Imaging findings of radiation-induced sarcoma of the head and neck

We set out to retrospectively review the clinical and imaging features of patients with post-radiation sarcoma, especially in the head and neck region. We reviewed the records of 4194 patients with carcinoma of the head and neck region who had a history of radiation. They had undergone CT and/or MRI. Medical records were reviewed for the primary diagnosis, radiation history and latency period to the development of sarcoma. The patients included four men and two women with a mean age of 64.5 years. The mean latency period for the development of sarcoma was 11.5 years. Primary diagnoses were maxillary carcinoma, nasopharyngeal carcinoma, adenoid cystic carcinoma of the oral floor, tonsilar carcinoma, soft palate carcinoma and tongue carcinoma. Histopathological examinations revealed osteosarcoma, spindle cell sarcoma, chondrosarcoma, malignant peripheral nerve sheath tumour, spindle cell carcinoma and malignant fibrous histiocytoma, respectively. Common findings were a heterogeneous and well-enhanced soft tissue mass and bone destruction. There is at present little or no prospect for the effective prevention of radiation-induced sarcoma of the head and neck. This emphasizes the importance of the earliest possible diagnosis for such patients. The imaging findings are not diagnosis specific, but strict follow-up within the radiation field by CT and MRI and an appreciation of the expected latency period may help to provide the diagnosis. When radiotherapy is performed for head and neck neoplasms, periodic follow-up observations may be necessary for many years.     

Postradiation sarcoma of bone in Hodgkin disease

We report 16 cases seen in the Memorial Sloan-Kettering Cancer Center (MSKCC) during the past 50 years. These patients had been treated with external radiation for Hodgkin disease and had developed sarcomas in the field 4–31 years after the diagnosis of Hodgkin disease. Most of the tumors (12 of 16) occurred in the chest wall. There were three tumors of the pelvis and an unusual osteosarcoma of the femur following treatment for a primary Hodgkin disease of the femur. The tumors were predominantly osteosarcomas (9). In addition, there were five malignant fibrous histiocytomas, one fibrosarcoma, and one chondrosarcoma. Prognosis was poor; the mean survival was 12 months. Survival of patients with other primary cancers who developed radiation sarcomas was not significantly different from that of patients with Hodgkin disease. Hodgkin disease is now the most common tumor among radiation-induced sarcomas in previously normal bone and has surpassed breast cancer, which was previously the most common original tumor.     

Value of FDG positron emission tomography in conjunction with MR imaging for evaluating therapy response in patients with musculoskeletal sarcomas

OBJECTIVE: The purpose of our study was to investigate the potential of FDG positron emission tomography (PET) to distinguish viable tumor from changes caused by therapy in areas with equivocal MR imaging findings in patients with musculoskeletal sarcomas. MATERIALS AND METHODS: We evaluated 12 patients (nine males, three females; age range, 9-56 years; mean age, 25 years) with a history of bone or soft-tissue sarcoma who had undergone various treatments (surgery, chemotherapy, radiation therapy, or a combination of treatments) and who presented with clinically suspected recurrent or residual tumor. All patients underwent gadopentetate dimeglumine-enhanced MR imaging and whole-body FDG PET. Imaging results were correlated with histologic findings or with clinical findings from long-term follow-up. RESULTS: In nine patients, MR imaging findings were equivocal in differentiating between posttherapeutic changes and tumor recurrence. FDG PET images showed increased uptake, suggestive of recurrent tumor, in five patients. These findings were confirmed by biopsy. Four patients showed no increased uptake on FDG PET and were closely monitored clinically. No tumor recurrence was found in these patients. One patient showed MR imaging findings suggestive of recurrent tumor that was confirmed on FDG PET and at histology. Two patients underwent a limb salvage procedure before MR imaging, but MR images were deemed inadequate for interpretation because of extensive metallic artifacts. FDG PET was helpful in evaluating these patients for tumor recurrence. CONCLUSION: FDG PET is a useful adjunct to MR imaging in distinguishing viable tumor from posttherapeutic changes in patients with bone and soft-tissue sarcomas.     

A revisit of MRI analysis for synovial sarcoma

We evaluated magnetic resonance imaging (MRI) findings of synovial sarcomas in 22 patients, and the most common MRI findings were oval and well-defined nodular masses with heterogeneous intermediate signal intensity (SI) on T1 weighted images (WI), high SI on T2-WI and heterogeneous contrast enhancement. A cystic component was seen in 77%, intratumoral hemorrhage in 73%, and calcification in three monophasic sarcomas. Metastases were noted in lung (mostly biphasic type), lymph node, and bone. Posttreatment changes revealed diffusely increased S1 on T2-W1 and slightly diffuse contrast enhancement with feathery appearance. Morphology and MR signal characteristics assist in synovial sarcoma management.     

Postradiation sarcomas of the pelvis after treatment for uterine cervical cancer: review of the CT and MR findings of five cases

Objective. To characterize the radiologic features of postradiation sarcomas arising in the pelvic bones following treatment for uterine cervical carcinoma. Design and patients. Five patients who developed postradiation sarcomas in the pelvic bones following radiation therapy for carcinoma of the uterine cervix within the irradiated field were evaluated. Pelvic radiographs, computed tomography (CT) and magnetic resonance (MR) imaging were undertaken in all patients. Histologic confirmation of the tumor type was obtained. Results. Three patients whose tumors were characterized as an osteosarcoma, an angiosarcoma and a malignant fibrous histiocytoma (MFH) showed a large round or oval mass mainly in the sacroiliac joint which extended into the posterior gluteal soft tissues. In a fourth patient an osteosarcoma developed in the central ilium extending widely into the soft tissues both anteriorly and posteriorly, with calcified areas within the extraosseous mass. The fifth patient had a MFH which showed osteolytic destruction of the cortex of the acetabulum, and minimal soft tissue extension. There were no specific features or signal intensity changes on MR imaging to differentiate these cases from primary sarcomas. Conclusion. Postradiation sarcoma must be considered in patients with uterine carcinoma when a soft tissue mass is seen in the previously irradiated field, especially if the mass is posterior to the sacroiliac joint and the latent period is more than 5 years. Received: 3 May 2000 Revision requested: 14 July 2000 Revision received: 28 July 2000 Accepted: 20 November 2000     

Diagnostic imaging of renal sarcomas and sarcomatoid renal cell carcinomas

Renal sarcomas and sarcomatoid renal cell carcinomas are extremely rare neoplasms of the kidney. The Authors reviewed the pathological files and report the features of 12 renal sarcomas and 22 sarcomatoid carcinomas. Leiomyosarcomas and liposarcomas were the most common tumors among the sarcomas, while sarcomatoid carcinomas presented different proportions of carcinomatous and sarcomatous elements. The findings of diagnostic imaging modalities, including plain film and intravenous urography (with nephrotomography), arteriography, ultrasonography and computed tomography, are reported. The findings enable the diagnosis of the nature of these masses. However, the actual experience does not allow a prospective diagnosis of renal sarcoma or of sarcomatoid carcinoma. The mesenchymal nature of the tumor may be suspected when the capsular or sinusal origin is evident, a fatty component is seen within a large aggressive mass and when a hypovascular mass with capsular vessels is seen in angiography. Correspondence to: L. Dalla-Palma     

Neoplastic transformation and tumour-like lesions in Paget's disease of bone: a pictorial review

The development of a sarcoma is the most serious complication of Paget's disease of bone. Although its incidence is <1% of those with the underlying disease, it is important to recognise the imaging features of these tumours as Paget's disease of bone is relatively common in the ageing population in certain parts of the world. The purpose of this pictorial review is to present the imaging features of Paget's sarcoma based on one orthopaedic oncology centres experience in 49 patients; however, not all masses or destructive lesions arising in association with Paget's disease are sarcomas and not all the tumours are malignant. This review also includes other malignancies which may arise in pagetic bone as well as tumour-like manifestations of Paget's disease.     

Evaluation of 99mTc-L-methionine brain SPECT for detection of recurrent brain tumor: a pilot study with radiological and pathological correlation

PURPOSE: To evaluate technetium labeled L-methionine for imaging recurrent brain tumors. MATERIAL AND METHODS: Brain SPECT with 99mTc-L-methionine was performed to evaluate tumor viability in 42 patients with primary brain tumor. Findings of SPECT were correlated with radiological and histopathological findings as reference. RESULTS: 99mTc-L-methionine showed localized increased uptake in 40 patients with tumor recurrence, whereas 2 patients with post-radiation gliosis did not show tracer accumulation. A low differential uptake rate (DUR) 2.43 +/- 0.74 and methionine retention (MR) index 0.93 +/- 0.03 was seen in cases of post-radiation gliosis. A high DUR (36.20 +/- 10.31) and MR index (4.87 +/- 2.37) was seen in cases of recurrent tumor. Mean DUR in high-grade tumors (44.01 +/- 8.46) was significantly higher (P<0.001) than in low-grade tumors (30.42 +/- 7.38), and mean MR index in high-grade tumors (7.03 +/- 2.05) was significantly higher than in low-grade tumors (3.27 +/- 0.82) (P<0.001). CONCLUSION: 99mTc-L-methionine can be used as a SPECT tracer to differentiate tumor recurrence from post-radiation gliosis.     

Radiation-induced soft-tissue and bone sarcoma.

From the records of Memorial Hospital of the past 50 years, 47 cases with an established diagnosis of radiation-induced sarcoma were identified and divided into two groups: the first included 20 cases of soft-tissue sarcoma arising from irradiated tissues, and the second comprised 27 cases of bone sarcoma arising from normal bones in the irradiated field. Medians for the latent periods from irradiation to diagnosis of bone and soft-tissue sarcoma were 11 and 12, years, respectively. In bone sarcomas, the latent period was longer after larger radiation doses and children appeared to be more susceptible to cancer induction than adults. Criteria for establishing the diagnosis of radiation-induced sarcoma and the magnitude of the risk of bone sarcoma are discussed.     

Radiation-induced sarcomas of bone

Historically, the literature reveals that the incidence of radiation induced bone sarcomas is very low. Details related to epidemiology cannot be identified, however, because of the difficulty of identifying precisely the patient population at risk for development of the radiation induced sarcoma. The change in character of practice in cancer management with ever increasing numbers of patients receiving both radiation therapy and chemotherapy should alert physicians to the potential for increased incidence of this rare and unusual tumor.     

Primary mediastinal synovial sarcoma: a report of 2 cases

Synovial sarcoma is the third most common histological type of extremity soft tissue sarcoma. However, primary mediastinal synovial sarcoma is extremely rare. We present 2 cases of unresectable primary mediastinal synovial sarcoma. The radiographic imaging of our present cases was characteristic of a heterogeneously enhancing mass. They were treated with radiotherapy and chemotherapy. However, there was complete obstruction of esophagus resulting from progressive diseases. The radiographic findings and treatment were discussed.     

放疗诱发第二原发肿瘤

放射治疗是恶性肿瘤治疗的重要手段之一。放疗与手术、系统治疗联合明显改善了患者预后,部分长期存活患者被诊断为第二原发恶性肿瘤如乳腺癌、食管癌、直肠癌、膀胱癌、肉瘤等。本文主要对放疗诱发第二原发肿瘤的剂量效应关系、潜伏期、影响因素、诊断、治疗、预后等内容进行阐述。     

Synovial sarcoma: imaging features of common and uncommon primary sites, metastatic patterns, and treatment response

OBJECTIVE: The purpose of this review is to describe the imaging features, common and uncommon sites, metastatic pattern, and treatment response of synovial sarcoma. CONCLUSION: Synovial sarcoma primarily occurs in young adults, most commonly in the lower extremities; presents as a large, noninfiltrative, well-circumscribed mass adjacent to joints, often with punctuate calcifications; and may exhibit a triple signal pattern on T2-weighted images. Small synovial sarcomas can mimic benign lesions. This tumor has a propensity for late local recurrence and metastasis, most commonly to lung.     

Adult rhabdomyosarcoma: cross-sectional imaging findings including histopathologic correlation

OBJECTIVE: The purpose of our study was to present the MRI and CT features of adult rhabdomyosarcomas with histopathologic correlation. Forty-nine sequential cases were incorporated over a 5-year period from the sarcoma unit database. Twenty-six patients had adequate imaging (16 MRI, 10 CT) and histopathology available for retrospective review. The alveolar subtype was present in 13 patients, embryonal subtype in four patients, and pleomorphic subtype in nine patients. On both CT and T1-weighted MRI, all tumors were isodense to skeletal muscle, although enhancement was variable after the administration of IV contrast material. Pleomorphic tumors were very high signal on T2-weighted/STIR imaging, and both pleomorphic and alveolar subtypes were extremely heterogeneous. Embryonal tumors were more homogeneous. CONCLUSION: Although adult rhabdomyosarcomas have certain imaging appearances in common with other soft-tissue sarcomas, features at presentation such as tumor heterogeneity, site, regional lymphadenopathy, and pulmonary metastasis should make the radiologist consider this important diagnosis.     

Radiologic assessment of rectosigmoid cancer before and after neoadjuvant radiation therapy: comparison between quantitation techniques

OBJECTIVE: Volumetric analysis was compared with conventional unidimensional measurements for follow-up of rectosigmoid cancer before and after radiation therapy. SUBJECTS AND METHODS: Fifteen patients with rectosigmoid cancer underwent helical CT before and after neoadjuvant radiation therapy. The helical CT examination was performed after colon distention with air and IV administration of an antiperistaltic drug. Two scans were obtained: one with the patient in the supine position and the other with the patient in the prone position after contrast medium injection. The maximal wall thickness and the volumetric analysis of the tumor were obtained through manual segmentation. RESULTS: The mean of the differences between the volumetric analysis of the scans obtained before and after radiation therapy was 8.3 +/- 10.3 (SD) mL (-22.7%) (p <0.05). The mean of the differences between the maximal wall thickness of the pre- and post-radiation therapy scans was 3.4 +/- 2.6 mm (-19.1%) (p <0.05). A significant difference was observed between the variation of the maximal wall thickness and the variation of volumetric analysis in pre- and post-radiation therapy scans (p <0.05). The patients could be classified in different response categories depending on the measurement method and on the response criteria. CONCLUSION: Volumetric analysis of rectosigmoid cancer is feasible. A long-term study is needed to correlate volumetric assessment with patient outcome.     

Diffusion-weighted MRI of soft tissue tumours

The purpose of this study was to evaluate the clinical utility of a multi-shot spin-echo echo-planar (SE-EPI) diffusion-weighted sequence in the diagnostic work-up of soft tissue tumours. There were 29 patients, 16 with a benign lesion and 13 with a sarcoma. Four of the sarcomas were examined both before and after radiation therapy. Diffusion-weighted imaging was performed with a multi-shot SE-EPI sequence. The b values were 0 and 600 s/mm². Phase navigation and pulse trigging were applied. The apparent diffusion constant (ADC) value of a large region of interest (ROI) representing the lesion was measured and compared to diagnosis and treatment. The ADC values of the benign lesions (mean 1.8×10^–3 mm²/s) overlapped with non-treated sarcomas (mean 1.7×10^–3 mm²/s). The ADC value increased in all radiated sarcomas. A multi-shot SE-EPI diffusion imaging sequence of less than 2-min duration is technically feasible in soft tissue tumours of the extremities and the trunk. The ADC values of benign soft tissue tumours and sarcomas overlapped and could not be used to differentiate between the bulk of benign and malignant tumours. However, the increase in ADC values of soft tissue sarcomas after radiotherapy warrants further studies of diffusion imaging for evaluating therapy response.     

Primary hepatic sarcomas: CT findings

Primary hepatic sarcomas are rare tumors that are difficult to diagnose clinically. Different primary hepatic sarcomas may have different clinical, morphologic, and radiological features. In this pictorial review, we summarized computed tomography (CT) findings of some relatively common types of hepatic sarcomas, including angiosarcoma, epithelioid hemangioendothelioma (EHE), liposarcoma, undifferentiated embryonal sarcoma (UES), leiomyosarcoma, malignant fibrous histiocytoma (MFH), and carcinosarcoma (including cystadenocarcinosarcoma). To our knowledge, hepatic cystadenocarcinosarcoma has not been described in the English literature. The CT findings in our case are similar to that of cystadenocarcinoma, a huge, multilocular cystic mass with a large mural nodule and solid portion. The advent of CT has allowed earlier detection of primary hepatic sarcomas as well as more accurate diagnosis and characterization. In addition, we briefly discuss the MRI findings and diagnostic value of primary hepatic sarcomas.     

Primary synovial sarcoma of the sternum: computed tomography and magnetic resonance imaging findings

We report the computed tomography (CT) and magnetic resonance imaging (MRI) findings of a rare case of synovial sarcoma of the sternum in an 86-year-old man. CT demonstrated an inhomogenously enhanced soft-tissue-density mass of the sternum that destroyed bone cortex and protruded anteriorly. On MRI, the tumor showed a multinodular mass with internal septation and heterogeneous enhancement. These CT and MRI findings were nonspecific, but were similar to those of soft tissue synovial sarcomas. The tumor was more clearly demarcated by MRI than CT. This is the first report concerning the CT and MRI findings of synovial sarcoma of the sternum. Synovial sarcoma should be added to the gamut of primary malignant neoplasms of the sternum.     

Neoplastic transformation and tumour-like lesions in Paget's disease of bone: a pictorial review

The development of a sarcoma is the most serious complication of Paget's disease of bone. Although its incidence is <1% of those with the underlying disease, it is important to recognise the imaging features of these tumours as Paget's disease of bone is relatively common in the ageing population in certain parts of the world. The purpose of this pictorial review is to present the imaging features of Paget's sarcoma based on one orthopaedic oncology centres experience in 49 patients; however, not all masses or destructive lesions arising in association with Paget's disease are sarcomas and not all the tumours are malignant. This review also includes other malignancies which may arise in pagetic bone as well as tumour-like manifestations of Paget's disease.

     

Bone Metastases from Soft Tissue Sarcomas

The incidence, distribution, time of appearance, and radiologic findings of bone metastases from soft tissue sarcomas, exclusive of lymphomas, were evaluated in 320 patients with soft tissue sarcomas. Thirty patients (9.4%) had evidence of 58 bone metastases. Five of 30 patients presented with metastases, and 25 of 30 patients developed metastases up to 66 months after presentation with a mean time interval of 21.3 months. The incidence of skeletal metastases differed among histologic subtypes of sarcomas; alveolar soft part sarcoma (5 of 8), dedifferentiated liposarcoma (2 of 4), angiosarcoma (2 of 4), and rhabdomyosarcoma (5 of 16) tended to show a higher incidence of bone metastases. The sarcomas metastasized to the regional bones close to the primary tumor in 16 (53%) of 30 patients and to the axial bones in 18 (60%). On conventional radiographs, the osseous metastases demonstrated predominantly osteolytic changes, and evidence of pathological fracture was observed in 31% of 58 metastases.