Participants receiving "Usual Care" group (A), will be recruited during the last two months of treatment (T-2). At the end of treatment (T0), participants will complete a knowledge questionnaire and will be followed for another 24 months. At six months after treatment completion (T6), a final follow-up knowledge assessment will be conducted. Participants will be enrolled into group A until the intended sample size of 50 participants is reached. Investigators estimated to have reached this number within four to six months based on recent survival rates.

A similar procedure will apply to the "Educational Intervention" group (B). Participants will complete a knowledge assessment before receiving an educational intervention between T-2 and T0. To evaluate early and late knowledge uptake, participants will complete a post-education knowledge assessment at T0 and a follow-up knowledge assessment at T6. Follow-up adherence will be evaluated at every three months for the first year and at every six months during the second year after treatment completion for both groups. Implementation measures will be captured starting at T3 until T24, together with a satisfaction questionnaire that will be administered at T6.

Healthcare provider training on survivorship will start at the same timepoint as recruitment of the "Educational Intervention" group (A) at T-2.

Follow-Up Forms will be introduced at the outpatient clinic once an estimated 30 healthcare providers have done the training (anticipated at T0). Healthcare providers will fill in a knowledge assessment directly pre- and post-training (T-2) and at six months post-training (T4).

Documentation of late effect symptoms will be monitored for twelve months, starting at T0. Implementation measures will be collected weekly starting from T0 and healthcare providers will be assigned to a satisfaction questionnaire at T6.

Caregivers will be invited to attend an educational group session. Each session will be organized weekly to monthly. A maximum of ten caregivers can be present at a session.

First a video will be displayed in which healthcare providers explain medical aspects of survivorship. Caregivers of survivors and young adult survivors discuss experiences after completing cancer treatment in the video.

Secondly, the present healthcare provider will hand over an information booklet 'Life after childhood cancer' to the caregivers. The booklet covers similar topics as presented in the video.

Lastly, a Survivorship Card will be shared with the caregivers. The card contains a record of the patient's cancer and treatment history and the expected follow-up appointment schedule. The survivor and family take one card home and a duplicate copy of the card remains in the medical file.

When survivors do not appear at a scheduled visit within four weeks before or after the scheduled date.

When survivors miss a scheduled appointment and do not revisit the follow-up clinic after a missed appointment for more than six months.

Reasons for non-adherence (death, relapse, other logistic issues) will be explored through a phone call.

Intentions to revisit the follow-up clinic (yes/no, what can hospital do to support participant in adhering to follow-up visit) will be explored through a phone call.

Caregivers' knowledge about disease history, treatment exposure, associations between treatment and late effects, follow-up care, late effects risk and risk perception.

Levels of knowledge (number of accurate/inaccurate/unknown responses), and knowledge uptake (changes in number of accurate responses) progression will be followed over time.