An observational study in Localized Prostate Cancer, sponsored by Regina Elena Cancer Institute. Recruiting at 1 site in Italy. Open to male participants aged 18 Years to 99 Years. Per ClinicalTrials.gov, last updated 2026-08-28.
Sponsored by Regina Elena Cancer Institute · Observational
HYPO62 SPECIAL is a monocentric, prospective observational cohort study promoted by IFO-IRE/ISG, designed to evaluate a moderately hypofractionated radiotherapy strategy with focal micro-boost in patients with localized intermediate- or high-risk prostate cancer.
Definitive radiotherapy is an established treatment option for localized prostate cancer. Over recent decades, technical advances such as 3D conformal radiotherapy, IMRT, and multiparametric MRI have enabled more precise dose delivery and better identification of dominant intraprostatic lesions. Since most local recurrences occur in the original tumor area, selective dose escalation to MRI-visible dominant lesions represents a rational strategy to improve biochemical control while limiting toxicity to surrounding organs at risk.
The study is based on previous evidence, including FLAME and DELINEATE, showing that focal boosting of dominant intraprostatic lesions can improve biochemical outcomes without significantly increasing toxicity when organ-at-risk constraints are respected. At the Regina Elena National Cancer Institute, the standard moderately hypofractionated schedule consists of 62 Gy in 20 fractions to the prostate. In this protocol, visible dominant intraprostatic lesions receive a focal micro-boost up to 71.3 Gy, while seminal vesicles may receive 56 Gy according to clinical risk.
The primary objective is to assess the oncological efficacy of this focal micro-boost strategy in terms of 3-year biochemical recurrence-free survival. Biochemical recurrence is defined according to the Phoenix criteria as PSA nadir plus 2 ng/mL or the start of salvage androgen deprivation therapy. Secondary and exploratory objectives include treatment-related toxicity assessed with CTCAE v5.0 at different timepoints, recurrence patterns, 3-year overall survival, and 3-year metastasis-free survival.
Eligible patients are adults with histologically confirmed prostate adenocarcinoma, intermediate- or high-risk disease according to NCCN criteria, no regional or distant metastases, ECOG performance status 0-1, and at least one mpMRI-visible PI-RADS 4 or 5 lesion, or a PI-RADS 3 lesion confirmed by biopsy. All patients will provide written informed consent.
Patients will be treated according to routine clinical practice with 20 fractions delivered five times per week. Treatment planning includes CT simulation and pre-treatment multiparametric MRI. The prostate, seminal vesicles when indicated, dominant lesions, and organs at risk will be contoured after CT-MRI registration. The planning target volume is generated from the clinical target volume with appropriate margins, while no additional margin is applied to the dominant intraprostatic lesion. Organ-at-risk constraints will take priority over full boost coverage.
A total of 82 consecutive patients are planned for inclusion. This sample size is considered adequate to test whether the 3-year biochemical recurrence-free survival improves from 68% to 80%, with 80% probability and a one-sided 5% significance level. Statistical analyses will include Kaplan-Meier survival estimates, log-rank testing, and multivariable logistic and Cox regression models. The expected enrolment and data collection period is 36 months, with a minimum observational follow-up of 36 months and an estimated total study duration of 72 months.
HYPO62 SPECIAL is a no-profit, single-centre, prospective observational cohort study promoted by IFO-IRE, Istituto Nazionale Tumore Regina Elena, IRCCS, Rome, Italy. The study is entitled "Moderately Hypofractionated Micro-Boost Radiotherapy for Localized Prostate Cancer (62SPECIAL): an Observational Study" and is coordinated by the Department of Radiation Oncology of IFO-IRE. The study focuses on patients with localized intermediate to high-risk prostate cancer who are eligible for moderately hypofractionated radiotherapy. The aim is to evaluate the oncological efficacy and safety of a radiotherapy strategy combining whole-gland moderately hypofractionated irradiation with a focal simultaneous integrated micro-boost to dominant intraprostatic lesions identified by multiparametric magnetic resonance imaging. Definitive radiotherapy is an established treatment option for localized prostate cancer. Over the last decades, radiotherapy techniques have progressively evolved from three-dimensional conformal radiotherapy to intensity modulated radiotherapy and image-guided approaches. These technical advances have allowed dose escalation to the prostate while improving sparing of adjacent organs at risk. However, whole-gland dose escalation is limited by the proximity of critical normal structures, particularly the rectum, bladder and urethra, and may increase late gastrointestinal or genitourinary toxicity. A key biological and clinical rationale for focal dose escalation is that most local prostate cancer recurrences occur within the original dominant tumour region. The availability of multiparametric MRI has made it possible to identify clinically significant intraprostatic lesions, commonly referred to as dominant intraprostatic lesions or DILs. These lesions are classified according to the Prostate Imaging Reporting and Data System, PIRADS. The protocol considers MRI-visible PI-RADS 4 or 5 lesions eligible for boosting, while PIRADS 3 lesions require pathological confirmation. The rationale of the study is supported by previous clinical evidence, particularly the FLAME and DELINEATE studies. The FLAME randomized phase III trial investigated focal boosting of macroscopic intraprostatic tumour areas in addition to whole-gland radiotherapy and demonstrated a significant improvement in biochemical control without a relevant increase in toxicity when organ at risk constraints were prioritized. The DELINEATE phase II study further supported the feasibility of delivering a selective boost to MRI-visible intraprostatic lesions within a 20-fraction moderately hypofractionated schedule. Based on these data, current guidelines allow a micro-boost strategy in selected patients with intermediate and high-risk localized prostate cancer. At the IRCCS Regina Elena National Cancer Institute, the standard moderately hypofractionated radiotherapy schedule consists of 62 Gy in 20 fractions to the prostate. In the HYPO62 SPECIAL study, the dominant intraprostatic lesion is planned to receive a focal micro-boost up to 71.3 Gy, corresponding to a dose escalation of approximately 15% over the whole gland dose. Seminal vesicles, when clinically indicated according to risk of involvement, are prescribed 56 Gy. This strategy aims to increase the biological dose delivered to the tumour focus while maintaining an isotoxic approach, meaning that organ-at-risk tolerance is prioritized over boost target coverage. The study is observational and does not introduce experimental treatments outside clinical practice. Patients will receive standard-of-care radiotherapy according to institutional practice. Clinical, radiological, dosimetric, toxicity and follow-up data will be prospectively collected and analysed.
Study Design HYPO62 SPECIAL is a prospective, observational, cohort, single centre study. The study will enrol consecutive patients treated at IFO-IRE who meet the predefined inclusion and exclusion criteria. Since the treatment is delivered according to routine clinical practice, the study is designed to evaluate outcomes in a real-world clinical setting while using a standardized data collection framework. The planned recruitment and data collection period is 36 months.
Treatment and Procedures All enrolled patients will undergo standard of care treatment consisting of moderately hypofractionated radiotherapy delivered in 20 fractions, five sessions per week. Patients will also undergo routine clinical follow-up according to institutional practice. Treatment planning includes a planning computed tomography scan and a pretreatment multiparametric MRI examination. The MRI protocol includes T2 weighted sequences, diffusion-weighted imaging and dynamic contrast enhanced sequences. The prostate gland is delineated on T2 weighted MRI. The clinical target volume includes the prostate gland and, depending on clinical risk, the seminal vesicles. Any tumour tissue visible within the clinical target volume on multiparametric MRI is contoured as the gross tumour volume, corresponding to the dominant intraprostatic lesion. After registration of MRI with planning CT, target volumes and organs at risk are delineated. The planning target volume is generated from the clinical target volume using margins ranging from 4 to 8 mm, depending on the treatment technique and image guidance strategy. No additional margin is applied to the dominant intraprostatic lesion. The prostate planning target volume is prescribed 62 Gy, while seminal vesicles, when included, are prescribed 56 Gy. The dominant intraprostatic lesion receives a simultaneous integrated focal micro-boost to 71.3 Gy, with an allowed variation of ±5%. Organ at risk constraints take priority over full coverage of the boosted lesion. If required to respect organ at risk tolerance, planning target volume coverage may be reduced, with V95% considered acceptable down to 90%. Radiotherapy may be delivered using VMAT or CyberKnife, according to clinical and technical indications. In case of CyberKnife treatment, margins may vary depending on fiducial tracking, with smaller margins when three fiducials are available and larger margins when only one or two fiducials are present.
7,046 studies on the registry are indexed under Prostatic Neoplasms; 1,580 are open to participants now.
This study's planned enrollment of 82 is below the median of 200 across 1,310 observational studies indexed under Prostatic Neoplasms.
Browse Prostatic Neoplasms studies →Regina Elena Cancer Institute is the lead sponsor of 94 studies on the registry; 51 are open to participants now.
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The study population includes adult patients with histologically confirmed prostate adenocarcinoma who are eligible for moderately hypofractionated radiotherapy in 20 fractions and have at least one MRI-visible lesion suitable for focal boosting. Patients must have intermediate or high-risk prostate cancer according to NCCN risk stratification. Unfavourable intermediate-risk disease includes patients without high-risk features but with two or three intermediate-risk factors, Grade Group 3 disease and/or more than 50% positive biopsy cores. Intermediate-risk factors include clinical stage T2b-T2c, Grade Group 2-3 and PSA between 10 and 20 ng/mL. High-risk disease includes clinical stage T3a, Grade Group 4-5 or PSA greater than 20 ng/mL.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The study population includes adult patients with histologically confirmed prostate adenocarcinoma who are eligible for moderately hypofractionated radiotherapy in 20 fractions and have at least one MRI-visible lesion suitable for focal boosting. Patients must have intermediate or high-risk prostate cancer according to NCCN risk stratification. Unfavourable intermediate-risk disease includes patients without high-risk features but with two or three intermediate-risk factors, Grade Group 3 disease and/or more than 50% positive biopsy cores. Intermediate-risk factors include clinical stage T2b-T2c, Grade Group 2-3 and PSA between 10 and 20 ng/mL. High-risk disease includes clinical stage T3a, Grade Group 4-5 or PSA greater than 20 ng/mL.
Assess the oncologic efficacy
To assess the oncologic efficacy of a focal micro-boost strategy in patients with intermediate to highrisk prostate cancer (IR-HR PCa) undergoing hypofractionated radiotherapy, in terms of biochemical relapse free survival (bRFS) at 3 years.
Time frame: From the last day of radiotherapy treatment to 36 months after treatment completion.
Plan to share: No — IPD will not be shared because participants' informed consent does not specifically cover external sharing of individual level data. To protect participant confidentiality and comply with GDPR and institutional privacy requirements, only aggregated and anonymized results will be made available.
Started Aug 2025 (actual). Primary completion is estimated for Dec 2027, 28 months after the start.
Of 541 non-industry observational studies under Prostatic Neoplasms, half reached primary completion within 67 months of starting (the median), counting those still running; a quarter within 29 and three quarters within 162. This study's planned 28 months is below that.
Counting every sponsor, half of 650 studies reached it within 60 months; a quarter within 29 and three quarters within 141.
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Regina Elena Cancer Institute