State-of-the-art of multidisciplinary approach of bone metastasis-directed therapy: review and challenging questions for preparation of a GEMO practice guidelines

Abstract

Bone is a common secondary site of dissemination during the course of cancer. Bone metastases (BM) can be associated with skeletal-related events (SRE) such as disabling pain, hypercalcemia, and bone instability that leads to pathological fractures or spinal cord compression. SRE contribute to high morbidity as well as, mortality, and have a negative economic impact. Modern management of BM integrates focal treatments (such as radiotherapy, surgery, and interventional radiology), orthoses, and antiresorptive and systemic oncological treatment. The choice of a metastasis-directed therapy depends on the objective of the treatment, the patient characteristics, and the complete assessment of the bone lesion (pain, neurological risk, and instability). In the narrative review present herein, we aim to provide an updated summary of the literature, with description of the advantages and disadvantages of current and emerging strategies in the multimodal treatment of BM and, based on these data, an updated algorithm for the management of BM.

Keywords: Bone metastases; Interventional radiology; Radiotherapy; Skeletal-related event; Surgery.

Fig. 1

Examples of multimodal metastasis-directed therapy: A osteolytic lesion of the lateral malleolus of the right tibia with soft tissue involvement treated with radiotherapy, cementoplasty, and percutaneous osteosynthesis (left to right: coronal computed tomography (CT) scan of the lesion before any treatment; coronal CT scan of the right tibia after cementoplasty and osteosynthesis; sagittal radiography of the right ankle after treatment); B unstable osteolytic lesion of C2 treated with cementoplasty, screw fixation and radiotherapy (left to right: sagittal CT scan of the cervical spine with untreated lesion of C2; sagittal view after treatment; coronal view after treatment)

Fig. 2

Summary of the main advantages and disadvantages of metastasis-directed therapies (MDT) in bone metastases management. This table describes the suitability of a technique for a given clinical objective. A green checkmark means that the technique makes it possible to achieve the objective. A orange checkmark means that the objective is partially met with the technique. The red cross means that the technique is unable to achieve the objective. OS: overall survival; PFS: progression-free survival; cRT: conventional radiotherapy; 3DRT: tridimensional radiotherapy; IMRT: intensity modulated radiation therapy; CRA: cryotherapy ablation; RFA: radiofrequency ablation; SBRT: stereotactic body radiation therapy; BRI: bone resorption inhibitor

Fig. 3

MDT-NOMS algorithm for metastasis-directed therapy on bone according to treatment objective. OS: overall survival; PFS: progression-free survival; LC: local control; SRE: skeletal-related events; IMRT: intensity modulated radiation therapy; CRA: cryotherapy ablation; RFA: radiofrequency ablation; SBRT: stereotactic body radiotherapy; QoL: quality of life; MESCC: metastatic epidural spinal cord compression; RT: radiotherapy; Gy: grays. ^*Bilsky classification. ^†Separation surgery + SBRT may be discussed in selected cases of patients with radioresistant primary tumor. ^‡In selected cases, a mini-invasive procedure (surgery or interventional radiology) may be discussed in case of symptomatic instability profoundly impacting quality of life