ESTRO 2022

Session Item

Monday

May 09

10:30 - 11:30

Poster Station 2

20: Head and neck

Chair: Annett Linge, Germany

Session Code: 3280

Session Type: Poster Discussion

Track: Clinical

Dose volume correlates of mouth opening reduction after radiotherapy for HNC: comprehensive analysis

Mariangela Massaccesi, Italy

Presentation Number: PD-0827

Abstract

Abstract Title:

Dose volume correlates of mouth opening reduction after radiotherapy for HNC: comprehensive analysis

Authors:

Mariangela Massaccesi¹, Valentina Fuga¹, Nicola Dinapoli¹, Cosimo Rupe², Michela Olivieri¹, Francesco Beghella Bartoli¹, Ciro Mazzarella¹, Marco Panfili³, Rosalinda Calandrelli³, Stefano Settimi⁴, Carlo Lajolo², Maria Antonietta Gambacorta¹, Francesco Miccichè¹

¹Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Radiation Oncology Department, Rome, Italy; ²Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Head and Neck Department, Rome, Italy; ³Fondazione Policlinico Universitario Agostino Gemelli IRCCS, UOC Radiologia e Neuroradiologia - Polo Diagnostica per immagini, radioterapia, oncologia ed ematologia, Area diagnostica per immagini, Rome, Italy; ⁴Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Institute of Otolaryngology, Head and Neck Surgery, Rome, Italy

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Purpose or Objective

In this observational study we observed the relationship between the variation of mouth opening over time and the dose to the mastication structures in patients with head and neck cancer (HNC) treated with radical radiotherapy.

Material and Methods

Mouth opening of HNC patients who underwent radiotherapy (RT) +/- concurrent chemotherapy with radical intent between 2017 and 2021 was prospectively measured prior to RT (baseline) and at regular follow-up appointments at 15 and 30 days during RT and 3 and 6 months post-RT.

Clinical factors (Sex, Age, Diabetes, Smoke, Stage, Anatomical site, concurrent chemotherapy, previous surgery) have been investigated with respect to the decrease of mouth opening.

The Histogram Dose-Volume (DVH) of each mastication structure (mandibular condyle, choroid process, intercondylar notch, glenoid rim, masseter, temporal, lateral and medial pterygoid muscles) was extracted and data were analyzed using DVHs sum for paired structures or the only remaining structures in case of single structure (after surgery). The outcome was evaluated as the maximum decrease of mouth opening measure.

Multiple linear regression models were computed, considering multiple VDoses for each DVH sum, at 0.1 Gy step. The best performing value of Vdose for each structure was selected according to the maximum value of adjusted R².

In multivariate analysis, the cross correlation among the selected VDose to each mastication structure was tested using the Pearson correlation test.

Results

One hundred and four consecutive patients were included (mean age 63 years, range 25-87), of which 68 were males and 36 females.

Among clinical factors, only the age was found to be correlated to the outcome.

Table 1 reports the performing value of Vdose for each mastication structure and its significance level.

Multivariate analysis showed that V42.3 Gy of the coronoid process and the V50.3 Gy of the medial pterygoid muscles were not significantly cross related.

Conclusion

High radiation doses to the choroid process (V42 Gy) and medial pterygoid muscles (V50 Gy) correlates with mouth opening reduction after radiotherapy