International Guideline on Dose Prioritization and Acceptance Criteria in Radiation Therapy Planning for Nasopharyngeal Carcinoma

Purpose: The treatment of nasopharyngeal carcinoma requires high radiation doses. The balance of the risks of local recurrence owing to inadequate tumor coverage versus the potential damage to the adjacent organs at risk (OARs) is of critical importance. With advancements in technology, high target conformality is possible. Nonetheless, to achieve the best possible dose distribution, optimal setting of dose targets and dose prioritization for tumor volumes and various OARs is fundamental. Radiation doses should always be guided by the As Low As Reasonably Practicable principle. There are marked variations in practice. This study aimed to develop a guideline to serve as a global practical reference. Methods and Materials: A literature search on dose tolerances and normal-tissue complications after treatment for nasopharyngeal carcinoma was conducted. In addition, published guidelines and protocols on dose prioritization and constraints were reviewed. A text document and preliminary set of variants was circulated to a panel of international experts with publications or extensive experience in the field. An anonymized voting process was conducted to rank the proposed variants. A summary of the initial voting and different opinions expressed by members were then recirculated to the whole panel for review and reconsideration. Based on the comments of the panel, a refined second proposal was recirculated to the same panel. The current guideline was based on majority voting after repeated iteration for final agreement. Results: Variation in opinion among international experts was repeatedly iterated to develop a guideline describing appropriate dose prioritization and constraints. The percentage of final agreement on the recommended parameters and alternative views is shown. The rationale for the recommendations and the limitations of current evidence are discussed. Conclusions: Through this comprehensive review of available evidence and interactive exchange of vast experience by international experts, a guideline was developed to provide a practical reference for setting dose prioritization and acceptance criteria for tumor volumes and OARs. The final decision on the treatment prescription should be based on the individual clinical situation and the patient's acceptance of optimal balance of risk. (C) 2019 Elsevier Inc. All rights reserved

International Recommendations on Reirradiation by Intensity Modulated Radiation Therapy for Locally Recurrent Nasopharyngeal Carcinoma

Purpose: Reirradiation for locally recurrent nasopharyngeal carcinoma (NPC) is challenging because prior radiation dose delivered in the first course is often close to the tolerance limit of surrounding normal structures. A delicate balance between achieving local salvage and minimizing treatment toxicities is needed. However, high-level evidence is lacking because available reports are mostly retrospective studies on small series of patients. Pragmatic consensus guidelines, based on an extensive literature search and the pooling of opinions by leading specialists, will provide a useful reference to assist decision-making for these difficult decisions. Methods and Materials: A thorough review of available literature on recurrent NPC was conducted. A set of questions and preliminary draft guideline was circulated to a panel of international specialists with extensive experience in this field for voting on controversial areas and comments. A refined second proposal, based on a summary of the initial voting and different opinions expressed, was recirculated to the whole panel for review and reconsideration. The current guideline was based on majority voting after repeated iteration for final agreement. Results: The initial round of questions showed variations in clinical practice even among the specialists, reflecting the lack of high-quality supporting data and the difficulties in formulating clinical decisions. Through exchange of comments and iterative revisions, recommendations with high-to-moderate agreement were formulated on general treatment strategies and details of reirradiation (including patient selection, targets contouring, dose prescription, and constraints). Conclusion: This paper provides useful reference on radical salvage treatment strategies for recurrent NPC and optimization of reirradiation through review of published evidence and consensus building. However, the final decision by the attending clinician must include full consideration of an individual patient's condition, understanding of the delicate balance between risk and benefits, and acceptance of risk of complications. (C) 2021 Elsevier Inc. All rights reserved

Interruption of G2-M and mitotic checkpoint (Influence on tumor radiosensitivity)

LE KREMLIN-B.- PARIS 11-BU Méd (940432101) / SudocSudocFranceF

Prognostic impact of tumor growth velocity in head and neck squamous cell carcinoma treated by radiotherapy: A pilot study.

BACKGROUND: When a patient is seen with a newly diagnosed oropharyngeal squamous cell carcinoma, it remains unclear to the treating physicians how fast the tumor growth rate is. METHODS: From patients with oropharynx squamous cell carcinoma treated by radiotherapy, the investigators selected comparable diagnostic CT-scan (DiCT) and radiotherapy planning CT-scan (RtCT). Tumor and pathological lymph node volumes were measured in order to calculate tumor progression. RESULTS: From the selection of 19 patients, the mean absolute tumor progression rate was 0.23 ± 0.2 cm3 /d and mean relative progression rate was 1.84 ± 1.64%/d. Mean tumor doubling time is 286 days (range 7-1282 days), demonstrating a wide range of tumor growth pattern. Significant tumor progression (>20%) between DiCT and RtCT was shown in 73% of patients, and 53% of the patients were seen a tumor progression of >50% within a mean waiting time of 42.1 days. Kaplan-Meier curves showed a non-significative link between fast progression tumors (>1%/d) and higher risk of recurrence (HR: 2.2; P = .23). CONCLUSIONS: Tumor progression can be assessed based on DiCT and RtCT. Treatment delay should be avoided at all cost. Different growth patterns were evidenced. For the fast-growing tumors subgroup, pejorative clinical outcomes were suggested. Prospective studies are needed to confirm a link between fast-growing tumors and higher risk for recurrence

Design and use of patient-specific atlases for radiotherapy planning of the head and neck region

International audienc

Anemia and neutrophil-to-lymphocyte ratio are prognostic in p16-positive oropharyngeal carcinoma treated with concurrent chemoradiation

Objectives: We investigated the prognostic value of pre-treatment hematological parameters in patients with p16-positive oropharyngeal squamous-cell carcinoma (OPSCC). Material and methods: Neutrophil count, lymphocyte count, neutrophil-to-lymphocyte ratio (NLR), and hemoglobin concentration measurement (Hb), were collected on day one of treatment. Endpoints were overall survival (OS) and progression-free survival (PFS). All patients were planned to receive concurrent chemoradiation. Staging were reviewed according to the recent AJCC 8th edition. Results: We included 167 patients in this study. In multivariate analyses, a smoking history > 30 packyears was associated with decreased OS (p = 0.009; HR, 3.4827) and PFS (p = 0.042; HR, 2.421); Hb 5 before treatment was associated with decreased OS (p = 0.042; HR, 2.945). Hemoglobin concentration and the NLR were not correlated (p = 0.577), nor anemia and an NLR > 5 (p = 0.167). Patients with an NLR > 5 had a significantly higher rate of disease recurrence (30.8% vs. 8.4%, p = 0.0299, RR = 3.922, 95% CI 1.351–11.386). Discussion: We found hemoglobin level and the NLR to be independent prognostic factors in p16-positive OPSCC patients. This approach is to be considered for further clinical investigations, and its significance in treatment decision-making should be further explored. Keywords: Oropharyngeal carcinoma, P16, Papillomavirus, Smoking, Hemoglobin, Neutrophil-to-lymphocyte rati

Computed tomography evaluation after induction chemotherapy for T3 laryngeal cancer: Does response correlate with vocal cord mobility?

International audienc