Defining a Therapeutic Ratio for Stereotactic Ablative Radiation Therapy in Oligometastatic Disease—Another Piece of the Puzzle
Mené au Canada entre 2016 et 2020 sur 381 patients atteints d'une maladie oligométastatique ou oligoprogressive (32 % de femmes ; âge moyen : 68 ans ; durée médiane de suivi : 25 mois), cet essai de phase II évalue la toxicité d'une radiothérapie stéréotaxique d'ablation
Résumé en anglais
For more than a century, radiation therapy has played a key role in palliating symptomatic, incurable cancers to alleviate localized symptoms for patients with metastatic cancer. In the past 2 decades since the potential existence of an oligometastatic state was described, there has been increased enthusiasm for treating metastatic cancer. As a result, technical advances in radiation delivery and research have sought to define a role for radiation beyond symptom relief.In this issue of JAMA Oncology, Olsen et al report their phase 2 trial of extracranial stereotactic ablative body radiotherapy (SABR) for oligometastatic (83%) or oligoprogressive (17%) cancer, with treatment toxic effects and patient-reported outcomes as the primary end points; safety is reported in the article, and quality of life data will be reported in the future. This prospective study of 381 patients allowed up to 5 sites of metastases to be treated with SABR, mostly treating lung (34%) or bone (58%) metastases. Treatment planning permitted clearly defined doses to metastatic tumors only if strict organ at risk dose constraints could be met. With a median follow-up time of 25 months, the reported 2-year risk of grade 2 or higher and grade 3 or higher toxic effects were 8% and 4%, respectively, with only 1 lethal adverse event. These results met the investigators’ predetermined criteria for safe treatment. Grade 2 treatment toxic effects were more than 20% with SABR for liver or adrenal metastases compared with only 9% for lung. Half of the grade 3 or higher toxic effects occurred more than 1 year after treatment with SABR (eTable 4 in Supplement 1 of the article). There is no evidence of any significant differences in treatment toxic effects in treatment-naive oligometastatic disease compared with oligoprogressive disease.
