Réirradiation des carcinomes de la tête et du cou

Initial experience of hypofractionated radiation retreatment with true beam and flattening filter free beam in selected case reports of recurrent nasopharyngeal carcinoma

AIM

To show our preliminary experience in using TrueBeam with RapidArc technology and FFF beam for stereotactic re-irradiation of nasopharyngeal carcinoma.

BACKGROUND

Thanks to new advanced techniques, as well as intensity modulated radiation therapy, it is possible to approach head and neck recurrences in selected patients. Volumetric Modulated Arc Therapy (VMAT) in its RapidArc(®) format, permits to reduce significantly the time to deliver complex intensity modulated plans, allowing to treat hypofractionated regimes within a few minutes. With TrueBeam it is possible to perform photon beams without usage of the flattening filter. It seems possible to expect a reduction of out-of-field dose when flattening filter free (FFF) beams are used. While research into the physics domain for FFF beams is increasing, there are very few clinical data where FFF beams are applied in clinical practice.

MATERIALS AND METHODS

We present here the cases of 4 patients with local or regional recurrence of nasopharyngeal carcinoma. All patients were treated using TrueBeam with RapidArc technology and FFF beam for stereotactic hypofractionated re-irradiation.

RESULTS

All patients concluded SBRT and showed good tolerability. During follow-up, complete response at imaging evaluation (PET and/or MRI) for all treated patients was documented.

CONCLUSIONS

Our preliminary experience using TrueBeam with RapidArc technology and FFF beam for stereotactic hypofractionated re-irradiation of nasopharyngeal carcinoma was safe and effective in all 4 treated patients. Longer follow-up and a larger population of study is needed to confirm these promising results.

[Reirradiation for recurrent or second primary head and neck cancers]

Recurrences or second primary head and neck cancers meant, for a long time, therapeutic dead ends. Surgery was the standard treatment, but could only be achieved in 25% of the patients. The GETTEC-GORTEC (99-01) randomized trial showed that radiochemotherapy improved disease-free survival for a highly selected population. For inoperable patients, three options can be discussed: supportive care only, chemotherapy or radiotherapy with or without chemotherapy. The EXTREME protocol showed that combining platinum, 5FU and cetuximab improved overall survival for recurrent or metastatic forms. This is certainly the best option for advanced forms, which are not accessible to radiotherapy. Concerning radiotherapy, only one randomized trial compared chemoradiotherapy to chemotherapy alone using methotrexate. The overall survival, the main objective in this study, was not improved, however, the enrollment was incomplete and included many advanced stage tumors. Other articles are based on Vokes' initial work of radiochemotherapy delivered in split-course over a period of 11 weeks. All conventional and conformational radiotherapy series showed improved local control and disease-free survival rates, but at the expense of acute and late toxicities demanding a drastic patients selection. New radiotherapy techniques such as intensity modulated radiotherapy (IMRT) and stereotactic body radiotherapy (SBRT) have reduced toxicities with a likely oncological results improvement, offering treatments which are spread over six to seven weeks for IMRT and two weeks for SBRT. The better treatment tolerance allows an increasing number of eligible patients. The main future objective will be to define the specific IMRT and SBRT indications.