Particle Therapy Using Protons or Carbon Ions for Unresectable or Incompletely Resected Bone and Soft Tissue Sarcomas of the Pelvis

Publication date: Available online 22 February 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Yusuke Demizu, Dongcun Jin, Nor Shazrina Sulaiman, Fumiko Nagano, Kazuki Terashima, Sunao Tokumaru, Takashi Akagi, Osamu Fujii, Takashi Daimon, Ryohei Sasaki, Nobukazu Fuwa, Tomoaki Okimoto
PurposeTo 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.MethodsBetween 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).ResultsThe 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).ConclusionsParticle 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.

Teaser

Ninety-one patients with no metastases from histologically-proven unresectable or incompletely resected bone and soft tissue sarcomas of the pelvis were treated with particle therapy using protons (52 patients) or carbon ions (39 patients). These treatments provided good overall survival, progression-free survival, and local control, although late skin and peripheral nerve toxicities were observed. Particle therapy was effective for unresectable or incompletely resected pelvic bone and soft tissue sarcomas.


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