Significance of radiation therapy in the myxoid round-cell liposarcoma treatment regimen.

BACKGROUND AND PURPOSE: Because myxoid liposarcomas are more radiosensitive than other soft tissue sarcomas, there have been several reports of 50 Gy preoperative radiation therapy combined with surgery, but the wound complication rate is reportedly high. We have performed preoperative irradiation at a reduced dose of 40 Gy and definitive radiation therapy for unresectable cases. This study aimed to report the tumor reduction rate and oncological results with a reduced dose of preoperative irradiation and the outcome of definitive irradiation for unresectable cases. MATERIALS AND METHODS: Forty-one patients with myxoid liposarcoma treated in our institution between 2002 and 2021 were included. We examined the tumor volume shrinkage rate with preoperative radiation, compared complications and oncological outcomes between preoperative radiation and surgery-only cases, and investigated the prognosis and tumor shrinkage of definitive radiation cases. RESULTS: The total dose irradiated was 40 Gy except in two cases. The mean tumor volume reduction rate was 52.0%. A decreased dose of preoperative radiation did not worsen clinical outcomes with fewer complications. The total dose of definitive radiation was approximately 60 Gy. The mean tumor volume reduction rate was 55.0%. The tumor shrinkage maintenance rate was 100% in a median follow-up period of 50.5 months. CONCLUSION: Preoperative radiation therapy for myxoid liposarcoma near vital organs is a good approach because even with a reduced dose of 40 Gy, significant tumor reduction and excellent results were achieved. Definitive radiation therapy is the recommended treatment for older patients with serious comorbidities or inoperable patients.

Clinical Outcome in Patients With High-grade Soft-tissue Sarcoma Receiving Prosthetic Replacement After Tumor Resection of the Lower Extremities: Tokai Musculoskeletal Oncology Consortium Study.

AIM: This multicenter retrospective study aimed to clarify the surgical and oncological outcomes of patients with high-grade soft tissue sarcoma (STS) who underwent prosthetic replacement reconstruction after lower extremity tumor resection. PATIENTS AND METHODS: We retrospectively collected the data of 27 patients with high-grade STS. The mean follow-up duration after prosthetic replacement was 44.7 months. RESULTS: The mean age at surgery was 63 years. The mean tumor size was 16 cm. For reconstruction, proximal femur replacement was performed in 15 patients, distal femur replacement in six, and total femur replacement in six. The major complications were infections in nine patients and aseptic loosening in four. Nine patients developed local recurrence. The cause of revision surgery was infection in five patients, aseptic loosening in three, and metal allergy in one. The 5-year prosthetic survival rate was 51.1%. At the final follow-up, amputation was performed in five patients. The 5-year limb salvage rate was 76.8%. The mean functional score of the 25 patients who could be assessed was 16.0 (53%). Of the 27 patients, five were excluded from the survival analysis because they underwent prosthetic replacement for local recurrence. The 5-year overall survival rate in the remaining 22 patients was 45.3%. CONCLUSION: We identified a high rate of surgical complications and poor survival in patients with high-grade STS who underwent tumor resection and reconstruction using prosthetic replacement of the lower extremities, although limb salvage was achieved in 81.5% of the patients. Careful follow-up is needed for surgical complications and oncological events after surgery.

Protocol for the 2ND-STEP study, Japan Clinical Oncology Group study JCOG1802: a randomized phase II trial of second-line treatment for advanced soft tissue sarcoma comparing trabectedin, eribulin and pazopanib.

BACKGROUND: Soft tissue sarcomas (STS) are a rare type of malignancy comprising a variety of histological diagnoses. Chemotherapy constitutes the standard treatment for advanced STS. Doxorubicin-based regimens, which include the administration of doxorubicin alone or in combination with ifosfamide or dacarbazine, are widely accepted as first-line chemotherapy for advanced STS. Trabectedin, eribulin, pazopanib, and gemcitabine plus docetaxel (GD), which is the empirical standard therapy in Japan, are major candidates for second-line chemotherapy for advanced STS, although clear evidence of the superiority of any one regimen is lacking. The Bone and Soft Tissue Tumor Study Group of the Japan Clinical Oncology Group (JCOG) conducts this trial to select the most promising regimen among trabectedin, eribulin, and pazopanib for comparison with GD as the test arm regimen in a future phase III trial of second-line treatment for patients with advanced STS. METHODS: The JCOG1802 study is a multicenter, selection design, randomized phase II trial comparing trabectedin (1.2 mg/m2 intravenously, every 3 weeks), eribulin (1.4 mg/m2 intravenously, days 1 and 8, every 3 weeks), and pazopanib (800 mg orally, every day) in patients with unresectable or metastatic STS refractory to doxorubicin-based first-line chemotherapy. The principal eligibility criteria are patients aged 16 years or above; unresectable and/or metastatic STS; exacerbation within 6 months prior to registration; histopathological diagnosis of STS other than Ewing sarcoma, embryonal/alveolar rhabdomyosarcoma, well-differentiated liposarcoma and myxoid liposarcoma; prior doxorubicin-based chemotherapy for STS, and Eastern Cooperative Oncology Group performance status 0 to 2. The primary endpoint is progression-free survival, and the secondary endpoints include overall survival, disease-control rate, response rate, and adverse events. The total planned sample size to correctly select the most promising regimen with a probability of > 80% is 120. Thirty-seven institutions in Japan will participate at the start of this trial. DISCUSSION: This is the first randomized trial to evaluate trabectedin, eribulin, and pazopanib as second-line therapies for advanced STS. We endeavor to perform a subsequent phase III trial comparing the best regimen selected by this study (JCOG1802) with GD. TRIAL REGISTRATION: This study was registered with the Japan Registry of Clinical Trials ( jRCTs031190152 ) on December 5, 2019.

Osteosclerotic change as a therapeutic response to gefitinib in symptomatic non-small cell lung cancer bone metastasis.

BACKGROUND: Despite improvement in the overall survival of patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutation, the effects of EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment on bone metastasis remain unclear. This study investigated radiological responses to gefitinib regarding bone metastasis in patients. METHODS: We treated 260 patients with NSCLC and symptomatic bone metastasis. Thirty-seven patients harboring EGFR mutation were treated with gefitinib for more than 30 days and followed up for more than 3 months (GEF group). We performed a retrospective observational study by selecting 36 cases without EGFR-TKI treatment, at least 3 months of follow-up, and at least two radiological evaluations as the control group. We assessed the best overall radiological response, interval from treatment initiation to appearance of a radiological response, and the local response maintenance rate. RESULTS: The best effect in the GEF group was 98% partial response or better, which was significantly higher than the 57% observed in the control group (p < 0.001). The GEF and control groups maintained 83% and 42% local response maintenance rates at one year, respectively (p < 0.001). In the GEF with radiotherapy group, the local response maintenance rate was maintained at 92% at 1 year, while in the GEF without RT group, there was a decrease in the local response maintenance rate from 270 days. CONCLUSION: Gefitinib treatment for bone metastases in patients harboring EGFR mutation resulted in a beneficial osteosclerotic change in most patients. Combined gefitinib and radiotherapy provide long-lasting local control of bone metastases.

Direct femoral head approach without surgical dislocation for femoral head chondroblastoma: a report of two cases.

BACKGROUND: Chondroblastomas are rare, benign, locally aggressive lesions that appear in the epiphysis. Surgery for femoral head chondroblastoma (FHCB) is difficult. Conventional treatment with curettage via a drilled tunnel along the femoral neck can damage the growth plate and is associated with high local recurrence rates. The trapdoor procedure, which directly facilitates lesion access from the femoral head articular surface, can reduce local recurrence and avoid growth plate damage, although it requires surgical dislocation. Little is known about the long-term results of this direct articular surface approach, and there are no case reports on trapdoor procedures without dislocation. CASE PRESENTATION: We report two cases (patients aged 12 and 15 years) of FHCB presented with coxalgia treated using the trapdoor procedure without surgical dislocation. Both surgeries were performed with patients in the semi-lateral position. The hip joint was exposed via an anterior approach, and a capsulotomy was performed at the superior rim of the acetabulum, followed by the external rotation of the hip joint. With a fine osteotome, a rectangular flap (trapdoor) was opened on the cartilage surface in the lateral non-weight-bearing area, and curettage of the lesion followed by bone and/or bone substitute grafting was performed. Subsequently, the trapdoor was replaced in its original position. There has been no local recurrence or femoral head aseptic necrosis after more than 6 and 12 years for patients 1 and 2, respectively. Both patients had musculoskeletal tumor society scores of 100% at follow-up and are enjoying a normal active life. CONCLUSIONS: This direct femoral head approach without dislocation may be a simple treatment alternative for FHCB.

Clinical outcome in patients who underwent amputation due to extremity soft tissue sarcoma: Tokai Musculoskeletal Oncology Consortium study.

BACKGROUND: Soft tissue sarcomas are a diverse group of rare malignant tumours, mostly occurring in the lower extremities. Amputations are necessary for achieving local control when the soft tissue sarcomas are too large and/or have neurovascular involvement. Patients who require amputation have a poorer prognosis than those who undergo limb-salvage surgery. PATIENTS AND METHODS: We investigated the tumour characteristics and the clinical outcomes in 55 patients with primary soft tissue sarcomas, who underwent amputation. We excluded patients with amputation performed distal to the wrist or ankle joints and those with recurrent soft tissue sarcomas. RESULTS: The mean tumour size was 11.1 cm. Hip disarticulation was performed in 6 patients, 20 underwent above the knee amputation, 8 underwent knee disarticulation and 12 underwent below the knee amputation. Shoulder disarticulation was performed in three patients, five underwent above the elbow amputation, and one underwent below the elbow amputation. The 5-year disease-specific survival rate was 52.8%. The 5-year recurrence-free survival rate and 5-year metastasis-free survival rates were 90.1% and 38.5%, respectively. Larger tumour size, age and the distant metastases at first presentation were predictors of poor prognosis for survival in multivariate analysis. Twenty-eight patients could walk using artificial limbs. The level of amputation (above versus below the knee) showed a significant difference in achieving independent gait. CONCLUSION: Amputation is a useful treatment option for achieving local control in patients with large soft tissue sarcomas. Patients had an opportunity of walking, especially for those who underwent below the knee amputation.

Effect of Neoadjuvant Therapies on Soft Tissue Sarcomas with Tail-like Lesions: A Multicenter Retrospective Study.

Several types of soft tissue sarcomas have peripheral infiltrative growth characteristics called tail-like lesions. The efficacy of neoadjuvant therapy for tumors with tail-like lesions has not been elucidated. From 2012 to 2019, we analyzed 36 patients with soft tissue sarcoma with tail-like lesions treated with neoadjuvant therapy, including chemotherapy, radiotherapy, or both. The effect of neoadjuvant therapy on the tail sign was investigated by analyzing the change in tail-like lesions during neoadjuvant therapy and histological responses. The median length of the tail-like lesion reduced from 29.5 mm at initiation to 19.5 mm after neoadjuvant therapy. The extent of shrinkage in tail-like lesions was related to the histopathological responses in the main part of the tumor. Complete disappearance of the tail-like lesion was observed in 12 patients; however, it was not related to achieving a microscopically negative margin. The oncologic outcomes did not significantly differ between cases with and without the complete disappearance of tail-like lesions. This study indicated that the shrinkage of tail-like lesions did not have a significant effect on complete resection or improvements of clinical outcomes. A more comprehensive evaluation is needed to elaborate on the surgical strategy.

Clinical Outcomes of Patients with Metastatic Solitary Fibrous Tumors: A Japanese Musculoskeletal Oncology Group (JMOG) Multiinstitutional Study.

BACKGROUND: Although the unpredictable malignant behavior of solitary fibrous tumors (SFTs) has been recognized, the clinical features and prognosis of metastatic SFTs have not been well documented due to the extreme rarity of these cases. The aim of this study is to investigate the clinical features, prognostic factors, and optimal management of patients with metastatic SFTs. PATIENTS AND METHODS: Sixty patients with metastatic SFT were retrospectively reviewed. Univariate and multivariate analyses were performed to identify the factors associated with survival. Time to next treatment (TNT) was used to evaluate the effects of various chemotherapy regimens. RESULTS: A total of 34 male and 26 female patients (median age 55 years, range, 23-87 years) were included in the study. The median follow-up period after metastasis was 32 months (range 1-126 months). Tumor location and local recurrence were correlated with late metastasis. The 3- and 5-year overall survival rates were 72.7% and 49.2%, respectively. Primary tumor location, number of metastases, and metastasectomy were significantly associated with survival. Metastasectomy was the only significant variable on multivariate analysis. The TNT was significantly different among the various regimens. CONCLUSIONS: Patients with metastatic SFTs had relatively longer survival periods compared with those with other metastatic soft-tissue sarcomas. Tumor location and number of metastases was associated with survival. Surgical resection of the metastatic lesions offers the best chance of survival, however further studies are warranted to define patients who would benefit from metastasectomy, and the most effective chemotherapeutic regimen for patients with metastatic SFTs remains unknown.

Surgery for femoral metastases.

AIMS: The aim of this study is to evaluate the clinical results of operative intervention for femoral metastases which were selected based on expected survival and to discuss appropriate surgical strategies. METHODS: From 2002 to 2017, 148 consecutive patients undergoing surgery for femoral metastasis were included in this study. Prognostic risk assessments were performed according to the Katagiri and revised Katagiri scoring system. In general, the low-risk group underwent resection and reconstruction with endoprosthetic replacement (EPR), while the high-risk group underwent internal fixation (IF) and radiation therapy. For the intermediate-risk group, the operative choice depended on the patient's condition, degree of bone destruction, and radio-sensitivity. Overall survival, local failure, walking ability, and systemic complications were evaluated. RESULTS: A total of 83 patients underwent EPR (low-risk, 23%; intermediate-risk, 60%; high-risk, 17%) and 65 patients underwent IF (low-risk, 0%; intermediate-risk, 32%; high-risk, 68%). The one-year survival rate was 71% for EPR and 15% for IF (p < 0.001). The one-year local failure-free survival was 93% for EPR and 67% for IF, and the two-year and five-year local failure-free survival for EPR were both 88% (p = 0.016). Although the ambulatory rate was 99% for EPR and 60% for IF, the median time to ambulation was shorter in the IF (EPR, 28 days, interquartile range (IQR) 25 to 35; IF, 23 days, IQR 18 to 28; p < 0.001) The cause of non ambulation was mainly due to progression of cancer (89%). The rate of systemic complications was comparable between the two groups (EPR, 18%; IF, 22%; p = 0.598). CONCLUSION: Selective use of EPR where survival is expected to be good offers correspondingly good long-term results. IF is less invasive with shorter treatment period, which is beneficial for patients with short-term expected survival. Prognosis is an important indicator in selecting operative procedures for femoral metastasis. Cite this article: Bone Joint J 2020;102-B(3):285-292.

Metastatic Malignant Peripheral Nerve Sheath Tumor With NF1 Successfully Treated With 'Gradual Subtraction' ICE Chemotherapy.

BACKGROUND: Prognosis of metastatic malignant peripheral nerve sheath tumor (MPNST) is poor and the role of chemotherapy is controversial. There has been no report of metastatic MPNST with a good prognosis without surgery for metastases. CASE REPORT: A 40-year-old man with neurofibromatosis type 1 (NF1)-related MPNST on his shoulder with multiple lung metastases visited our hospital. After two cycles of chemotherapy with ifosfamide, carboplatin and etoposide (ICE), the primary lesion and lung metastases had shrunk. The primary lesion was resected with negative margins. Subsequently, 'gradual subtraction' ICE was administered, wherein the dose was reduced and the treatment interval was increased. After 14 courses of ICE over a period of 2 years, the lung metastases disappeared; there has been no recurrence for over 12 years. CONCLUSION: ICE can be an excellent, inexpensive treatment for NF1-related MPNST. 'Gradual subtraction' chemotherapy allowed us to maintain long-term efficacy, induce tumor dormancy, and reduce side-effects.

Efficacy and safety of trabectedin for patients with unresectable and relapsed soft-tissue sarcoma in Japan: A Japanese Musculoskeletal Oncology Group study.

BACKGROUND: Although initial trabectedin (1.2 mg/m2 ) is safe and effective for patients with translocation-related sarcoma (TRS) in Japan, its efficacy in other types of soft-tissue sarcomas (STSs) remains unknown. This study retrospectively investigated its efficacy and safety through postmarketing surveillance of trabectedin in patients with unresectable and relapsed STS. METHODS: One hundred forty patients received intravenous trabectedin (1.2 mg/m2 on day 1 every 21 days) over the course of 24 hours. The primary endpoint was the efficacy and safety of trabectedin. RESULTS: Grade 3 or higher adverse events occurred in 100 patients (71%) and included hepatotoxicity (37.8%), neutropenia (32.8%), and rhabdomyolysis (3.6%). Patients at high risk for grade 3 or higher rhabdomyolysis (36%) were classified by height (≥170.3 cm) and age (≤32 years) through a classification and regression tree model (area under the curve, 0.9). The overall median progression-free survival (PFS) was 3.7 months; with respect to the histological type, the median PFS was 17.4 months for myxoid liposarcoma, 4.9 months for leiomyosarcoma, 5.6 months for synovial sarcoma, and 3.7 months for dedifferentiated liposarcoma. Histological type (liposarcoma/leiomyosarcoma [L-sarcoma] and TRS) and grade 3 neutropenia (but not grade 4) were associated with significantly improved PFS after trabectedin treatment (P = .003, P = .04, and P = .001). The median growth modulation index (GMI) was 0.91; 37 patients (36.7%) experienced a GMI > 1.33, and among patients with solitary fibrous tumors and undifferentiated pleomorphic sarcoma, 60% and 42.9%, respectively, had a GMI > 1.33. The median overall survival (OS) was 16.4 months. A GMI > 1.33 was associated with significantly improved OS (P = .0006). CONCLUSIONS: Initial trabectedin at 1.2 mg/m2 has clinically meaningful benefits for patients with L-sarcoma and certain histological subtypes of TRS.

Pro-gastrin-releasing peptide as a marker for the Ewing sarcoma family of tumors.

BACKGROUND: Pro-gastrin-releasing peptide (ProGRP) is an established tumor marker of small cell lung cancer. The purpose of this study was to determine if ProGRP could serve as a tumor marker for the Ewing sarcoma family of tumors (ESFTs). METHODS: Sixteen patients with ESFTs (mean age 32 years) were included in this study. As a control group, 42 patients with other tumor types that clinically or pathologically mimic ESFTs were also analyzed. Pre-treatment serum ProGRP and neuron-specific enolase (NSE) levels, the relationships between these levels, and tumor volume were investigated. In addition, serial changes in the serum or plasma ProGRP (6 patients) and NSE levels (5 patients) were measured over the course of treatment. RESULTS: Pre-treatment serum ProGRP levels were higher than the normal range in 8 of 16 patients; for these eight patients, ProGRP levels positively correlated with tumor volume (R = 0.99). In the control group, ProGRP levels were within the normal range, except for the two patients. Changes in ProGRP levels during treatment were consistent with tumor volume. Serum NSE levels were elevated in 14 of 16 patients with ESFTs and 8 of 42 patients with other tumor types. The range of NSE elevation was much smaller compared to that of ProGRP. Our data indicate that ProGRP is superior to NSE in terms of specificity. CONCLUSIONS: Serum ProGRP levels were elevated in half of the patients with ESFTs and reflected therapeutic response. ProGRP is a reliable tumor marker for the diagnosis of ESFTs and evaluation of treatment response.

Radiotherapy combined with zoledronate can reduce skeletal-related events in renal cell carcinoma patients with bone metastasis.

BACKGROUND: Skeletal-related events (SRE) are common in patients with renal cell carcinoma (RCC) that includes bone metastasis. The purpose of this study was to clarify the effectiveness of zoledronate with and without sunitinib, combined with radiotherapy, for the treatment of bone metastasis from RCC. METHODS: We retrospectively analyzed 62 RCC patients with bone metastasis, who had been treated with radiotherapy at our institution. We divided the study cohort into two groups: patients treated with radiotherapy alone (RT; n = 27) and those treated with radiotherapy combined with zoledronate (RT + Z; n = 35). We investigated the overall survival and post-irradiation (PI)-SRE-free rate for each group, as well as the effect of sunitinib in the RT + Z treatment group. In addition, we determined treatment effectiveness by imaging assessments and relative response rates. RESULTS: There was no significant difference in the survival rates between the RT and RT + Z treatment groups (p = 0.11). However, the PI-SRE-free rate in the RT + Z group was significantly higher than that in the RT group (p = 0.02). The PI-SRE-free rate was significantly higher in patients who were treated with sunitinib after radiotherapy than in those who were treated without sunitinib (p = 0.03). However, there was no significant difference in the relative response rates, as assessed by imaging, in each group. CONCLUSION: Radiotherapy combined with zoledronate is an effective treatment for RCC with bone metastasis to prevent PI-SRE. Sunitinib may reduce PI-SRE if used after radiotherapy and combined with zoledronate.

Posterior reversible encephalopathy syndrome (PRES) induced by pazopanib, a multi-targeting tyrosine kinase inhibitor, in a patient with soft-tissue sarcoma: case report and review of the literature.

Posterior reversible encephalopathy syndrome (PRES) is a clinical entity characterized by acute neurological symptoms such as severe headache, seizures, and visual disturbance, and by typical reversible lesion on brain magnetic resonance (MR) images. Since PRES is thought to be caused by vascular endothelial injury due to cytotoxic agents or acute systemic hypertension, the number of reports on PRES associated with angiogenesis inhibitors has been increasing. Although five cases that developed PRES due to pazopanib for renal cell carcinoma have already been reported, none of PRES due to pazopanib for soft-tissue sarcoma has been reported thus far. We describe a case of a 49-year-old woman with retroperitoneal soft-tissue sarcoma who developed PRES during pazopanib administration. Pazopanib at 800 mg/day was administered as her third-line treatment at relapse. After 38 days of pazopanib, she was admitted to our hospital with severe headache, vomiting, and systemic hypertension. The next day, she developed consciousness deterioration and visual disturbance together with exacerbated systemic hypertension. Brain MR images revealed hyper-intense signals on FLAIR sequences in the bilateral occipital lobes and the left thalamus. Intravenous nicardipine injection was immediately started to control her blood pressure and pazopanib was discontinued. Her symptoms gradually improved and disappeared on the fifth hospital day. After 2 weeks, hyper-intense signals on a FLAIR sequence disappeared completely. She restarted a low dose of pazopanib under good blood pressure control and experienced no subsequent recurrence of PRES.

Fracture after radiation therapy for femoral metastasis: incidence, timing and clinical features.

We analyzed 428 femoral metastases initially treated with radiotherapy between 2002 and 2011 to clarify the clinical details of post-irradiation fractures of femoral metastasis. Patients included 161 men and 167 women, with a mean age of 62 years. Fracture incidence, fracture site, fracture risk based on X-ray images before radiotherapy, and interval from completion of radiotherapy to fracture occurrence were assessed. In addition, 24 pathological specimens obtained during 27 surgeries for these fractures were examined. Fractures occurred in 7.7% of 428 femoral metastases (total 33: 28 actual fractures and five virtual fractures with progressive pain and bone destruction). The fracture rate was 7.8% in the proximal femur and 1.5% in the shaft (P = 0.001). Fractures occurred a median of 4.4 months after radiotherapy, with 39.4% occurring within 3 months and 63.6% within 6 months. Among femurs with high fracture risk according to Harrington's criteria or Mirels' score, the fracture rate was 13.9% and 11.8%, respectively. Viable tumor cells were detected in all five patients with painful virtual fracture, in 85.7% of femurs with actual fractures that occurred within 3 months, and in only 25.0% of actual fractures occurring after 3 months. Post-irradiation fractures of femoral metastasis most frequently occurred within 3 months after radiotherapy, and were more common in the peritrochanteric area than in the shaft. Radiological evidence of impending fracture did not correlate with a high fracture rate. Actual fractures occurring after more than 3 months were likely caused by post-irradiation fragility of the femur, without viable tumor cells.

Asymmetrical vertebral collapse from spinal metastasis in lower thoracic and lumbar spine.

OBJECTIVE: The purpose of this study was to investigate the differences between spinal metastasis and osteoporotic compression fractures on plain X-ray images, focusing on asymmetrical vertebral collapse and fracture level. MATERIALS AND METHODS: This study included 180 patients with pathological collapse from spinal metastasis (188 vertebrae) who were treated at our institution and 70 patients (92 vertebrae) with osteoporotic compression fractures. Anteroposterior X-ray images of the lower thoracic and lumbar spine were evaluated for asymmetrical collapse deformity. RESULTS: Asymmetrical collapse was found in 134 vertebrae (71.3%) with metastasis, and in 20 osteoporotic vertebrae (21.7%); this difference was significant (p < 0.0001). The asymmetrical collapse angle in spinal metastasis patients ranged from 0 to 18°, with a mean of 7.0 and a standard deviation (SD) of 4.5. In contrast, the asymmetrical collapse angle in patients with osteoporotic fractures ranged from 0 to 13°, with a mean of 3.1 and a SD of 2.8. The difference in collapse angle between the two groups was statistically significant (p < 0.001). The cutoff value to suspect spinal metastasis was determined to be 5° or more (sensitivity 0.67, specificity 0.74). Fracture at Th10 or below L3 was found in 20.2% of spinal metastasis patients; only 3% of osteoporotic fractures occurred at these levels. CONCLUSION: Asymmetrical collapse with an angle of 5° or more and fractures at atypical levels on plain radiographs can be useful clues to spinal metastasis.

Clinical outcome for patients of solitary bone only metastasis.

BACKGROUND: Solitary bone only metastasis (SBOM) is a rare condition in which metastasis is limited to a single skeletal lesion originating from a previously treated or controllable primary lesion. The study objective was to evaluate the clinical features and survival regarding this rare condition and to clarify its treatment strategy. METHODS: A total of 1453 patients with bone metastasis registered in our hospital database were enrolled. To assess the primary and/or metastatic lesion we used plain X-ray images, CT, MRI and FDG-PET scans as well as bone scans. RESULTS: Among the patients, only 27 (1.8%) had SBOM. The primary cancers responsible for SBOM were lung in seven patients, breast in five, kidney in four, prostate in two, uterus in two and other types in seven. Treatment of SBOM involved resection in four patients, radiotherapy only in 17, radiotherapy in combination with zoledronate in six and chemotherapy with zoledronate in one. Local recurrence did not develop in the four cases treated with resection. However, in-field recurrence was found in 4 of 22 (18%) patients who underwent radiotherapy. All three patients who received >40 Gy did not develop in-field recurrence. The overall and event free survival rates at 5 years were 63% and 41%, respectively. CONCLUSIONS: Solitary bone only metastasis should be treated with wide resection or long-course radiotherapy at doses 40-50 Gy to achieve long lasting local tumor control.