[Second malignancies after radiotherapy for testicular seminoma: 2 cases]

International audienceOrchiectomy with adjuvant radiotherapy of retroperitoneal paraaortic and ipsilateral iliac nodes is the standard treatment for localized testicular seminoma (I, IIA, IIB). Post therapeutic follow-up allows to detect local relapse and radio-induced second cancer. Nevertheless, evaluation of risk of second malignancy still remains difficult. We report 2 cases of rectal cancer after radiotherapy for testicular seminoma

Esophageal cancer: determination of internal target volume for conformal radiotherapy.

International audienceBACKGROUND AND PURPOSE: To evaluate esophageal tumor and OAR movement during the respiratory cycle in order to obtain optimal values for ITV and PRV. To correlate tumor motion with chest wall displacement - information of value in the free-breathing gating system. MATERIAL AND METHOD: Inclusion criteria were: histologically proven squamous-cell carcinoma (SCC) or adenocarcinoma at stage T3 - T4 NX or TX N1 M0 according to the UICC 1997 classification. Two spiral scans were performed with breath-hold respiration under spirometric control: one at end expiration (EBH) and the other at end inspiration (IBH). Displacements between exhalation and inhalation were calculated according to ICRU report 42 recommendations. For the correlation study, CT-scan acquisition was performed at the isocenter over a 20 - 40 s period. After Fourier Transform, frequency spectra for amplitude and phase of tumor and chest wall motions were performed for each patient. RESULTS: Cumulative distribution of CTV motion in absolute values showed that 95% of data ranged from 0 to 1 cm. Cumulative distribution of GTV motion in absolute values showed that 95% of data ranged from 0 to 0.8 cm. The correlation study demonstrated no specific relationship between respiratory and esophageal motions. CONCLUSION: The ITV margin for 3D conformal radiotherapy in esophageal cancer was 1 cm when 95% of motions were taken into account in this clinical study involving eight patients. Before using a free-breathing gating system, the correlation between external markers and target displacement during irradiation must be established for each patient

Dosimetric consequences of breath-hold respiration in conformal radiotherapy of esophageal cancer.

International audienceThe objective of this paper is to study the dosimetric impact of respiratory gated radiotherapy in locally advanced esophageal carcinomaand to define the optimal respiratory phase for this treatment. The study included 8 consecutive patients with squamous-cell carcinoma (SCC) or histologically proved adenocarcinoma, for both at least T3-T4 NX or TX N1 M0 stage. Informed consent was obtained before beginning the study. Three spiral scans were performed in breath-hold respiration: one acquisition in end expiration (EBH), one in end inspiration (IBH) and one in deep inspiration breathhold (DIBH); and one acquisition was performed in Free Breathing (FB). A 3 mm-margin was defined as Internal Target Volume (ITV) on FB CT-scan. No ITV was applied on EBH, IBH and DIBH CT-scan. Target volumes were analyzed and we performed dosimetric comparisons on DVH data of each CT-scan for PTV and Organs at Risk (OAR) (Conformity Index, V(dose), D(mean), Equivalent Uniform Dose). DIBH and IBH correlated with a 32% (p=0.77) and 20% (p=0.52) decrease in lung V(20) respectively as compared to FB (13.5%and 15.6% respectively versus 19.9%). DIBH and IBH correlated with a 25% (p=0.25) and 17% (p=0.39) decrease in cardiac V(40) respectively, as compared with FB (16.9% and 18.9% respectively versus 22.7%). For spinal cord irradiation, the minimum dose was obtained in IBH (36.5 Gy). Conformal radiotherapy with respiratory gating for esophageal cancer decreases the irradiated dose to OAR. We suggest that DIBH technique should be used when irradiation is performed using the spirometric system. In the Tidal Volume, the inspiration phase is the most favourable and should be chosen for irradiation with a free breathing gating system

Equivalent uniform dose concept evaluated by theoretical dose volume histograms for thoracic irradiation.

International audienceBACKGROUND AND PURPOSE: The goal of our study was to quantify the limits of the EUD models for use in score functions in inverse planning software, and for clinical application. MATERIALS AND METHODS: We focused on oesophagus cancer irradiation. Our evaluation was based on theoretical dose volume histograms (DVH), and we analyzed them using volumetric and linear quadratic EUD models, average and maximum dose concepts, the linear quadratic model and the differential area between each DVH. RESULTS: We evaluated our models using theoretical and more complex DVHs for the above regions of interest. We studied three types of DVH for the target volume: the first followed the ICRU dose homogeneity recommendations; the second was built out of the first requirements and the same average dose was built in for all cases; the third was truncated by a small dose hole. We also built theoretical DVHs for the organs at risk, in order to evaluate the limits of, and the ways to use both EUD(1) and EUD/LQ models, comparing them to the traditional ways of scoring a treatment plan. For each volume of interest we built theoretical treatment plans with differences in the fractionation. CONCLUSION: We concluded that both volumetric and linear quadratic EUDs should be used. Volumetric EUD(1) takes into account neither hot-cold spot compensation nor the differences in fractionation, but it is more sensitive to the increase of the irradiated volume. With linear quadratic EUD/LQ, a volumetric analysis of fractionation variation effort can be performed

Démocratie sanitaire : le patient partenaire de sa prise en charge

International audienceIn 2019, the scientific committee of the French society of radiation oncology (SFRO) created an ethics committee. Its mission is to provide our professional community with food for thought on ethical issues, and to identify its specificities within the radiation oncology departments. For the 2020 annual conference, the commission looked into the evolution of the patient-carer relationship, and more particularly to the strong idea of patient partnership. Indeed, the writing of the White Book of Cancer gave voice to sick people and stressed the need for new devices, such as the Caregiving Time. Patients can no longer be considered as objects of care but as people whose dignity and autonomy must be imperatively respected. The acquisition of knowledge allows a bilateral exchange, prerequisite of a dynamic collaboration. Patients can be partners in their own care, partners in training and research (expert patient), but also partners in health institutions and policies. It is this notion of partnership and involvement of the person in their path of care in radiation oncology that we will analyse here. It will be about defining it, by developing the concept of autonomy, and bringing out its complexity and ambivalence through two examples from our clinical practice: the shared decision-making process for patients with localized prostate cancer and the patient's involvement in the success of his radiotherapy