Radiation Oncology/Sarcoma/Chondrosarcoma

Epidemiology Heterogenous group of tumors forming cartilagenous tumors If there is evidence of osteoid or bone production, the tumor is classified as an osteosarcoma Median age in 3rd to 4th decades; 50% in patients >40 Distribution: Pelvis (31%) Femur (21%) Shoulder girdle (13%) Diaphyseal portion of long bones Skull base - can be a clinical challenge, since frequently limited resectability Clinical presentation Pain is a sign of active growth, and is an ominous sign Otherwise symptoms depend on location Radiographic presentation Two distinct patterns Small, well-defined lytic lesion within a narrow zone of transition, with surrounding sclerosis No sclerotic border Endosteal scalloping is a key sign of malignancy Histologic Subtypes Central (76%) Peripheral Mesenchymal: high rate of metastatic spread Dedifferentiated: may resemble a fibrosarcoma or osteosarcoma; highly aggressive Clear cell: slow growing, multiple local recurrences Most tend to be low grade Treatment Overview Treatment is maximum surgical resection while minimizing functional disability. Decompression of visual and other neural structures, blood vessels, and brain stem should be achieved. Adjuvant RT typically indicated in cases of incomplete resection No effective chemotherapy at this time Radiotherapy MDACC; 1982 (1961-76) 6806219 -- "Fifteen year radiotherapy experience with chondrosarcoma of bone." (McNaney D, Int J Radiat Oncol Biol Phys. 1982 Feb;8(2):187-90.) Retrospective. 20 pts treated with curative intent (11, definitive RT; 3 post-op RT; 3 RT + chemo; 3 recurrent after surgery). RT doses 4000 - 7000 cGy (1000 / wk) using photons and/or neutrons. Sites: 13 pelvis, 4 spine, 2 distal femur, 1 H&N Subgroups: RT alone: 5 of 11 (45%) alive without progressive local disease (at median 30 months). OS 54% at 30 months. Median dose 6600 cGy. 4 pts treated with mixed photons + neutrons. The rest treated with photons alone. Post-op: 2 of 3 alive w/o progressive disease at 44 and 52 months. Dose range 4500-6000 cGy. RT+chemo w/o surgery: 2 of 3 alive w/o progressive disease at 15 and 29 months. Dose range 4000-6400 cGy. RT for recurrence: 2 of 3 alive w/o progressive disease at 19 and 77 months. Dose range 6200-7000 cGy. 11 of 20 (55%) show no evidence of progressive local disease at median 30 months. Two additional patients surgically salvaged after RT failure; overall survival rate 65% (13/20). Severe complications in 5 pts: 3 foot drop, 1 subcutaneous fibrosis, 1 eye enucleation. Princess Margaret; 1980 (1958-76) 7379008 -- "Radiotherapy of chondrosarcoma of bone." (Harwood AR, Cancer. 1980 Jun 1;45(11):2769-77.) Retrospective. 31 pts (20 pts - definitive RT, 11 pts - palliative). Conclusion: "Our experience shows quite clearly that chondrosarcoma of bone can no longer be classified as a radioresistant tumor." Proton Beam Radiotherapy Orsay; 2008 (France)(1996-2006) 18440726 -- "Proton therapy in pediatric skull base and cervical canal low-grade bone malignancies." (Habrand JL, Int J Radiat Oncol Biol Phys. 2008 Jul 1;71(3):672-5. Epub 2008 Apr 25.) Retrospective. 30 children with chordoma (n=26), chondrosarcoma (n=3), and chondroma (n=1). Location in skull base (n=13), skull base with extension to cervical canal (n=12), or cervical canal (n=1). Median age 13.5 years. Surgery followed by photon/proton therapy. Mean total dose 68.4 CGE (54.6-71); mean photon dose 37.4 Gy (30.6-45), mean proton dose 32.1 CGE (20-70.2). F/U 2.2 years Outcome: Local control chordoma 21/26 (81%), chondrosarcoma 3/3 (100%), chondroma 1/1 (100%). 5-year PFS chordoma 77%, chondrosarcoma 100% Toxicity: Grade 3 auditory toxicty 1 patient, Grade 2 pituitary failure 7 patients Conclusion: Well tolerated, excellent local control MGH, 1999 - 10555005 -- "Chondrosarcoma of the base of the skull: a clinicopathologic study of 200 cases with emphasis on its distinction from chordoma." Rosenberg AE et al. Am J Surg Pathol 1999 Nov;23(11):1370-8. 200 pts w/ chondrosarcoma tx'd w/ proton/photon radiation as a portion of tx regimen. Pts received 64.2-79.6 CGE (median 72 CGE). 5 yr local control 99%, 10 yr local control 98%. 5 and 10 yr dz specific survival rate both 99%. Conclusion: excellent prognosis w/ aggressive management in contrast to chordoma which has substantially worse prognosis. Loma Linda, 1999 (1992-98) - 10470818 -- "Proton radiation therapy for chordomas and chondrosarcomas of the skull base." Hug EB et al. J Neurosurg. 1999 Sep;91(3):432-9. 25 chondrosarcomas (and 33 chordoma) pts tx'd w/ proton beam irradiation after maximal surgery. Dose range of 64.8-79.2 CGE. 5yr OS for chondrosarcoma was 100%. 5yr local control for chondrosarcoma was 92%. Control rates were influenced by brainstem involvement and tumor volume. Chondrosarcoma with better outcomes than chordoma. Netherlands, 1998 - 9667567 -- "Intracranial chondrosarcoma: review of the literature and report of 15 cases." Korten AG et al. J Neurol Neurosurg Psychiatry. 1998 Jul;65(1):88-92. Reviewed all cases of intracranial chondrosarcoma in the Netherlands and available data in the literature. Found surgery alone to have a 53% local recurrence rate w/ average time to recurrence of 32 months. Adjuvant charged particle irradiation had local control of 78-91% at 5 yrs, and 5 yr OS of 83-94%.