Role of reirradiation in the management of relapses local nasopharyngeal cancer
Purpose/Objective
The local control rate of nasopharyngeal carcinomas has increasingly increased
since the routine use of intensity-modulated conformal radiotherapy.
The treatment of local recurrences is essentially based on reirradiation; but it is limited
by the doses previously received by the organs at risk in series.
Evaluate the Efficacy and Toxicity of Reirradiation of Local Relapses of Nasopharyngeal Carcinoma
Material/Methods
This is a retrospective study, including 12 patients re-irradiated at the National Institute
of Oncology in Rabat for a local or locoregional relapse between 2015 and 2020.
Results
Among 600 irradiated patients, 12 patients had a local or locoregional recurrence for which
they received intensity-modulated reirradiation. The average age of patients at the time of
initial diagnosis was 40.8 years (range 22 to 52 years). The tumor was initially classified
according to the AJCC 2017 classification stage II, stage III and stage IV in 2 cases (16%), 4
cases (34%) and 6 cases (50%) respectively. Initial treatment was based on neoadjuvant
chemotherapy followed by concomitant chemoradiotherapy in 9 patients (75%) and
concomitant chemoradiotherapy alone in 3 patients (30%). Initial irradiation was using a
conventional three-dimensional technique having delivered a total dose of 70 Gy at a rate
of 2 Gy per session. All patients were in complete remission. The average time to local
relapse was 7 years (range: 3 years – 10 years). The diagnosis was confirmed by a
pathological study in all patients. Recurrence was classified stage II, stage III and stage IV
respectively in 3 cases (25%), 5 cases (41%) and 4 cases (33%).
Therapeutically, 5 patients (50%) received neoadjuvant chemotherapy followed by
concomitant chemoradiotherapy; 6 patients (90%) received radiochemotherapy
concomitant therapy alone and one patient received exclusive radiotherapy. The reirradiation
was with intensity modulation by Arc Therapy, having delivered a total dose of 60 Gy in all
patients at a rate of 2Gy per fraction.
After a mean follow-up of 19 months (range: 10 months – 34 months), seven patients were
in complete remission; two died of the disease after an average follow-up of 10 months
and three patients were lost to follow-up. The late toxicity of reirradiation was an increase
in hearing toxicity (grade 3 becoming grade 4) in 4 patients, trismus
in two patients and cervical fibrosis in two patients.
Conclusion
Reirradiation is the only salvage treatment for recurrences of nasopharyngeal
carcinomas, precisely conformal radiotherapy with intensity modulation which makes
it possible to deliver sufficient doses to the tumor volume while sparing the organs at
risk already irradiated; however, given the associated toxicity,
patients must be rigorously selected.
