Feasibility of CBCT-Guided Online Adaptive Radiotherapy (FASCINATE)

General Inclusion Criteria: * Patient, age ≥ 18 years, referred for a radiotherapy schedule as described in one of the cohorts. * WHO performance score 0-3. * Provision of signed, written and dated IC prior to any study specific procedures. Specific inclusion criteria for prostate cohort: * Accepted for radiotherapy of the prostate and pelvic lymph node areas. * Pathology-proven prostate cancer. * cT1-4 * cN1 on PSMA-PET/CT or pN1 based on node biopsy, SN-procedure or lymph node dissection. * cM0 on PSMA-PET/CT (except for patients with M1a disease who are still considered for radiotherapy of the prostate and pelvic lymph node areas). Specific inclusion criteria for cervical cohort: * Accepted for radiotherapy of the cervix (with or without chemotherapy) and pelvic lymph node areas (25 fractions, followed by either a brachytherapy or external radiotherapy boost). * Pathology-proven cervical cancer. * FIGO IIA2, IB3 and \> 6cm, IIB-IVA or N+. Or other stage and unfit for surgery. * cM0 or cM1 and accepted for locoregional radical (chemo)radiation in 25 fractions. Specific inclusion criteria for bladder cohort: * Accepted for radiotherapy of the bladder, either to the entire bladder or with a boost to the tumor area (with or without chemotherapy). * Pathology-proven bladder carcinoma. * cT1-4 * cN0 or cN1-2 after induction treatment (with or without lymph node dissection) Specific inclusion criteria for lung cohort: * Accepted for radiotherapy for lung cancer with lymph node metastases (with or without chemotherapy). * Non-small cell lung cancer (either pathology proven or enough clinical suspicion to warrant radiotherapy to primary tumor and pathologic lymph nodes. * cT1-4 and cN1-3. * M0 or m1 and accepted for radical radiotherapy in 24 fractions of 1 or more lymph node metastases and a primary tumor and/or pulmonary metastases. Specific inclusion criteria for head and neck cohort: * Accepted for radiotherapy for head and neck cancer (with or without chemotherapy). * Pathology-proven carcinoma of the pharynx, oral cavity or larynx. * cT1-4 * cN0-3 and indication for elective neck radiation (either 1 or 2 sides). * cM0 General Exclusion Criteria: * Patients who are pregnant. Specific for prostate cohort: * Patients with a medical condition that severely compromises CBCT image quality (mainly hip prostheses). * Severe lower urinary tract symptoms that could make the longer treatment time problematic (according to judgement of treating physician). Specific for cervical cohort: \- Patients with a medical condition that severely compromises CBCT image quality (mainly hip prostheses). Specific for bladder cohort: * Patients with a medical condition that severely compromises CBCT image quality (mainly hip prostheses). * Severe lower urinary tract symptoms that could make the longer treatment time problematic (according to judgement of treating physician). Specific for lung cohort: \- Severe pulmonary complaints that could make the longer treatment time problematic (according to judgement of treating physician). Specific for head and neck cohort: * Severe complaints that could make the longer treatment time problematic (according to judgement of treating physician). * Pulmonary fibrosis