Particle Therapy Using Protons or Carbon Ions for Unresectable or Incompletely Resected Bone and Soft Tissue Sarcomas of the Pelvis
Menée au Japon à partir de données portant sur 91 patients atteints d'un sarcome non résécable ou partiellement résécable des os ou des tissus mous de la région du bassin (âge médian des patients : 67 ans ; durée médiane de suivi : 32 mois), cette étude évalue l'efficacité, du point de vue du contrôle local de la maladie et des taux de survie à 3 ans, et la toxicité d'une radiothérapie par ions carbone et d'une protonthérapie
Purpose : To retrospectively analyze the treatment outcomes of particle therapy using protons or carbon ions for unresectable or incompletely resected bone and soft tissue sarcomas (BSTSs) of the pelvis. Methods : Between May 2005 and December 2014, 91 patients with non-metastatic histologically-proven unresectable or incompletely resected pelvic BSTSs were treated using particle therapy with curative intent at XXXX. The particle therapy used protons (52 patients) or carbon ions (39 patients). All patients received a dose of 70.4 Gy (relative biological effectiveness) in 32 fractions (55 patients) or 16 fractions (36 patients). Results : The median patient age was 67 years (range: 18–87 years). The median planning target volume (PTV) was 455 mL (range: 108–1,984 mL). The histological types were chordoma (53 patients), chondrosarcoma (14 patients), osteosarcoma (10 patients), malignant fibrous histiocytoma/undifferentiated pleomorphic sarcoma (5 patients), and others (9 patients). Eighty-two patients had a primary tumor, and 9 patients had a recurrent tumor. The median follow-up was 32 months (range: 3–112 months). The 3-year rates of overall survival (OS), progression-free survival (PFS), and local control (LC) were 83%, 72%, and 92%, respectively. A Cox proportional-hazards model revealed that chordoma histology and a PTV of ≤500 mL were significantly associated with better OS, while a primary tumor and a PTV of ≤500 mL were significantly associated with better PFS. Ion type and number of fractions were not significantly associated with OS, PFS, or LC. Late grade ≥3 toxicities were observed in 23 patients. Compared to the 32-fraction protocol, the 16-fraction protocol was associated with significantly more frequent late grade ≥3 toxicities (18/36 versus 5/55; P < 0.001). Conclusions : Particle therapy using protons or carbon ions was effective for unresectable or incompletely resected pelvic BSTSs, and the 32-fraction protocol was effective and relatively less toxic. Nevertheless, a longer follow-up is needed to confirm these results.
http://www.redjournal.org/article/S0360-3016(17)30408-X/fulltext