Imaging oligometastatic cancer before local treatment

Abstract

With the advent of novel treatment strategies to help widen the therapeutic window for patients with oligometastatic cancer, improved biomarkers are needed to reliably define patients who can benefit from these treatments. Multimodal imaging is one such option and should be optimised to comprehensively assess metastatic sites, disease burden, and response to neoadjuvant treatment in each disease setting. These features will probably remain important prognostic biomarkers, and are crucial in planning multidisciplinary treatment. There are opportunities to extract additional phenotypic information from conventional imaging, while novel imaging techniques can also reveal specific aspects of tumour biology. Imaging can both characterise and localise the phenotypic heterogeneity of multiple tumour sites. Novel approaches to existing imaging datasets and correlation with tumour biology will be important in realising the potential of imaging to guide treatment in the oligometastatic setting. In this Personal View, we discuss the current status and future directions of imaging before treatment in patients with extracranial oligometastases.

Use of modern imaging methods to facilitate trials of metastasis-directed therapy for oligometastatic disease in prostate cancer: a consensus recommendation from the EORTC Imaging Group

“…The main imaging requirements for efficient OMD screening include high sensitivity, specificity, but also high negative predictive value at the patient, region, and lesion levels. It is also critical to have standardized acquisition, validated repeatability and reproducibility, reading recommendations and response measurement criteria 14 . Comparisons of SIMs and MIMs have repeatedly shown the superiority of MIMs, and in particular the deficiency of SIMs to meet the requirements for precision medicine 15,16 .…”

Progression-directed Therapy for Oligoprogression in Castration-refractory Prostate Cancer

“…majority of lesions are controlled by the ongoing systemic therapy [3]. This heterogeneous response to treatment reflects the heterogeneity of subclones within the different metastatic spots [4]. When oligoprogression occurs, only a minor fraction of the total disease burden progresses.…”

[18F]Fluorocholine PET/CT-guided stereotactic body radiotherapy in patients with recurrent oligometastatic prostate cancer

“…Otherwise, systemic therapy was initiated. Since the prerequisite for a curative SBRT is an accurate patients’ selection, one of the most critical issues on oligometastatic patients with PCa is the accurate definition of the tumor burden, a critical aspect to planning local treatments [13]. In this study, we aimed to validate [ 18 F]FMCH PET/CT as the technique of choice in selecting patients and active metastases to be treated with SBRT.…”