Predicting clinical outcomes in chordoma patients receiving immunotherapy: a comparison between volumetric segmentation and RECIST

Abstract

BackgroundThe Response Evaluation Criteria in Solid Tumors (RECIST) are the current standard for evaluating disease progression or therapy response in patients with solid tumors. RECIST 1.1 calls for axial, longest-diameter (or perpendicular short axis of lymph nodes) measurements of a maximum of five tumors, which limits clinicians’ ability to adequately measure disease burden, especially in patients with irregularly shaped tumors. This is especially problematic in chordoma, a disease for which RECIST does not always adequately capture disease burden because chordoma tumors are typically irregularly shaped and slow-growing. Furthermore, primary chordoma tumors tend to be adjacent to vital structures in the skull or sacrum that, when compressed, lead to significant clinical consequences.MethodsVolumetric segmentation is a newer technology that allows tumor burden to be measured in three dimensions on either MR or CT. Here, we compared the ability of RECIST measurements and tumor volumes to predict clinical outcomes in a cohort of 21 chordoma patients receiving immunotherapy.ResultsThere was a significant difference in radiologic time to progression Kaplan-Meier curves between clinical outcome groups using volumetric segmentation (P = 0.012) but not RECIST (P = 0.38). In several cases, changes in volume were earlier and more sensitive reflections of clinical status.ConclusionRECIST is a useful evaluation method when obvious changes are occurring in patients with chordoma. However, in many cases, RECIST does not detect small changes, and volumetric assessment was capable of detecting changes and predicting clinical outcome earlier than RECIST. Although this study was small and retrospective, we believe our results warrant further research in this area.

Modern approach to the treatment of sacrococcygeal chordomas

“…Наиболее информативными в диагностике хордом крестца являются магнитнорезонансная (МРТ) и ком пьютерная (КТ) томография [18]. Стандартные рент генография, КТ и МРТисследования необходимы для определения точной анатомической локализации опухоли и планирования хирургического вмешатель ства [19].…”

Chordoma: Etiology, Pathogenesis, Diagnosis, Treatment

“…Для выявления хордомы необходимо тщательное неврологическое обследование, а также использование лучевых методов исследования (рентгенография, компьютерная томография, магнитно-резонансная томография). Из методов лучевой диагностики наиболее информативными признаны магнитно-резонансная (МРТ) и компьютерная (КТ) томография [24]. В настоящее время применяется такая технология исследования, как объемная сегментация.…”

“…В настоящее время применяется такая технология исследования, как объемная сегментация. Эта технология позволяет определить размеры опухоли в трех измерениях на МРТ или КТ, что важно для выявления локализации и масштаба поражения кости [24].…”

Phase I Trial of a Modified Vaccinia Ankara Priming Vaccine Followed by a Fowlpox Virus Boosting Vaccine Modified to Express Brachyury and Costimulatory Molecules in Advanced Solid Tumors

“…Interestingly, volumetric measurement (segmentation) of the patient's scans showed an 83% decrease in the volume of their target lesions, which may be equivalent to partial response per RECIST version 1.1 as a 30% decrease in diameter is equivalent to 65% reduction in volume . This suggests that restricting response evaluations to single diameter measurements may be inappropriate for tumors with a nonspherical growth pattern (such as chordoma) and that volumetric tumor assessment, although time consuming, may better determine the potential treatment benefit . Another patient with chordoma (patient 1) has had stable disease for at least 40 weeks and came off treatment because of patient choice (unconfirmed disease progression at week 51).…”