Proposition de sélection et délimitation des volumes cibles microscopiques péritumoraux dans les cancers de la cavité buccale et de l'oropharynx (aires ganglionnaires exclues)

Interpreting the patterns of local failure following postoperative volumetric-modulated arctherapy in oral cavity and oropharynx cancers: Impact of the different methods of analysis

PURPOSE

Intensity-modulated radiation therapy or volumetric-modulated arctherapy is nowadays the recommended radiation technique for the treatment of head and neck cancers. However, by providing a significant dose gradient between target volumes and organs at risk, there is a risk of target missing and thus recurrence in case of inadequate delineation. It is therefore necessary to determine the origin of these recurrences to improve clinical practice. Over the past years, different methods have been described for the analysis of recurrences. Using the patterns of failure of patients with oral cavity and oropharynx carcinoma, treated with postoperative volumetric-modulated arctherapy in our institution, the purpose of this work was to analyse the sites of local recurrences and to evaluate the disparity in the classification of recurrences when different methods were used.

MATERIAL AND METHODS

Between 2011 and 2019, 167 patients who underwent postoperative volumetric-modulated arctherapy for oral cavity or oropharyngeal cancers were included (60 and 40 % respectively). Two or three dose levels were prescribed (54Gy, 59.4/60Gy±66Gy). Local recurrence occurred in 17 patients (10.2 %). We assessed the patterns of local recurrences according to four methods: 1/ volume-based method using the volume overlap between the recurrence volume and initial target volumes; 2/ volume-based method of overlap between the recurrence volume and the 95 % treatment isodose; 3/ point-based method using the position of the barycentre of the recurrence volume; 4/ combined centroid method classifying recurrences according to both the initial target volumes and dose distribution. Each case was reviewed to make a clinical judgment on these classifications and assessed them as "appropriate", "possible", or "inappropriate".

RESULTS

For the volume-based method using overlap between the recurrence volume and the initial clinical target volume, this classification was clinically judged as inappropriate in 11 out of 17 cases (65 %). For the volume-based method using overlap between the recurrence volume and the 95 % prescribed isodose, this classification was clinically judged as appropriate in 15 out of 17 cases (88 %). For the point-based method, this classification was clinically judged as appropriate in 14 out of 17 cases (82 %). Thirteen out of 17 local recurrences had the same classification between this point-based method and the volume-based method of overlap between the recurrence volume and the 95 % prescribed isodose. For the combined centroid method, among 17 local recurrences nine were classified as type A, two as type B, two as type C, three as type D and one as type E. This classification was clinically judged as appropriate in 15 out of 17 cases (88 %). Only five out of 17 of the local recurrences were classified the same way according to the four different methods (29 %).

CONCLUSION

Recurrences that are "marginal" or "outfield" represent a major challenge for intensity-modulated radiation therapy/volumetric-modulated arctherapy quality assurance and improvement of delineation recommendations. To date, there are no published methods that give complete satisfaction.

Outcomes among oropharyngeal and oral cavity cancer patients treated with postoperative volumetric modulated arctherapy

Background

Presently, there are few published reports on postoperative radiation therapy for oropharyngeal and oral cavity cancers treated with IMRT/VMAT technique. This study aimed to assess the oncological outcomes of this population treated with postoperative VMAT in our institution, with a focus on loco-regional patterns of failure.

Material and methods

Between 2011 and 2019, 167 patients were included (40% of oropharyngeal cancers, and 60% of oral cavity cancers). The median age was 60 years. There was 64.2% of stage IV cancers. All patients had both T and N surgery. 34% had a R1 margin, 42% had perineural invasion. 72% had a positive neck dissection and 42% extranodal extension (ENE). All patients were treated with VMAT with simultaneous integrated boost with three dose levels: 66Gy in case of R1 margin and/or ENE, 59.4-60Gy on the tumor bed, and 54Gy on the prophylactic areas. Concomittant cisplatin was administrated concomitantly when feasible in case of R1 and/or ENE.

Results

The 1- and 2-year loco-regional control rates were 88.6% and 85.6% respectively. Higher tumor stage (T3/T4), the presence of PNI, and time from surgery >45 days were significant predictive factors of worse loco-regional control in multivariate analysis (p=0.02, p=0.04, and p=0.02). There were 17 local recurrences: 11 (64%) were considered as infield, 4 (24%) as marginal, and 2 (12%) as outfield. There were 9 regional recurrences only, 8 (89%) were considered as infield, and 1 (11%) as outfield. The 1- and 2-year disease-free survival (DFS) rates were 78.9% and 71.8% respectively. The 1- and 2-year overall survival (OS) rates were 88.6% and 80% respectively. Higher tumor stage (T3/T4) and the presence of ENE were the two prognostic factors significantly associated with worse DFS and OS in multivariate analysis.

Conclusion

Our outcomes for postoperative VMAT for oral cavity and oropharyngeal cancers are encouraging, with high rates of loco-regional control. However, the management of ENE still seems challenging.

Afatinib maintenance therapy following post-operative radiochemotherapy in head and neck squamous cell carcinoma: Results from the phase III randomised double-blind placebo-controlled study BIB2992ORL (GORTEC 2010-02)

OBJECTIVE

We investigated the efficacy and safety of afatinib maintenance therapy in patients with head and neck squamous cell carcinoma (HNSCC) with macroscopically complete resection and adjuvant radiochemotherapy (RCT).

METHODS

This French multicentric randomised phase III double-blind placebo-controlled study included adult patients with ECOG-PS≤2, normal haematological, hepatic and renal functions, and non-metastatic, histologically confirmed HNSCC of the oral cavity, oropharynx, larynx or hypopharynx, with macroscopically complete resection and adjuvant RCT (≥2 cycles of cisplatin 100 mg/m2 J1, J22, J43 and 66Gy (2Gy/fraction, 5 fractions/week, conventional or intensity modulated radiotherapy ≥60Gy). Randomised patients were planned to receive either afatinib (afa arm) or placebo (control arm (C)) as maintenance therapy for one year. Primary endpoint was disease free survival (DFS). A 15% improvement in DFS was expected at 2 years with afatinib (from 55 to 70%).

RESULTS

Among the 167 patients with resected HNSCC included in 19 cancer centres and hospitals from Dec 2011, 134 patients were randomised to receive one-year maintenance afatinib or placebo (afa:67; C:67). Benefit/risk ratio was below assumptions and independent advisory committee recommended to stop the study in Feb 2017, the sponsor decided premature study discontinuation, with a 2-year follow-up for the last randomised patient. 2y-DFS was 61% (95% CI 0.48-0.72) in the afatinib group and 64% (95% CI 0.51-0.74) in the placebo group (HR 1.12, 95% CI 0.70-1.80).

CONCLUSION

Maintenance therapy with afatinib compared with placebo following post-operative RCT in patients with HNSCC did not significantly improve 2y-DFS and should not be recommended in this setting outside clinical trials.

CLINICALTRIALS

gov identifier NCT01427478.

Radiotherapy for oral cavity cancers

Intensity modulated radiation therapy and brachytherapy are standard techniques of irradiation for the treatment of oral cavity cancers. These techniques are detailed in terms of indication, planning, delineation and selection of the volumes of interest, dosimetry and patients positioning control. This is an update of the guidelines of the French Society of Radiotherapy Correspondence.

Management and work-up procedures of patients with head and neck malignancies treated by radiation

Radiotherapy alone or in association with systemic treatment plays a major role in the treatment of head and neck tumours, either as a primary treatment or as a postoperative modality. The management of these tumours is multidisciplinary, requiring particular care at every treatment step. We present the update of the recommendations of the French Society of Radiation Oncology on the radiotherapy of head and neck tumours from the imaging work-up needed for optimal selection of treatment volume, to optimization of the dose distribution and delivery.

[Impact of reconstructive or minimal invasive surgery on the assessment of current definitions of postoperative clinical target volume for head and neck cancers]

Advances in the reconstructive surgery and minimally invasive endonasal endoscopic surgery of head and neck is poorly evaluated in terms of their impact on radiotherapy planning and outcomes. These surgical advances have resulted in reduced morbidity with equivalent or better tumor control. In the absence of a recommendation on how to delineate target volumes in patients with flaps or to consider margins after endoscopic endonasal surgery, radiotherapy practices are inevitably heterogeneous. Efforts are needed to increase the therapeutic index of postoperative radiotherapy in these situations. We analysed the rare existing literature and outlined a preliminary basis for a recommendation. Strengthening of multidisciplinarity to accurately define target volumes in these complex and relatively new situations, and "delineation concertation meetings" between radiologists, surgeons and radiation oncologists could probably contribute to improved outcomes.

[Individualization of dose and fractionation of radiotherapy for head and neck cancers]

Head and neck cancers comprise a variety of tumours depending on the sub-site, for which target volumes and the prescribed doses need to be individualized according to each patient's history and presentation. This article aims at describing the main factors involved in decision-making regarding dose and volume, as well as ongoing research. Contouring and treatment guidelines, use of altered fractionation, major prognostic factors, the role of Human papillomavirus and of functional imaging will be presented and discussed.

Volumetric and dosimetric comparison of two delineation guidelines for the radiation treatment of laryngeal squamous cell carcinoma

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The delineation of target volumes for Head and Neck IMRT is complex.

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There have been several approaches for the delineation of the primary tumor clinical target volume: the anatomical guidelines, the geometric guidelines and more recently the international guidelines.

Purpose

Three methods have been recently proposed for the delineation of the primary tumor clinical target volume (CTV-P) in Head and Neck Cancers: the anatomic method popularized in the French literature by Lapeyre et al. the geometric methods proposed by the DAHANCA group, and more recently the international guidelines promoted by Grégoire et al. integrating the latter two. The aim of this study was to perform a volumetric and dosimetric comparison of the French and the International consensus methods in laryngeal SCC.

Patients and methods

Two radiation oncologists independently delineated the high dose and low dose primary tumor CTV in four patients with T2 or T3 N0-M0 laryngeal SCC following either the so-called French guidelines or the International guidelines. For the 4 cases, the GTV was delineated by a single radiation oncologist. Nodal CTVs were delineated by one radiation oncologist for the 4 cases using International guidelines. Dose optimization was then performed with VMAT (MONACO version 5.11) using 6 MeV photons. Differences in target volumes and dose distributions in OARs and PTVs were then evaluated with various metrics such as the DICE Similarity Coefficient and the homogeneity index.

Results

Major differences were observed in the CTV delineation between the 2 delineation methods for the low dose volumes and to a lower extend for the high dose volumes. These differences translated into variations in dose distribution favoring the International guidelines for decreasing dose to various OARs. Such differences toned down when dose distribution on the primary tumors PTVs and nodal PTVs were combined.

Conclusion

This study demonstrated large differences in CTV delineation between the 2 delineation guidelines. Such differences translated into differences in dose distribution.

Intensity-modulated radiotherapy or volumetric-modulated arc therapy in patients with head and neck cancer: Focus on salivary glands dosimetry

BACKGROUND

Despite radiotherapy (RT) technical improvements, high salivary dysfunction rates are still reported in patients with head and neck squamous cell carcinoma (HNSCC). The purpose of the present study was to report salivary glands dosimetry with volumetric-modulated arc therapy (VMAT) and intensity-modulated RT (IMRT).

METHODS

Dosimetry of consecutive patients receiving IMRT or VMAT for proven HNSCC between 2007 and 2013 were retrospectively reviewed.

RESULTS

Data of 609 patients were studied. Mean dose, mean maximum dose, and mean percentage of salivary gland volume receiving at least 26 Gy (V26) of the contralateral parotid were 24.50 Gy (range, 0-70.4 Gy), 39.08 Gy (range, 0.38-76.45 Gy), and 40.92% (range, 0% to 100%), respectively. Mean and maximum dose on contralateral submandibular gland were 48.18 Gy (range, 0.19-70.73 Gy), and 61.25 Gy (range, 0-75.8 Gy), respectively.

CONCLUSION

Target volume coverage still has to be prioritized over organs at risk (OAR) sparing with new RT techniques. Submandibular glands are not sufficiently taken into account in guidelines. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1028-1034, 2016.

Real-life assessment of Volumetric Modulated Arc Therapy (VMAT) toxicity in Head and Neck Squamous Cell Carcinoma (HNSCC) treatment

CONCLUSION

The present study demonstrates the feasibility of VMAT in association with platin or cetuximab in HNSCC and reports VMAT-related acute and late toxicities for the first time.

OBJECTIVES

New radiotherapy techniques, such as Volumetric Modulated Arc Therapy (VMAT) were developed to lower RT-related toxicity. The aim of the present study was to investigate acute and late toxicities of head and neck squamous cell carcinoma (HNSCC) patients treated using VMAT.

METHODS

This study investigated retrospectively all patients with HNSCC who received VMAT in curative intent.

RESULTS

From 2010-2013, 150 patients were treated. Seventy-five patients (50%) received concurrent chemotherapy with VMAT, 51 patients (34%) received VMAT alone and 24 patients (16%) received concurrent cetuximab with VMAT. Mean delivered dose to planning target volume tumor (PTV T), high risk nodes (PTV HNR), low risk nodes (PTV LNR) and prophylactic nodes (PTV PN) were: 65.2 Gy, 62.9 Gy, 55.4 Gy, and 51.5 Gy, respectively. PTV mean coverages were higher than 96.5%. Most common grade 3/4 acute infield toxicities were mucosis (n = 28, 19%), dysphagia (n = 24, 16%), and dermatitis (n = 24, 16%). With a median follow-up of 16.0 months, most common late toxicities were dysphagia (n = 30, 20%), xerostomia (n = 28, 19%), larynx stiff (n = 17, 11%), and skin fibrosis (n = 14, 9%).

[Quality criteria in radiotherapy for head and neck cancers under the aegis of Head and Neck Intergroup]

The aim of radiotherapy is to deliver enough radiation to the tumor in order to achieve maximum tumour control in the irradiated volume with as few serious complications as possible with an irradiation dose as low as possible to normal tissue. The quality of radiotherapy is essential for optimal treatment and quality control is to reduce the bias in clinical trials avoiding possible major deviations. The assurance and quality control programs have been developed in large european (EORTC, GORTEC) and american cooperative groups (RTOG) of radiation oncology since the 1980s. We insist here on the importance of quality assurance in radiotherapy and the current status in this domain and the criteria for quality control especially for current clinical trials within GORTEC are discussed here.

IMRT: preliminary results in a series of advanced head-and-neck cancer patients

PURPOSE

To determine retrospectively 2-3 year local and regional control (LRC), free-of-disease survival (FDS) and overall survival (OS), as well as summarized toxicities in a group of 31 advanced head-and-neck cancer patients, treated at our institution between 2004 and 2011 with definitive IMRT low-dose concomitant boost, the majority of them with concurrent chemotherapy based on cisplatin. The results are also shown in the sub-group of nasopharyngeal cancer patients (NPC: 15 cases).

PATIENTS AND METHODS

Radiological basal and contrasted CT series, MR-CT or PET/CT fused images in the setup position with immobilization mask were registered in simulation therapy patients. Planed doses were: 70 Gy in primary tumor and positive nodes >1 cm; 63 Gy in high-risk areas of microscopic diseases +10 mm safety margin; and 56 Gy in low risk of diseases regional lymph nodes. Treatment was delivered using a Varian 2100 Clinac with sliding windows IMRT. Spinal cord doses were limited to a strict maximum of 45 Gy, and optimization aimed for mean doses in parotid glands below 26 Gy, especially in the contralateral parotid gland. Online DRR-portal X-ray comparison images were taken every day with a deviation module tolerance ≤3 mm.

RESULTS

The mean follow-up since IMRT was 34 months (interval: 8-89; median 31 months). Median follow-up in living patients was 22 months. The 2-year rate for global LRC was 64 %, for FDS 61 % and OS 77 %. For the NPC group after 2 years, LRC was 73 %, FDS 73 % and OS 93 %. The 3-year rates were similar. Seven patients died as a consequence of local and/or regional progression (mean time 10 months). Relapses were observed in eight patients (26 %), but only seven could be confirmed by biopsy (22.6 %; mean time to relapse: 8.6 months). Global acute mucositis was 61 % and chronic mucositis was shown in six cases which developed xerostomia (19 %) in the first control after IMRT, but 1 year later it was reduced to only four patients, two Grade 2 and two Grade 1.

CONCLUSIONS

No excessive, unwarranted toxicities were observed using concomitant low doses boost in IMRT. High rates of compliance to concurrent chemotherapy were achieved. Late xerostomia associated with this regime decreased 1 year after conclusion of treatment. The implementation of IMRT requires advances in imaging for better tumor delineation; otherwise the physician loses the advantage of dose modulation or faces a risk of geographical miss.

Intensity-modulated radiotherapy in head and neck cancer: results of the prospective study GORTEC 2004-03

BACKGROUND AND PURPOSE

In 2003, the French Authority for Health (HAS) recommended the use of intensity modulated radiotherapy (IMRT) in prospective trial before its routine use. The Oncology and Radiotherapy Group for Head and Neck Cancer (GORTEC) proposed to evaluate prospectively acute and late toxicities, locoregional control and overall survival for patients treated for head and neck cancer (HNC) with IMRT and bilateral neck irradiation.

MATERIALS AND METHODS

Between 2002 and 2008, 208 patients with HNC were treated with IMRT in 8 centres. There were 38 nasopharynx, 117 oropharynx, 25 pharyngo-larynx, 24 oral cavity and 4 unknown primary (28.5% stage I-II and 71% Stage III-IV). Ninety-three patients (46%) had postoperative IMRT and 78 patients (37.5%) received concurrent chemotherapy. The doses were 70 Gy to the gross tumour, 66 Gy to the high-risk postoperative sites and 50 Gy to the subclinical disease. Toxicities were graded according to the RTOG-EORTC scales.

RESULTS

The median follow-up was 25.3 months (range: 0.4-72 months). There were 29 local-regional failures: 24 were in-field, three were marginal and one was out-field. The two-year loco-regional control and overall survival were 86% and 86.7%, respectively. At 18 months, grade ≥ 2 xerostomia was 16.1%. A mean dose to the spared parotid below 28 Gy led to significantly less grade ≥ 2 xerostomia (8.5% vs 24%) with a relative risk of 1.2 [95% CI: 1.02-1.41, p = 0.03]. Grade ≥ 2 xerostomia increased by approximately 3% per Gy of mean parotid dose up to 28, Gy then 7% per Gy above 33 Gy.

CONCLUSIONS

IMRT for HN cancer seems to reduce late toxicities without jeopardising local control and overall survival.

Conservation of salivary function and new external head and neck radiation techniques

INTRODUCTION

New radiation therapy techniques seek to adapt dose distribution to three-dimensional tumor geometry, so as to deliver the lowest possible dose to normal tissue and at-risk organs. This is expected to enhance locoregional control and survival and to reduce complications and thereby improve quality of life. Post-radiation xerostomia significantly deteriorates quality of life.

MATERIAL AND METHODS

New external radiation techniques (such as intensity-modulated conformal radiation therapy, RapidArc VMAT arc therapy, tomotherapy, CyberKnife(®), protontherapy, use of carbon ions) applicable in ENT are reviewed.

RESULTS

Preliminary data show interesting results in terms of salivary function with highly conformal techniques.

CONCLUSION

In France, assessment is ongoing, financed under the Health Ministry's "Support for Expensive Innovatory Techniques" scheme (STIC [Soutien aux techniques innovantes coûteuses]), as routine use is growing rapidly.

Evidence-based radiation oncology in head and neck squamous cell carcinoma

BACKGROUND AND PURPOSE

Historically, radiation therapy (RT) has been an available treatment option for patients with early resectable head and neck squamous cell carcinoma (HNSCC) and the sole therapy for those with unresectable or inoperable disease. Recently, four noteworthy strategies have emerged for the improvement of therapeutic outcome in the curative treatment of HNSCC: they include the development of altered fractionation radiotherapy, integration of chemotherapy with radiotherapy, incorporation of intensity-modulated radiotherapy and the introduction of targeted biological therapy. These strategies are briefly reviewed in an effort to help interpret evidence-based data and to facilitate clinical-decision making in a clinical context.

MATERIALS AND METHODS

For patients with early stage HNSCC no level 1 study exists in which radiation therapy is compared with conservative surgery for the evaluation of local control or survival. Only evidence from prospective and retrospective cohort studies is available to evaluate the role external radiotherapy and/or brachytherapy currently play in limited disease. For patients with locally advanced HNSCC the recommendations to address the questions about better treatment in resectable and unresectable tumors are based on more than 100 randomized Phase III trials included in six meta-analyses on chemo-radiotherapy and/or altered fractionation. Data from phase II trials and cohort studies help interpret the advances in intensity-modulated radiotherapy.

RESULTS

External radiotherapy and/or brachytherapy are crucial treatment options in patients with early stage HNSCC. For patients with locally advanced HNSCC, where outcome with conventional radiotherapy is poor, meta-analyses and collective data showed that loco-regional control may be improved at high level of evidence by altered fractionation radiotherapy, chemo-radiotherapy with concomitant approach or association of selected hypoxic cell radiosensitizer with radiotherapy. For these patients, overall survival may be improved at high level of evidence by concomitant chemo-radiotherapy or hyperfractionated RT delivered with increased total dose. Also EGFR-inhibitors (cetuximab)-radiotherapy strategy offers at a lower level of evidence better loco-regional control and overall survival than radiotherapy alone. Chemo-radiotherapy programs can achieve an improved larynx-function preservation program without the risk of overall survival reduction, for patients with larynx or hypopharynx tumors who are candidates to radical surgery followed by radiotherapy. Recently, strong evidence for an improved outcome for high-risk resected patients has been shown by the use of adjuvant concomitant chemo-radiotherapy. Despite improved results, a higher severe toxicity has been largely evidenced with concomitant chemo-radiotherapy by reducing the gain in the therapeutic index with new treatment strategies. Three-dimensional conformal radiotherapy is the minimal standard of technique in HNSCC: however, as advances are promising, intensity-modulated radiotherapy should be largely implemented.

CONCLUSIONS

Stepwise improvements in HNSCC non-surgical therapy have shown favorable impact on loco-regional control and overall survival. However, despite hundreds of clinical trials in patients with advanced disease, there is no absolute consensus about patient selection for altered fractionation regimens, type of chemo-radiotherapy association, radiation or chemotherapy dose schedule. Nevertheless, many well-conducted clinical studies have expanded therapy options besides standard radiotherapy and have contributed to defining the evolving standard of care for patients with HNSCC.