Evaluation of DIR algorithm performance in real patients for radiotherapy treatments: A systematic review of operator-dependent strategies.

PURPOSE: The performance of deformable medical image registration (DIR) algorithms has become a major concern. METHODS: We aimed to obtain updated information on DIR algorithm performance quantification through a literature review of articles published between 2010 and 2022. We focused only on studies using operator-based methods to treat real patients. The PubMed, Google Scholar and Embase databases were searched following PRISMA guidelines. RESULTS: One hundred and seven articles were identified. The mean number of patients and registrations per publication was 20 and 63, respectively. We found 23 different geometric metrics appearing at least twice, and the dosimetric impact of DIR was quantified in 32 articles. Forty-eight different at-risk organs were described, and target volumes were studied in 43 publications. Prostate, head-and-neck and thoracic locations represented more than ¾ of the studied locations. We summarized the type of DIR and the images used, and other key elements. Intra/interobserver variability, threshold values and the correlation between metrics were also discussed. CONCLUSIONS: This literature review covers the past decade and should facilitate the implementation of DIR algorithms in clinical practice by providing practical and pertinent information to quantify their performance on real patients.

Detecting anomalies in a deliberately biased tomotherapy plan: Comparison of two patient-specific quality assurance processes involving ArcCHECK® and Gafchromic® EBT3 films.

PURPOSE: This work proposes a comparative evaluation of two of our patient-specific quality assurance processes involving ArcCHECK® (Sun Nuclear) and Gafchromic® EBT3 films (Ashland) in order to determine which detector is able to most effectively detect an anomaly in a deliberately biased tomotherapy plan. MATERIAL AND METHODS: A complex clinical head and neck tomotherapy plan was deliberately biased by introducing six errors: multileaf collimator leaf positional errors by leaving one and two central leafs closed during the whole treatment, initial radiation angle errors (+0.5° and +1.0°) and multileaf collimator leafs opening time errors (+0.5% and +1.0%). For each error-induced plan, comparison of ArcCHECK® with Gafchromic® EBT3 films (20.3×25.4cm2) was performed through two methods: a dose matrices subtraction study and a gamma index analysis. RESULTS: The dose matrices subtraction study shows that our ArcCHECK® processing is able to detect all the six induced errors contrary to the one using films, which are only able to detect the two biases involving multileaf collimator leaf positional errors. The gamma index analysis confirms the previous method, since it shows all six errors induced in the reference plan seem to be widely detected with ArcCHECK® with the more restrictive 1%/1mm gamma criterion, whereas films may only be able to detect biases in relation to multileaf collimator leaf positional errors. It also shows the common 3%/3mm gamma criterion does not allow deciding between both detectors in the detection of the six induced biases. CONCLUSION: Both comparative methods showed ArcCHECK® processing is more suitable to detect the six errors introduced in the reference treatment plan.

[Pediatric medulloblastoma: Retrospective series of 52 patients]. / Médulloblastomes de l'enfant: étude rétrospective portant sur 52 patients.

PURPOSE: Retrospective analysis of the results of 52 children irradiated for a medulloblastoma. PATIENTS AND METHODS: Between 1974 and 2012, 52 children with an average age of 6 years and a half (11 months-17 years and a half) were treated with surgery then with radiotherapy at the Comprehensive Cancer Centre of Strasbourg (France). For 44 children, the treatment consisted of a chemotherapy. RESULTS: After a mean follow-up of 106.6 months (7-446 months), 13 relapses and 24 deaths were observed. Overall survival at 5 years and 10 years were 62% and 57%, respectively. Disease-free survival at 5 years and 10 years were 80% and 63%, respectively. Univariate analysis found the following adverse prognostic factors: the existence of a postoperative residue, the positivity of the cerebrospinal fluid, the metastatic status and medulloblastoma of high-risk. Positivity of the cerebrospinal fluid remains a negative factor in multivariate analysis. CONCLUSION: These results confirm the survival rate obtained by a conventional approach (surgery then irradiation). Insufficiency of results and rarity of medulloblastoma require the establishment of international protocols.

[Adult medulloblastoma: Retrospective series of 21 patients]. / Médulloblastomes de l'adulte: étude rétrospective portant sur 21 patients.

PURPOSE: Retrospective analysis of the results of 21 adults treated for medulloblastoma. PATIENTS AND METHODS: Between 1978 and 2011, 21 adults with an average age of 31 years (18.3-50) were treated with surgery then with radiotherapy (n=20) at the Comprehensive Cancer Center of Strasbourg. For some (n=12), treatment consisted of chemotherapy. RESULTS: After a mean follow-up of 122 months (19-423), six relapses and seven deaths were observed. Overall survival at 5 years and 10 years was 89.4 ± 7.1% for both. Disease-free survival at 5 years and 10 years was 79.6 ± 9.2% and 85.7 ± 7.6% and 60.6 ± 17.7%, respectively. CONCLUSION: The rarity of medulloblastoma, especially in adults and these results confirm the necessity of international protocols.

[General anesthesia in pediatric radiotherapy]. / Anesthésie générale en radiothérapie pédiatrique.

BACKGROUND: The majority of children under 3 years require anesthesia for radiotherapy. METHODS: This work reports the experience of Paul-Strauss Center over a 4-year period on 15 children and covering 386 general anesthesia. RESULTS AND CONCLUSION: The rate of anesthesia-related complications was low (0.5%) subject to the experience of the anesthesiologists and follow-up recommendations.

[Constraints of the dentist are consistent with the results of an optimal irradiation with modulated intensity in N0 oropharyngeal cancer]. / Les contraintes du chirurgien dentiste sont compatibles avec les résultats d'une irradiation optimale avec modulation d'intensité dans les cancers de l'oropharynx de stade N0.

PURPOSE: We compared intensity-modulated radiotherapy and 3D-conformal irradiation in oropharyngeal cancers according to the requirement of dentists. MATERIAL AND METHODS: From the files of seven patients with cancer of the oropharynx, two dosimetry plannings for 3D-conformal radiotherapy and intensity-modulated radiotherapy with tomotherapy were performed. The dose distributions in the target volumes and organs at risk in relation to the dental sphere were compared. RESULTS: For the planning target volume of the primitive tumour sites, average values of V95%, D2%, D98% and of the conformal index were statistically in favour of tomotherapy. For the planning target volume of node areas, averages values of V95%, D2%, D98% were statistically in favour of tomotherapy. For ipsi- and controlateral parotide glands, average values of V15Gy, V26Gy, V30Gy, V40Gy were significantly lower for tomotherapy. For the submaxillary glands, average values of mean doses and V40Gy were statistically in favour of tomotherapy. For the buccal cavity, the average values of V45Gy were statistically in favour of tomotherapy. For ipsi- and controlateral masseter muscles, the average values of mean doses were statistically in favour of tomotherapy. For the ipsi- and controlateral temporomandibular joints, average values of mean doses and V60Gy were statistically in favour of tomotherapy. For mandibular bone, average values of mean doses and V40Gy, V50Gy, V60Gy and V70Gy were statistically in favour of tomotherapy. For maxillary bone, average values of V40Gy, V50Gy and V60Gy were statistically in favour of tomotherapy. CONCLUSION: The radiation oncologist can constrain the intensity-modulated radiotherapy dosimetry to the needs of dentists to prevent or improve dental care and quality of life.

[Comparison of three dosimetric techniques for lung tumor irradiation]. / Analyse des contraintes dosimétriques obtenues par trois techniques d'irradiation de tumeurs pulmonaires.

PURPOSE: Comparison of three dosimetric techniques of lung tumor delineation to integrate tumor motion during breathing. PATIENTS AND METHODS: Nineteen patients with T1-3N0M0 malignant lung tumor were treated with definitive chemoradiotherapy (14 cases) or pre-surgery chemoradiation. Doses were, respectively, 66 and 46Gy. CT-scan for delineation was performed during three phases of breathing: free breathing and deep breath-hold inspiration and expiration. GTV (gross tumor volume) was delineated on the three sequences. The classic technique included GTV from the free-breathing sequence plus a CTV (clinical target volume) margin of 5 to 8mm plus a PTV (planning target volume) margin of 7 to 10mm (including ITV [internal target volume] margin and set-up margin). The gating-like technique included GTV from the deep breath-hold inspiration sequence plus a CTV margin of 5 to 8mm plus a PTV margin of 2mm. The three-volume technique, included GTV as a result of the fusion of GTVs from the three sequences plus a CTV margin of 5 to 8mm plus a PTV margin of 2mm. Dosimetry was calculated for the three PTVs, if possible, with the same fields number and position. Dose constraints and rules were imposed to accept dosimetries: firstly spinal cord maximal dose less than 45Gy, followed by V95 % for PTV greater than or equal to 95 %, and V20 GY(Gy) for lung less than or equal to 30 %, V30 GY(Gy) for lung less than or equal to 20 %. RESULTS: GTVs were not statistically different between the three methods of delineation. PTVs were significantly lower with the gating-like technique. V95% of the PTV were not different between the three techniques. With the classic-, the gating-like- and the 3-volume techniques, dosimetry was considered as acceptable, respectively in 15, 18 and 15 cases. Comparisons of constraint values showed that the gating-like method gave the best results. In the case of pre-operative management, the gating-like method allowed the best results even for the V95% values. However, in the absence of gating device or without the possibility to use it, the 3-volume method allowed to take into account more precisely the organ motion than the classical technique. CONCLUSION: The 3-volume method can be done. It is a good method to take into account the organ motions. However, the gating-like method gives the best results leading to propose its use even for pre-operative patients with upper tumors.

[New technologies in lung cancer radiotherapy]. / Techniques innovantes en radiothérapie des cancers bronchopulmonaires.

Since ten years, lung cancer radiotherapy improved thanks to capacities of imagery, softwares, hardwares which allowed developing and transforming drastically radiotherapy procedures. Improvements were performed in all steps of the lung treatment, immobilization, three dimensional imagery, delineation of the targets and organs at risk, simulation and ballistic, dose calculation, daily set-up, breathing control, and treatment verifications. Furthermore, new technology implies technical adjustments but also a change of physicians and physicists minds.

Synthesis of sulphated acrylic polymers and their evaluation as inhibitors of basic fibroblast growth factor-dependent cell growth.

Sulphated acrylic polymers have been synthesised and evaluated as potential inhibitors of basic fibroblast growth factor-dependent cell growth. The polymers were synthesised with a range of molar masses using both a thermal radical method and a room temperature reduction activation route. The polymers had bimodal molar mass distributions, but much of the low molar mass component could be removed by dialysis. Some of these polymers were effective inhibitors, their effectiveness being dependent on the molar mass. IC50 values as low as 5 microg/ml could be obtained with up to 73% inhibition by 100 microg/ml. These polymers are of interest as potentially readily accessible materials for cancer therapy.

[Activity of renal hydrolases in pre- and postnatal development of mice]. / Activités des hydrolases rénales au cours du développement pré- et post-natal de la souris.

The fetal and postnatal activity patterns of different hydrolytic enzymes (alkaline phosphatase, gamma-glutamyltransferase, trehalase, maltase, glucoamylase, lactase, and sucrase) have been examined in mouse renal homogenates. Alkaline phosphatase and gamma-glutamyltransferase activities presented approximately similar changes. They increased from 18 days of gestation up to 30 days after birth. These activities showed marked increases during the 3rd and 4th postnatal weeks. A similar important rise was observed for trehalase activity at the end of the suckling period. Maltase activity increased gradually after birth. Traces of lactase, sucrase, and glucoamylase activities were detected at each developmental stage.

[Ultrastructural modifications in the thyroid glands of mice treated with lithium gluconate]. / Modifications ultrastructurales de la thyroïde de Souris traitée au gluconate de lithium.

The various morphological and functional changes produced by lithium gluconate treatment of Mouse thyroid and ultimobranchial cells show complex interactions, involving direct and indirect effects. In most of the cases these effects determine metabolism (thyroid cells) or differentiation (ultimobranchial cell) disturbances. In most of the cases analysed changes do not concern the whole gland and should not have important consequences on its general activity-so it is more likely that at low concentration the effects of lithium gluconate on the thyroid gland of manic depressive patients might be neglected at the level of the functional state of the whole gland.