The primary treatment of chordoma is wide surgical resection (Fig. 17.7) and the goal of surgery is wide excision with negative margins. This is sometimes an unrealistic goal due to the difficult locations of this tumor, especially clival or skull-base tumors, or high-level sacral tumors. Nonetheless, multiple studies have demonstrated a correlation between recurrence rate and positive margins (Boriani et al. 2006; Bilsky et al. 2004; Fuchs et al. 2005). Boriani et al. (2006) demonstrated that in the absence of negative margins, the recurrence rate was approximately 70 and 100 % following radiation treatment alone, palliative care, or intralesional excision. When wide excision with adequate margins was obtained, there was a recurrence rate of 20 % diagnosed at 56–94 months post surgery. In a group of patients all treated with en bloc excision for sacrococcygeal chordoma, Fuchs et al. (2005) demonstrated an overall survival rate of 74 % at 5 years, 52 % at 10 years, and 47 % at 15 years. Interestingly, the survival rate in this group of patients was significantly higher when negative margins were obtained, and the most significant predictor of survival was a wide margin. The size of the tumor, level of resection, and surgical approach did not significantly impact the survival rate.

Sacral resection can be achieved using either a combined anterior-posterior approach or a posterior-only approach. Generally, for tumors with significant anterior soft tissue mass, or high sacral resections, there is a benefit to first ­performing an anterior dissection prior to resection from a posterior approach. This was best shown by Fuchs et al. (2005) in a series from the Mayo Clinic in which 81 % of patients with combined anterior-posterior approaches had negative margins. Based on these results, it was recommended that a combined dual approach should be used for any patients with tumors above S3.

After chordoma resection, functional deficit is dependent on the extent of the surgery. To maximize survival rates and to prepare patients for postoperative deficits, careful preoperative planning and discussion of possible neurological problems is important. Whether partial or total sacrectomy is performed, usually one or more sacral nerve roots will need to be sacrificed, leading to a motor deficit, sensory impairment, sphincter loss, and/or sexual dysfunction. Fourney et al. (2005) developed a classification system describing the type of sacrectomy based on the level of nerve root sacrificed, as opposed to the site of the osteotomy. The type of resection was defined as low, middle, high sacral amputation, total sacrectomy, or hemicorporectomy. Sacral amputations are considered “low” if at least one S4 nerve root is sacrificed, “middle” if at least one S3 nerve root is sacrificed, and “high” if at least one S2 nerve root is sacrificed. If neither S1 nerve root can be spared, then the required amputation is a total sacrectomy. A hemicorporectomy (translumbar amputation) is performed when the tumor extends to the lumbar spine. Functionally, if both S2 roots can be spared, half of the patients or more will have normal bowel and bladder function. If an S3 root is preserved as well, these odds improve. However, perineal numbness and sexual dysfunction are still commonly observed, the latter more common in the elderly. If one S2 root is sacrificed, typically some amount of voluntary control is compromised. Sacrifice of one S1 or S2 nerve root and all lower roots, as seen in high sacral amputations, commonly leads to urinary or fecal incontinence leading to the possibility for the need of indwelling urinary catheters, intermittent straight catheterization, colostomy, or digital stimulation to defecate (Hulen et al. 2006). Loss of ankle plantar flexion is also seen after the loss of the S1 nerve root.

If resection of the lumbar spine or pelvis is required at the time of sacral amputation, spinopelvic instability must be assessed. If instability is observed, then instrumentation is warranted (Fig. 17.8). In general, about 50 % of the sacroiliac joint can be removed before instability is seen, provided the ligamentous structure of the remainder of the joint is preserved (Gunterberg et al. 1976; Stener and Gunteberg 1978). Chordomas of the mobile spine are also best treated with resection with negative margins. To achieve this goal, a total spondylectomy is the surgery of choice and is generally done through a combined anterior and posterior approach (Boriani et al. 2006).

In the skull base, despite multiple surgical approaches, wide resection surgery is rarely possible (Singh et al. 2010; Holzmann et al. 2010). Nonetheless, radiation therapy is effective in managing microscopic or limited gross amounts of residual tumor (Potluri et al. 2011). For this reason the recommended approach in these difficult anatomic areas is aggressive near-total intralesional excision that maximally preserves neurologic function.

Radiation therapy has become increasingly important in the management of chordomas. As a result of advances in radiation techniques and modalities, it is now possible to deliver higher doses to the tumor while sparing critical surrounding structures. The limiting factor is the tolerance of the spinal cord, in particular at its upper end, which is lower than the dose needed to effectively treat the tumor. In general, conventional external beam radiation alone, at doses of 40–60 Gy, is suboptimal for treatment of chordoma, resulting in 5-year local control of 10–40 % (Catton et al. 1996; Cummings et al. 1983). Doses of up to 80 Gy have a high rate of associated radiation-induced myelopathy.

Use of high-dose protons and charged particles such as carbon, helium, or neon ions (collectively categorized as hadrons) enables higher doses to be delivered to tumors with limited radiation damage to critical surrounding structures. Indeed, as proton therapy has no measurable exit dose, peripheral structures are spared. Proton beam treatment of chordomas, either alone or in combination with photons, when used in conjunction with primary resection surgery, has proven to be an excellent method for local control (Hug et al. 1999; Noël et al. 2001; Fuji et al. 2011). This is particularly relevant to skull-base tumors since the tolerance is lower than in the peri-sacral regions. In the sacrum, primary surgery and radiation provide better results when compared with treating chordoma reoccurrence, thereby supporting a role for this approach as an effective first-line treatment option (Park et al. 2006).

Carbon-ion radiotherapy has also been studied in chordoma management. Since carbon ions are heavier than protons, this approach is thought to provide a higher biological effectiveness. Interestingly the effectiveness increases with depth, reaching its peak at the end of the beam’s range. This is an extremely attractive property for local control of cancer and as such has led to significant use of carbon-ion therapy in the management of chordoma. 5-year local control rates of 70–88 % and 10-year local control rates of 80–82 % have been reported in skull-base tumors using carbon-ion therapy (Schulz-Ertner et al. 2007; Mizoe et al. 2009; Tsujii and Kamada 2012).