Organes à risque en radiothérapie conformationnelle des tumeurs de la tête et du cou : aspect pratique de leur délinéation et des contraintes de dose

Radiotherapy of salivary gland tumours

Primary tumours of the salivary glands account for about 5 to 10% of tumours of the head and neck. These tumours represent a multitude of situations and histologies, where surgery is the mainstay of treatment and radiotherapy is frequently needed for malignant tumours (in case of stage T3-T4, nodal involvement, extraparotid invasion, positive or close resection margins, histological high-grade tumour, lymphovascular or perineural invasion, bone involvement postoperatively, or unresectable tumours). The diagnosis relies on anatomic and functional MRI and ultrasound-guided fine-needle aspiration for the diagnostic of benign or malignant tumors. In addition to patient characteristics, the determination of primary and nodal target volumes depends on tumor extensions and stage, histology and grade. Therefore, radiotherapy of salivary gland tumors requires a certain degree of personalization, which has been codified in the recommendations of the French multidisciplinary network of expertise for rare ENT cancers (Refcor) and may justify a specialised multidisciplinary discussion. Although radiotherapy is usually recommended for malignant tumours only, recurrent pleomorphic adenomas may sometimes require radiotherapy based on multidisciplinary discussion. An update of indications and recommendations for radiotherapy for salivary gland tumours in terms of techniques, doses, target volumes and dose constraints to organs at risk of the French society for radiotherapy and oncology (SFRO) was reported in this article.

Observer variation in the delineation of organs at risk for head and neck radiation therapy treatment planning: a systematic review protocol

REVIEW QUESTION

The objective of this review is to examine inter- and intra-observer agreement and reliability in the delineation of head and neck organs at risk (OAR) as part of the radiation therapy treatment planning process.More specifically, the objectives are to identify.

[Nasal cavity and paranasal sinus cancer]

The nasal cavity and parasinusal cancer are rare (10% of tumors of the head and neck) and are mainly represented by squamous cell carcinoma of the nasal cavity or the maxillary sinus and adenocarcinoma of the ethmoid sinus (occupational disease, wood dust). The most common clinical sign is nasal obstruction, but tumors can also manifest as rhinorrhea and/or epistaxis (usually unilateral signs). A magnetic resonance imaging of the facial structure is systematic for staging before treatment. The treatment consists of a first surgery if the patient is operable with a resectable tumor. If it is not the case, the treatment consists of radiotherapy (RT) associated with chemotherapy (CT) according to the initial data (T3/T4 or N+). After first surgery, RT is indicated (except T1N0 with complete resection) associated with a CT based on postoperative data (capsular effraction or incomplete resection). Lymph node irradiation is considered case by case, but is indicated in any nodal involvement. RT must be an intensity modulated RT (IMRT), static or dynamic, and must be imagery guided (IGRT). According to ICRU 83, doses to organs at risk and target volumes must be carried. Finally, after a post-treatment baseline imaging between 2 and 4 months, monitoring will be alternated with the ENT surgeon every 2 or 3 months for 2 years, then every 4 to 6 months for 5 years.

[Radiotherapy of a glioma in a pregnant woman: evaluation of the foetal dose in conformational 3D or intensity-modulated]

The purpose was to assess three treatments planning techniques including one in intensity-modulated radiation therapy (IMRT) for cerebral irradiation of pregnant woman, in order to limit the dose delivered to the foetus. The treatment provided was 60 Gy to the planning target volume. Estimated foetal dose was measured using an anthropomorphic phantom, on the upper and middle part of the uterus. The first plan consisted in four beams in conformational technique delivered from a Varian accelerator with a 120 leaves collimator, the second one used non-coplanar fields and the third one assessed IMRT. With the conformational technique, the dose at the upper part of the uterus was 8.3 mGy and 6.3 mGy at the middle part. The dose delivered to the foetus was higher with the non-coplanar fields. In IMRT, the dose at the upper part of the uterus was 23.8 mGy and 14.3 mGy at the middle part. The three plans used 6 MV X-rays. Because of the use of leaves and non-coplanar fields, IMRT does not seem to be the optimal technique for the treatment of pregnant woman. However, the dose delivered to the foetus remains low and below the dose of 100 mGy recommended by the International Commission of Radiological Protection. It seems possible to consider the use of this technique for a better sparing of organs at risk for the mother.

[Re-evaluation of 191 larynx cancer surgeries according to the Open Partial Horizontal Laryngectomies classification proposed by European Laryngological Society working committee in 2014]

AIM

of study was to present material of open partial horizontal laryngectomies (OPHL) in T1b, T2 and T3 larynx cancer treatment in single tertiary referral institution.

MATERIAL AND METHODS

Retrospective analysis of operating protocols in patients treated in Poznań ENT University Department between 2000-2012 with glottis (T1b - 185, T2 - 185, T3 - 231) and supraglottis tumors (T1 - 80, T2 - 104, T3 - 206), potentially available for organ preservation treatment. Transoral laser microsurgery, OPHL, radiotherapy and total laryngectomy were treatment options in 210, 191, 271 and 326 patients respectively. OPHL was applied in glottic tumors: 21 - T1b, 103 - T2, 27 - T3 and in supraglottic tumors: 4 - T1, 29 - T2. All procedures were re-evaluated acc. to European Laryngogical Society working committee on nomenclature new classification presented in 2014.

RESULTS

There was no discrepancies in supraglottic laryngectomies (4 cases), classified as OPHL Typ I. All the rest: 84 transglottic, 96 supracricoid with CHEP and 7 supracricoid with CHP laryngectomies were re-classified into Typ II (172) and Type III (15) OPHL. Thus, revision of inferior incision changed classification of procedure into supratracheal laryngectomy in 15 cases. Transglottic laryngectomies, in which upper part of thyroid cartilage was preserved and crito-thyreo-pexy was performed (84 pts), have not been distinguished any more. In 7 cases superior incision included epiglottis; thus 165 patients were distinguished as Typ II a and 7 patients as Typ IIb OPHL. The most pronounced difference was stated in description of structures additionally included into surgical specimen: arytenoid (+ARY) in 24, crico-arytenoid-unit (+CAU) in 5 and piriform sinus (+PIR) in 17 cases; none had the base of tongue (+BOT) resected.

CONCLUSIONS

In 36/191 additional structures and in 15/191 the cricoid ring resection was re-evaluated and pointed out. All these data were available retrospectively in the operating protocols but not pronounced in surgery headlines. Thanks to the univocal, simple new classification all operation details can be included into operation title.