Inventory, Net

Inventory consists of sub-assemblies, components, and raw materials, and work-in-process. Inventory not expected to be sold or consumed within one year, including inventory expected to be capitalized into property and equipment as cyclotron systems are completed, is classified as inventory, non-current. The composition of inventory, non-current as of March 31, 2026 and December 31, 2025 is as follows:

The Company maintains an allowance for inventory obsolescence to reduce the carrying value of slow-moving, obsolete, or damaged inventory to its estimated net realizable value. The allowance is based on historical write-offs, current inventory aging, and management’s assessment of future demand. No allowance for inventory obsolescence was recorded against inventory included in total current assets during the three months ended March 31, 2026 or March 31, 2025.

Activity in the allowance for inventory obsolescence, related solely to inventory, non-current was as follows:

No provision for inventory obsolescence was charged to cost of revenue for the three months ended March 31, 2025.

Prepaid Expenses and Other Current Assets

The composition of prepaid expenses and other current assets as of March 31, 2026 and December 31, 2025 is as follows:

Property and Equipment, Net

The composition of property and equipment, net as of March 31, 2026 and December 31, 2025 is as follows:

Construction in progress represents costs incurred for leasehold improvements and a cyclotron system that were not substantially complete and ready for their intended use as of March 31, 2026 and December 31, 2025. Construction in progress includes direct costs of acquisition, installation, and other expenditures necessary to bring the assets to the condition necessary for their intended use. No depreciation is recorded on construction in progress until the related assets are substantially complete and placed into service.

Depreciation expense was $912 and $806 for the three months ended March 31, 2026 and March 31, 2025, respectively.

Accrued Expenses and Other Current Liabilities

The composition of accrued expenses and other current liabilities as of March 31, 2026 and December 31, 2025 is as follows:

Other Non-Current Liabilities

The composition of other non-current liabilities as of March 31, 2026 and December 31, 2025 is as follows:

Inventory, Net

Inventory included in total current assets consists solely of assemblies and raw materials. The composition of inventory, non-current as of December 31, 2025 and 2024 is as follows:

The Company maintains an allowance for inventory obsolescence to reduce the carrying value of slow-moving, obsolete, or damaged inventory to its estimated net realizable value. The allowance is based on historical write-offs, current inventory aging, and management’s assessment of future demand. No allowance for inventory obsolescence was recorded against inventory included in total current assets as of December 31, 2025 or 2024.

Activity in the allowance for inventory obsolescence, related solely to inventory, non-current was as follows:

Prepaid Expenses and Other Current Assets

The composition of prepaid expenses and other current assets as of December 31, 2025 and 2024 is as follows:

Property and Equipment, Net

The composition of property and equipment, net as of December 31, 2025 and 2024 is as follows:

Construction in progress represents costs incurred for leasehold improvements and a cyclotron system that were not substantially complete and ready for their intended use as of December 31, 2025 and 2024. Construction in progress includes direct costs of acquisition, installation, and other expenditures necessary to bring the assets to the condition necessary for their intended use. No depreciation is recorded on construction in progress until the related assets are substantially complete and placed into service.

Depreciation expense was $3.6 million and $2.5 million for the years ended December 31, 2025 and 2024, respectively.

Accrued Expenses and Other Current Liabilities

The composition of accrued expenses and other current liabilities as of December 31, 2025 and 2024 is as follows:

Other Non-Current Liabilities

The composition of other non-current liabilities as of December 31, 2025 and 2024 is as follows:

Government grant obligation

During 2025, the Company received a government grant of $750 in connection with an economic development program. The grant is subject to specified conditions that must be satisfied through June 2030 and includes provisions requiring repayment if such conditions are not met. As of December 31, 2025, the Company has not satisfied the required conditions. Accordingly, the $750 was recorded as a government grant obligation included in other non-current liabilities in the consolidated balance sheet. The amount will be recognized in the consolidated statements of operations as the related conditions are satisfied and it becomes probable that repayment will not be required.