Single Dose Radiotherapy (SDRT) in Oligometatstasis Ablation

This study focuses on treatment outcomes of human metastatic cancer which usually fares with dismal (\<5%) survival at 5 years following first diagnosis of a metastasis. However, a subgroup of patients with an initial oligometastatic presentation (i.e. 1-5 clinically detectable lesions) have been reported to respond to complete surgical removal of detectable deposits with up to 20% disease-free survival at 10 years. Patients relapsing with a second oligometastatic presentation respond to a second round of ablation with encouraging rates of 5-year disease free survival. Based on patterns of response to therapy and relapse, we propose investigate on the hypothesis that metastatic disease may be limited in extent, slowly growing and amenable to successive eradication of metastatic deposits. For visible tumor ablation, we propose to employ the effective and safe technique of Single Dose Image-Guided Radiotherapy (SDRT) and to optimize its use in conjunction with systemic therapy. Where SDRT at a full ablative dose (24Gy) is deemed unfeasible, hypofractionated SBRT (9Gy x3) will be offered. Response assessment will be via local control, poly-metastasis-free survival and overall survival rates. Preliminary phase I/II studies indicate remarkable benefits from the SDRT/SBRT in patients with limited metastatic disease. The expected outcomes may be significant conceptual and practical changes in the management of selected metastatic settings resulting in long-term periods of disease-free and overall survival in settings presently associated with dismal prognosis.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

* Histologic confirmation of malignancy;
* FDG PET/CT (or other tracer) PET/CT evidence of limited (1-5) metastases;
* All detectable lesions must be considered amenable to SDRT or hypofractionated ablation;
* Age ≥ 18 years;
* Life expectancy \> 6 months;
* EGOG Performance Status 0-2;
* Signed informed consent form for treatment;

Exclusion Criteria:

* Overt poly-metastatic disease (≥5 lesions) as shown by PET/CT scanning;
* Performance status \>2;
* Severe, active co-morbidity;
* Significant psychiatric illness;

• DERIVEDGreco C, Kolesnick R, Fuks Z. Conformal Avoidance of Normal Organs at Risk by Perfusion-Modulated Dose Sculpting in Tumor Single-Dose Radiation Therapy. Int J Radiat Oncol Biol Phys. 2021 Jan 1;109(1):288-297. doi: 10.1016/j.ijrobp.2020.08.017. Epub 2020 Aug 7. PMID 32777335