Breast NeoplasmHOBBIT-METANCT06100068
HOBBIT 3: Mental Exercises and Temporal Alteration
A study testing Mental Exercises and Temporal Alteration in people with Breast Neoplasm and Radiotherapy, run by University Hospital, Ghent at 1 site in Belgium.
Trial summary
In the HOBBIT-trial by Vakaet et al. A protocol was developed to increase breath-hold time using (voluntary) hyperventilation and oxygenation to achieve DIBH times around 3 minutes. Multiple non-medical interventions are being investigated to prolong a L-DIBH that are feasible in clinical practice. Read more about this study
- Who is it for?
- Ages 18 years and older, women onlyHealthy volunteers can take part
- Conditions the study is for
- Breast Neoplasm, Radiotherapy, Breath Holding
- What is being tested?
- Mental Exercises and Temporal Alteration
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 siteBelgium
- Study dates
- 27 Nov 2023to 2 Apr 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Volunteer
- Karnofsky index of at least 90
- Able to perform a single DIBH of at least twenty seconds without assistance
- Age ≥ 18 years
- Informed consent obtained, signed and dated before specific protocol procedures
- Female
Who cannot join
- Pregnant women
- Volunteers above WHO Obesity class II (BMI>35kg/m²)
- Subjects on oxygen treatment during day or night
- COPD or Asthma patients
- Volunteers with pulmonary hypertension
- Gastric tube present
Show all 9Show fewer
- Smoking
- Previous and substantial breath-holding experience in the past year (e.g., diver, etc.)
- Mental condition rendering the volunteer unable to understand the nature, scope and possible consequences of the study
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Hyperventilation and Oxygenation to Increase Breath Hold in Breast Cancer Irradiation Treatment (HOBBIT) 3: Mental Exercises and Temporal Alteration
In the HOBBIT-trial by Vakaet et al. A protocol was developed to increase breath-hold time using (voluntary) hyperventilation and oxygenation to achieve DIBH times around 3 minutes.
Multiple non-medical interventions are being investigated to prolong a L-DIBH that are feasible in clinical practice. One of these methods will be to alter the time perception of the subjects. It has been noted in multiple studies (both medical and not) that slowing a person's perception of time results in an increase in breath-hold time. This alteration in time perception can be achieved with the use of a slowed clock as well as the usage of mental or physical exercises to preoccupy the subjects.
Volunteers will then be randomised into either the standard arm or the intervention arm. The intervention arm will follow standard protocol regarding DIBH preparation, though during the L-DIBH they will be asked to perform a simple mental exercise on a tablet. After 2 sessions of 3 L-DIBHs each, there will be a cross-over to the other arm in order to ascertain comfort and preference with each technique.
Read the detailed description
Adjuvant radiation therapy has a well-established role in the treatment of breast cancer complementing surgery and systemic treatment, improving survival and local control in both local and regional disease. The long-term follow-up, however, does show increased cardiac morbidity and mortality. The risk of heart disease is greatest in patients receiving a higher heart dosage i.e., left sided breast cancer and irradiation of the internal mammary lymph nodes and does not appear to have a threshold. Lowering heart dose can be achieved by improved planning methods as well as increasing the distance between the target volume and the heart. A deep inspiration breath-hold (DIBH) is often used to this end.
An unassisted DIBH is between 12 and 30 seconds; a simple breast irradiation averages 4 DIBHS for completion. More advanced radiotherapy plans (including lymph nodes) needs up to 20 DIBHs. This great amount is both physically and mentally exhausting.
A protocol was developed to increase breath-hold time using (voluntary) hyperventilation and oxygenation to achieve DIBH times around 3 minutes.
Multiple non-medical interventions are being investigated to prolong a L-DIBH that are feasible in clinical practice. One of these methods will be to alter the time perception of the subjects. It has been noted in multiple studies (both medical and not) that slowing a person's perception of time results in an increase in breath-hold time. This alteration in time perception can be achieved with the use of a slowed clock as well as the usage of mental or physical exercises to preoccupy the subjects.
Other important factors on the duration of breath holds are stress and anxiety, which may also be influenced by (relaxation) exercises (including Abdominal breathing).
The standard protocol for the first phase will be based on the results of the original HOBBIT trial.
40 Volunteers will be asked to perform 3 L-DIBHs each preceded by 3 minutes of hyperventilation at 16 breaths/min with 40L/min at FiO2 60%.
Volunteers will then be randomised into either the standard arm or the intervention arm. The intervention arm will follow standard protocol regarding DIBH preparation, though during the L-DIBH they will be asked to perform a simple mental exercise on a tablet.
Data regarding L-DIBH time, side-effects and volunteer reported stress and comfort will be reported.
Volunteers in each group will be asked to perform 2 series of 3 L-DIBHs on 2 separate days. After having finished these 2 series, there will be a cross-over to the other arm. This cross-over will evaluate the known effect of the learning bias that we see with breath-hold and show whether this effect has an impact on the anticipated benefit of the intervention. With the cross-over we can also ascertain volunteer comfort and preference with each the technique.
- Conditions
- Breast Neoplasm, Radiotherapy, Breath Holding, Mental Test
- Being tested
- Mental Exercises and Temporal Alteration
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Mental Exercises and Temporal AlterationBehavioural
Mental exercises during L-DIBH to distort the awareness of passage of time
| Study group | Role | What they receive |
|---|---|---|
| Standard L-DIBH | Active comparator | Starts with 2 sessions of normal L-DIBH followed by 2 sessions of L-DIBH combined with mental exercises. Receives: Behavioral: Mental Exercises and Temporal Alteration |
| Intervention L-DIBH | Experimental | Starts with 2 sessions of of L-DIBH combined with mental exercises followed by 2 sessions of normal L-DIBH. Receives: Behavioral: Mental Exercises and Temporal Alteration |
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference in average L-DIBH time between standard and experimental L-DIBH
Difference in average L-DIBH time between standard and experimental L-DIBH
Measured: 1 year
Secondary outcomes (9)
Patient reported comfort
Comfort on a scale of 0 to 10 where 0 is not comfortable at all and 10 is very comfortable
Measured: 1 year
Patient preferece for standard or experimental L-DIBH setup
What setup do patients prefer
Measured: 1 year
Average L-DIBH time
average time of a L-DIBH (in standard and experimental setup)
Measured: 1 year
Median L-DIBH time
Median time of a L-DIBH (in standard and experimental setup)
Measured: 1 year
Minimum and Maximum L-DIBH time
Minimum and Maximum time of a L-DIBH (in standard and experimental setup)
Measured: 1 year
Oxygen Saturation
Oxygen Saturation during the L-DIBH
Measured: 1 year
Heart Rate
Heart Rate during the hyperventilation and during the L-DIBH
Measured: 1 year
Patient report Pain
Pain on a scale of 0 to 10 where 0 is no pain and 10 is the worst pain possible
Measured: 1 year
Correctness of the mental exercise
A grading (perfect-good-fair-poor) regarding the score achieved during the mental exercise
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Oct 2023
- Study start27 Nov 2023
- Primary completion31 Dec 2024
- Study completion2 Apr 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Breast NeoplasmStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital, Ghent
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06100068
- Sponsor's protocol ID
- EC/2023/0256 (PA-2023-0017)
- Acronym
- HOBBIT-META
- Status last verified
- Feb 2026
- First submitted
- 3 Oct 2023
- Last updated
- 13 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Early Breast Cancer Trialists' Collaborative Group (EBCTCG); Darby S, McGale P, Correa C, Taylor C, Arriagada R, Clarke M, Cutter D, Davies C, Ewertz M, Godwin J, Gray R, Pierce L, Whelan T, Wang Y, Peto R. Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10,801 women in 17 randomised trials. Lancet. 2011 Nov 12;378(9804):1707-16. doi: 10.1016/S0140-6736(11)61629-2. Epub 2011 Oct 19.
PubMed 22019144Darby SC, Ewertz M, McGale P, Bennet AM, Blom-Goldman U, Bronnum D, Correa C, Cutter D, Gagliardi G, Gigante B, Jensen MB, Nisbet A, Peto R, Rahimi K, Taylor C, Hall P. Risk of ischemic heart disease in women after radiotherapy for breast cancer. N Engl J Med. 2013 Mar 14;368(11):987-98. doi: 10.1056/NEJMoa1209825.
PubMed 23484825Vakaet V, Van Hulle H, Schoepen M, Van Caelenberg E, Van Greveling A, Holvoet J, Monten C, De Baerdemaeker L, De Neve W, Coppens M, Veldeman L. Prolonging deep inspiration breath-hold time to 3 min during radiotherapy, a simple solution. Clin Transl Radiat Oncol. 2021 Feb 23;28:10-16. doi: 10.1016/j.ctro.2021.02.007. eCollection 2021 May.
PubMed 33732910Schwarz MA, Winkler I, Sedlmeier P. The heart beat does not make us tick: the impacts of heart rate and arousal on time perception. Atten Percept Psychophys. 2013 Jan;75(1):182-93. doi: 10.3758/s13414-012-0387-8.
PubMed 23143915Vigran HJ, Kapral AG, Tytell ED, Kao MH. Manipulating the perception of time affects voluntary breath-holding duration. Physiol Rep. 2019 Dec;7(23):e14309. doi: 10.14814/phy2.14309.
PubMed 31833235
Study at a glance
From the registry record, last updated by the sponsor on 13 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Hyperventilation and Oxygenation to Increase Breath Hold in Breast Cancer Irradiation Treatment (HOBBIT) 3: Mental Exercises and Temporal Alteration
- ClinicalTrials.gov ID
- NCT06100068
- Acronym / sponsor ID
- HOBBIT-META / EC/2023/0256 (PA-2023-0017)
- Conditions
- Breast Neoplasm, Radiotherapy, Breath Holding, Mental Test
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 36 participants (actual)
- Lead sponsor
- University Hospital, GhentUniversity, hospital or other
- Study start
- 27 Nov 2023 (actual)
- Primary completion
- 31 Dec 2024 (actual)
- Study completion
- 2 Apr 2025 (actual)
- First posted
- 25 Oct 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
In the HOBBIT-trial by Vakaet et al. A protocol was developed to increase breath-hold time using (voluntary) hyperventilation and oxygenation to achieve DIBH times around 3 minutes.
Multiple non-medical interventions are being investigated to prolong a L-DIBH that are feasible in clinical practice. One of these methods will be to alter the time perception of the subjects. It has been noted in multiple studies (both medical and not) that slowing a person's perception of time results in an increase in breath-hold time. This alteration in time perception can be achieved with the use of a slowed clock as well as the usage of mental or physical exercises to preoccupy the subjects.
Volunteers will then be randomised into either the standard arm or the intervention arm. The intervention arm will follow standard protocol regarding DIBH preparation, though during the L-DIBH they will be asked to perform a simple mental exercise on a tablet. After 2 sessions of 3 L-DIBHs each, there will be a cross-over to the other arm in order to ascertain comfort and preference with each technique.
Detailed description
Adjuvant radiation therapy has a well-established role in the treatment of breast cancer complementing surgery and systemic treatment, improving survival and local control in both local and regional disease. The long-term follow-up, however, does show increased cardiac morbidity and mortality. The risk of heart disease is greatest in patients receiving a higher heart dosage i.e., left sided breast cancer and irradiation of the internal mammary lymph nodes and does not appear to have a threshold. Lowering heart dose can be achieved by improved planning methods as well as increasing the distance between the target volume and the heart. A deep inspiration breath-hold (DIBH) is often used to this end.
An unassisted DIBH is between 12 and 30 seconds; a simple breast irradiation averages 4 DIBHS for completion. More advanced radiotherapy plans (including lymph nodes) needs up to 20 DIBHs. This great amount is both physically and mentally exhausting.
A protocol was developed to increase breath-hold time using (voluntary) hyperventilation and oxygenation to achieve DIBH times around 3 minutes.
Multiple non-medical interventions are being investigated to prolong a L-DIBH that are feasible in clinical practice. One of these methods will be to alter the time perception of the subjects. It has been noted in multiple studies (both medical and not) that slowing a person's perception of time results in an increase in breath-hold time. This alteration in time perception can be achieved with the use of a slowed clock as well as the usage of mental or physical exercises to preoccupy the subjects.
Other important factors on the duration of breath holds are stress and anxiety, which may also be influenced by (relaxation) exercises (including Abdominal breathing).
The standard protocol for the first phase will be based on the results of the original HOBBIT trial.
40 Volunteers will be asked to perform 3 L-DIBHs each preceded by 3 minutes of hyperventilation at 16 breaths/min with 40L/min at FiO2 60%.
Volunteers will then be randomised into either the standard arm or the intervention arm. The intervention arm will follow standard protocol regarding DIBH preparation, though during the L-DIBH they will be asked to perform a simple mental exercise on a tablet.
Data regarding L-DIBH time, side-effects and volunteer reported stress and comfort will be reported.
Volunteers in each group will be asked to perform 2 series of 3 L-DIBHs on 2 separate days. After having finished these 2 series, there will be a cross-over to the other arm. This cross-over will evaluate the known effect of the learning bias that we see with breath-hold and show whether this effect has an impact on the anticipated benefit of the intervention. With the cross-over we can also ascertain volunteer comfort and preference with each the technique.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Standard L-DIBH | Active comparator | Behavioral: Mental Exercises and Temporal AlterationStarts with 2 sessions of normal L-DIBH followed by 2 sessions of L-DIBH combined with mental exercises. |
| Intervention L-DIBH | Experimental | Behavioral: Mental Exercises and Temporal AlterationStarts with 2 sessions of of L-DIBH combined with mental exercises followed by 2 sessions of normal L-DIBH. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Volunteer
- Karnofsky index of at least 90
- Able to perform a single DIBH of at least twenty seconds without assistance
- Age ≥ 18 years
- Informed consent obtained, signed and dated before specific protocol procedures
Key exclusion criteria (9 listed)
- Pregnant women
- Volunteers above WHO Obesity class II (BMI>35kg/m²)
- Subjects on oxygen treatment during day or night
- COPD or Asthma patients
- Volunteers with pulmonary hypertension
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Mental Exercises and Temporal AlterationMental exercises during L-DIBH to distort the awareness of passage of time | Behavioural | Intervention L-DIBH, Standard L-DIBH |
Primary outcome
Difference in average L-DIBH time between standard and experimental L-DIBH
Time frame: 1 year
Difference in average L-DIBH time between standard and experimental L-DIBH
9 secondary outcomes
Patient reported comfort
Time frame: 1 year
Patient preferece for standard or experimental L-DIBH setup
Time frame: 1 year
Average L-DIBH time
Time frame: 1 year
Median L-DIBH time
Time frame: 1 year
Minimum and Maximum L-DIBH time
Time frame: 1 year
Oxygen Saturation
Time frame: 1 year
Heart Rate
Time frame: 1 year
Patient report Pain
Time frame: 1 year
Correctness of the mental exercise
Time frame: 1 year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Feb 2026.
- Background: PubMed 22019144Early Breast Cancer Trialists' Collaborative Group (EBCTCG); Darby S, McGale P, Correa C, Taylor C, Arriagada R, Clarke M, Cutter D, Davies C, Ewertz M, Godwin J, Gray R, Pierce L, Whelan T, Wang Y, Peto R. Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10,801 women in 17 randomised trials. Lancet. 2011 Nov 12;378(9804):1707-16. doi: 10.1016/S0140-6736(11)61629-2. Epub 2011 Oct 19.
- Background: PubMed 23484825Darby SC, Ewertz M, McGale P, Bennet AM, Blom-Goldman U, Bronnum D, Correa C, Cutter D, Gagliardi G, Gigante B, Jensen MB, Nisbet A, Peto R, Rahimi K, Taylor C, Hall P. Risk of ischemic heart disease in women after radiotherapy for breast cancer. N Engl J Med. 2013 Mar 14;368(11):987-98. doi: 10.1056/NEJMoa1209825.
- Background: PubMed 33732910Vakaet V, Van Hulle H, Schoepen M, Van Caelenberg E, Van Greveling A, Holvoet J, Monten C, De Baerdemaeker L, De Neve W, Coppens M, Veldeman L. Prolonging deep inspiration breath-hold time to 3 min during radiotherapy, a simple solution. Clin Transl Radiat Oncol. 2021 Feb 23;28:10-16. doi: 10.1016/j.ctro.2021.02.007. eCollection 2021 May.
- Background: PubMed 23143915Schwarz MA, Winkler I, Sedlmeier P. The heart beat does not make us tick: the impacts of heart rate and arousal on time perception. Atten Percept Psychophys. 2013 Jan;75(1):182-93. doi: 10.3758/s13414-012-0387-8.
- Background: PubMed 31833235Vigran HJ, Kapral AG, Tytell ED, Kao MH. Manipulating the perception of time affects voluntary breath-holding duration. Physiol Rep. 2019 Dec;7(23):e14309. doi: 10.14814/phy2.14309.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Mental Exercises and Temporal Alteration in people with Breast Neoplasm and Radiotherapy, run by University Hospital, Ghent at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Difference in average L-DIBH time between standard and experimental L-DIBH (time frame: 1 year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06100068, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Feb 2026; AzTrials last refreshed its copy on 28 Oct 2026.