Sacral insufficiency fractures after high-dose carbon-ion based radiotherapy of sacral chordomas

Hypofractionated proton and carbon ion beam radiotherapy for sacrococcygeal chordoma (ISAC): An open label, randomized, stratified, phase II trial

INTRODUCTION

Sacrococcygeal chordomas have high recurrence rates and are challenging to treat.

METHODS

In this phase II prospective, randomized, stratified trial, the safety and feasibility of hypofractionated ion radiation therapy were investigated. The primary focus was monitored through the incidence of Grade 3-5 NCI-CTC-AE toxicity. Secondary endpoints included local progression-free (LPFS) and overall survival (OS).

RESULTS

The study enrolled 82 patients with primary (87 %) and recurrent (13 %) inoperable or incompletely resected sacral chordomas from January 2013 to July 2022, divided equally into proton therapy (Arm A) and carbon ion beam therapy (Arm B) groups, each receiving a total dose of 64 Gy (RBE) in 16 fractions, 5-6 fractions per week. Overall 74 % of patients received no previous surgery and 66 % of tumors were confirmed by a brachyury staining. The mean and median Gross Tumor Volume at the time of treatment (GTV) was 407 ml and 185 ml, respectively. The median follow-up of the surviving patients was 44.7 months, and the 2-year and 4-year OS rates were 96 % and 81 %, respectively. Factors such as smaller GTV and younger age trended towards better OS. The LPFS after 2-year and 4-year was 84 % and 70 %, respectively. Male gender emerged as a significant predictor of LPFS. There was no significant difference between the treatment groups. We observed five grade 4 wound healing disorders (6 %).

CONCLUSION

The initial response rates were promising; however local control was not sustained. More comparative research on fractionation schemes is essential to refine treatment approaches for inoperable sacral chordoma.

A Comprehensive Narrative Review of the Impact of Pelvic Radiotherapy on Pelvic Bone Health: Pathophysiology, Early Diagnosis, and Prevention Strategies

Radiotherapy is a commonly used modality in pelvic malignancies such as prostate, gastrointestinal, or gynecological, either as a primary treatment or an adjuvant post-surgery. Despite its positive impact on the prognosis of these patients, it was found in several studies that it contributes to insufficiency fractures in different sites of the pelvis, more commonly in the sacral ala. This is particularly true for elderly patients. There are several hypotheses on how radiotherapy affects bone health, as it destroys the bone matrix and causes obliterative vasculitis. Several imaging techniques, particularly magnetic resonance imaging (MRI), help detect the radiotherapy-induced fracture and distinguish it from metastases. Some modalities, such as intensity-modulated radiotherapy (IMRT) and brachytherapy, have decreased fracture risk by escaping the adjacent structures to the targeted organ. Pharmacological interventions such as amifostine and desferrioxamine are promising in terms of bone protection, which necessitates further studies to confirm their mechanism of action.

Sacral insufficiency fracture: a single-center experience of 185 patients with a minimum 5-year follow-up

PURPOSE

Sacral insufficiency fracture (SIF) is a commonly underdiagnosed etiology of back pain, especially in the geriatric and osteoporotic population. In this clinical study, we present our experience of 185 patients who were diagnosed with SIF and managed either with conservative or surgical treatment with a minimum 5-year follow-up.

MATERIALS AND METHOD

Patients who were diagnosed with SIF, managed either conservatively or surgically, and had a minimum 5-year follow-up medical record were included in this study. CT scans and MR imaging including coronal STIR sequence were obtained from all. Bone densitometry (DEXA) was performed to detect accompanying osteopenia or osteoporosis. Patients were treated either conservatively or surgically. VAS and ODI scores were evaluated prior to the treatment and 1st day, 10th day, 3rd month, and 1st year postoperatively.

RESULTS

The mean age of 185 patients was 69.2 and the mean follow-up period was 7.23 years (range: 5-11 years). 46 (24.9%) patients had a previous spinal or spinopelvic surgery and spinal instrumentation was implemented in 22(11.89%) of them. The time interval between the fusion surgery and the diagnosis of SIF was approximately 9.48 weeks. The fracture line could be detected with the MRI in 164 patients and with the CT in 177 patients. The fracture was bilateral in 120 (64.8%) patients. 102 patients were treated conservatively, and 83 received sacroplasty. VAS and ODI scores showed better improvement in pain and functionality in the surgical management group than in the conservative management group.

CONCLUSION

SIF should be considered in the differential diagnosis of back and pelvic pain, especially in elderly and osteoporotic patients. MRI with coronal STIR imaging should be a standard protocol for patients with a risk of SIF. Our results show that sacroplasty provides better and faster pain relief and recovery than conservative management.

Radiotherapy for Mobile Spine and Sacral Chordoma: A Critical Review and Practical Guide from the Spine Tumor Academy

Chordomas are rare tumors of the embryologic spinal cord remnant. They are locally aggressive and typically managed with surgery and either adjuvant or neoadjuvant radiation therapy. However, there is great variability in practice patterns including radiation type and fractionation regimen, and limited high-level data to drive decision making. The purpose of this manuscript was to summarize the current literature specific to radiotherapy in the management of spine and sacral chordoma and to provide practice recommendations on behalf of the Spine Tumor Academy. A systematic review of the literature was performed using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) approach. Medline and Embase databases were utilized. The primary outcome measure was the rate of local control. A detailed review and interpretation of eligible studies is provided in the manuscript tables and text. Recommendations were defined as follows: (1) consensus: approved by >75% of experts; (2) predominant: approved by >50% of experts; (3) controversial: not approved by a majority of experts. Expert consensus supports dose escalation as critical in optimizing local control following radiation therapy for chordoma. In addition, comprehensive target volumes including sites of potential microscopic involvement improve local control compared with focal targets. Level I and high-quality multi-institutional data comparing treatment modalities, sequencing of radiation and surgery, and dose/fractionation schedules are needed to optimize patient outcomes in this locally aggressive malignancy.

Management of Chordoma of the Sacrum and Mobile Spine

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Chordomas account for 1% to 4% of primary tumors of the spine and sacrum.

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En bloc resection is the preferred surgical treatment for the management of chordomas.

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Proton beam radiation is increasingly being used as a postoperative radiation modality for the treatment of chordomas.

Sacral Insufficiency Fractures

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Primary osteoporosis is the most common cause of sacral insufficiency fractures (SIFs). Therefore, a multidisciplinary team approach is necessary for treatment of the fracture and the underlying biologic pathology, as well as prevention of future fragility fractures.

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The presentation of SIFs typically includes lower back or buttock pain after a ground-level fall or without an identified trauma. Symptoms often have an insidious onset and are nonspecific; consequently, a delay in diagnosis and treatment is common. Clinicians need to have a high index of suspicion, particularly in high-risk patients.

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Postmenopausal women who are >55 years of age are the most common demographic affected by SIFs. Other risk factors include osteoporosis, history of a prior fragility fracture, local irradiation, long-term corticosteroid use, rheumatoid arthritis, metabolic bone disorders, vitamin D deficiency, pregnancy, history of prior multilevel spinal fusion, and malignancy.

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Typical imaging on computed tomography (CT) shows sclerosis of cancellous bone in the sacral ala, with or without a discrete fracture line or displacement. Magnetic resonance imaging is more sensitive than CT and shows hypointense signal on T1-weighted sequences and hyperintensity on T2-weighted or short tau inversion recovery sequences.

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The treatment of SIFs is dependent on the severity of symptoms, fracture displacement, and instability of the pelvis. Accepted treatments include nonoperative rehabilitation, sacroplasty, iliosacral screw fixation, transsacral bar or screw fixation, transiliac internal fixation, and lumbopelvic fixation.

Clinical and MRI features of sacral insufficiency fractures after radiotherapy in patients with cervical cancer

Background

To determine the incidence, clinical and MRI features of sacral insufficiency fracture (SIF) after radiotherapy (RT) in patients with cervical cancer.

Methods

Our study included 167 patients with cervical cancer after radiotherapy that underwent pelvic MRI for follow-up. MRIs included pre-enhanced T1-weighted, coronal fat-Suppressed T2-weighted (FS-T2W) and enhanced T1-weighted imaging. The clinical and MRI dates were reviewed. The gold standard of SIF was based on radiologic findings, clinical data and follow-up at least 12 months.

Results

28 patients (10.8%) with 47 sites were diagnosed with SIFs, including 9 patients with unilateral SIF and 19 patients with bilateral SIFs. The median age was 60 years (range 41–72 years), and 89.3% (25/28) of patients were postmenopausal. 64.3% (18/28) of patients were symptomatic, and 53.6% of patients (15/28) had concomitant pelvic fractures. The median interval time from RT to SIFs was 10 months (range 3–34 months). For the lesion-wise analysis based on all MR images, all lesions were detected by visualizing bone marrow edema patterns, and fracture lines were detected in 64.6% (31/47) of SIFs. No soft-tissue tumors were founded. For each MRI sequence analysis, coronal FS-T2WI detected the most bone marrow edema pattern and fracture line than T1WI or enhanced T1WI.

Conclusion

SIF is a common complication in cervical cancer after radiotherapy, which has some certain clinical and MRI features. Coronal FS-T2WI may be more useful to detect and characterize these fractures than other imaging sequences.

Laparoscopic left-sided mesocolic leaf flap repair for pelvic reconstruction after sacral tissue necrosis. A case report

Radical surgical procedures for malignant diseases of the pelvis result in a large pelvic defect that requires soft tissue reconstruction. The mesentery can be used for pelvic floor reconstruction when debridement with intestinal resection is required. A 75-year-old woman was diagnosed with sacral necrosis, infection and sepsis after carbon ion radiotherapy for sacral chordoma. She underwent sacral debridement three times, which resulted in a large pelvic defect of 14 × 13 cm. Surgery was performed to completely resect the necrotic tissue. We performed extended debridement of sacrum and adjacent tissue around the rectum and anus. Since it was impossible to preserve the anus, laparoscopic left hemicolectomy, abdominosacral resection, and left-sided mesocolic leaf repair for the pelvic defect, and reconstructed the pelvis and buttocks using a gluteal thigh flap were performed. Indocyanine green fluorescent (ICG) imaging was used to detect the margin of the pelvic floor and necrotic tissue and the blood flow of the left-sided mesocolic leaf flap. Left-sided mesocolic leaf reconstruction is useful for large pelvic defects. ICG imaging enabled the detection of the resection margins and the blood flow of the mesocolic leaf.

Management of chordoma of the sacrum and mobile spine

Chordoma is a very rare, poorly known malignancy, with slow progression, mainly located in the sacrum and spine. All age groups may be affected, with a diagnostic peak in the 5th decade of life. Clinical diagnosis is often late. Histologic diagnosis is necessary, based on percutaneous biopsy. Specific markers enable diagnosis and prediction of response to novel treatments. New radiation therapy techniques can stabilize the tumor for 5 years in inoperable patients, but en-bloc resection is the most effective treatment, and should be decided on after a multidisciplinary oncology team meeting in an expert reference center. The type of resection is determined by fine analysis of invasion. According to the level of resection, the patients should be informed and prepared for the expected vesico-genito-sphincteral neurologic sequelae. In tumors not extending above S3, isolated posterior resection is possible. Above S3, a double approach is needed. Anterior release of the sacrum is performed laparoscopically or by robot; resection uses a posterior approach. Posterior wall reconstruction is performed, with an associated flap. Spinopelvic stabilization is necessary in trans-S1 resection. Total or partial sacrectomy shows high rates of complications: intraoperative blood loss, infection or mechanical issues. Neurologic sequelae depend on the level of root sacrifice. No genital-sphincteral function survives S3 root sacrifice. Patient survival depends on initial resection quality and the center's experience. Immunotherapy is an ongoing line of research.

Radiation Strategies for Spine Chordoma: Proton Beam, Carbon Ions, and Stereotactic Body Radiation Therapy

Surgery alone provides suboptimal local control of spine and sacral chordomas. Radiotherapy (RT) may improve local control in patients undergoing surgery and be used as definitive-intent treatment in patients not undergoing surgery. Although conventional-dose RT is inadequate for these radioresistant tumors, newer techniques allow treatment of the tumor to higher, more effective doses while limiting spinal cord dose to safe levels. The best local control is achieved when RT is delivered in the primary setting; RT dose is a critical determinant of local control. RT should be considered for all spine and sacral chordoma patients.

Therapy-Related Imaging Findings in Patients with Sarcoma

Knowledge of imaging findings related to therapy administered to patients with sarcoma is pivotal in selecting appropriate care for these patients. Imaging studies are performed as surveillance in asymptomatic patients or because symptoms, including anxiety, develop. In addition to detection of recurrent disease and assessment of response to therapy, diagnosis of conditions related to therapy that may or may not need treatment has a marked positive impact on quality of life. The purpose of this review is to assist radiologists, nuclear physicians, and others clinicians involved in the diagnosis and treatment of these patients in recognizing imaging findings related to therapy and not to activity of the previously treated sarcoma. Imaging findings are time dependent and often specific in relation to therapy given.

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.

The sacral chordoma margin

OBJECTIVE

Aim of the manuscript is to discuss how to improve margins in sacral chordoma.

BACKGROUND

Chordoma is a rare neoplasm, arising in half cases from the sacrum, with reported local failure in >50% after surgery.

METHODS

A multidisciplinary meeting of the "Chordoma Global Consensus Group" was held in Milan in 2017, focusing on challenges in defining and achieving optimal margins in chordoma with respect to surgery, definitive particle radiation therapy (RT) and medical therapies. This review aims to report on the outcome of the consensus meeting and to provide a summary of the most recent evidence in this field. Possible new ways forward, including on-going international clinical studies, are discussed.

RESULTS

En-bloc tumor-sacrum resection is the cornerstone of treatment of primary sacral chordoma, aiming to achieve negative microscopic margins. Radical definitive particle therapy seems to offer a similar outcome compared to surgery, although confirmation in comparative trials is lacking; besides there is still a certain degree of technical variability across institutions, corresponding to different fields of treatment and different tumor coverage. To address some of these questions, a prospective, randomized international study comparing surgery versus definitive high-dose RT is ongoing. Available data do not support the routine use of any medical therapy as (neo)adjuvant/cytoreductive treatment.

CONCLUSION

Given the significant influence of margins status on local control in patients with primary localized sacral chordoma, the clear definition of adequate margins and a standard local approach across institutions for both surgery and particle RT is vital for improving the management of these patients.

Sacral Insufficiency Fractures: a Review of Risk Factors, Clinical Presentation, and Management

PURPOSE OF THE REVIEW

Sacral insufficiency fractures (SIF) are a common and often underdiagnosed source of low back pain. In patients with SIF, there is both a compromised sacroiliac joint and weakened sacrum, resulting in decreased resistance to torsional stress, leading to fracture. While conservative medical management is a safe option, minimally invasive intervention may provide improved short and long-term relief of low back pain in patients presenting with SIF. This comprehensive review is undertaken to provide an update to the current understanding of SIF with description of risk factors, clinical presentation, and management.

RECENT FINDINGS

Sacroplasty is a minimally invasive procedure in which polymethylmethacrylate (PMMA) cement is inserted into bone to improve its structural integrity and alleviate symptoms. Balloon sacroplasty (BSP) has also been successful in alleviating pain with minimal cement leakage in SIF patients. Various other interventional techniques, including navigation-assisted screw fixation have been used to address SIF and have shown improvement in pain with minimal side effects. This review included various modalities of treatments available to manage SIF. This review shows that in comparison with nonsurgical management, sacroplasty has been shown to have greater pain reduction and improved mobility.