers in the management of patients with this malignancy. METHODS: Data were identified by searching Medline and the personal reference lists of members of the expert groups. Once the guidelines were defined, the document was submitted for review to 43 independent reviewers, and to the medical committees of the 20 French Cancer Centres. RESULTS: The main recommendations are: 1) CA 15.3 and CEA are the serum tumour markers most often used in breast cancer (standard). 2) If the CA 15.3 is raised at presentation, there is no place for the measurement of other tumour markers (standard, expert agreement). 3) All analyses for each patient must be performed in the same laboratory, using the same technique (standard, expert agreement). 4) CA 15.3 should not be used for screening or diagnosis. 5) The level of CA 15.3 before treatment is a recognised prognostic factor, the independent value of which has not been proven (standard, level of evidence C). 6) If the initial value of CA 15.3 is greater than 50 kU.L(-1), disseminated disease should be actively sought before any treatment decisions are made (standard, expert agreement). 7) An initial elevation of CA 15.3 that does not return to normal, reflects a lack of response to treatment and is a strong adverse prognostic factor (standard, level of evidence C). 8) The accuracy of tumours markers (especially CA 15.3) as early indicators of metastatic disease is well recognised (standard) but the clinical benefit has not been established. 9) There is a correlation between tumour markers and clinical response in the treatment of metastatic disease (level of evidence C). The level of CA 15.3 in metastatic disease does not predict response to treatment.

Biomarkers, Tumor↗

Prognostic value of uPA and p53 accumulation measured by quantitative biochemical assays in 1245 primary breast cancer patients: a multicentre study.

The purpose of this retrospective multicentre study was to assess the prognostic value of urokinase plasminogen activator (uPA) and p53 levels in a large series of primary breast cancer, using an automatic quantitative luminometric method. Samples of 1245 operable breast tumours were collected from seven French institutions and patients were followed for a median of 75 months. The median uPA and p53 levels assayed in cytosols by means of the immunoluminometric technique (LIA) were 0.31 and 0.20 ng mg(-1) of protein respectively. In univariate analysis, high levels of uPA and p53 were associated with shorter disease-specific survival, disease-free interval, and distant recurrence-free interval. The 5-year survival rates were 95.5% among patients with uPA values below the 20th percentile, and 77.5% in those with values above the 80th percentile. The 5-year survival rates were 91.0% in patients with p53 values below the 20th percentile, and 77.6% in those with values above the 80th percentile. In multivariate analysis, the risk of disease-related death increased with uPA levels after adjustment for tumour size, histological grade, lymph node involvement, and estrogen receptor status. A high level of uPA was also related to a shorter disease-free interval and distant recurrence-free interval. In node-negative patients, a high level of uPA remained strongly related to the three outcomes. When adjusted for other prognostic factors, p53 was no longer significantly related to the outcomes. Given its rapidity and simple application to routinely prepared cytosols, this LIA may be useful for evaluating the prognostic impact of uPA in primary breast cancer, particularly in node-negative patients. According to our results, the prognostic value of p53 accumulation is limited when uPA is included in multivariate analysis.

Adult↗

Values for the free to total prostate-specific antigen ratio as a function of age: necessity of reference range validation.

OBJECTIVE: To measure the levels of free prostate-specific antigen (PSA), total PSA, and free to total PSA ratio in a population of men with no known prostate pathology aged from 20 to 70 years. PATIENTS AND METHODS: Serum total PSA and free PSA values were determined in 1,502 patients due for a systematic health examination. The digital rectal examination was only proposed for those over 50 years of age. The assays were determined on the AsXYM apparatus, from Abbott laboratories, by MEIA technology with monoclonal antibodies. RESULTS: 1,274 men were available for study. The mean age was 43.6 +/- 11 years (range 20-69 years). The total PSA level was stable up to 40 years. Beyond that, it increased with age. There was a linear regression between the age and the logarithm of the total PSA rate (r = 0.26, p < 0.0001) from 40 to 70 years. The upper limit of the normal value (95th percentile) increased from 1.07 for the 20- to 30-year age range to 2.82 for the 60- to 70-year range. The free PSA level was stable up to 50 years of age. It then significantly increased. The upper limit of the normal value was measured as 0.42 in the range of 20-30 years and as 0.53 in the range of 60-70 years with an annual average increase rate of roughly 0.5%. Overall there was a linear regression between age and the free PSA rate (r = 0.12, p < 0.0001). The upper limit of the free to total PSA ratio, measured as being 0.68 in the range of 20-29 years, dropped towards 60-69 years with an upper limit of the normal of 0.48. The average annual reduction rate was around 0.70%. There was a linear regression between the age and the free to total PSA ratio (r = 0.17, p < 0.0001). CONCLUSION: These total PSA levels are lower than the ones measured in other studies with other assay methods. These variations stress the importance of validating reference values of total PSA and free PSA as a function of the assay method and the population to which they are applied before using them as an aid in the diagnosis of prostate cancer.

Adult↗

A new approach for clinical biological assay comparison and standardization: application of principal component analysis to a multicenter study of twenty-one carcinoembryonic antigen immunoassay kits.

BACKGROUND: Principal component analysis (PCA) is a powerful mathematical method able to analyze data sets containing a large number of variables. To our knowledge, this method is applied here for the first time in the field of medical laboratory analysis. METHODS: PCA was used to evaluate the results of a blind comparative study of 21 carcinoembryonic antigen (CEA) reagent kits used to determine CEA concentration in a panel of sera from 80 patients. RESULTS: The mathematical technique first eliminated the variations attributable to the use of different calibrators. The PCA representation then gave a global view of the dispersion of the kits and allowed the identification of a main homogeneous group and of some discrepant kits. CONCLUSIONS: PCA applied to the in vitro diagnostic reagent field could contribute to the standardization process and improve the quality of medical laboratory analyses. A standardization method using a panel of patient sera is proposed.

Biomarkers, Tumor↗

Kinetics of serum tumor marker concentrations and usefulness in clinical monitoring.

Only a few markers have been instrumental in the diagnosis of cancer. In contrast, tumor markers play a critical role in the monitoring of patients. The patient's clinical status and response to treatment can be evaluated rapidly using the tumor marker half-life (t(1/2)) and the tumor marker doubling time (DT). This report reviews the interest of determining these kinetic parameters for prostate-specific antigen, human chorionic gonadotropin, alpha-fetoprotein, carcinoembryonic antigen, cancer antigen (CA) 125, and CA 15-3. A rise in tumor markers (DT) is a yardstick with which benign diseases can be distinguished from metastatic disease, and the DT can be used to assess the efficacy of treatments. A decline in the tumor marker concentration (t(1/2)) is a predictor of possible residual disease if the timing of blood sampling is soon after therapy. The discrepancies in results obtained by different groups may be attributable to the multiplicity of immunoassays, the intrinsic characteristics of each marker (e.g., antigen specificity, molecular heterogeneity, and associated forms), individual factors (e.g., nonspecific increases and renal and hepatic diseases) and methods used to calculate kinetics (e.g., exponential models and timing of blood sampling). This kinetic approach could be of interest to optimize patient management.

Biomarkers, Tumor↗

Quantitative determination of c-erbB-2 in human breast tumours: potential prognostic significance of low values.

The purpose of this prospective multicentric study was to quantify the c-erbB-2 protein and investigate its relationship with DNA amplification and with various prognostic parameters of breast cancer. A total of 1062 primary operable human breast tumours were collected from six French anticancer centres. The c-erbB-2 protein was measured using an enzymoimmunoassay using two monoclonal antibodies directed against the extracellular domain of the protein. The results were expressed in arbitrary units/mg membrane protein (AU) after adjustment for the anticancer centre. A significant association was found between the dosage of the protein and DNA amplification (P = 0.0001). A value of 200 AU was found to maximise sensibility and specificity and was chosen as a cut-off for over-expression. Significant associations were found between c-erbB-2 values and oestrogen receptor (ER) (P = 0.01), progesterone receptor (PgR) (P = 0.0001) and histological grading (P = 0.01). The extreme high values (above the mean plus one standard deviation, S.D.) were significantly more numerous in ER- (P = 10(-16)), PgR- (P = 10(-14)) and grade III (P = 10(-8)) tumours. The extreme low values (below the mean minus one S.D.) were significantly more numerous in ER- (P = 10(-9)) and PgR- (P = 0.02) tumours. This prospective study confirms that high c-erbB-2 protein values are linked to poor prognostic factors and shows for the first time that low values are also linked to hormone receptor negative tumours, suggesting that these low values might also have a negative prognostic significance.

Adult↗

p185 overexpression in 220 samples of breast cancer undergoing primary surgery: comparison with c-erbB-2 gene amplification.

In breast cancer, DNA amplification of the oncogene c-erbB-2, encoding for the p185 protein, is associated with a poor prognosis. A retrospective study on a population of 220 cases of primary breast cancer permitted a quantitative measure of p185 oncoprotein overexpression by an immunoenzymetric assay and the determination of c-erbB-2 amplification by the Southern blot method. A correlation existed between the two measurements (r=0.85) using the double cut-off: DNA 2 copies and p185 400 U/mg protein, and only 2.7% of the cases were discordant. 13.2% of the tumors showed p185 overexpression. The percentage of tumors overexpressing p185 was significantly different between the groups with amplified and non-amplified c-erbB-2. We observed a significant correlation between p185 levels and tumor grade (p=0.03), and an inverse correlation with hormonal receptors (p=0.0001). The p185 assay could be an additional prognostic factor to better define patient subgroups with node negative, grade II, and positive or negative hormonal receptors.

Adenocarcinoma↗

Influence of scanning doses of iodine-131 on subsequent first ablative treatment outcome in patients operated on for differentiated thyroid carcinoma.

UNLABELLED: The therapeutic outcome after (131)I first ablative treatment in patients operated on for nonmedullary differentiated thyroid carcinoma was compared after both the currently used scanning dose of 111 MBq (131)I and a scanning dose of 37 MBq (131)I. METHODS: Two-hundred twenty-nine consecutive patients with no known metastases were retrospectively studied. They were divided in two populations according to the scanning dose (127 patients with 111 MBq and 102 patients with 37 MBq). All patients received 111 or 37 MBq (131)I for diagnostic purposes and 3.7 GBq (131)I for ablative therapy 9 days later. To assess the efficacy of the treatment, all patients were studied with (131)I and with thyroglobulin plasma assays 6-17 mo later. RESULTS: Successful outcome was significantly more frequent after a scanning dose of 37 MBq (131)I than after a scanning dose of 111 MBq (76% versus 50%, p < 0.001). The treatment efficacy was particularly enhanced after 37 MBq in patients with associated lymphocytic thyroiditis. CONCLUSION: In patients with no known metastases, our data suggest that the impairment of the treatment efficacy observed after a scanning dose of 111 MBq (131)I is related to a stunning effect on the thyroid remnants. The threshold amount above which this effect begins to occur in thyroid remnants could be between 37 and 111 MBq (131)I. Consequently, a scanning dose of only 37 MBq (131)I could be recommended before first ablative treatment. The absence of metastatic patients in our study prevents any conclusion about the possible stunning of the neoplastic tissue. Nevertheless, we must suspect such an effect and try to avoid it, especially during follow-up after first radioiodine therapy. For instance, one may consider postponing radioiodine treatment several weeks or even months after scanning dose administration or using only thyroglobulin measurement for patients who are likely to receive a subsequent radioiodine treatment.

Adenocarcinoma, Follicular↗