Worse Outcomes for Head and Neck Rhabdomyosarcoma Secondary to Reduced-dose Cyclophosphamide.

Related Articles

Worse Outcomes for Head and Neck Rhabdomyosarcoma Secondary to Reduced-dose Cyclophosphamide.

Int J Radiat Oncol Biol Phys. 2018 Nov 30;:

Authors: Casey DL, Wexler LH, Wolden SL

Abstract
PURPOSE: Recent trends including the use of proton therapy and administration of reduced-doses of cyclophosphamide have been adapted in head and neck rhabdomyosarcoma (HN-RMS) to reduce late morbidity. Our primary goal was to analyze local control and survival outcomes after photon versus proton irradiation in pediatric patients with HN-RMS, with the secondary goal of analyzing the effect of cyclophosphamide dose on disease outcomes.
METHODS AND MATERIALS: This single-institution cohort study was comprised of 76 pediatric HN-RMS patients treated with definitive chemoradiation from 2000 to 2018. Fifty-one patients (67%) received intensity-modulated photon radiation therapy (IMRT) and 25 (33%) proton therapy.
RESULTS: Local failure (LF) at 2 years was 12.5% for parameningeal RMS and 0% for orbital RMS and other head and neck sites (p=0.24). Patients treated with protons were more likely to have received reduced-dose cyclophosphamide (p<0.0001). The 2-year LF was 7.9% in the IMRT cohort versus 14.6% in the proton cohort (p=0.07), with no difference in survival outcomes. Cumulative cyclophosphamide dose was significantly associated with 2-year LF: 0% for cumulative dose of >20g/m2 versus 15.3% for ≤20g/m2 (p=0.04). Among parameningeal RMS patients (n=59), both cumulative cyclophosphamide dose and dose-intensity were associated with local failure (p=0.01). There was a trend toward worse event-free survival for parameningeal RMS patients who received reduced-dose-intensity cyclophosphamide (59.2% versus 70.6%, p=0.11).
CONCLUSIONS: Both dose-intensity and cumulative cyclophosphamide dose seem to play an important role in achieving local control for HN-RMS patients treated with either protons or photons. Longer follow-up is needed to further assess disease outcomes with proton therapy.

PMID: 30508617 [PubMed - as supplied by publisher]

from PubMed via alexandrossfakianakis on Inoreader https://ift.tt/2rpK5iB