FLASH Radiotherapy for Skin Cancer

Not Applicable

Recruiting

• Conditions: Basal Cell Carcinoma; Cutaneous Squamous Cell Carcinoma
• Interventions: Device: FLASH RT; Device: Conventional RT

• Registration Number: NCT05724875
• Lead Sponsor: Centre Hospitalier Universitaire Vaudois

Brief Summary

This is a single center randomized selected Phase II study of FLASH radiotherapy (RT) versus standard of care (SOC) radiotherapy in patients with localized Cutaneous Squamous Cell Carcinoma (cSCC) or Basal Cell Carcinoma (BCC).

In summary, the aims of the study are to describe and compare the toxicity and efficacy of high dose rate radiotherapy (FLASH therapy) to SOC conventional radiotherapy (according to the standard guidelines per lesion size) through a randomized Phase II selection study in patients presenting localized cSCC or BCC requiring a radiotherapy treatment.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2023-01-17
• Study First Submitted QC: 2023-02-02
• Study First Posted: 2023-02-13
• Study Start: 2023-06-22
• Status Verified: 2025-02
• Last Update Submitted: 2025-02-21
• Last Update Posted: 2025-02-24
• Primary Completion: 2026-09
• Study Completion: 2026-09

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• Signed study Informed Consent Form
• Karnofsky Performance Status (KPS) ≥ 60
• Age ≥ 60 years
• Patients with histologically proven cSCC or patients with BCC either histologically proven or proven by non-invasive imaging: either Optical Coherence Tomography (OCT), Line-field OCT (LC-OCT) or Reflectance Confocal Microscopy (RCM)
• Patients requiring radiotherapy treatment according to the dermato-oncology tumor board: patients who cannot undergo surgical procedure or patients who decline surgical resection, and/or anatomical locations where surgery can compromise function or cosmesis.
• T1-T2 N0 lesions with a small (T1; lesion ≤ 2cm in diameter) or large (T2; 2cm < lesion ≤ 4 cm) volume (TNM Classification of Malignant Tumours (TNM) Union for International Cancer Control (UICC), 8th Edition)
• Lesions should be at least 4 cm apart if treated with 2 different modalities (including surgical treatment of lesions). Lesions should not be located on the face, except on the forehead, above a line situated 1 cm above the eyebrows. Lesions located on the scalp can be treated.

Exclusion Criteria

• Previous radiotherapy in the treated area
• Concomitant auto-immune disease with skin lesions
• Concomitant use of radio-sensitizer drug
• Cognitive disorders not compatible with the signature of informed consent or that may compromise compliance with the requirements of the study
• Current, recent (within 10 days prior to start of study treatment), or planned participation in an experimental drug study (before end of treatment (EOT) visit)
• Concomitant use of systemic chemotherapy for a cancer other than the skin cancer(s)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Arm A: FLASH RT	FLASH RT	-
Arm B: Conventional RT	Conventional RT	-

Primary Outcome Measures

Name	Time	Method
Hierarchically tested efficacy measured by local control rate	From Day 1 up to 12 months post-treatment	At day 1, 21, 28, 42, and months 3, 6, and 12 post-treatment, the investigator will measure (with a caliper) the largest diameter of selected lesions for irradiation.; Tumor response of each irradiated lesion will be assessed by the investigator as follow: * Complete Response: the irradiated lesion is no more visualized; * Partial Response: the irradiated largest lesion dimension decreased by 30% at least from baseline (day 1); * Progressive Disease: the irradiated largest lesion dimension increased by 20% at least from baseline (day 1); * Stable Disease: no Complete Response, no Partial Response, no Progressive Disease
Frequency of ≥ grade 3 skin toxicity adverse events (AEs) according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0	up to 6 weeks after radiotherapy	To evaluate the safety of FLASH radiotherapy measured by the collection of ≥ grade 3 skin toxicity AEs according to CTCAE version 5.0. The severity of a specific event is graded i.e. mild (grade 1), moderate (grade 2), severe (grade 3), life-threatening (grade 4), or death (grade 5) using the CTCAE Grading Table.

Secondary Outcome Measures

Name	Time	Method
Frequency of late side effects observed "in radiation field"	from ≥ 3 months after radiotherapy until 12 months post-treatment start
Vessel density measured by OCT	at baseline, at 4 weeks, at 6 months, and at 12 months post-treatment	Vessel density, expressed as percent of the surface covered by the vessels in the examined area, will be measured by OCT and compared between irradiated skin and normal non-irradiated skin
Number of hairs counted by OCT	at baseline, at 4 weeks, at 6 months, and at 12 months post-treatment	Number of hairs in the examined area will be counted by OCT and compared between irradiated skin and normal non-irradiated skin
Evaluation of tumor response	From Day 1 up to 12 months post-treatment	Blinded Imaging Central Review (BICR) of photographs will evaluate tumor response by grading the size of the residual tumor in comparison to the size of the tumor on the day of irradiation (in percentage). 0% means no residual tumor and treatment success, 100% or more indicate a total lack of tumor response.; A baseline photograph will be taken the day of the treatment (day 1) in a pre-therapeutic setting with skin delineation of the lesion. Then photos will be repeated at day 21 (+/-2d), day 28 (+/-2d), day 42 (+/-3d) after treatment, then at 3 (+/-7d), 6 (+/-14d), 12 (+/-14d) months after treatment, and at progression.
Epidermis thickness measured by Optical coherence tomography (OCT)	at baseline, at 4 weeks, at 6 months, and at 12 months post-treatment	Epidermis thickness in micrometer will be measured by OCT and compared between irradiated skin and normal non-irradiated skin
Plexus depth measured by OCT	at baseline, at 4 weeks, at 6 months, and at 12 months post-treatment	Plexus depth in micrometer will be measured by OCT and compared between irradiated skin and normal non-irradiated skin
Size of hairs measured by OCT	at baseline, at 4 weeks, at 6 months, and at 12 months post-treatment	Mean size (in micrometer) of all hairs in the examined area will be measured by OCT and compared between irradiated skin and normal non-irradiated skin
Epidermis roughness measured by OCT	at baseline, at 4 weeks, at 6 months, and at 12 months post-treatment	Epidermis roughness in micrometer will be measured by OCT and compared between irradiated skin and normal non-irradiated skin
Size of vessels measured by OCT	at baseline, at 4 weeks, at 6 months, and at 12 months post-treatment	Mean size (in micrometer) of all vessels in the examined area will be measured by OCT and compared between irradiated skin and normal non-irradiated skin
Frequency of acute side effects observed "in radiation field"	up to 3 months after radiotherapy
Evaluation of "in radiation field" normal tissues reaction around the treated tumors	From Day 1 up to 12 months post-treatment	Blinded Imaging Central Review (BICR) of photographs will evaluate "in radiation field" normal tissues reaction around the treated tumors by grading radiation induced skin reactions, grade 1-5, using the CTCAE scale.; A baseline photograph will be taken the day of the treatment (day 1) in a pre-therapeutic setting with skin delineation of the lesion. Then photos will be repeated at day 21 (+/-2d), day 28 (+/-2d), day 42 (+/-3d) after treatment, then at 3 (+/-7d), 6 (+/-14d), 12 (+/-14d) months after treatment, and at progression.

Trial Locations

Locations (1)

Centre Hospitalier Universitaire Vaudois (CHUV); 🇨🇭 Lausanne, Vaud, Switzerland