Impact of head and neck cancer adaptive radiotherapy to spare the parotid glands and decrease the risk of xerostomia

被引：122

作者：

Castelli, Joel ^{[1
,2
,3
]}

Simon, Antoine ^{[2
,3
]}

Louvel, Guillaume ^{[1
]}

Henry, Olivier ^{[1
]}

Chajon, Enrique ^{[1
]}

Nassef, Mohamed ^{[2
,3
]}

Haigron, Pascal ^{[2
,3
]}

Cazoulat, Guillaume ^{[2
,3
]}

Ospina, Juan David ^{[2
,3
]}

Jegoux, Franck ^{[4
]}

Benezery, Karen ^{[5
]}

de Crevoisier, Renaud ^{[1
,2
,3
]}

机构：

[1] Ctr Eugene Marquis, Dept Radiotherapy, F-35000 Rennes, France

[2] Univ Rennes 1, LTSI, F-35000 Rennes, France

[3] INSERM, U1099, F-35000 Rennes, France

[4] CHU Pontchaillou, F-35000 Rennes, France

[5] Ctr Antoine Lacassagne, F-06100 Nice, France

来源：

RADIATION ONCOLOGY | 2015年 / 10卷

关键词：

Head and neck cancer; Anatomical variation; Adaptive RT; Xerostomia; INTENSITY-MODULATED RADIOTHERAPY; STAGE NASOPHARYNGEAL CARCINOMA; SQUAMOUS-CELL CARCINOMA; RADIATION-THERAPY; COMPLICATION PROBABILITY; VOLUME; IMRT; STRATEGIES; REGISTRATION;

D O I：

10.1186/s13014-014-0318-z

中图分类号：

R73 [肿瘤学];

学科分类号：

100214 [肿瘤学];

摘要：

Background: Large anatomical variations occur during the course of intensity-modulated radiation therapy (IMRT) for locally advanced head and neck cancer (LAHNC). The risks are therefore a parotid glands (PG) overdose and a xerostomia increase. The purposes of the study were to estimate: - the PG overdose and the xerostomia risk increase during a "standard" IMRT (IMRTstd); - the benefits of an adaptive IMRT (ART) with weekly replanning to spare the PGs and limit the risk of xerostomia. Material and methods: Fifteen patients received radical IMRT (70 Gy) for LAHNC. Weekly CTs were used to estimate the dose distributions delivered during the treatment, corresponding either to the initial planning (IMRTstd) or to weekly replanning (ART). PGs dose were recalculated at the fraction, from the weekly CTs. PG cumulated doses were then estimated using deformable image registration. The following PG doses were compared: pre-treatment planned dose, per-treatment IMRTstd and ART. The corresponding estimated risks of xerostomia were also compared. Correlations between anatomical markers and dose differences were searched. Results: Compared to the initial planning, a PG overdose was observed during IMRTstd for 59% of the PGs, with an average increase of 3.7 Gy (10.0 Gy maximum) for the mean dose, and of 8.2% (23.9% maximum) for the risk of xerostomia. Compared to the initial planning, weekly replanning reduced the PG mean dose for all the patients (p < 0.05). In the overirradiated PG group, weekly replanning reduced the mean dose by 5.1 Gy (12.2 Gy maximum) and the absolute risk of xerostomia by 11% (p < 0.01) (30% maximum). The PG overdose and the dosimetric benefit of replanning increased with the tumor shrinkage and the neck thickness reduction (p < 0.001). Conclusion: During the course of LAHNC IMRT, around 60% of the PGs are overdosed of 4 Gy. Weekly replanning decreased the PG mean dose by 5 Gy, and therefore by 11% the xerostomia risk.

引用

页数：10

共 40 条

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Quantification of volumetric and geometric changes occurring during fractionated radiotherapy for head-and-neck cancer using an integrated CT/linear accelerator system [J].