Extreme Hypofractionation Research Articles

Image-guided Hypofractionated Radiotherapy as an Alternative to Radical Prostatectomy in Localized Prostate Cancer in Elderly Patients with Low Life Expectancy.

Radical prostatectomy is appropriate for any patient whose cancer appears clinically localised to prostate. However because of potential perioperative morbidity, radical prostatectomy is generally reserved for patients whose life expectancy is more than ten years. Moderate hypofractionation for localized prostate cancer is safe and effective. There is a growing body of evidence in support of extreme hypofractionation for localized prostate cancer. Hypofractionation for prostate cancer was originally carried out in the pursuit of efficiency and convenience, but has now attracted greatly renewed interest based upon a hypothesis that prostate cancers have a higher sensitivity to fraction size, reflected in a low α/β ratio, then do late responding organs at risk such as the rectum or bladder. From January 2017 to December 2020 we treated 112 patients of localised Prostate Cancer with Image Guided Radiotherapy (IGRT). They were in range of 75-85 years. They were of stage T1-T3, N0 or N1. There were significant comborbidities. ECOG performance status was 0-1. They were given 3 months of Androgen Deprivation Therapy (ADT) before starting IGRT. Patients were immobilised with casts and subject to CT simulation. CBCT was taken daily. Dose was 70 Gy @ 250 cGy per fraction at a frequency of 5 fractions per week. Complete blood counts were done weekly for assessment of haematological toxicity. Androgen Deprivation Therapy was continued post IGRT. All the patients were able to complete the treatment. Evaluation was done at one month, three month and six months post treatment. 104 out of 112 patients achieved complete response. Other 8 had near complete response. There were no acute grade 3-4 toxicities. Grade 1-2 toxicities like skin desquamation, diarrhoea, burning micturition were managed conservatively. Late toxicity was rectal bleeding seen after one year of completion of treatment and was managed with steroid enemas. 23 patients required argon plasma laser therapy. Image guided radiotherapy is well tolerated, easy to implement and an effective alternative to radical prostatectomy in elderly patients with comorbidities and low life expectancy.

Extreme-hypofractionated RT with concomitant boost to the DIL in PCa: a 5-year update on oncological and patient-reported outcomes for the phase II trial "GIVE ME FIVE".

The present work reports updated oncological results and patients-reported outcomes at 5years of phase II trial "Short-term high precision RT for early prostate cancer with SIB to the dominant intraprostatic lesion (DIL) for patients with early-stage PCa". Data from patients enrolled within AIRC IG-13218 (NCT01913717) trial were analyzed. Clinical and GU/GI toxicity assessment and PSA measurements were performed every 3months for at least 2years after RT end. QoL of enrolled patients was assessed by IPSS, EORTC QLQ-C30, EORTC QLQ-PR25, and IIEF-5. Patients' score changes were calculated at the end of RT and at 1, 12, and 60months after RT. A total of 65 patients were included. At a median follow-up of 5years, OS resulted 86%. Biochemical and clinical progression-free survival at 5years were 95%. The median PSA at baseline was 6.07ng/ml, while at last follow-up resulted 0.25ng/ml. IPSS showed a statistically significant variation in urinary function from baseline (p = 0.002), with the most relevant deterioration 1month after RT, with a recovery toward baseline at 12months (p ≤ 0.0001). A numerical improvement in QoL according to the EORTC QLQ-C30 has been reported although not statistically significant. No change in sexual activity was recorded after RT. The study confirms that extreme hypofractionation with a DIL boost is safe and effective, with no severe effects on the QoL. The increasing dose to the DIL does not worsen the RT toxicity, thus opening the possibility of an even more escalated treatment.

Ultra-hypofractionated one-week locoregional radiotherapy for patients with early breast cancer: Acute toxicity results

PurposeModerate hypofractionated radiotherapy is the standard of care for all patients with breast cancer, irrespective of stage or prior treatments. While extreme hypofractionation is accepted for early-stage tumours, its application in irradiating locoregional lymph nodes remains controversial. Materials and methodsA prospective registry analysis from July 2020 to September 2023 included 276 patients with early-stage breast cancer treated with one-week ultra-hypofractionation (UHF) at 26 Gy in 5 fractions on the whole breast (58.3 %) or thoracic wall (41.7 %) and ipsilateral regional lymph nodes and simultaneous integrated boost (58.3 %). Primary endpoint was assessment of acute adverse events (AEs). Secondarily, onset of early-delayed toxicity was assessed. A minimum 6-month follow-up was required for assessing potential treatment-related early-delayed complications. Acute or late complications attributable to treatment were assessed at inclusion using the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 criteria. ResultsWith a median follow-up of 19 months (range 1–49 months), 159 (57.6 %) patients reported AEs, predominantly grade (G) 1 (n = 139, 50.4 %) and G2 (n = 20, 7.8 %). Skin acute toxicity was common (G1/2: 134, G3: 14), while breast oedema occurred in 10 patients (G1: 9, G2: 1), and 15.9 % reported breast pain (G1: 42, G2: 2). Ipsilateral arm oedema was observed in 1.8 % patients. For patients with a follow-up beyond 6 months (n = 213), 23.4 % patients reported G1/G2 skin AEs, 8.8 % had G1/G2 breast/chest wall oedema, and 8.9 % experienced arm lymphedema. There were no cases of brachial plexopathy or G3 toxicity in this group of patients. ConclusionsOne-week UHF adjuvant locoregional radiation is well-tolerated, displaying low-toxicity profiles comparable to other studies using similar irradiation schedules.

Towards optimal heterogeneous prostate radiotherapy dose prescriptions based on patient-specific or population-based biological features.

Escalation of prescribed dose in prostate cancer (PCa) radiotherapy enables improvement in tumor control at the expense of increased toxicity. Opportunities for reduction of treatment toxicity may emerge if more efficient dose escalation can be achieved by redistributing the prescribed dose distribution according to the known heterogeneous, spatially-varying characteristics of the disease. To examine the potential benefits, limitations and characteristics of heterogeneous boost dose redistribution in PCa radiotherapy based on patient-specific and population-based spatial maps of tumor biological features. High-resolution prostate histology images, from a cohort of 63 patients, annotated with tumor location and grade, provided patient-specific "maps" and a population-based "atlas" of cell density and tumor probability. Dose prescriptions were derived for each patient based on a heterogeneous redistribution of the boost dose to the intraprostatic lesions, with the prescription maximizing patient tumor control probability (TCP). The impact on TCP was assessed under scenarios where the distribution of population-based biological data was ignored, partially included, or fully included in prescription generation. Heterogeneous dose prescriptions were generated for three combinations of maps and atlas, and for conventional fractionation (CF), extreme hypo-fractionation (EH), moderate hypo-fractionation (MH), and whole Pelvic RT+SBRT Boost (WPRT+SBRT). The predicted efficacy of the heterogeneous prescriptions was compared with equivalent homogeneous dose prescriptions. TCPs for heterogeneous dose prescriptions were generally higher than those for homogeneous dose prescriptions. TCP escalation by heterogeneous dose prescription was the largest for CF. When only using population-based atlas data, the generated heterogeneous dose prescriptions of 55 to 58 patients (out of 63) had a higher TCP than for the corresponding homogeneous dose prescriptions. The TCPs of the heterogeneous dose prescriptions generated with the population-based atlas and tumor probability maps did not differ significantly from those using patient-specific biological information. The generated heterogeneous dose prescriptions achieved significantly higher TCP than homogeneous dose prescriptions in the posterior section of the prostate. Heterogeneous dose prescriptions generated via biologically-optimized dose redistribution can produce higher TCP than the homogeneous dose prescriptions for the majority of the patients in the studied cohort. For scenarios where patient-specific biological information was unavailable or partially available, the generated heterogeneous dose prescriptions can still achieve TCP improvement relative to homogeneous dose prescriptions.

Métier de manipulateur en radiothérapie en tension en France : conséquences organisationnelles et difficultés à déployer de nouvelles missions et/ou délégation de tâches

PurposeRadiation therapists shortage has been evaluated at national level in France, specifically in oncology radiotherapy, in terms of: (i) organizational adaptations, (ii) impact on patients care, and (iii) difficulties in deploying new missions and/or tasks delegation. Materials and methodsFrench professional organisations representing radiation therapists – SFRO, SNRO and AFPPE – sent their members a national survey (ten questions on 32 items). ResultsFrom 18 November 2022 to 31 December 2022, 55 responses were received (response rate: 31%) from radiotherapy managers or department heads; 51% had a structure comprising three to five treatment rooms (receiving 500 to 1000 patients per year [36%], or 1500 to 2000 patients per year [33%]). Activities performed were intensity-modulated radiotherapy (100%), stereotaxic radiotherapy (85%), brachytherapy (40%), adaptive radiotherapy (34%). These structures described consequences in closing machine time for 25% of them (reduction of the hourly volume greater than 10% in 57%) with the following consequences in the last 6 months: (i) an extension of the period of medical care (78%), a closing of one or more accelerators (50%) and the development of moderate hypofractionation scheme or extreme hypofractionation (50%). In current functioning, linear accelerators can deliver treatments with a team of two radiation therapists per room for a short day (43%) or two to four radiation therapists per room teams for a long day (40%). During the last 6 months, there has been a 10% increase in linear accelerators operating with a single team. (ii) regarding treatment planning: 16.4% reported a decrease in the opening amplitude (less than 20% in 44% of cases, from 20 to 50% in 33 % of cases). The initial scheduling of appointments for radiotherapy sessions was carried out by radiation therapists in 84% of the departments in current functioning (0.1 to 1 FTE dedicated to this activity in 62% of the departments). Over the last 6 months, there has been a clear reduction in the number of dedicated FTEs: [FTE=0.1 to 1]=–8%; [FTE=0]=+7%. (ii) Regarding tasks delegation (excluding the decree on acts and activities carried out by the radiation therapist): organ at risk delineation is partially performed by radiation therapist in 26% of the centres; caregiver support time in 78% (56% totally or 22% partially). This activity has been reduced by 42%. Seventy-five percent of departments want to develop new techniques, patient-centered approaches (44%), implement task delegation (organ at risk delineation: 58%; weekly consultations: 67%; positioning imaging validation: 71%), and 78% of departments are interested in developing advanced radiotherapy practice. However, the number of radiation therapists is considered insufficient in their implementation in 76% of cases (one to two FTE missing for 72% of structures). ConclusionThis survey shows a significant impact of radiation therapist shortage in radiotherapy oncology care (treatment delays, access to caregiver support time, workload on treatment teams), and represents a major obstacle to the development of radiotherapy structures.

Radiothérapie du cancer du sein en cinq fractions

Extreme hypofractionation in adjuvant breast radiotherapy currently generates a lot of interest. We propose here a synthesis of hypofractionation trials and present the DESTHE COL and DESTHE GR projects, encouraged by the French National Cancer Institute (INCa), which experiment care pathways in order to deploy effective strategies to de-escalate the therapeutics and to reduce sequelae after cancer treatment.

PO-1496 Acute toxicity rates and predictors in extreme hypofractionation for localized prostate cancer

PO-1496 Acute toxicity rates and predictors in extreme hypofractionation for localized prostate cancer

PO-1493 Health-related quality of life in extreme hypofractionation for localized prostate cancer

PO-1493 Health-related quality of life in extreme hypofractionation for localized prostate cancer

PO-1295 MELT: A novel tool to select the most suitable patients for extreme hypofractionation

PO-1295 MELT: A novel tool to select the most suitable patients for extreme hypofractionation

Lateral wedge with medial only cardiac shielding (LEMONADE) technique in left breast radiotherapy

This dosimetric study analyzed the lateral wedge with medial only cardiac shielding (LEMONADE) technique for left breast radiotherapy (LBRT) against three other commonly used techniques which is a follow-up from our earlier publication of LEMONADE technique in left chest wall (LCW) radiotherapy.
 Dosimetric parameters of 30 consecutive patients who underwent LBRT with LEMONADE technique (P1) after breast conserving surgery (BCS) were compared with 3 other virtually reconstructed plans: no cardiac shielding with paired wedges; P2 (paired wedges and medial only Y-direction shielding) and P3 (paired wedges and bilateral Y-direction shielding).
 P1 had target volume (TV) coverage [mean 90% isodose coverage of 89.00% ± 3.96 vs 86.28% ± 4.80 and 84.43% ± 5.70 for P2 and P3, respectively]. While there is 3.07% drop in TV coverage compared to no cardiac shielding, the V26Gy of heart dropped from 5.26% to a negligible 0.56% for P1. Low dose region (TV receiving < 30Gy) is also significantly lesser for P1 compared to P2 and P3 (1.50% vs 3.61% and 5.65%).
 The earlier positive LEMONADE dosimetric study of LCW radiotherapy has been replicated in this study with much better dose volume parametres likely due to the physical properties of intact breast. LEMONADE is an easily re-producible and simple radiotherapy technique that can be implemented in most radiotherapy centres. Further study is needed on the use of LEMONADE technique in extreme hypofractionation.

Abstract P1-10-03: Ultra-hypofractionated Radiotherapy for Breast Cancer: A Brazilian Single-Institutional Series

Abstract INTRODUCTION Extreme hypofractionation in patients with early-stage breast cancer has been studied in randomized phase III non-inferiority trials. There is scarce data on this strategy in Latin American patients. OBJECTIVES To describe the profile of patients diagnosed with breast cancer treated with radiotherapy with an ultra-hypofractionated regimen (5 fractions of 5.2 Gy, in one week), as well as the dosimetric aspects and acute toxicity related to the treatment. METHOD Retrospective cohort through a Brazilian uni-institutional series, with analysis of pathological, dosimetric, and toxicity variables. RESULTS Between May 2020 and March 2022, 67 patients were included, with a median age at diagnosis of 71 years (41-93). Regarding staging, 25.8% had in situ tumors, 60.6% of patients were IA, and only 3% were stage IIA. Nineteen percent of patients had histological grade 3; 24.6%, had nuclear grade 3. Hormone receptors were positive in 92.1% of patients. The mean ki67 was 19%, and HER2 was negative at 84.5%. All patients underwent conservative surgery, and 5 underwent reconstruction with autologous flaps. Fifty-one patients underwent hormone therapy and only 2 underwent adjuvant chemotherapy. All but two patients were treated with the conformal technique (VMAT was used due to unfavorable anatomy). The mean volume of the irradiated breast was 926 cm3 (ranging from 920 to 932 cm3). Regarding the constraints of the organs at risk, the average V8Gy of the ipsilateral lung was 11.4%, ranging from 0 to 24%. In the heart, the average volumes receiving 1.5Gy and 7Gy were, respectively, 9.2% and 0.7%. No patient had acute toxicity greater than grade 2. The effects on the skin appeared on average 20 days after the end of treatment, with resolution in a maximum of 3 months. The median follow-up time was 10 months (3 - 26). We did not observe any case of local-recurrence, of breast-cancer-related death. CONCLUSION Although our follow-up time is premature, we have found that ultra-hypofractionated radiotherapy was feasible, tolerable, and safe, for patients with early breast cancer. Also, the constraints on the organs at risk were respected. There were no high-grade acute toxicities. Besides convenience, ultra-hypofractionation can improve access to radiotherapy in resource-scarce settings. Citation Format: Leticia Hernandes de Brito, Felipe Cicci Farinha Restini, Maria Thereza Mansur Starling, Gabriela Silva Moreira de Siqueira, Gustavo Nader Marta, Heloisa de Andrade Carvalho, Samir Abdallah Hanna. Ultra-hypofractionated Radiotherapy for Breast Cancer: A Brazilian Single-Institutional Series [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-10-03.

Imaginando el futuro

We present the futuristic vision of their specialty of seven opinion leaders closely involved in breast pathology. The specialties were radiology, pathology, surgery, plastic surgery, nuclear medicine, medical oncology, and radiation oncology. In this article, the authors express their opinions and criteria regarding the advances they foresee for their professional future.Key concepts such as radiation-free screening systems, clinical transcriptomics, functional tumor diagnosis, artificial intelligence, intraoperative navigation, liquid biopsy, circulating tumor DNA, reconstruction with advanced microsurgical techniques, extreme hypofractionation or theragnosis are some of the concepts presented and discussed.The authors justify their points of view, suggesting lines of work to optimize efforts and future knowledge.

62: Acute Toxicity in High-Risk Prostate Cancer Patients Treated with Extreme Hypofractionation (HRPC-SBRT)

62: Acute Toxicity in High-Risk Prostate Cancer Patients Treated with Extreme Hypofractionation (HRPC-SBRT)

Prostate Volume Changes during Extreme and Moderately Hypofractionated Magnetic Resonance Image-guided Radiotherapy

AimsProstate morphological changes during external beam radiotherapy are poorly understood. Excellent soft-tissue visualisation offered by magnetic resonance image-guided radiotherapy (MRIgRT) provides an opportunity to better understand such changes. The aim of this study was to quantify prostate volume and dimension changes occurring during extreme and moderately hypofractionated schedules. Materials and methodsForty prostate cancer patients treated on the Unity 1.5 Tesla magnetic resonance linear accelerator (MRL) were retrospectively reviewed. The cohort comprised patients treated with 36.25 Gy in five fractions (n = 20) and 60 Gy in 20 fractions (n = 20). The volume of the delineated prostates on reference planning computed tomography (fused with MRI) and daily T2-weighted 2-min session images acquired on Unity were charted. Forty planning computed tomography and 500 MRL prostate volumes were evaluated. The mean absolute and relative change in prostate volume during radiotherapy was compared using a paired t-test (P value <0.01 considered significant to control for multiple comparisons). The maximum dimension of the delineated prostate was measured in three isocentric planes. ResultsSignificant prostate volume changes, relative to MRL imaging fraction 1 (MRL#1), were seen at all time points for the five-fraction group. The peak mean relative volume increase was 21% (P < 0.001), occurring at MRL#3 and MRL#4 after 14.5 and 21.75 Gy, respectively. Prostate expansion was greatest in the superior–inferior direction; the peak mean maximal extension was 5.9 mm. The maximal extension in the left–right and anterior–posterior directions measured 1.1 and 2.2 mm, respectively. For the 20-fraction group, prostate volume increased relative to MRL#1, for all treatment time points. The mean relative volume increase was 11% (P < 0.001) at MRL#5 after 12 Gy, it then fluctuated between 8 and 13%. From MRL#5 to MRL#20, the volume increase was significant (P < 0.01) for 12 of 16 time points calculated. The peak mean maximal extension in the superior–inferior direction was 3.1 mm. The maximal extension in the left–right and anterior–posterior directions measured 1.7 and 3.7 mm, respectively. ConclusionSignificant prostate volume and dimension changes occur during extreme and moderately hypofractionated radiotherapy. The extent of change was greater during extreme hypofractionation. MRIgRT offers the opportunity to reveal, quantify and correct for this deformation.

Extreme hypofractionation in radiation therapy for patients with early breast cancer: what is the optimal technique?

Many radiation techniques have been employed in the trend of moving towards more hypofractionated regimens in the treatment of early breast cancer. This editorial articulates the advantages of using multi-catheter interstitial brachytherapy when delivering extreme hypofractionation for partial breast radiation.

Hypofractionated Radiation Therapy in Keratinocyte Carcinoma

Hypofractionated radiation therapy regimens are well suited to the management of keratinocyte carcinomas. Most lesions are small, superficial and not close to critical organs at risk. Fewer visits to the cancer centre are advantageous for the frail and elderly patient population. No difference in cosmesis or local control has been found when comparing hypofractionated with conventionally fractionated radiation therapy schedules, although most of the data in the literature are retrospective, highlighting the need for prospective trials. As keratinocyte carcinomas can present anywhere on the skin surface, a wide variety of techniques may be used to optimise treatment delivery, including external beam radiation with kilovoltage, electron beams and megavoltage photons. Brachytherapy can also be used with radionuclide and electronic-based applicators, surface applicators and interstitial techniques for lesions >5 mm deep. Stereotactic body radiotherapy, or extreme hypofractionation, is an emerging treatment option that delivers an ablative dose to the tumour while minimising dose to organs at risk through precision planning and delivery techniques. Frail elderly patients with medically inoperable disease not suitable for conventionally fractionated radiation therapy may achieve durable locoregional control with dose escalation. Ongoing studies following local control and toxicity are warranted. The aim of this article is to provide clinical oncologists with an overview of hypofractionation for keratinocyte carcinomas.

Simultaneous integrated boost (SIB) to dominant intra-prostatic lesions during extreme hypofractionation for prostate cancer: the impact of rectal spacers

PurposeBoosting dominant intra-prostatic lesions (DILs) has the potential to increase the therapeutic ratio in prostate cancer radiotherapy. In this study, employing 5-fraction stereotactic ablative radiotherapy (SABR) volumetric modulated arc therapy (VMAT) to deliver 40 Gy to the prostate clinical target volume (CTV) while boosting the DIL up to 50 Gy was evaluated for patients before and after rectal spacer insertion.Materials and methods24 Computed Tomography (CT) scans of 12 prostate cancer patients with unfavourable intermediate or high risk prostate cancer were employed in this study. At least two treatment plans were generated for each patient to compare pre- and post-spacer insertion plans. Plans were evaluated for target coverage, organs-at-risk doses, and the achievable boost dose level.ResultsThe CTV coverage was significantly better in plans with a spacer, V40Gy 98.4% versus 97.0% (p = 0.012). Using spacers significantly reduced rectal dose in all 12 patients in this study. It was possible to boost DIL to 50 Gy to without violating dose constraints in 6 of 12 patients and to 47.5 Gy in 3 patients post-spacer insertion. For 3 patients (25%) it was not possible to boost DIL above 45 Gy even with a spacer in situ. Without a spacer, for 6 patient (50%) clinically acceptable plan were only achieved when the DIL dose was lowered to 45 Gy. In five of these 6 patients the dose limiting structure was the urethra (urethra planning risk volume V45Gy [cc] ≤ 0.1 cc constraint).ConclusionsClinically acceptable plans for 5 fraction SABR, 40 Gy to the prostate CTV, with a SIB to DIL (45–50 Gy) were achieved. The boost dose achieved was DIL location dependent and primarily affected by DIL’s proximity to the urethra. Compared to plans before spacer insertion, higher DIL dose were achieved with spacer in situ for 25% of the patients. Moreover, significant reduction in rectal dose and better target coverage were also achieved for all patients with spacers in situ.

Stereotactic Radiotherapy after Radical Prostatectomy in Patients with Prostate Cancer in the Adjuvant or Salvage Setting: A Systematic Review.

Simple SummaryStereotactic body radiotherapy, a type of high-precision radiotherapy delivering high doses within few treatment sessions has proven to be effective and well tolerated in prostate cancer patients treated with definite radiotherapy. This systematic review summarizes the available data and analyzes whether this modern treatment may routinely be offered to prostate cancer patients after radical prostatectomy.(1) Background: Prostate cancer is the most common cancer in men and can be treated with radical prostatectomy (RPE) or radiotherapy in the primary setting. Stereotactic radiotherapy (SBRT) has proven to be effective and well tolerated in this setting. However, if SBRT is an equally promising treatment option if applied in the adjuvant or salvage setting after RPE remains unknown. (2) Methods: We searched the PubMed and Embase databases with the following full-text queries in August 2021 for any combination of the terms “SBRT”, “prostate”, “adjuvant”, “postoperative”, “salvage”, “stereotactic radiotherapy”, “prostate bed”. There were no limitations regarding publication date or language. We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. (3) Results: We identified 11 individual studies that were included in this systematic review. Three publications included patients without prior radiotherapy and the remaining eight patients with prior radiotherapy. In all but two publications the radiation target was the macroscopic recurrence. SBRT was overall well tolerated with acceptable rates of acute and late gastrointestinal or genitourinary toxicity. Quality of life was published for two phase I trials with good results. There was a very heterogeneous reporting on biochemical control after SBRT. (4) Conclusions: At this point, ultra-hypofractionated RT using SBRT to the prostate bed remains experimental and its use should be restricted to clinical trials. Given the biological rationale for extreme hypofractionation in patients with prostate cancer and the acceptable toxicity rates that have been reported, further exploration of this field is warranted.

2021 ASTRO annual meeting.

Cameron Thorpe (Mayo Clinic Arizona, Phoenix, AZ, USA) presented early results from the MC1635 trial. 107 patients with localised breast cancer who had breast-conserving surgery were randomly assigned (1:1) to whole-breast radiotherapy with moderate hypofractionation (40 Gy in 15 fractions; n=54) or extreme hypofractionation (25 Gy in five fractions; n=55). At a median follow-up of 20 months, there were no grade 3 adverse effects; grade 2 adverse effects were reported in 7% of patients in each group. Average cosmesis and quality-of-life scores were similar between groups. Moderate to severe radiation skin burns were more common with moderate hypofractionation (58·7%) than with extreme hypofractionation (27·9%; odds ratio 3·7, 95% CI 1·5–8·9; p=0·004).

OD45 - Clinical kick-off of Ra yPilot® HypoCath® real time tracking: a novel electromagnetic device without surgical intervention to evaluate the intrafraction motion during extreme hypofractionation of localized prostate cancer stereotactic body radiation therapy (SBRT)

OD45 - Clinical kick-off of Ra yPilot® HypoCath® real time tracking: a novel electromagnetic device without surgical intervention to evaluate the intrafraction motion during extreme hypofractionation of localized prostate cancer stereotactic body radiation therapy (SBRT)