Clinical practice in European centres treating paediatric posterior fossa tumours with pencil beam scanning proton therapy.

BACKGROUND AND PURPOSE: As no guidelines for pencil beam scanning (PBS) proton therapy (PT) of paediatric posterior fossa (PF) tumours exist to date, this study investigated planning techniques across European PT centres, with special considerations for brainstem and spinal cord sparing. MATERIALS AND METHODS: A survey and a treatment planning comparison were initiated across nineteen European PBS-PT centres treating paediatric patients. The survey assessed all aspects of the treatment chain, including but not limited to delineations, dose constraints and treatment planning. Each centre planned two PF tumour cases for focal irradiation, according to their own clinical practice but based on common delineations. The prescription dose was 54 Gy(RBE) for Case 1 and 59.4 Gy(RBE) for Case 2. For both cases, planning strategies and relevant dose metrics were compared. RESULTS: Seventeen (89 %) centres answered the survey, and sixteen (80 %) participated in the treatment planning comparison. In the survey, thirteen (68 %) centres reported using the European Particle Therapy Network definition for brainstem delineation. In the treatment planning study, while most centres used three beam directions, their configurations varied widely across centres. Large variations were also seen in brainstem doses, with a brainstem near maximum dose (D2%) ranging from 52.7 Gy(RBE) to 55.7 Gy(RBE) (Case 1), and from 56.8 Gy(RBE) to 60.9 Gy(RBE) (Case 2). CONCLUSION: This study assessed the European PBS-PT planning of paediatric PF tumours. Agreement was achieved in e.g. delineation-practice, while wider variations were observed in planning approach and consequently dose to organs at risk. Collaboration between centres is still ongoing, striving towards common guidelines.

A software tool to support follow-up care in a French childhood cancer cohort: construction and feasibility.

BACKGROUND: Treatment summaries and a personalized survivorship care plans based on internationally approved, organ-specific follow-up care recommendations are essential in preserving the health and quality of life for cancer survivors. Cohorts made up of survivors of childhood cancer have made significant contributions to the understanding of early mortality, somatic late complications, and psychosocial outcomes among former patients. New treatment protocols are needed to enhance survival and reduce the potential risk and severity of late effects, and working with treatment databases is crucial in doing so. CONSTRUCTION AND CONTENT: In the GOCE (Grand Ouest Cancer de l'Enfant [Western Region Childhood Cancer]) network, in a participative approach, we developed the LOG-after medical tool, on which health data are registered and can be extracted for analysis. Its name emphasizes the tool's goal, referring to 'logiciel' (the French word for software) that focuses on the period "after" the acute phase. This tool is hosted on a certified health data server. Several interfaces have been developed that can be used depending on the user's profile. Here we present this innovative co-constructed tool that takes national aspects into account, including the results of the feasibility/satisfaction study and its perspective. UTILITY AND DISCUSSION: The database contains data relating to 2558 patients, with samples from 1702 of these (66.54%) being held in a tumor bank. The average year in which treatment started was 2015 (ranging from December 1967 to November 2022: 118 patients were treated before 2012 and registered retrospectively when seen in long-term follow-up consultations or for another cancer since November 2021). A short questionnaire was distributed to healthcare professionals using the tool (physicians and research associates or technicians, n = 14), of whom 11 answered and were all satisfied. Access to the patient interface is currently open to 124 former patients. This was initially offered to 30 former patients who were over 15 years old, affected by the disease within the last 5 years, and had agreed to test it. Their opinions were collected by their doctor by e-mail, telephone, or during a consultation in an open-ended question and a non-directive interview. All patients were satisfied with the tool, with interest in testing it in the long term. Some former patients found that the tool provided them with some ease of mind; one, for instance, commented: "I feel lighter. I allow myself to forget. I know I will get a notification when the time comes." CONCLUSIONS: Freely available to all users, LOG-after: (1) provides help with determining personalized survivorship care plans for follow-up; (2) builds links with general practitioners; (3) empowers the patient; and (4) enables health data to be exported for analysis. Database URL for presentation: https://youtu.be/2Ga64iausJE.

Post-operative flank irradiation using conformal versus highly conformal radiotherapy techniques for paediatric renal tumours: Results from the French registry PediaRT.

PURPOSE: Three-dimensional conformal RT (3D-RT) techniques are gold standard for post-operative flank radiotherapy (RT) in paediatric renal tumours. Recently, highly conformal RT (HC-RT) techniques have been implemented without comparative clinical data. The main objective of this multicentre study was to compare locoregional control (LRC) in children treated either with HC-RT or 3D-RT techniques. METHODS: Patients treated with post-operative flank RT for renal tumour registered in the national cohort PediaRT between March 2013 and September 2019 were included. Treatment and follow-up data, including toxicities and outcomes, were retrieved from the database. LRC was calculated, and dose reconstruction was performed in case of an event. RESULTS: Seventy-nine patients were included. Forty patients were treated with HC-RT and 39 with 3D-RT. Median follow-up was 4.5 years. Three patients had locoregional failure (LRF; 4%). HC-RT was not associated with a higher risk of LRF. Three-year LRC were 97.4% and 94.7% in the HC-RT and 3D-RT groups, respectively. The proportion of planning target volumes receiving 95% or more of the prescribed dose did not significantly differ between both groups (HC-RT 88%; 3D-RT 69%; p = .05). HC-RT was better achieving dose constraints, and a significant mean dose reduction was observed in the peritoneal cavity and pancreas associated with lower incidence of acute gastrointestinal toxicity. CONCLUSION: LRF after post-operative flank RT for renal tumours was rare and did not increase using HC-RT versus 3D-RT techniques. Dose to the pancreas and the peritoneal cavity, as well as acute toxicity, were reduced with HC-RT compared to 3D-RT.

Use of expanders for bowel protection in pediatric pelvic tumor radiation therapy: 15 years of tolerance results.

PURPOSE: Bowel is often the dose-limiting organ in curative pelvic irradiation because of radiation enteritis when dose exceeds 40 to 45 Gy. To limit radiation enteritis, a silicone tissue-expander prothesis (STEP) connected to a subcutaneous self-sealing valve was prospectively used in children undergoing pelvic or abdominal radiation therapy. This study reports the 15-year long-term outcomes of this prospective series. METHODS AND MATERIALS: Between 1987 and 2008, 29 children from 3 Paris institutions received pelvic radiation therapy after surgical placement of a STEP in the pelvis. The median prescribed dose was 50.4 Gy (44.1-55 Gy) using 5 daily fractions of 1.8 Gy per week, except for 1 patient receiving 4 fractions of 2.5 Gy per week. The median treatment duration was 40 days (29-49 days). After 2000, computed tomography (CT) conformal 3-dimensional radiation therapy was used, and 12 patients had CT simulation. Four had CT before and after insertion of the STEP, enabling us to compare pre- and postprosthesis insertion bowel dose-volume histograms. Acute and late toxicities were captured using the Radiation Therapy Oncology Group or the National Cancer Institute Common Terminology Criteria for Adverse Events 4.0 scale. RESULTS: No patient experienced significant perioperative complications. Pre- and post-STEP insertion small bowel dose-volume histograms show significant reductions in small bowel: 51%, 45%, and 64%, respectively, in V10, V15, and V40 (Vx = irradiated volume by x Gy). Twenty-five patients (86%) completed their radiation therapy with no or minimal small bowel toxicity. One patient also treated with neutrons developed delayed grade 4 toxicities. The 15-year complication-free survival for those surviving was 70.3%. CONCLUSIONS: We report the long-term follow-up of STEP prosthesis insertion in children to reduce the small bowel volume in the radiation field. The acute and long-term tolerances were excellent. The STEP reduced the bowel dose over 40 Gy by 64%.

Radiotherapy associated with concurrent bevacizumab in patients with non-metastatic breast cancer.

The purpose of this multicenter prospective and descriptive study was to determine late toxicities and outcomes among patients with non-metastatic breast cancer receiving concurrent bevacizumab (BV) and radiation therapy (RT) in the clinical trials. Early and late toxicities were assessed and evaluation was available for 63 patients (pts) at 12 months. Acute radiation dermatitis was observed in 48 (76%): grade 1 for 27, grade 2 for 17 and grade 3 for 4 pts. Grade 2 acute oesophagitis was observed in one patient (2%). Little toxicity was described 1 year after the completion of RT: 7 pts (12%): grade 1-2 pain, 3 (5%) presented grade 1 fibrosis, and 2 pts (4%) - telangiectasia. One patient (2%) experienced grade 1 dyspnoea. Five grade 1-2 lymphoedema occurred. Only one patient experienced a LEVF value less than 50% one year after the end of RT. In conclusion, the concurrent BV with locoregional RT provides acceptable toxicities.

Waiting times before initiation of radiotherapy might not affect outcomes for patients with glioblastoma: a French retrospective analysis of patients treated in the era of concomitant temozolomide and radiotherapy.

Purpose of this study was to determine the effect of waiting time for radiotherapy on overall survival of patients with glioblastoma treated in the EORTC-NCIC trial at 18 centers in France. A total of 400 adult patients with glioblastoma who were treated between January 1, 2006 and December 31, 2006 were included. There were 282 patients with "minimum criteria" according to the EORTC-NCIC trial: (i) concurrent chemotherapy with temozolomide; and (ii) age between 18 and 70 years old. Among these patients, 229 were treated with adjuvant temozolomide and were classified as "maximal criteria". One-hundred and eighteen patients were in the "without minimal criteria" group. Waiting time from the first symptom (FS-RT), pathology diagnosis (P-RT), multidisciplinary meeting (MM-RT), surgery (S-RT), and CT scan for delineation (CT-RT) until the start of radiotherapy were recorded. Median follow-up for all patients was 327 days. Overall, median FS-RT, P-RT, MM-RT, CT-RT, and S-RT times were 77, 36, 32, 12, and 41 days, respectively. Median, and 12 and 24-month overall survival were 409 days, and 56.3 ± 2.1 % and 27.6 ± 2.6 %, respectively. Univariate analysis failed to reveal a difference in survival, irrespective of the delay. In multivariate analysis, independent favorable prognostic factors for overall survival were age (p ≤ 0.0001) and type of surgery (p = 0.0006). In this large series treated during the EORTC-NCIC protocol period, waiting time until radiotherapy did not seem to affect patient outcome.