[en] Short communication

[en] The STIC 2001 and STIC 2002 projects intend to allow the implementation and the assessment of Intensity Modulated Radiation Therapy in France. IMRT is an innovative technique in which the high-dose radiation volume conforms to an accurately defined target volume with less morbidity to the surrounding normal tissues. The main medical objectives of the projects are (1) to improve the therapeutic index while decreasing acute toxicity and late sequelae (mainly xerostomia and acute mucite for head and neck tumors), which allows an increase in the radiation dose to the tumor and then a better tumor control; (2) to propose a salvage treatment to patients who locally recurred in previously irradiated sites; (3) to determine the optimal treatment guidelines for a safe use of the technique in clinical routine. Our projects also aim at comparing IMRT and 3D conformal treatments on the one hand (STIC 2001), and IMRT and conventional treatments on the other hand (STIC 2002), with regard to costs. As a matter of fact, the use of IMRT is presently limited in France because its implementation requires high investment and personnel costs. The seventeen French Regional Cancer Centres involved in the two projects intend to study the additional cost of the use IMRT in comparison with the use of standard techniques, which appears to be a step for a wide use of this technique in France. Each of the studies is two-year prospective, and includes patients with head and neck tumors treated with a curative intend (post operative or exclusive treatments for STIC 2002 and STIC 2002), and patients with a prostate cancer (STIC 2001). (author)

[en] Based on the review of currently published data, the importance of radiotherapy as a part of the standard treatment in soft tissue sarcoma will be outlined. The relative advantage of pre-operative compared to post-operative radiotherapy is based on the reduction of total irradiated volume and hence overall toxicity. Results in local control and survival are similar although comparison of different publications is difficult. Moreover, there are no randomized trials designed to compare these two modalities. The pre-operative and/or interstitial approach offer the advantage of relying more often on a multidisciplinary approach. New treatment modalities (High-LET radiation, proton beam, hyperfractionation, radiosensitizing, hyperthermia), aimed at optimizing the treatment, will be briefly discussed. (6 tabs.)

[en] When considering three-dimensional conformal radiotherapy for non-small cell lung cancer, the uncertainties about treatment can be quite significant, due to set-up errors and organ or tumor motion. These can be important causes of treatment failure. Immobilization devices have only been studied recently in a scientific manner in the domain of chest tumors, presumably because other factors such as tumor motion were felt to be more important causes of treatment uncertainties. An international survey on immobilization devices in the treatment of non-small cell lung cancer has shown that about half of the centers are using three-dimensional conformal radiotherapy, and among these, only two-thirds use immobilization devices on a routine basis. Very few use internal fiducial. Current data on set-up errors show that the average discrepancy is about 5 mm, but in some cases it can be more than 15 mm. A recent study has demonstrated that less positioning corrections during treatments were needed for the patients who were immobilized. Another work indicates that there were no differences between a T-bar immobilization device and a system using chemical foams. Other works indicate that internal motion of bronchial tumors can vary greatly, depending on their location. A number of clinical groups are looking at minimizing the consequences of internal motion, but the currently proposed techniques appear to be cumbersome. New studies will be necessary in order to improve the knowledge of daily positioning and the effect of internal motion. Until then, it is essential to take care when considering narrow margins in conformal radiotherapy of non-small cell lung cancer. (author)

[en] The survival, pattern of failure and complications in 47 patients with Stage III and IV cancers of the glottis, supraglottis and hypopharynx treated with surgery and postoperative radiotherapy using a new treatment technique referred to as mini-mantle were analyzed. The absolute survival probability of the entire group was 53 and 31% at 3 and 5 years. The local control probability at 3 and 5 years was 63 and 58%, and was higher for the supraglottic/hypopharyngeal than for glottic carcinomas. Five patients developed complications requiring surgical correction, but none experienced mortality. Moderate complications were treated conservatively without lasting sequelae. This technique is a reasonable safe and efficient procedure and can be effectively employed for the management of advanced laryngeal and hypopharyngeal carcinomas after definitive surgery

[en] Purpose/Objective: The treatment of inoperable Stage III NSCLC with conventional RT alone results in a high incidence of local and distant failures and in very limited long-term survival rates. In two consecutive phase II cooperative trials, we evaluated the combination of alternating hyperfractionated accelerated radiotherapy and cisplatin-based chemotherapy. Materials and Methods: A total of one hundred and thirty two patients were enrolled. Between 2/86 and 9/89, 65 patients were entered in the first trial (G.I) and between 12/89 and 10/92 67 were enrolled in the second trial (G.II). In both protocols, RT was administered twice daily, with 6 hours interval, 5 days a week, to a total dose of 63 Gy in 42 fractions of 1.5 Gy. RT was given during weeks 2, 3 and 6, 7, over an elapsed time of 6 weeks. In G.I, 3 cycles of cisplatin, 60 mg/m2 d.1, mitomycin, 8 mg/m2 d.1 and vindesin 3 mg/m2 d.1 and 8, were given during weeks 1, 5 and 9, whereas in G.II, cisplatin 70 mg/m2 d.1 and vinblastin 5 mg/m2 d.1 and 8 were given during weeks 1, 5, 9, 13, 17 and 21. Patients' characteristics included the following : median age was 55.5 years (28-70), male to female ratio was 7.3 : 1, tumor Stage were III_A in 44% and III_B in 56%, performance status (P.S.) were 0 in 36%, 1 in 52% and 2 in 12%. Histologic type consisted in squamous cell carcinoma in 60%, adenocarcinoma in 22%, large cell carcinoma in 14% and undifferentiated NSCLC in 4%. Results: With a minimum follow-up of 3 years, the 1, 2, 5 and 8 year overall survival probability was 56% (95% C.I. 47% - 64%), 27% (20% - 35%), 12% (7% - 18%) and 9% (3% - 16%) respectively, with a median survival of 13.6 months (11.4 - 16.8). Median follow-up for survivors was 6 years (3.3 - 9.9). There were no survival differences between Stage III_A and III_B (p = .84), PS 0, ,, 2 (p = .87), sex (p = .45) or between the two treatment protocols. At this time, 14 patients are alive, and 118 have died : 102 from NSCLC, 4 from acute toxicity, 2 from secondary surgery, 4 from other medical causes and 6 from unknown causes. One hundred and twenty-six patients were evaluable for response, with 17% CR, 51% PR, 15% NC, and 17% PD. However correlation between response and long-term survival was poor. One hundred twelve patients relapsed. First site of relapse was local in 31% of patients, distant in 43%, local and distant in 15% and unknown in 11%. Twenty percent of patients had CNS metastases as a first site of relapse. Main grade III-IV acute toxicities were nausea-vomiting (17%), mucositis (15%), leukopenia (41%) and thrombocytopenia (11%). Eight patients presented with symptomatic lung fibrosis. Conclusions: Based on this experience with 132 patients, this aggressive combination of RT and CT for inoperable Stage III NSCLC is feasible with acceptable toxicity, and long-term results suggest a gain in survival when compared to those obtained with conventional RT alone

[en] The authors assessed the dose-dependence of repair of potentially lethal damage in Chinese hamster ovary cells x-irradiated in vitro. The recovery ratio (RR) by which survival (SF) of the irradiated cells was enhanced increased exponentially with a linear and a quadratic component namely ζ and ψ: RR=exp(ζD+ψD²). Survival of irradiated cells can thus be expressed by a combined linear-quadratic model considering 4 variables, namely α and β for the capacity of the cells to accumulate sublethal damage, and ζ and ψ for their capacity to repair potentially lethal damage: SF=exp((ζ-α)D+ (ψ-β)D²). author. 26 refs.; 1 fig.; 1 tab

[en] A dosimetry comparison was made between helical tomo-therapy, I.M.R.T. and classical conformal three dimensional radiotherapy for twelve first patients that received a image guided radiotherapy, the toxicity was tackled with a minimum follow-up of fourteen months. In conclusion, the CT-guided radiotherapy allows to save organs at risks superior to I.M.R.T. and conformal radiotherapy and a best homogeneity in the target volume. the toxicity is moderated and the break time is limited. (N.C.)

[en] Two stereotactic surgery methods, arc and micro-multileave collimator (MMLC) therapy, were compared in the particular case of arteriovenous malformations (AVMs) treatment. Different methods of the treatment optimisation were used. The comparison covered a group of 22 patients suffering from peripheral and central AVMs of different sizes who underwent initially arc therapy. Several parameters were evaluated to compare the two methods: 2D and 3D isodose representations, dose-volume histograms (DVHs) and probability of success. The 3D isodoses were compared for the 22 patients showing a better conformity for the MMLC (three cases are presented). The DVHs of the AVM were also in favour of MMLC. In terms of probability of success, the results showed that are therapy was superior only in the case of small spherical lesions. MMLC therapy proved to be superior to arc therapy in all cases but central spherical small volume AVMs. (orig.)

No abstract available