Nano-X Image Guidance: CBCT With Gravity-induced Motion

A pilot stage, device feasibility trial, to investigate the feasibility of acquiring cone beam computed tomography (CBCT) images for image guidance for radiation therapy by maintaining a fixed imaging system and rotating the participant about the horizontal axis using the Nano-X patient rotation system. It is a single-arm, controlled, single-blinded, non-treatment, non-invasive, single-institution trial.

Primary objective:

To investigate the feasibility of volumetric image guidance for the Nano-X patient rotation system (PRS).

Secondary objectives:

1. To develop image reconstruction methods that allow target and normal tissue visualisation at all treatment angles to a clinical cone beam computed tomography (CBCT) standard.
2. To determine the reproducibility and variability in Nano-X CBCT compared to clinical CBCT.
3. To measure the magnitude of gravity-induced anatomical deformation and translation.
4. To develop treatment plan adaptation methods to compensate for gravity-induced target motion based on Nano-X CBCT image reconstruction at varying treatment angles.
5. To quantify the participant experience of horizontal rotation using the Nano-X PRS for volumetric image guidance CBCT acquisition.

The investigators will perform a pilot stage, device feasibility trial, to investigate the feasibility of acquiring CBCT images for image guidance by maintaining a fixed imaging system and rotating the participant about the horizontal axis using the Nano-X PRS. It is a single-arm, controlled, single-blinded, non-treatment, non-invasive, single-institution trial.

Eligible participants will be asked to attend the Nelune Comprehensive Cancer Centre (NCCC) at the Prince of Wales Hospital on two separate occasions to obtain Nano-X CBCT scans. For each scan the participant will be rotated 360° about the horizontal axis which will take approximately 72 seconds to complete.

Participants will be asked to complete validated psychometric questionnaires before and after each Nano-X CBCT. The questionnaire responses will be used to quantify their experiences of anxiety and motion sickness, and report previous experiences of claustrophobia, in order to identify determinants of tolerance level.

The projection data sets from the Nano-X CBCT scans, along with conventional CBCTs obtained for the participants' standard radiotherapy treatment, will be used to investigate the image-related objectives. The two Nano-X CBCT data sets from each participant will be used to compare Nano-X CBCT variability and reproducibility to clinical CBCT acquisition.

Eligibility Criteria:
Inclusion Criteria:

1. Cancer patients that are receiving radiation therapy that are able to be imaged with the Nano-X PRS with one of the following tumour sites:

   1. in the head/neck region
   2. in the chest/abdomen/pelvic region with fast CBCT used for standard of care image guidance and is aged 60 years or older
   3. in the chest/abdomen/pelvic region not receiving CBCT for standard of care image guidance and is aged 70 years or older
   4. diagnosis of lung cancer with stage II-IV
2. ≥18 years of age
3. ECOG Performance Status 0-2
4. Must be able to communicate fluently in English to:

   i. Receive instructions from operators of the PRS for safety entering and leaving the Patient Rotation System and required conduct during the during the rotation session, and ii. Communicate their level of comfort or distress to operators of the equipment.
5. Signed, written informed consent or approved alternative, non-contact method for informed consent.

Exclusion Criteria:

1. Pregnant women
2. Patients for whom attaining informed consent would not be possible, including mentally impairment
3. Patients with severe vertigo or recent a diagnosis of Benign Paroxysmal Positioning Vertigo.