High-dose carbon-ion based radiotherapy of primary and recurrent sacrococcygeal chordomas: long-term clinical results of a single particle therapy center.

BACKGROUND: This study aimed to analyze the oncological long-term results and late toxicity of carbon ion-based radiotherapy (RT) of patients with sacral chordoma and to identify potential prognostic factors for local control (LC) and overall survival (OS). METHODS: A total of 68 patients with sacral chordoma treated at the Heidelberg Ion Beam Therapy Center were included in this study. Of these 52 patients (77%) received a primary RT and 16 patients (23%) received a RT in a recurrent situation. All patients were treated with carbon ion RT (CIRT), either in combination with photons (n = 22; 32%) or as a monotherapy (n = 46; 68%), with a median radiation dose of 66 Gy RBE (range 60-74 Gy). In 40 patients (59%), RT was performed in the postoperative situation. Postoperative care included regular MRI scans. Local progression was defined as an enlargement of the maximum tumor diameter by 10% or a new tumor growth within the planning target volume (PTV). LC and OS were determined using the Kaplan-Meier method. Furthermore, the relevance of various prognostic factors for LC and OS was assessed by univariate and multivariate analysis. RESULTS: The median follow-up period was 60 months (range 1.3-97.4 months). The 5-year rates for LC, progression-free survival, metastasis-free survival and OS were 53, 53, 52 and 74%, respectively. Local recurrence was observed in 31 patients (46%), occurring after a median follow-up time of 25 months (range 2.5-73.1 months). Only 10% of local recurrences occurred later than 5 years after RT. Statistical analysis showed that RT in the relapse situation corresponded to inferior LC rates compared to the primary situation, while other factors such as the GTV, radiation dose (EQD2) and treatment approach (CIRT alone vs. CIRT combined with photons) were insignificant. For OS after RT, patient age and PTV size proved to be significant predictors. The incidence of late toxicity ≥ III° according to CTCAE v5.0 was 21%. Sacral insufficiency fractures occurred in 49% of patients (maximum III°: 16%) and were thus by far the most frequent late side effect in our analysis. Radiogenic damage to the peripheral nerves, intestinal tract and skin was observed in only 9% (≥ III°: 5%), 3% (all II°) and 9% (all I°) of patients. CONCLUSION: Our analysis showed only moderate long-term LC rates after carbon ion-based RT, with sacral chordomas having a particularly poor prognosis in the recurrent situation. Therefore, future studies should evaluate the safety and effectiveness of further dose escalation and hypofractionation of RT in sacral chordoma and weight potential benefits of dose escalation against side effects.

Randomized phase II trial of hypofractionated proton versus carbon ion radiation therapy in patients with sacrococcygeal chordoma-the ISAC trial protocol.

BACKGROUND: Chordomas are relatively rare lesions of the bones. About 30% occur in the sacrococcygeal region. Surgical resection is still the standard treatment. Due to the size, proximity to neurovascular structures and the complex anatomy of the pelvis, a complete resection with adequate safety margin is difficult to perform. A radical resection with safety margins often leads to the loss of bladder and rectal function as well as motoric/sensoric dysfunction. The recurrence rate after surgery alone is comparatively high, such that adjuvant radiation therapy is very important for improving local control rates. Proton therapy is still the international standard in the treatment of chordomas. High-LET beams such as carbon ions theoretically offer biologic advantages in slow-growing tumors. Data of a Japanese study of patients with unresectable sacral chordoma showed comparable high control rates after hypofractionated carbon ion therapy only. METHODS AND DESIGN: This clinical study is a prospective randomized, monocentric phase II trial. Patients with histologically confirmed sacrococcygeal chordoma will be randomized to either proton or carbon ion radiation therapy stratified regarding the clinical target volume. Target volume delineation will be carried out based on CT and MRI data. In each arm the PTV will receive 64 GyE in 16 fractions. The primary objective of this trial is safety and feasibility of hypofractionated irradiation in patients with sacrococygeal chordoma using protons or carbon ions in raster scan technique for primary or additive treatment after R2 resection. The evaluation is therefore based on the proportion of treatments without Grade 3-5 toxicity (CTCAE, version 4.0) up to 12 months after treatment and/or discontinuation of the treatment for any reason as primary endpoint. Local-progression free survival, overall survival and quality of life will be analyzed as secondary end points. DISCUSSION: The aim of this study is to confirm the toxicity results of the Japanese data in raster scan technique and to compare it with the toxicity analysis of proton therapy given in the same fractionation. Using this data, a further randomized phase III trial is planned, comparing hypofractionated proton and carbon ion irradiation. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01811394.

Iodine-125 seed implantation in the treatment of sacrococcygeal chordoma: a case report.

The objective of this was to summarize the efficacy and safety of iodine-125 seed implantation in the treatment of sacrococcygeal chordoma. CT-guided implantation of radioactive iodine-125 seed was applied in treating a patient with sacrococcygeal chordoma. The incidence of complications was recorded and the results were evaluated and analyzed, to compare the postoperative complications and recurrence rate of sacrococcygeal chordoma. The patient was followed up to 15 months after operation. The minimum peripheral dose was 180 Gy, and 8 months after the implantation, the tumor mass was reduced significantly. There was no serious complications detected during the follow-up period. Radioactive iodine-125 seed implantation can improve the target volume dose, with the high doses of radioactive iodine-125 seed, the tumor, which was refractory and insensitive to chemotherapy and radiotherapy, can be effectively controlled and complications are less than surgical treatment. However, the long-term efficacy of this treatment needs further follow-up.

Intensity-modulated radiotherapy of sacral chordoma--a case report and a comparison with stereotactic conformal radiotherapy.

In a case of partially resected sacral chordoma, the planning target volume (PTV) received 60 Gy and the gross target volume (GTV) 72 Gy using inversely planned, intensity-modulated, radiation therapy (IMRT). IMRT was compared with 3D-conformal radiotherapy (CRT). With IMRT, it was found that dose distribution is more homogeneous within the PTV outside the GTV and allows simultaneous dose escalation within the GTV. The volume of bowel receiving a dose higher than 40 Gy was reduced from 400 cc with CRT to 220 cc with IMRT. If particle therapy is not available, IMRT seems to be a promising alternative in the treatment of sacral chordomas.

Management of sacral and perineal defects following abdominoperineal resection and radiation with transpelvic muscle flaps.

PURPOSES: In this study we present our experience with treating persistent sacral and perineal defects secondary to radiation and abdominoperineal resection with or without sacrectomy. METHODS: Fifteen consecutive patients were treated with an inferiorly based transpelvic rectus abdominis muscle or musculocutaneous flap. RESULTS: Fourteen of the 15 patients achieved healing, and 7 patients had no complications. The remaining eight patients required one or more operative debridements and/or prolonged wound care to accomplish a healed wound. Our technique for the dissection and insetting of the transpelvic muscle flap is presented. CONCLUSION: The difficult postirradiated perineal and sacral wounds can be healed with persistent surgical attention to adequate debridement, control of infections, and a well-vascularized muscle flap. The most satisfying aspects for patients are the discontinuance of foul-smelling discharge, discontinuation of multiple, daily dressing changes, and reduction in the degree of chronic pain.

Retroperitoneal transfer of a transverse rectus abdominis musculocutaneous flap for closure of a sacral radiation ulcer.

Closure of sacral wounds remains a challenge, especially when dealing with previously irradiated tissue. A report of a chronic sacral radiation ulcer successfully closed with the retroperitoneal transfer of a transverse rectus abdominis musculocutaneous flap is presented. Anatomical and technical details are highlighted.

Radiation therapy in the neonate.

Radiation therapy (RT) is frequently used in the management of children with cancer, but neonatal neoplasms are rare. Newborns represent 1.5% of the children with malignant diseases in the Tumor Registry at the Children's Hospital of Philadelphia over the last 30 years. Thus, occasionally the pediatrics radiation therapist must consider treating the very young infant. The specific radiation effects on growth and development must be weighed in reaching a therapeutic decision. All children are vulnerable to the late effects of radiation therapy, but the neonates may be more susceptible because of the immaturity of important organs such as the brain, lung, liver, kidney, and bone. In general, radiation therapy, should be avoided during the first several weeks of life because of the potential increased sensitivity of the liver and kidneys during that period. If radiation therapy is used at all during infancy, the benefits must be weighed against the possibility of significant late effects. Increasing knowledge of pediatric neoplasms has shown that some tumors (such as mesoblastic nephroma) require no treatment except for surgical excision; and other tumors, such as Stage IV-S neuroblastoma, may require very little treatment. In those tumors that require radiation therapy, the use of chemotherapy may allow reduction of the radiation dose. Furthermore, alterations of time-dose-fractionation schemes and careful attention to tumor volume with the use of special techniques, such as "shrinking fields," may decrease the late adverse effects of treatment.