Laryngectomy plus postoperative radio(system)therapy versus primary radio(system) therapy for the treatment of locally advanced laryngeal and hypopharyngeal cancer - results from the University Clinical Cancer Registry Regensburg.

BACKGROUND: There are few adequate randomized clinical trials directly comparing the therapeutic options of primary laryngectomy (pLE) vs. primary radio(system)therapy (pR(S)T) in patients with locally advanced laryngeal and hypopharyngeal carcinoma and thus little clear scientific evidence to decide which patients will benefit most from which procedure. AIMS/OBJECTIVES: Aim was to compare survival between the therapeutic options and to learn from the limitations of this study, especially in the context of improved clinical assessment. MATERIAL AND METHODS: The clinical data of patients treated between January 2010 and February 2022 were obtained from the electronic database of the University Hospital Regensburg. Overall survival (OS) and progression-free survival (PFS) were compared between the treatment groups. RESULTS: The study included 193 patients (pLE n = 68, pR(S)T, n = 125). Median OS was 31.2 months and median PFS was 24.7 months with no significant difference between the treatment groups (p > .050). Patients who did not receive complete treatment as recommended by the tumor conference (n = 47, 24.4%) had a higher risk of death (p = .024). CONCLUSIONS AND SIGNIFICANCE: The results of our study are consistent with the survival data reported in the literature. More detailed systematic data in clinical routine (e.g. relevant comorbidities) are required to ensure guideline-based recommended therapy.

A database for oncological research and quality assurance: implementation and first experiences with the University Clinical Cancer Registry Regensburg.

Legal requirements, certification specifications, as well as the demand for real world data on cancer research and treatment led to the decision to establish the University Clinical Cancer Registry Regensburg. The first organizational step in the implementation process of this oncological data registry was the evaluation and acquisition of suitable tumor documentation and database software. For this purpose, an evaluation matrix comprising required database software criteria was designed and consented by a multidisciplinary group of experts. Next, a yearly report of the Institute for Cancer Center Certification (OnkoZert 2019) was considered to identify database software already in use. The identified systems were rated according to the established criteria matrix and other relevant aspects. Onkostar was the system considered most suited for building up an oncological data repository. In the second step, the central IT department implemented Onkostar on-premise and migrated digitally available data after an adaptation and verification process. In parallel, a uniformed process for handling emerging oncological research questions was established. For research requirements, a data analysis concept was established comprising a proposal for data extraction, procedural instructions, and statistical training materials. In the final step, the implemented software and the process for handling research requirements in practice were evaluated by using two exemplary use cases with the focus on clinic-wide analyses and currently relevant scientific topics. A 2-month test phase conducted by various user groups showed a preference for Onkostar tumor documentation software from IT-Choice, mainly because of its adjustability to support research and treatment. Newly added and migrated data can be used for certification and research purposes. This software also provides support in current tumor documentation by displaying the course of cancer disease for individual patients over time. Such oncological data registries can be a powerful tool for legally required cancer registration, the certification of medical centers, as well as for additional oncological research. Tumor databases can be helpful in projects on cancer treatment and scientific aims. The experiences made at the University Hospital Regensburg may be used as a guidance for implementing clinical databases in similar settings with interdisciplinary responsibilities.

Stereotactic radiosurgery of brain metastases: a retrospective study.

BACKGROUND: Single-fraction stereotactic radiosurgery (SRS) is an established standard for radiation therapy of brain metastases although recent developments indicate that multi-fractionated stereotactic radiotherapy (FSRT) results in lower radiation necrosis especially for larger metastases, and the same or even better local control in comparison to SRS. METHODS: Seventy-two patients with 111 brain metastases received SRS with a single dose of 18 Gy between September 2014 and December 2021. The dose prescription was either 18 Gy given to the enclosing 80% isodose with a normalization to Dmax = 100% of 22.5 Gy (part I) or 18 Gy = D98, while D0.03 cc of 21.6-22.5 Gy was accepted (part II). The study retrospectively evaluated local progression-free survival (LPFS), response on the first follow-up magnetic resonance imaging (MRI), and radiation necrosis. RESULTS: Melanoma brain metastases (n = 44) were the most frequent metastases. The median gross tumor volume (GTV) was 0.30 cm³ (IQR, 0.17-0.61). The median follow-up time of all patients was 50.8 months (IQR, 30.4-64.6). Median LPFS was 23.5 months (95%CI 17.2, 29.8). The overall LPFS rates at 12-, 18-, 24- and 30 months were 65.3%, 56.3%, 46.5%, and 38.8%. Brain metastases with radioresistant histology (melanoma, renal cell cancer, and sarcoma) showed a 12-month LPFS of 60.2%, whereas brain metastases with other histology had a 12-month LPFS of 70.1%. The response of brain metastases on first follow-up MRIs performed after a median time of 47 days (IQR, 40-63) was crucial for long-term local control and survival. Eight brain metastases (7.2%) developed radiation necrosis after a median time of 18.4 months (IQR, 9.4-26.5). In multivariate analyses, a GTV > 0.3 cm³ negatively affected LPFS (HR 2.229, 95%CI 1.172, 4.239). Melanoma, renal cell cancers, and sarcoma had a lower chance of LPFS in comparison to other cancer types (HR 2.330, 95%CI 1.155, 4.699). CONCLUSIONS: Our results indicate a reasonable 1-year local control of brain metastases with radiosensitive histology. Radioresistant metastases show a comparatively poor local control. Treatment refinements merit exploration to improve local control of brain metastases. TRIAL REGISTRATION: This study is retrospectively registered (ethics approval number 23-3451-104).

S3 guideline "actinic keratosis and cutaneous squamous cell carcinoma" - update 2023, part 2: epidemiology and etiology, diagnostics, surgical and systemic treatment of cutaneous squamous cell carcinoma (cSCC), surveillance and prevention.

Actinic keratosis (AK) are common lesions in light-skinned individuals that can potentially progress to cutaneous squamous cell carcinoma (cSCC). Both conditions may be associated with significant morbidity and constitute a major disease burden, especially among the elderly. To establish an evidence-based framework for clinical decision making, the guideline "actinic keratosis and cutaneous squamous cell carcinoma" was updated and expanded by the topics cutaneous squamous cell carcinoma in situ (Bowen's disease) and actinic cheilitis. The guideline is aimed at dermatologists, general practitioners, ear nose and throat specialists, surgeons, oncologists, radiologists and radiation oncologists in hospitals and office-based settings, as well as other medical specialties, policy makers and insurance funds involved in the diagnosis and treatment of patients with AK and cSCC. A separate guideline exists for patients and their relatives. In this part, we will address aspects relating to epidemiology and etiology, diagnostics, surgical and systemic treatment of cutaneous squamous cell carcinoma (cSCC), surveillance and prevention.

Head and neck oncology management in the time of COVID-19: results of a head and neck cancer center.

PURPOSE: Given the concerns about the effects of the COVID-19 pandemic on cancer care, we analyzed the treatment quality of the head and neck cancer center Regensburg before and throughout 2 years of the pandemic. We included data of 3 years to reflect the extended pandemic period as new developments continued to influence its course. METHODS: This retrospective review included all patients diagnosed with head and neck cancer in 2019, 2020, and 2021 who had not started treatment elsewhere prior to being referred to the head and neck cancer center. We compared tumor characteristics and times to therapy of patients diagnosed before COVID-19 in 2019 (n = 253), during COVID-19 in 2020 (n = 206), and in a phase of partial normalization in a persistent pandemic situation in 2021 (n = 247). RESULTS: Our data revealed no decrease in diagnoses or drift in stages toward more advanced stages. There was an increased percentage of diagnoses confirmed at the head and neck cancer center from 2019 (57.3%) to 2020 (68.0%) and to 2021 (65.6%) compared to confirmation at other institutions (2019, 42.7%; 2020, 32.0%; 2021, 34.4%; P = 0.041). Surgery and radiotherapy were performed with the same frequency. The median days between diagnosis and surgery were decreased in 2020 (19.5 days; P = 0.049) and 2021 (20.0 days; P = 0.026) in comparison to 2019 (23 days). The days to radiotherapy were not affected. CONCLUSION: The data indicate a consistent oncological performance for head and neck cancer patients in all waves of the pandemic and thereafter without a decrease in diagnoses or shift in stages.

Analysis of long-term mortality after total body irradiation-based and melphalan-based chemotherapy conditioning for acute myeloid leukemia.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment option for selected patients with acute myeloid leukemia. Yet, the influence of total body irradiation (TBI)-based conditioning as compared to non-TBI-based conditioning on long-term mortality is unclear. We retrospectively evaluated outcomes after TBI-based (n = 91) and non-TBI-based conditioning (melphalan-based, n = 248) for 1st allo-HSCT patients transplanted at the University Hospital Regensburg between 1999 and 2020. TBI was performed with an average dose rate of 4 cGy/min. Median follow-up was 8.3 years (interquartile range, 4.8-12.9 years). Cumulative incidence rates of 5-year non-relapse mortality (NRM) were 17% (95% confidence interval, CI, 10-25) and 33% (95% CI, 27-40) after TBI- and non-TBI-based conditioning (P < 0.001). Five-year cumulative incidences of relapse (CIR) were 42% (95% CI, 32-52) and 29% (95% CI, 23-35) after TBI- and non-TBI-based conditioning (P = 0.030). The 5-year OS was 54% (95% CI, 43-64) and 55% (95% CI, 48-62) after TBI- and non-TBI-based conditioning. Both groups had similar 100-day acute graft-versus-host disease (aGVHD, 43% vs. 40%) and 5-year chronic GVHD (34% vs. 36%). The multivariable regression models found no associations of TBI with the outcomes NRM, CIR, PFS, OS, aGVHD, and cGVHD. TBI was no risk factor for NRM, even including mortality caused by secondary malignancies. NRM was influenced by patient age, advanced disease status, and the use of female donors for male recipients. TBI- and non-TBI-based conditioning appear to be equally effective and tolerable for AML patients eligible for 1st allo-HSCT.

Fractionated stereotactic radiotherapy of brain metastases: results of a retrospective study.

BACKGROUND: Lasting local control of brain metastases following stereotactic radiotherapy is becoming increasingly relevant since systemic treatment constantly improves the prognosis of patients with extracranial metastases. METHODS: 73 patients with 103 brain metastases received hypofractionated stereotactic radiotherapy (FSRT) in 6 fractions of 5 Gy between January 2017 and December 2021 at the University Hospital Regensburg, Germany. The study retrospectively evaluated local progression free survival (LPFS), overall survival (OS) and distant brain progression free survival (DPFS) of patients without prior radiotherapy of the brain. Response rate and brain radiation necrosis were reported. Cox proportional hazard models evaluated prognostic factors of OS and LPFS. RESULTS: The median patient age was 61.0 years (Interquartile range, IQR 51.0, 67.5). The most common tumor types were malignant melanoma (34.2%) and non-small cell lung adenocarcinoma (26.0%). The median gross tumor volume (GTV) was 0.9 cm³ (IQR 0.4, 3.6). The median follow-up time of all patients was 36.3 months (95%CI 29.1, 43.4). The median OS was 17.4 months (95%CI 9.9, 24.9). Overall survival rates at 6-, 12-, 18-, 24-, and 30 months were 81.9%, 59.1%, 49.0%, 41.3%, and 37.2%, retrospectively. The mean LPFS was 38.1 months (95%CI 31.4, 44.9), while the median LPFS has not been reached. LPFS rates at 6-, 12-, 18-, 24- and 30 months were 78.9%, 68.7%, 64.3%, 61.6% and 58.7%, retrospectively. Median DPFS of all patients was 7.7 months (95%CI 6.1, 9.3). Six, 12-, 18-, 24- and 30 months DPFS rates were 62.1%, 36.3%, 31.1%, 24.8% and 21.7%. Five brain metastases (4.8%) developed brain radiation necrosis. In multivariate analysis, the number of brain metastases negatively affected LPFS. Non-melanoma and non-renal cell cancer was associated with a higher chance of LPFS in comparison to other cancer. A GTV > 1.5 cm³ translated into a higher risk of death compared to a GTV ≤ 1.5 cm³ and Karnofsky performance score was predictive of OS. CONCLUSIONS: FSRT in 6 fractions of 5 Gy seems to be an effective treatment with an acceptable local control for patients with brain metastases although melanoma and renal cell cancer seem to have a worse local control in comparison to other cancer. TRIAL REGISTRATION: This study is retrospectively registered.

Impact of chronic graft-versus-host disease on quality of life and cognitive function of long-term transplant survivors after allogeneic hematopoietic stem cell transplantation with total body irradiation.

BACKGROUND: Total body irradiation (TBI)-based-conditioning before allogeneic hematopoietic stem cell transplantation (allo-HSCT) is standard of care in patients with acute myeloid leukemia (AML) but can cause long-term morbidity. Data on the impact of chronic Graft-versus-host disease (cGvHD) on cognitive function (CF) and quality of life (QoL) of long-term transplant survivors are sparse. METHODS: We analyzed patient-reported outcomes focusing on progression-free AML patients and 1st allo-HSCT applying a standardized TBI-technique with an average dose rate of 4 cGy/min to the total body and lung shielding in case of doses > 8 Gy. Instruments included the Functional Assessment of Cancer Therapy-Bone marrow transplant (FACT-BMT, version 4), the FACT-Cognition Function (FACT-Cog, version 3) and the Patient Health Questionaire-4 (PHQ-4). We put focus on the impact of cGvHD and compared the results to normative data derived from the general population. RESULTS: Out of 41 eligible patients contacted, 32 (78.0%) patients with a medium follow-up of 154 months (Interquartile range 113, 191 months) participated in the study. Eleven patients (34.4%) had active cGvHD, 11 (34.4%) resolved cGvHD and 10 (31.3%) never had cGvHD. Patients with active cGvHD had poorer FACT-BMT, FACT-Cog and higher PHQ-4 scores compared to patients with resolved cGvHD or who never had cGvHD. Outcomes were similar in patients with resolved cGvHD and those who never had cGvHD. Patients with active cGvHD had similar FACT-Cog, but lower FACT-BMT in comparison to normative data. However, the overall patient sample had similar FACT-BMT and FACT-Cog in comparison to normative data. CONCLUSION: Our data indicate that CF of long-term survivors upon TBI-based allo-HSCT is not impaired, even in the presence of active cGvHD. However, active cGvHD has a negative impact on QoL. Trial registration  The local Ethics Board of the University of Regensburg approved this study (Number 20-1810_1-101).

Noninvasive treatment of two deeply invasive cutaneous squamous cell carcinomas of the midface located close to the orbits with intensity-modulated arc therapy: A case report.

Definitive radiotherapy is a curative and noninvasive treatment modality for cutaneous squamous cell carcinomas of the midface when surgery has an impact on function and cosmetics. Volumetric modulated arc therapy provides optimal dose coverage for complex-shaped tumors without compromising adjacent organs at risk.

Dramatic radiotherapy response of a giant T4 cutaneous squamous cell carcinoma of the scalp with extensive bone destruction: a case report.

BACKGROUND: Patients with large cutaneous squamous cell carcinoma of the scalp are a treatment challenge. We report a case of dramatic radiotherapy response of a patient with a giant cutaneous squamous cell carcinoma of the scalp with extensive skull destruction and suspected infiltration of the dura mater and superior sagittal sinus. This case is the first report of this kind in the literature that shows that large bone defects can heal with the resolution of tumor and inflammation by secondary intention without surgical reconstruction. We want to put an end to concerns about radiocurability of tumors with extensive bone involvement, and show sustained complete response after definitive radiotherapy and programmed cell death protein-1 inhibiting antibody therapy. CASE PRESENTATION: A 74-year-old White man presented with a 7.2 × 6.8 × 5.5 cm painless tumor on the right parietal region of the scalp. Medical imaging revealed widespread destruction of the skull and suspected infiltration of the dura mater and superior sagittal sinus. Biopsies showed cutaneous squamous cell carcinoma (cT4a cN0 cM0, stage IVA). The patient was treated with a total dose of 60 Gy, at 2 Gy per daily fraction with volumetric modulated arc therapy using 6 megavoltage photons. The biologically effective dose (alpha/beta 10 Gy) was 72 Gy. The tumor response correlated with dose received. The patient had a massive tumor necrosis secondary to tumor shrinkage after 18 fractions (36 Gy, biologically effective dose 43.2 Gy). Leakage of cerebrospinal fluid did not occur. Radiotherapy did not hamper the patient's quality of life. The patient had a clear regression of the initial tumor on the final day of radiotherapy. The bone defect healed by secondary intention without surgical interventions. The patient achieved a complete response with a good cosmetic result after 82 days follow-up. He started a programmed cell death protein-1 inhibiting antibody therapy with cemiplimab 2 months after radiotherapy, and is now at 10 months follow-up without evidence of recurrence. CONCLUSION: Definitive radiotherapy is a safe and highly effective therapy for giant tumors of the scalp with extensive bone destruction. We report a sustained complete response with a good cosmetic result after secondary wound healing.

Secondary malignancy risk for patients with localized prostate cancer after intensity-modulated radiotherapy with and without flattening filter.

Men treated for localized prostate cancer by radiotherapy have often a remaining life span of 10 yr or more. Therefore, the risk for secondary malignancies should be taken into account. Plans for ten patients were evaluated which had been performed on an Oncentra® treatment planning system for a treatment with an Elekta Synergy™ linac with Agility™ head. The investigated techniques involved IMRT and VMTA with and without flattening filter. Different dose response models were applied for secondary carcinoma and sarcoma risk in the treated region and also in the periphery. As organs at risk we regarded for carcinoma risk urinary bladder, rectum, colon, esophagus, thyroid, and for sarcoma risk bone and soft tissue. The excess absolute risk (EAR) was found very similar in the treated region for both techniques (IMRT and VMAT) and also for both with and without flattening filter. The secondary sarcoma risk resulted about one magnitude smaller than the secondary carcinoma risk. The EAR to the peripheral organs was statistically significant reduced by application of the flattening filter free mode concerning the flattening filter as main source of scattered dose. Application of flattening filter free mode can thus support to reduce second malignancy risk for patients with localized prostate cancer.

Single-institution cross-sectional study to evaluate need for information and need for referral to psychooncology care in association with depression in brain tumor patients and their family caregivers.

BACKGROUND: The prognosis of patients with brain tumors is widely varying. Psychooncologic need and depression are high among these patients and their family caregivers. However, the need for counselling and need for referral to psychooncology care is often underestimated. METHODS: We performed a single-institution cross-sectional study to evaluate psychooncologic need, depression and information need in both patients and their family caregivers. The Hornheider Screening Instrument (HSI) and the Patient Health Questionnaire (PHQ-9) were used to evaluate psychooncologic need and depression, and a study-specific questionnaire was developed to evaluate information need. Multivariable analyses were performed to detect correlations. RESULTS: A total of 444 patients and their family caregivers were approached to participate, with a survey completion rate of 35.4%. More than half of the patients and family caregivers were in need for referral to psychooncology care and 31.9% of patients suffered from clinically relevant depression. In multivariable analysis, psychooncologic need were positively associated with mild (odds ratio, OR, 7.077; 95% confidence interval, CI, 2.263-22.137; p = 0.001) or moderate to severe (OR 149.27, 95% CI 26.690-737.20; p <  0.001) depression. Patient information need was associated with depression (OR 3.007, 95% CI 1.175-7.695; p = 0.022). CONCLUSIONS: Unmet counselling need in brain tumor patients and their family caregivers associate to high psychooncologic need and depression. Adequate information may decrease the need for referral to psychooncology care and treatment of depression in these patients. Future studies should further explore these relations to promote development of supportive structures.

The influence of radiotherapy techniques on the plan quality and on the risk of secondary tumors in patients with pituitary adenoma.

BACKGROUND: This planning study compares different radiotherapy techniques for patients with pituitary adenoma, including flatness filter free mode (FFF), concerning plan quality and secondary malignancies for potentially young patients. The flatness filter has been described as main source of photon scatter. MATERIAL AND METHODS: Eleven patients with pituitary adenoma were included. An Elekta Synergy™ linac was used in the treatment planning system Oncentra® and for the measurements. 3D plans, IMRT, and VMAT plans and non-coplanar varieties were considered. The plan quality was evaluated regarding homogeneity, conformity, delivery time and dose to the organs at risk. The secondary malignancy risk was calculated from dose volume data and from measured dose to the periphery using different models for carcinoma and sarcoma risk. RESULTS: The homogeneity and conformity were nearly unchanged with and without flattening filter, neither was the delivery time found substantively different. VMAT plans were more homogenous, conformal and faster in delivery than IMRT plans. The secondary cancer risk was reduced with FFF both in the treated region and in the periphery. VMAT plans resulted in a higher secondary brain cancer risk than IMRT plans, but the risk for secondary peripheral cancer was reduced. Secondary sarcoma risk plays a minor role. No advantage was found for non-coplanar techniques. The FFF delivery times were not shortened due to additional monitor units needed and technical limitations. The risk for secondary brain cancer seems to depend on the irradiated volume. Secondary sarcoma risk is much smaller than carcinoma risk in accordance to the results of the atomic bomb survivors. The reduction of the peripheral dose and resulting secondary malignancy risk for FFF is statistically significant. However, it is negligible in comparison to the risk in the treated region. CONCLUSION: Treatments with FFF can reduce secondary malignancy risk while retaining similar quality as with flattening filter and should be preferred. VMAT plans show the best plan quality combined with lowest peripheral secondary malignancy risk, but highest level of second brain cancer risk. Taking this into account VMAT FFF seems the most advantageous technique for the treatment of pituitary adenomas with the given equipment.

Adherence to guidelines and benefit of adjuvant radiotherapy in patients with invasive breast cancer: results from a large population-based cohort study of a cancer registry.

PURPOSE: According to German S3 guidelines, radiotherapy (RT) is indicated in patients with invasive breast cancer after breast-conserving therapy (BCT). The aim of this analysis was to assess adherence to guidelines, long-term survival, recurrence rates, and recurrence-free survival after adjuvant RT in patients with BCT in daily clinical practice. METHODS: This retrospective cohort study comprised data from the population-based clinical cancer registry of the Tumor Centre Regensburg (Bavaria, Germany). 6370 patients with non-metastatic invasive breast cancer and UICC tumor stages I, II, and III who were treated in certified breast cancer centers by BCT and diagnosed between 2003 and 2013 were included in the study. RESULTS: 6184 (97.1%) breast cancer patients received guideline concordant RT and showed a 3-year overall survival (OAS) of 96.8% in contrast to 90.9% in patients without RT (5-year OAS of 93.1% vs. 79.0%, p < 0.001). In multivariable Cox regression models, better overall survival was confirmed for the RT group (HR 0.64, 95% CI 0.46-0.88, p = 0.007). The 5-year local recurrence-free survival rate (RFS) in the irradiated patients was 92.1% vs. 62.0% in the comparison group (p < 0.001). The 10-year RFS was 80.5% vs. 36.0% (p < 0.001). This difference persisted after adjusting in multivariable analysis (HR 0.20, 95% CI 0.16-0.26, p < 0.001). CONCLUSIONS: This population-based analysis showed that the implementation of German guidelines in clinical routine was successful and guideline concordant adjuvant radiotherapy after BCT leads to better overall and recurrence-free survival and lower local recurrence rates.

Second cancer risk after radiation therapy of ependymoma using the flattening filter free irradiation mode of a linear accelerator.

Pediatric patients suffering from ependymoma are usually treated with cranial or craniospinal three-dimensional (3D) conformal radiotherapy (3DCRT). Intensity-modulated techniques spare dose to the surrounding tissue, but the risk for second malignancies may be increased due to the increase in low-dose volume. The aim of this study is to investigate if the flattening filter free (FFF) mode allows reducing the risk for second malignancies compared to the mode with flattening filter (FF) for intensity-modulated techniques and to 3DCRT. A reduction of the risk would be advantageous for treating pediatric ependymoma. 3DCRT was compared to intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) with and without flattening filter. Dose-volume histograms (DVHs) were compared to evaluate the plan quality and used to calculate the excess absolute risk (EAR) to develop second cancer in the brain. Dose verification was performed with a two-dimensional (2D) ionization chamber array and the out-of-field dose was measured with an ionization chamber to determine the EAR in peripheral organs. Delivery times were measured. Both VMAT and IMRT achieved similar plan quality in terms of dose sparing in the OAR and higher PTV coverage as compared to 3DCRT. Peripheral dose in low-dose region, which is proportional to the EAR in organs located in this region, for example, gonads, bladder, or bowel, could be significantly reduced using FFF. The lowest peripheral EAR and lowest delivery times were hereby achieved with VMATFFF . The EAR calculated based on DVH in the brain could not be reduced using FFF mode. VMATFFF improved the target coverage and homogeneity and kept the dose in the OAR similar compared to 3DCRT. In addition, delivery times were significantly reduced using VMATFFF . Therefore, for radiotherapy of ependymoma patients, VMATFFF may be considered advantageous for the combination of Elekta Synergy linac and Oncentra External Beam planning system used in this study.

Volumetric-modulated arc therapy and intensity-modulated radiation therapy treatment planning for prostate cancer with flattened beam and flattening filter free linear accelerators.

This study on patients with localized prostate cancer was set up to investigate valuable differences using flattened beam (FB) and flattening filter free (FFF) mode in the application of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT). For ten patients, four different plans were calculated with Oncentra planning system of Elekta, using Synergy machines: IMRT and VMAT, with and without flattening filter. Homogeneity and conformity indexes, dose to the organs at risk, and measurements of peripheral dose and dosimetric plan verification including record of the delivery times were analyzed and statistically evaluated. The indexes for homogeneity and conformity (CTV and PTV) are either advantageous or not significantly different for FFF compared to FB with one minor exception. Regarding the doses to the organs at risk and the measured peripheral dose, equivalent or lower doses were delivered for FFF than with FB. Furthermore, the delivery times were significantly shorter for FFF. VMAT compared to IMRT reveals benefits or at least equivalent values. VMAT-FFF combines the most advantageous plan quality parameters with the shortest delivery times and reduced peripheral dose and is therefore recommended for the given equipment and cancer localization.