Research status and progress of radiomics in bone and soft tissue tumors: A review

Bone and soft tissue tumors are diverse, accompanying by complex histological components and significantly divergent biological behaviors. It is a challenge to address the demand for qualitative imaging as traditional imaging is restricted to the detection of anatomical structures and aberrant signals. With the improvement of digitalization in hospitals and medical centers, the introduction of electronic medical records and easier access to large amounts of information coupled with the improved computational power, traditional medicine has evolved into the combination of human brain, minimal data, and artificial intelligence. Scholars are committed to mining deeper levels of imaging data, and radiomics is worthy of promotion. Radiomics extracts subvisual quantitative features, analyzes them based on medical images, and quantifies tumor heterogeneity by outlining the region of interest and modeling. Two observers separately examined PubMed, Web of Science and CNKI to find existing studies, case reports, and clinical guidelines about research status and progress of radiomics in bone and soft tissue tumors from January 2010 to February 2023. When evaluating the literature, factors such as patient age, medical history, and severity of the condition will be considered. This narrative review summarizes the application and progress of radiomics in bone and soft tissue tumors.

Risk Factors Analysis of Phantom Limb Pain in Amputees with Malignant Tumors

Purpose

Postamputation neuropathic pain is a common disease in patients with malignant tumor amputation, seriously affecting amputees' quality of life and mental health. The objective of this study was to identify independent risk factors for phantom limb pain in patients with tumor amputation and to construct a risk prediction model.

Methods

Patients who underwent amputation due to malignant tumors from 2013 to 2023 were retrospectively analyzed and divided into phantom limb pain group and non-phantom limb pain group. To determine which preoperative factors would affect the occurrence of phantom limb pain, we searched for candidate factors by univariate analysis and used multivariate logistic regression analysis to identify independent factors and construct a predictive model. The receiver operating characteristic curve (ROC) was drawn to further evaluate the accuracy of the prediction model in evaluating the phantom limb pain after amputation of bone and soft tissue tumors.

Results

Multivariate analysis showed that age (OR, 1.054; 95% CI, 1.027 to 1.080), preoperative pain (OR, 5.773; 95% CI, 2.362 to 14.104), number of surgeries (OR, 3.425; 95% CI, 1.505 to 7.795), amputation site (OR, 5.848; 95% CI, 1.837 to 18.620), amputation level (OR, 8.031; 95% CI, 2.491 to 25.888) were independent risk factors for phantom limb pain for bone and soft tissue tumors. The the area under the curve (AUC) of this model was 0.834.

Conclusion

Risk factors for postoperative phantom limb pain were the site of amputation, proximal amputation, preoperative pain, multiple amputations, and older age. These factors will help surgeons to individualize and stratify phantom limb pain and help patients with risk counseling. In particular, an informed clinical decision targeting those modifiable factors can be considered when needed.

Clinical Outcomes of Intensity-modulated Carbon-ion Radiotherapy for Bone and Soft Tissue Tumors

BACKGROUND/AIM

Carbon-ion radiotherapy (CIRT) for bone and soft tissue tumors (BSTs) has been reported to have favorable clinical outcomes. Intensity-modulated CIRT (IMCT) techniques have been developed to further reduce dose delivery to adjacent organs compared to conventional CIRT. We retrospectively analyzed the clinical results of IMCT for BSTs and investigated treatment efficacy and toxicity.

PATIENTS AND METHODS

This study included 9 consecutive BSTs patients who underwent IMCT at the Kanagawa Cancer Center from January 2016 to April 2021. IMCT was administered at a dose of 60.8-70.4 Gy (relative biological effect) in 16 fractions. The time to event was calculated from the initiation of IMCT. Toxicities were evaluated using the Common Terminology Criteria for Adverse Events version 5.0.

RESULTS

The median age was 49 (range=16-71) years. The median observation period was 57.6 (range=7.0-77.8) months. There were 7 and 2 cases for IMCT because of proximity to the spinal cord and intestinal tract, respectively. There was one death during the observation period, which occurred 7.0 months after the initiation of treatment. Clinical recurrence occurred in 3 patients at 1.3, 17.8, and 22.4 months after the initiation of treatment, respectively. Acute toxicity of Grade 2 or higher was seen in 2 patients with Grade 2 pharyngeal mucositis. Late toxicities of Grade 2 or higher included 1 case each of Grade 2 neuralgia and peripheral neuropathy, as well as 1 case of Grade 3 fracture.

CONCLUSION

IMCT for BSTs showed good local therapeutic efficacy and tolerable toxicity in patients with bone and soft tissue tumors.

Treating Low-Grade Myxofibrosarcoma With Stereotactic Body Radiation Therapy Using CyberKnife®

Myxofibrosarcoma (MFS) is one of the most common soft tissue sarcomas. Low-grade MFS has a high local recurrence rate, similar to that of high-grade MFS. Hence, appropriate adjuvant therapy is required to control low-grade MFS. In this report, we present a case in which recurrent low-grade MFS was successfully treated with stereotactic body radiation therapy (SBRT) using CyberKnife® (CK) (Accuray Incorporated, Sunnyvale, CA). A 76-year-old man underwent SBRT using CK for recurrent low-grade MFS in the right posterior chest wall after undergoing resection and skin grafting four and three times, respectively. We planned CK treatment separately for each in two parts. For the lesion on the scapula side, the target volume was 109 cm³ and the total prescribed dose was 34.6 Gy, while the lesion on the spinal side had a target volume of 72 cm³ and a total prescribed dose of 36 Gy, both in five fractions. Each SBRT was performed on alternate days in a span of 14 days. The tumors gradually reduced in size with tolerable levels of toxicity. SBRT using CK could be a safe and effective adjuvant therapy for low-grade MFS.

Mismatch repair deficiency is rare in bone and soft tissue tumors

Introduction

There has been an increased demand for mismatch repair (MMR) status testing in sarcoma patients after the success of immune checkpoint inhibition (ICI) in MMR deficient tumors. However, data on MMR deficiency in bone and soft tissue tumors is sparse, rendering it unclear if routine screening should be applied. Hence, we aimed to study the frequency of MMR deficiency in bone and soft tissue tumors after we were prompted by two (potential) Lynch syndrome patients developing sarcomas.

Methods

Immunohistochemical expression of MLH1, PMS2, MSH2 and MSH6 was assessed on tissue micro arrays (TMAs), and included 353 bone and 539 soft tissue tumors. Molecular data was either retrieved from reports or microsatellite instability (MSI) analysis was performed. In MLH1 negative cases, additional MLH1 promoter hypermethylation analysis followed. Furthermore, a systematic literature review on MMR deficiency in bone and soft tissue tumors was conducted.

Results

Eight MMR deficient tumors were identified (1%), which included four leiomyosarcoma, two rhabdomyosarcoma, one malignant peripheral nerve sheath tumor and one radiation‐associated sarcoma. Three patients were suspected for Lynch syndrome. Literature review revealed 30 MMR deficient sarcomas, of which 33% were undifferentiated/unclassifiable sarcomas. 57% of the patients were genetically predisposed.

Conclusion

MMR deficiency is rare in bone and soft tissue tumors. Screening focusing on tumors with myogenic differentiation, undifferentiated/unclassifiable sarcomas and in patients with a genetic predisposition / co‐occurrence of other malignancies can be helpful in identifying patients potentially eligible for ICI.

Investigation of multiple primary cancers in patients with bone and soft tissue primary malignancies: A retrospective, institution-based study

In the aging society in Japan, the occurrence of multiple primary cancers has recently increased due to an increase in life expectancy and increased development in cancer diagnostic technology and improvement in treatment outcomes. However, few reports have focused on multiple primary cancers in patients with bone and soft tissue tumors. The present study aimed to analyze the clinical characteristics of patients with multiple malignancies of the bone and soft tissue. Between April 2008 and April 2017, among 973 patients treated at the Department of Orthopedic Surgery, Osaka City University Hospital, those with multiple primary cancers involving bone and soft tissue were identified. The number of cases with multiple cancers in the present study was 30/973 (3.08%), including 21 males and 9 females. The median age at diagnosis of patients with bone and soft tissue sarcoma was 73.5 years (range, 7-83 years). There were 22 patients with double cancers, and 5, 2 and 1 patients with triple, quadruple and quintuple cancers, respectively. Colorectal cancer was the most common primary cancer (n=9). In total, 28.6% of patients had simultaneous cancer, while 71.4% of patients had heterochronous cancer. The overall 5-year survival for all patients was 75.6%. The prognosis of patients with double cancer of bone and soft tissue sarcoma was not necessarily poor. However, it is necessary to pay attention to the possibility of secondary malignancy. Therefore, it is essential to be careful and well organized when selecting treatment modalities and to adopt a logistical approach for the care of patients with ongoing multiple malignancies.