PubMed Health⌕ Search

Biomedical subjects

J Chavaudra

Publications and source records attributed to J Chavaudra.

41 records · Page 3Linked to original sources
PubMedDate not supplied

Thyroid carcinomas after irradiation for a first cancer during childhood.

BACKGROUND: The thyroid gland is among the most radiosensitive organs. However, little is known about the long-term risk of developing a thyroid tumor after fractionated external radiotherapy for cancer during childhood. OBJECTIVE: To study the long-term risk of developing a thyroid tumor in 4096 three-year survivors of childhood cancer treated between May 1942 and December 1985 in 8 centers in France and the United Kingdom, 2827 of whom had received external radiotherapy. METHODS: A wide range of radiation doses were given to the thyroid: 1164 children received less than 0.5 Gy and 812 received more than 5.0 Gy, the average dose being 7.0 Gy. RESULTS: After mean follow-up of 15 years (range, 3-45 years), 14 patients-all of whom had received radiotherapy-developed a clinical thyroid carcinoma. Within the cohort, the relation between radiation dose to the thyroid and risk of thyroid carcinoma and adenoma was similar to that observed in patients who received radiotherapy during childhood for other reasons, such as an excess relative risk per gray of 4 to 8, up to a few gray. In contrast, compared with thyroid cancer incidence in the general population, the standardized incidence of thyroid carcinoma was much higher than expected from the dose-response relationship estimated within the cohort and from patients who received radiotherapy during childhood for other reasons: a dose of 0.5 Gy was associated with a standardized incidence ratio of 35 (90% confidence interval, 10-87) and a dose of 3.6 Gy with a standardized incidence ratio of 73 (90% confidence interval, 28-153). We did not show a reduction in excess relative risk per gray with use of an increasing number of fractions. CONCLUSION: Although we cannot estimate the exact proportion, it is probable that some or all children who are treated for cancer are predisposed to developing a thyroid carcinoma.

Adenoma↗
PubMedDate not supplied

[Last ICRU recommendations for the prescription, recording and reporting of external bean therapy].

Due to the evolution of radiotherapy techniques and equipment, in 1993 the ICRU decided to modify the guidelines that had been published in the ICRU report 29 (1978) in regard to photon beam therapy and to insert them in Report number 50 (1993). Changes that were introduced mainly concerned the prescription, recording and reporting of external beam therapy with photons. While awaiting for the upcoming publication of the report focusing on external beam therapy with electrons, the ICRU decided to publish a supplement to Report 50, as new insights had been gained after discussions with the Nordic Association of Clinical Physicists (NACP). This supplement includes the following: more accurate definitions of the margins allowing the planned target volume to be derived from the clinical target volume, the internal target volume, the expected volume of organs at-risk and the conformity index. All three points will be included in the report focusing on external beam therapy with electrons as well as extensive discussions relating to the implementation of these new recommendations.

Documentation↗