Feasibility Study of FLASH Radiotherapy for the Treatment of Symptomatic Bone Metastases

Varian, a Siemens Healthineers Company10 enrolled

Overview

This purpose of this study is to assess the feasibility of FLASH radiotherapy for the palliative treatment of painful bone metastases. FLASH radiotherapy is radiation treatment delivered at ultra-high dose rates compared to conventional radiation treatment.

This clinical investigation is designed to assess the workflow feasibility of FLASH radiotherapy treatment in a clinical setting, as well as the toxicities, and pain relief when used to treat bone metastasis(-es) in the extremities (excluding feet, hands, wrists). FLASH radiotherapy has been shown in preclinical studies to cause less injury to surrounding normal tissues during radiation treatment, while still having similar tumor cell killing. Patients at least 18 years of age with painful bone metastases located in the limbs will be considered for the study. These patients represent an ideal population for a feasibility study of FLASH radiotherapy as they are known to benefit from the palliative effects of radiotherapy using single dose radiation regimens of 8Gy which is what is being used in this investigation. After treatment, patients will be assessed for pain response as well as any adverse side-effects of radiation. The workflow feasibility of the treatment will also be evaluated.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Bone Metastasis

Interventions

FLASH RadiotherapyRADIATION

FLASH radiotherapy is radiation treatment delivered at ultra-high dose rates compared to conventional radiation treatment.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Patient age at least 18 years * Up to 3 painful bone metastasis(-es) in the extremities * Bone metastases that can be treated using pre-defined treatment field sizes (7.5 cm x 7.5 cm; 7.5 cm x 10 cm; 7.5 cm x 12 cm; 7.5 cm x 14 cm; 7.5 cm x 16 cm; 7.5 cm x 18 cm; 7.5 cm x 20 cm), without overlap of radiation fields * Life expectancy of \>2 months (in the judgement of the investigator) * Patients who are able to comply with the protocol * Provision of signed and dated informed consent form Exclusion Criteria: * Prior radiotherapy to the treatment site(s) * Lesions of the feet, hands, wrists are not eligible treatment sites for FLASH * More than 3 painful bone metastases of the limbs requiring palliative radiotherapy * Tumor lysis of \>50% of the circumferential bone cortex, or other factors considered to place the subject at significant risk of pathologic fracture * Patients with bone fractures and/or metal implants in the treatment field * Patients who will receive cytotoxic chemotherapy within 1 week prior to or 1 week following their planned radiation treatment * Prior local therapy modality to the treatment site(s) within 2 weeks of study enrollment * Patients with pacemakers or other implanted devices at risk of malfunction during radiotherapy * Patients with any other medical condition or laboratory value that would, at the discretion of the investigator, preclude the patient from participation in this clinical investigation * Patients at known risk of enhanced normal tissue sensitivity to radiotherapy due to inherited predisposition or documented comorbidity that might lead to hypersensitivity to ionizing radiation * Patients enrolled in any other clinical studies the investigator believes to be in conflict with this clinical investigation. * Patients who are pregnant or nursing

Locations (1)

Cincinnati Children's Proton Therapy Center

Cincinnati, Ohio, United States

Outcomes

Primary Outcomes

Workflow Feasibility

Number of participants with total time on table under one hour. The investigational site staff will measure the time for participant set-up and positioning on the treatment couch, imaging and FLASH treatment delivery. The workflow feasibility outcome measure is met for an individual subject if total time on table is measured as less than one hour. The outcome measure data table provides the mean and full range of time on table (as measured in minutes) for the 10 participants. The participant with a treatment time of 33 minutes received treatment to two separate metastatic sites; remaining 9 participants received treatment to a single metastatic site.

Time frame: Will be assessed on day of treatment delivery which occurs within 3 weeks of subject enrollment.

Workflow Feasibility

Number of participants whose treatment was delayed by more than 7 business days from simulation to treatment when related to the investigational device (excluding delays due to patient or facility factors not related to study treatment). The investigational site staff will measure the number of days delay in time to treatment due to problems involving the investigational device. The workflow feasibility outcome measure is met for an individual subject if the delay is measured as less than 7 days. The outcome measure data table provides the mean and full range days of treatment delay for the 10 participants.

Time frame: Will be assessed within 4 weeks of subject enrollment.

Assessment of Radiation-related Toxicities That Are Possibly, Probably, or Definitely Related to FLASH Radiotherapy.

Toxicities that are possibly, probably, or definitely related to FLASH radiotherapy. Toxicities will be classified per CTCAE version 5.0. The outcome measure data table summarizes the total number of adverse events possibly, probably, definitely related to treatment that were reported in the 10 participant cohort. Eleven adverse events were grade 1 and one adverse event was grade 2, as classified by CTCAE version 5.0.

Time frame: Assessed from start of treatment until subject death or lost to follow-up, up to 17.8 months

Secondary Outcomes

Data from ClinicalTrials.gov

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Pain Relief

Percentage of treated sites achieving pain relief as measured using patient reported outcome questionnaires (Brief Pain Inventory Questionnaire, Treated Sites Pain Questionnaire). Categories of pain relief included complete, partial, stable or progressive response. Complete response (CR) = no pain at 3 months Partial response (PR) = an average pain score that is ≥2 points lower than initial Stable disease (SD) = an average pain score that is ±1 point change from initial Progressive disease (PD) = an average pain score that is ≥2 points higher than initial

Time frame: At 3 month follow up

Number of Participants Who Experienced a Pain Flare.

Pain was assessed by patient reported validated 10 point pain flare questionnaire. Pain flare is defined as either of the following: A) a minimum of a two-point increase in the worst pain score for the treated site without a reduction in analgesic intake; or B) a 25% or greater increase in analgesic intake based on daily oral morphine equivalence without a reduction in the worst pain score.

Time frame: First 10 days post FLASH treatment

Number of Participants With Increased Use of Pain Medication in First 10 Days Post FLASH Treatment

Use of pain medication by study participant during days 1-10 following FLASH treatment was collected as it constituted one of the defining criteria (criteria B) for the pain flare outcome measure. Pain flare is defined as either of the following: A) a minimum of a two-point increase in the worst pain score for the treated site without a reduction in analgesic intake; or B) a 25% or greater increase in analgesic intake based on daily oral morphine equivalence without a reduction in the worst pain score.

Time frame: Within 10 days after treatment.