Setup margins and geometric uncertainties in intensity-modulated radiation therapy in treating pituitary adenomas: the experience of Lyon Sud Hospital.

PURPOSE: The authors retrospectively evaluated the setup uncertainties in Intensity-Modulated Radiation Therapy (IMRT) for pituitary adenomas and verified the margins used in daily practice (3 mm). MATERIALS AND METHODS: Craniocaudal (CC), anteroposterior (AP) and laterolateral (LL) displacements were measured during the first 3 days of treatment and then weekly by comparing two orthogonal images obtained by an electronic system of portal imaging with Digitally Reconstructed Radiographs (DRRs). Setup Margins (SM) were defined according to the International Commission on Radiation Units (ICRU)-62 formula, the Stroom equation and the van Herk equation. The systematic (Σ) and random (σ) errors of the population were calculated as standard deviation (SD) of the population mean and the mean of SDs for every patient, respectively. RESULTS: Twenty patients were treated by IMRT for pituitary adenomas, and a total of 231 measurements were obtained. Σ and σ were 0.6 and 1.3 mm, 0.8 and 1 mm, 1.2 and 1.5 mm in the AP, LL and CC direction, respectively. Larger setup margin was 2.4, 2.7 and 4 mm in the AP, LL and CC direction, respectively (van Herk formula). CONCLUSIONS: IMRT is a highly sophisticated treatment technique that requires precise definition and optimisation of local setup errors and, finally, of the irradiated volumes. The role of image-guided RT in these kinds of treatments should be prospectively evaluated.

Does weight loss predict accuracy of setup in head and neck cancer patients treated with Intensity-Modulated Radiation Therapy?

PURPOSE: This prospective study reports the impact of weight loss on setup of head and neck (H&N) cancer patients treated by Intensity-Modulated Radiation Therapy (IMRT). MATERIALS AND METHODS: Setup errors of H&N cancer patients treated by IMRT from January to June 2010 were prospectively analysed and statistically related to weight loss. A mixed linear model was used for statistical evaluations. Setup margins of our institute were also calculated. RESULTS: Twenty-two patients and 128 pairs of Electronic Portal Images (EPI) were analysed. Setup errors varied between -0.6 and +0.6, -0.7 and +0.8 and -0.2 and +0.8 in the anterior-posterior, superior-inferior and right-left direction, respectively. Median and mean weight loss were 2.1 and 3.1 kg (range 0-12 kg), respectively; median and mean percent of weight loss were 2.95% and 4.64% (range 0.3-19.7%), respectively. No statistical relation was seen between weight loss and the setup errors. CONCLUSIONS: Weight loss is not a good clinical parameters for predicting an increase of setup errors. Other clinical and/or anthropometrical features should be prospectively evaluated in order to assess the need for re-planning.

[Propositions for the selection and the delineation of peritumoral microscopic disease volumes in oral cavity and oropharyngeal cancers (lymph nodes excluded)]. / Proposition de sélection et délimitation des volumes cibles microscopiques péritumoraux dans les cancers de la cavité buccale et de l'oropharynx (aires ganglionnaires exclues).

This article reviews the concept of selectivity in peritumoral microscopic disease to be included in the Clinical Target Volume (CTV) for elective treatment for oral cavity and oropharyngeal squamous cell carcinoma, using the local tumoral spread. The objective of the present article is to present a procedure for the delineation of the target volumes, required for an appropriate application of 3-DCRT and IMRT for head and neck cancers. These propositions are for the delineation of microscopic peritumoral target volumes when external beam irradiation is required. CTVs are illustrated on CT sections.

[Local control in the management of cancer: a few thoughts]. / Le contrôle local en cancérologie: quelques réflexions.

Cancer is still considered from a physiopathological point of view as a disease of the cell. This concept is underlying the idea of cure. Treatment with curative intent should aim at eradicating all the tumoral cells. Local control is mandatory and essential in cancers localized in organ with vital function. In breast cancer a complex and controversial relationship exists between local relapse and increased risk of fatal distant metastasis. In case of organ preserving treatment, a complete local control is necessary from the start. If a too high risk of local relapse is foreseable, conservative treatment should not be recommended.

Management of inguinal lymph node metastases in patients with carcinoma of the anal canal: experience in a series of 270 patients treated in Lyon and review of the literature.

BACKGROUND: The authors performed a specific analysis of the clinical significance of inguinal lymph nodes metastases in patients with anal canal carcinoma (ACC). METHODS: A retrospective analysis was conducted of 270 patients who were treated in Lyon between 1980 and 1996 with radiotherapy with curative intent for ACC: No elective irradiation of clinically normal inguinal areas was performed. Patients with metastatic inguinal lymph nodes were treated with inguinal dissection and postoperative irradiation with a dose of 50 grays over 5 weeks. Concomitant chemoradiation, usually with a regimen of fluorouracil and cisplatinum, was given to 159 patients. RESULTS: The median follow-up for the whole series was 72 months. Synchronous inguinal metastases were observed in 10% of patients (n = 27; the rate was 16% for patients with T3--T4 lesions), and the 5-year overall survival rate was 54.4%. Metachronous inguinal metastases were seen in 19 patients (7.8%), and the 5-year overall survival rate of these patients was 41.4%. An original finding was that, when the primary tumor clearly was located on a single lateral side of the anal canal, the inguinal lymphatic metastases was always homolateral to it (36 of 36 synchronous plus metachronous tumors). CONCLUSIONS: The data from this series of patients and a review of the literature are in favor of a selective approach in the management of inguinal lymph node involvement for patients with ACC, depending on the disease stage and the location of the primary tumors.

[Production process in external radiotherapy and cost-inducers research in 2 hospital units]. / Processus de production en radiothérapie externe et recherche d'inducteurs de coûts dans deux services hospitaliers.

PURPOSE: To analyse the process of outpatient radiation therapy by dividing it into elementary acts, and to determine the cost-inducers (staff and machine time, equipment) in order to enhance the value of radiotherapy activity. MATERIAL AND METHODS: The care process was analysed from 1 June 1997 to 1 September 1997, in two institutions (Centre hospitalo-universitaire de Saint Etienne and centre de Lutte contre le Cancer de Lyon), in terms of consumption of human and equipment means, representing a cost for the care institution. The valorization was expressed in physics units for material means, and in time units for human and heavy equipment. Parameters able to modify the consumption of means had been defined. The following data had been collected for each activity: patient characteristics, characteristics of the process, specific parameters of each activity, data related to the care staff and care unit. RESULTS: The importance of the specific data of each activity was noteworthy. Two criteria modified the valorization: the complexity level of dosimetry and inclusion in a research trial. Total body irradiation and conformal radiotherapy were well individualized. There was no difference between the two care units. The lack of cost-inducers for the 'immobilization-simulation' activity reflects the large diversity of practice, and requires a global analysis of the 'treatment preparation' process. CONCLUSION: The cost-inducers found in this study could permit the elaboration of the 'relative cost index' in radiation therapy. (The results obtained must be validated in other types of care units.) These relative cost indexes would describe the various phases of the treatment, such as treatment preparation, dosimetry, treatment, quality control. This approach is currently used by workshops in PMSI (Programme de Médicalisation des Systèmes d'Information) and NGAP (Nomenclature Générale des Actes Professionnels).

[Local excision and adjuvant radiotherapy for rectal adenocarcinoma T1-2 N0]. / Exérèse locale et radiothérapie adjuvante des adénocarcinomes rectaux T1-2 N0.

AIM: To study retrospectively the relapse rate, the functional results and the survival rate in patients with rectal carcinoma treated with local excision and adjuvant radiotherapy. METHODS: Between 1980 and 1995, 43 patients were treated. All cancers were infiltrating tumours except 4 high grade dysplasias with positive margins. The pT classification was: pT1 (n=34), pT2 (n=4), pT3 (n=1). In 4 cases the depth of penetration of the tumor into the bowel wall was not evaluable. The endo-anal excision was performed by surgery (n=20) or by endoscopy (n=23). Only the tumor bed was irradiated in 35 cases (contact x-ray therapy: 30, interstitial iridium implant: 5) and in 8 cases the whole rectum was irradiated with external beam radiotherapy (+/- endocavitary irradiation). RESULTS: Median follow-up was 72 months. Four malignant relapses were observed (local: 1, perirectal lymphatic: 2, distant metastasis: 1). The overall 5- and 10-year survival rates were 80 and 68%, respectively. A total of 41 patients preserved a normal sphincter (95%). The anal function was evaluated as excellent or good in all the cases. No severe radiation toxicity was observed. CONCLUSION: Small rectal carcinomas T1 N0 can be effectively treated in most cases by local excision and postoperative radiation therapy. A close multidisciplinary collaboration is necessary to achieve an optimal result.