Prospective Randomized Phase 2 Trial of Hypofractionated Stereotactic Radiation Therapy of 25 Gy in 5 Fractions Compared With 35 Gy in 5 Fractions in the Reirradiation of Recurrent Glioblastoma

PURPOSE

The aim of this work was to investigate whether reirradiation of recurrent glioblastoma with hypofractionated stereotactic radiation therapy (HSRT) consisting of 35 Gy in 5 fractions (35 Gy/5 fx) compared with 25 Gy in 5 fractions (25 Gy/5 fx) improves outcomes while maintaining acceptable toxicity.

METHODS AND MATERIALS

We conducted a prospective randomized phase 2 trial involving patients with recurrent glioblastoma (per the 2007 and 2016 World Health Organization classification). A minimum interval from first radiation therapy of 5 months and gross tumor volume of 150 cc were required. Patients were randomized 1:1 to receive HSRT alone in 25 Gy/5 fx or 35 Gy/5 fx. The primary endpoint was progression-free survival (PFS). We used a randomized phase 2 screening design with a 2-sided α of 0.15 for the primary endpoint.

RESULTS

From 2011 to 2019, 40 patients were randomized and received HSRT, with 20 patients in each group. The median age was 50 years (range, 27-71); a new resection before HSRT was performed in 75% of patients. The median PFS was 4.9 months in the 25 Gy/5 fx group and 5.2 months in the 35 Gy/5 fx group (P = .23). Six-month PFS was similar at 40% (85% CI, 24%-55%) for both groups. The median overall survival (OS) was 9.2 months in the 25 Gy/5 fx group and 10 months in the 35 Gy/5 fx group (P = .201). Grade ≥3 necrosis was numerically higher in the 35 Gy/5 fx group (3 [16%] vs 1 [5%]), but the difference was not statistically significant (P = .267). In an exploratory analysis, median OS of patients who developed treatment-related necrosis was 14.1 months, and that of patients who did not was 8.7 months (P = .003).

CONCLUSIONS

HSRT alone with 35 Gy/5 fx was not superior to 25 Gy/5 fx in terms of PFS or OS. Due to a potential increase in the rate of clinically meaningful treatment-related necrosis, we suggest 25 Gy/5 fx as the standard dose in HSRT alone. During follow-up, attention should be given to differentiating tumor progression from potentially manageable complications.

Fractionated Stereotactic Radiotherapy Compared to Stereotactic Radiosurgery for Vestibular Schwannoma in Patients with Type 2 Neurofibromatosis

BACKGROUND

The use of radiotherapy (RT) for the treatment of vestibulocochlear schwannomas is standard in patients with type 2 neurofibromatosis (NF2). In the general population, fractionated RT (FRT) can achieve good results compared to single-dose radiosurgery (SRS). We aimed to assess whether this is true for NF2 patients as well.

METHODS

This retrospective cohort study included 34 patients and 54 lesions treated between 2010 and 2023 in a single university hospital.

RESULTS

Thirty-four patient charts were assessed. The median follow-up was 62.6 months (range, 7.1-135.8 months). Lesion size (median larger diameter, 2.5 cm) was correlated with the use of FRT (P > 0.001). Younger age also was correlated with FRT (P = 0.006). Median overall survival and progression-free survival (PFS) were not reached. The overall control rate was 76.5%, and the mean PFS was 49.8 months, compared with . 90.5% and 57.2 months, respectively, for SRS and 66.7% and 44.9 months, respectively, for FRT. There were no differences between the 2 groups in hearing loss, tinnitus, and facial palsy.

CONCLUSIONS

In the NF2 population, FRT may yield worse control rates than SRS. Whenever possible, it is preferable to not fractionate treatment for these patients. Nevertheless, the FRT results were still good. More and larger prospective trials are warranted.

Stereotactic Radiosurgery or Fractionated Stereotactic Radiotherapy for Arteriovenous Malformation

BACKGROUND

The best management for AVM, particularly high-grade ones and those that have been ruptured before, is still unknown. Data from prospective data lacks support for the best approach.

METHODS

We retrospectively review patients with AVM at a single institution that were treated with radiation or a combination of radiation and embolization. These patients were divided into two groups based on radiation fractionation: SRS and fSRS.

RESULTS

One-hundred and thirty-five (135) patients were first assessed and 121 met study criteria. Mean age at treatment was 30.5 years, and most patients were male. The groups were otherwise balanced, except for nidus size. SRS group had smaller lesions (P > 0.005). SRS correlates to better chance of nidus occlusion and lesser chance of retreatment. Complications such as radionecrosis (5%) and bleeding after nidus occlusion (1 patient) were rare.

CONCLUSIONS

Stereotactic radiosurgery plays an important role on the treatment of AVM. Whenever possible, SRS should be preferred. Data from prospective trials about larger and previously ruptured lesions are needed.

ATRT-06. Atypical Teratoid Rhabdoid Tumors (ATRT): results from a Single Institution in Brazil - São Paulo University

OBJECTIVES: Atypical teratoid/rhabdoid tumor (AT/RT) is a rare, highly malignant tumor of the central nervous system with poor prognosis. Nowadays, multimodal management, including surgery, chemotherapy (CMT), radiation therapy (RT) and Bone Marrow Transplantation (BMT). The aim of this study was to assess the experience and survival in a center of reference of treatment in childhood cancer in Brazil. PATIENTS AND METHODS: Medical records of AT/RT patients who underwent surgery from 2008 to 2020 at a center of childhood cancer treatment (ITACI) in São Paulo University were retrospectively reviewed and statistically analyzed. RESULTS: Eight patients (2 males and 6 females) were presented with AT/RTs. Median age during presentation was 22 months (range, 0 - 6 years). Seven patients (88%) were < 18 months and one patient were >18 months. Tumor location was supratentorial in four patients, infratentorial in 2 patients. Kidney disease as the primary diagnosis in 2 patients (25%). Surgical treatment was performed in 4 patients. Seven children underwent total CMT and 3 children were treated with RT. Only 3 patients underwent Autologous Bone Marrow Transplantation (ABMT). The chemotherapy management protocol of the patients was variable: 2 patients received the EU-RHAB protocol, 2 patients received the HEAD START III protocol, 3 patients received chemotherapy in the ICE regimen (Ifosfamide + Carboplatin + Etoposide) and 1 patient received chemotherapy in the CDDP+CTX+VCR (Cyclophosphamide + Cisplatin + Vincristine) regimen. All patients had episodes of neutropenic fever when they received chemotherapy, requiring hospitalization and use of an antibiotic treatment. Among the 8 patients analyzed, all died. CONCLUSIONS: Despite progress in treatment, AT/RT of the CNS disease or primary kidney disease associated with a lack of standardization in a regimen contributes to the dismal prognosis. There is a high mortality in patients with AT/RT, similar to that found in the literature.

Radiotherapy for early and advanced stages Follicular Lymphoma

OBJECTIVES

To evaluate the results of radiotherapy (RT) for follicular lymphoma (FL) under different management scenarios.

METHODS

We retrospectively assessed consecutive patients with FL who had undergone irradiation between 2010 and 2018. All patients had biopsy-proven FL and were positron emission tomography-staged, although some (35.3%) were reassessed with computed tomography after treatment alone. Rituximab was only available to FL patients after 2016.

RESULTS

Thirty-four patients were selected, with a mean age at diagnosis of 61.6 years (34-89 years). The median follow-up duration was 49.4 months. Most patients were female (58.8%) and showed good performance on the Eastern Cooperative Oncology Group (ECOG) scale (ECOG 0-55.9%). The mean overall survival (OS) and progression-free survival were 48.7 and 33.6 months, respectively, with four deaths reported. OS rates at 2 and 3 years were 94.1% and 91.2%, respectively. Four patients showed transformation into aggressive lymphomas and underwent rituximab-based systemic treatment. Transformation-free survival was 47.8 months, and all patients with transformed disease were alive at assessment. Five patients had in-field relapse, all of them also relapsed elsewhere, and the mean relapse-free survival time was 40.3 months. No median end points were reached on assessment.

CONCLUSION

FL is an indolent disease. Our findings show good outcomes for patients treated with radiation, with a low transformation rate and excellent management of relapsed disease. RT is an important part of these results.

EPID-05. EVALUATION OF THE INCIDENCE OF CENTRAL NERVOUS SYSTEM TUMORS IN A CHILDHOOD CANCER TREATMENT CENTER AND THE CREATION OF A SPECIFIC GROUP

Central Nervous System Tumors (CNST) are the main solid neoplasm of childhood, representing 20% diagnosis. Based on this information, a search was carried out at a reference treatment center for childhood cancer in the state of Sao Paulo, belonging to University of Sao Paulo- ITACI/HCFMUSP, and at between 2017 and 2019, 352 new patients, 116 of which were neoplasm of CNS (32.9%). Aiming at an incidence of new cases, in 2019, an institutional group was created, with a team composed of Pediatric Oncologists, Neurosurgeons, Radiologists, Radiotherapists and Pathologists. In this first year, 31,8% of the 132 new patients were diagnosed with CNS tumor. According to WHO 2016, 15 patients were classified as a group that includes Diffuse Astrocytomas, Oligodendrioglial Tumors and Other Astrocytic Tumors. Among the other patients, 14.2% were Medulloblastomas, 4.7% Embryonic Tumors and 2.3% ART / RT. Patients diagnosed with diffuse brainstem glioma accounted for 11.9% of the total. The institution had a diagnosis of Angiocentric Glioma, Craniopharyngioma, Plexiform Neurofibroma and Anaplastic Ependymoma. Neuronal-glial tumors accounted for 9.5% of cases. Choroid plexus tumors represents 5%. Among them, 4.72% had metastatic tumors: Neuroblastoma and Ewing’s Sarcoma. Of the total of 42 patients, there were 5 deaths, 4 due to disease progression and one due to clinical complications. With the group, the discussions were carried out, allowing us to analyze that the presence of the Radiotherapy, Neurosurgery and Pathology team from the first moment, optimized the beginning of treatment and increased the patients’ survival.

Survival and consolidative radiotherapy in patients living with HIV and treated for diffuse large B-cell lymphoma

Objectives

Current guidelines tend to treat HIV positive (HIV+) patients as their seronegative counterparts with diffuse large B-cell lymphoma (DLBCL) but little is known about their radiotherapy responses differences.

Patients and Methods

A retrospective cohort of all consecutive HIV+ DBCL patients treated with chemotherapy between 2004 and 2018 was assessed. All patients had biopsy-proven lymphomas. They were included if the proposed radical treatment was done without progression or death during chemotherapy and had at least 6 months of follow-up or were followed until death.

Results

Fifty-three (53) patients were selected, with a median age at diagnosis of 41.39 years (20-65 years). Median follow-up of 35.16 months (1.4-178.7 months). Male patients accounted for 54.7% and most had a good performance in the ECOG scale at diagnoses (81.1% are ECOG 0-1). Median overall survival was not reached. Mean OS was 41.5 months with 16 deaths. Age had an impact on OS, with patients older than 60 years at more risk (p = 0.044), as did longtime use of HAART, with those that started antiretroviral therapy within the diagnose of the lymphoma at greatest risk (p = 0.044). RT did not have an impact on OS (p = 0.384) or PFS (p = 0.420), although survival curves show better OS in the radiotherapy group. Toxicities were rare, since none of the patients had grade 3 or superior toxicity.

Conclusion

RT did not impact survival or progression in our limited sample, but a longer OS may occur after the first-year post RT. RT should be tested in prospective data in the HIV+ population with DLBCL.

Impact of HIV infection on consolidative radiotherapy for non-Hodgkin diffuse large B-cell lymphoma

Objectives

Even though frequent, it is not known how HIV infection and treatment impact in the consolidation by radiotherapy of non-Hodgkin diffuse large B-cell lymphomas (DBCL). This article aim to assess that difference that HIV makes on radiation treatment.

Patients and methods

A retrospective cohort of all DBCL patients treated with chemotherapy and consolidative radiotherapy at a single institution between 2010 and 2018 was assessed. All patients had biopsy-proven lymphoma and were included if radiation was part of the treatment and had at least 6 months of follow-up or were followed until death.

Results

Three-hundred fifty-nine (359) patients were selected, with a median age at diagnosis of 57.7 years (13–90 years). Twenty-eight patients (7.8%) were HIV positive. Median follow-up was 48.0 months. Female patients were 51.3% and most had a good performance in the ECOG scale (78.8% are ECOG 0–1). Median overall survival was not reached, but mean OS was 50.1 months with 86 deaths. Median progression-free survival was 48.7 months. HIV infection had no impact on OS (p = 0.580) or PFS (p = 0.347) among patients treated with RT. HIV positive patients were more frequently staged only with CT (p > 0.05) with no impact on PFS (p = 0.191). No HIV positive patient received rituximab due to local policy restrictions and HIV positive patients were more prone to receive CHOP-like chemotherapy (p < 0.05), specially ones with etoposide (CHOEP). CHOP was associated with better survival (p = 0.015) in the overall population and in the HIV negative population (p = 0.002), but not in the HIV positive population (p = 0.982). RT toxicities were not overall more frequent in the HIV positive population (p = 0.567), except for fatigue (p < 0.05) and hematological toxicities (p = 0.022).

Conclusion

HIV status did not influence on survival when patients were treated with consolidative radiotherapy. HIV infection was a bias on our sample for staging methods and chemotherapy regimens choices. For HIV positive patients there was an increase in fatigue and hematological toxicities of any grade with radiation.

Intensity-modulated ventricular irradiation for intracranial germ-cell tumors: Survival analysis and impact of salvage re-irradiation

Background and purpose

The roles of surgery, chemotherapy, and parameters of radiation therapy for treating very rare central nervous system germ cell tumors (CNS-GCT) are still under discussion. We aimed to evaluate the survival and recurrence patterns of patients with CNS-GCT treated with chemotherapy followed by whole ventricle irradiation with intensity-modulated radiation therapy.

Materials and methods

We reviewed the clinical outcomes of 20 consecutive patients with CNS-GCT treated with chemotherapy and intensity-modulated radiation therapy from 2004 to 2014 in two partner institutions.

Results

Twenty children with a median age of 12 years were included (16 males). Sixteen tumors were pure germinomas, and 4 were non-germinomatous germ cell tumors (NGGCT). All patients were treated with intensity-modulated radiation therapy guided by daily images, and 70% with volumetric intensity-modulated arc radiotherapy additionally. The median dose for the whole-ventricle was 25.2 Gy (range: 18–30.6 Gy) and 36 Gy (range: 30–54 Gy) for the tumor bed boost. The median post-radiation therapy follow-up was 57.5 months. There were 3 recurrences (2 NGGCT and 1 germinoma that recurred as a NGGCT), with 1 death from the disease and the other 2 cases each successfully rescued with chemotherapy and craniospinal irradiation. The overall survival at 5 years was 95% and disease-free survival was 85%.

Conclusions

The results of this study suggest that the combined use of chemotherapy followed by whole ventricle irradiation with intensity-modulated radiation therapy is effective for CNS-GCTs, especially pure germinomas. Even being rescued with craniospinal irradiation, the NGGCT cases have markedly worse prognoses and should be more rigorously selected for localized treatment.

Involvement of the central nervous system in neuroblastomas: A potential direct pathway

Although frequently disseminated to other anatomical sites, neuroblastoma (NB) is rarely reported as involving the central nervous system (CNS), which may reflect insufficient research in poorly controlled systemic disease. Here we demonstrate the involvement of the CNS in patients with NB over 18 months of age at diagnosis of extensive systemic disease. Meningeal metastases were observed even in the presence of complete systemic control. Although no improvement in patient's survival was observed, radiotherapy was effective in preventing CNS recurrence after observation of actual or previous dural disease. In conclusion, this study uncovered the uncommon pathologic involvement of the CNS in children with advanced NB and underscores the meningeal surface as a potential pathway for this to occur.

Consensus for vaginal stenosis prevention in patients submitted to pelvic radiotherapy

OBJECTIVE

To propose a consensus for prevention of vaginal stenosis in patients submitted to pelvic radiotherapy.

METHOD

In this methodological study, Delphi technique was applied for content validation on vaginal stenosis prevention. Data regarding content validation were collected from 32 specialists practicing in the oncology profession. The content validity index of items in the consensus was calculated based on the evaluations by the specialists.

RESULTS

In the first round, of the 38 items evaluated, 29 items reached a Content Validity Index (CVI-I) greater than 80%, and 9 items had a CVI lower than 80%. Of the items that did not obtain agreement, 2 items were excluded, and 7 were reformulated and included in the second round. In the second round, all 7 items obtained a CVI-I greater than 80%. The final instrument consisted of 29 items validated in the first round, plus 7 items reformulated and consolidated in the second round. The judges agreed that it is the responsibility of the health professionals to consult the patients undergoing radiation therapy in the area of sexuality to patients. The radiation oncologist should be the first professional to address this issue and the nurse oncologist in the follow-up consultation should pass the guidelines to the patients as comprehensively as possible. Patients should be informed about vaginal dilation, regardless of whether they are sexually active or have a partner. They should also be informed of when they can resume sexual activity. The procedure of vaginal dilation should be individualized. The prescribed vaginal dilators should be used with a lubricant for a duration of at least 5-10 minutes, 2-3 times a week, as per the need of each patient (sexual activity and/or clinical follow-up) for an indefinite time. Patients should seek medical help in case they experience pain, discomfort, or bleeding during dilation.

CONCLUSION

The Brazilian version of the consensus for vaginal stenosis prevention in patients submitted to pelvic radiotherapy was validated with 36 items in 7 categories related to Responsibility; Target population; Rationale; Vaginal dilator; Content instructions; Information provision; and Patient support. In Brazil, the educational practices on vaginal dilation for patients submitted to radiotherapy partly revealed similar difficulties as identified in other studies as well as countries with reference to specific guidelines for the start and duration of vaginal dilation. The final consensus developed in this study could strengthen the guidelines for education of patients in Brazil and provide a future scope to establish a single and safe guideline.

Adjuvant Radiotherapy Did Not Reduce Recurrence of World Health Organization Grade I Meningiomas with Venous Sinus Involvement: A Propensity Score Adjusted Analysis and Literature Review

BACKGROUND

Most meningiomas are classified as World Health Organization (WHO) grade I. Adjuvant radiation therapy (RT) is commonly recommended for subtotal resections with documented progressive regrowth of lesions with venous sinus involvement. We investigated if recurrence of WHO grade I meningiomas was influenced by adjuvant RT.

METHODS

From 2000 to 2014, patients with grade I meningiomas with at least one venous sinus involvement and at least 4 years of follow-up were included. Demographics, venous sinus involvement, histology, and extent of resection (EOR) were characterized. Because patients undergoing RT tend to differ from those for whom adjuvant therapy was not prescribed, we used propensity scores to adjust for confounding variables.

RESULTS

Sixty-two patients were included; of these, 18 (29.0%) had recurrences. The mean age was 52.8 ± 12.3 years, and 79.0% were women. A total of 34 cases (54.8%) were submitted to adjuvant RT. Adjuvant RT was more frequent in those who had tumor recurrence (77.8% vs. 45.5%, P = 0.020). RT was more frequent in superior sagittal sinus (SSS) invasion (76.5% vs. 50.0%, P = 0.030) and less prevalent after gross total resection (GTR) (32.4% vs. 67.9%, P = 0.005). Propensity score adjusted analysis suggested no adjuvant RT benefit (odds ratio [OR], 2.51; 95% confidence interval [CI], 0.68-9.28; P = 0.167), independent of the EOR. SSS involvement increased recurrence risk (OR, 12.69; 95% CI, 1.46-110.27; P = 0.021), whereas GTR tended to decrease it (OR, 0.26; 95% CI, 0.06-1.09; P = 0.065).

CONCLUSIONS

Adjuvant RT does not seem to be a pivotal criterion to reduce the recurrence rate in patients with grade I meningioma, even when venous sinuses are involved.

Radiotherapy Facilities, Equipment, and Staffing in Brazil: A Survey by the Brazilian Society of Radiation Oncology

Background: The rising incidences in cancer, together with the population aging have increased the demand for radiotherapy (RT) services in Brazil. Currently, Brazil faces a dearth of RT and solutions to provide a more universal care to cancer is a hot topic in this country. Aim: To evaluate the current status of RT department, staffing, and techniques in Brazil for 2017 following the launch of the National Cancer Program and the EXPANDE program. Methods: The Brazilian Society for Radiation Oncology (SBRT), sent detailed, online-based survey to heads of departments of all Brazilian RT centers (public and private), located in the 27 states in 2017. The survey included questions related to personnel, equipment, type of the center, and % of patients treated (private exclusive (≥ 90% of the treatments focused the private system) or public exclusive (≥ 90% of the treatments focused the public system) or mixed). Respondents were asked to provide average data from the last 5 year. For final analysis we grouped the states per region north, northeast (NE), central-west (C), southeast (SE) and south. A descriptive analysis was performed. Results: A total of 142 responses from 212 sent surveys (67% response rate) were received from 23 states. The total number of the departments and median functioning years per federative region was: 7 departments and 8 years in the north; 27 and 13 years in the NE; 7 and 11.5 years in the central; 27 and 17 years in the south; and 72 and 20 years in the SE region, respectively. The rate of radiation oncologist, physicist, nurse and dosimetrist per department was 3.0, 2.0, 1.7, 0.2 (north), 3.2, 2.4, 1.6, 0.7 (NE), 2.5, 1.7, 1.0, 0.3 (central), 3.4, 2.6, 1.6, 0.7 (south) and 3.9, 2.8, 1.6, 0.9 (SE), respectively. High dose rate brachytherapy was offered by 70% of the departments in the north, 55% in the NE, 30% in the central, 40% in the SE and 37% in the south region, respectively. Ninety-five percent of the department had at least one linear accelerator and only 5% had exclusively cobalt machines. The minority of the centers offered intensity modulated RT (36%) and image-guided RT (42%). 3D-conformal was the technique offered by 87% of the departments and 18% of them still treat patients with 2D technique. Overall, 30% of the departments provide services to the public health system exclusively, 1% to the private sector only and 69% of the department to both private and public. Conclusion: Important heterogeneity in the number of departments and professionals involved within RT services among Brazilian regions was found. Most departments were found to be in operation > 10+ years, indicating the need for recent hardware and software update and/or maintenance. 3D-conformal is the most common offered technique and mixed approach (public and private partnership) is the most common model of business in the country.

Genitourinary and gastrointestinal toxicity among patients with localized prostate cancer treated with conventional versus moderately hypofractionated radiation therapy: systematic review and meta-analysis

BACKGROUND

Hypofractionated (HRT) prostate radiation therapy has the potential to deliver a higher biologically effective dose over a shorter time compared with conventional fractionation (CRT). HRT, giving fewer fractions each with higher dose, might improve the therapeutic ratio, resource use and patient convenience but the toxicity is still controversial. Our objective was to compare the gastroinstestinal (GI) and genitourinary (GU) toxicity of HRT versus CRT.

METHODS

Systematic review and meta-analysis of randomized clinical trials studies in PubMed, Cochrane and EMBASE databases published through December 2016 was done. Only randomized trials that evaluated patients with localized prostate cancer (PCa) undergoing CRT or HRT were included. In these studies, the daily dose was 1.8 Gy or 2 Gy per day for CRT and 2.4 to 3.4 Gy for HRT.

RESULTS

7317 patients in nine studies were analyzed. Six studies included acute GU toxicity data which showed similar rates for both HRT and CRT (32.6vs. 31.9%; RD 0.00; 95% CI; -0.03,0.03; p = .81; I² = 0%). Similarly, seven studies showed no difference in late GU toxicity based on treatment schedule (28.7 vs. 28.0%; RD -0.01; 95% CI; -0.04,0.03; p = .67; I² = 52%). GI toxicity at three months after radiotherapy was higher in patients treated with HRT in six studies (27.5 vs. 21.9%; RD 0.06; 95% CI; 0.02,0.10; p = .004; I² = 39%); however, eight studies showed GI toxicity 12 months or more after radiotherapy that was statistically the same (12.9 HRT vs. 16.2% CRT; RD -0.01; 95% CI; -0.04,0.02; p = .41; I² = 58%).

CONCLUSION

In meta-analysis of the available randomized trials on moderate HRT versus CRT for prostate cancer, acute and late GU toxicity were similar for both treatment schemes. While HRT was associated with higher acute GI toxicity, late toxicity was similar.

Evaluation of a new predictor of heart and left anterior descending artery dose in patients treated with adjuvant radiotherapy to the left breast

Background

Heart-sparing techniques are time and resource intensive, although not all patients require the use of these strategies. This study evaluates the performance of different distance metrics in predicting the need for breath-hold radiotherapy in left-sided breast cancer patients receiving adjuvant radiotherapy.

Methods

Fifty left-sided breast cancer patients treated with breast conserving surgery and adjuvant radiotherapy to the breast from a single institution were retrospectively studied. The left breast and organs at risk were contoured in accordance to guidelines and a plan with tangents was obtained using the free-breathing CT in supine position. Heart (mean heart dose (MHD), heart V25 Gy) and left anterior descending artery dosimetry were computed and compared against distance metrics under investigation (Contact Heart, 4th Arch and 5th Arch). Recursive partitioning analysis (RPA) was used to determine optimal cut-points for distance metrics for dosimetric end points. Receiver operating characteristic curves and Pearson correlation coefficients were used to evaluate the association between distance metrics and dosimetric endpoints. Univariable and multivariable logistic regression analysis was performed to identify significant predictors of dosimetric end points.

Results

The mean MHD and heart V25 Gy were 2.3 Gy and 10.4 cm³, respectively. With tangents, constraints for MHD (< 1.7 Gy and V25 Gy < 10 cm³) were unattainable in 80% and 46% of patients, respectively. Optimal RPA thresholds included: Contact Heart (73 mm), 4th Arch (7 mm) and 5th Arch (41 mm). Of these, the 4th Arch had the highest overall accuracy, sensitivity, concordance index and correlation coefficient. All metrics were statistically significant predictors for MHD ≥ 1.7 Gy based on univariable logistic regression. Fifth Arch did not reach significance for heart V25 Gy ≥ 10 cm³. Fourth Arch was the only predictor to remain statistically significant after multivariable analysis.

Conclusions

We propose a novel “4th Arch” metric as an accurate and practical tool to determine the need for breath-hold radiotherapy for left-sided breast cancer patients undergoing adjuvant radiotherapy with standard tangents. Further validation in an external cohort is necessary.

Intensity-modulated radiation therapy (IMRT) versus 3-dimensional conformal radiation therapy (3D-CRT) for head and neck cancer: cost-effectiveness analysis

SUMMARY BACKGROUND: A cost-effectiveness analysis of IMRT compared to 3D-CRT for head and neck cancer patients (HNCPs) was conducted in the Brazilian Public Health System. METHODS: A Markov model was used to simulate radiation therapy-induced dysphagia and xerostomia in HNCPs. Data from the PARSPORT trial and the quality-of-life study were used as parameters. The incremental cost-effectiveness ratio (ICER) and cost per quality-adjusted life-year (QALY) gained were calculated. RESULTS: At 2 years, IMRT was associated with an incremental benefit of 0.16 QALYs gained per person, resulting in an ICER of BRL 31,579 per QALY gained. IMRT was considered cost-effective when using the guideline proposed by the World Health Organization (WHO) of three times the national gross domestic product (GDP) per capita (BRL 72,195). Regarding life expectancy (15 years), the incremental benefit of IMRT was 1.16 QALYs gained per person, with an ICER of BRL 4,341. IMRT was also cost-effective using the WHO definition, which states that the maximum cost is equal to the GDP per capita (BRL 24,065). CONCLUSIONS: IMRT was considered cost-effective from the perspective of the Brazilian public health system.

Cancer Deaths due to Lack of Universal Access to Radiotherapy in the Brazilian Public Health System

AIMS

Radiotherapy plays a fundamental role in the treatment of cancer. Currently, the Brazilian public health system cannot match the national radiotherapy demand and many patients requiring radiotherapy are never exposed to this treatment. This study estimated the number of preventable deaths in the public health system if access to radiotherapy was universal.

MATERIALS AND METHODS

Incidence rates for the year 2016 provided by Instituto Nacional de Cancer were used in this analysis. The number of untreated patients requiring radiotherapy was obtained through the difference between the total number of patients requiring radiotherapy and the total amount of delivered radiotherapy treatments in the public health system. The number of deaths for the three most common cancers in each gender due to radiotherapy shortage was calculated. Initially, the total number of patients per cancer type was divided in stages using Brazilian epidemiological data. Subsequently, previously published tree arm diagrams were used to define the rate of patients requiring radiotherapy in each specific clinical setting. Finally, the clinical benefit of radiotherapy in overall survival was extracted from studies with level 1 evidence.

RESULTS

Over 596 000 cancer cases were expected in Brazil in 2016. The public health system covers more than 75% of the Brazilian population and an estimated 111 432 patients who required radiotherapy in 2016 did not receive this treatment. Breast, colorectal and cervix cancers are the most frequent malignant tumours in women and prostate, lung and colorectal in men. The number of deaths due to a radiotherapy shortage in the year 2016 for these types of cancer were: (i) breast: 1011 deaths in 10 years; (ii) cervix: 2006 deaths in 2 years; (iii) lung: 1206 deaths in 2 years; (iv) prostate, intermediate risk: 562 deaths in 13 years; high risk: 298 deaths in 10 years; (v) colorectal: 0 deaths, as radiotherapy has no proven benefit in overall survival.

CONCLUSION

Thousands of cancer patients requiring radiotherapy do not have access to this treatment in the Brazilian public health system. The shortage of radiotherapy has a significant detrimental effect on cancer survival; over 5000 deaths would probably be prevented in the most common cancer types if radiotherapy access was universal.

Minimizing the uncertainties regarding the effects of delaying radiotherapy for Glioblastoma: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Previous studies have provided no clear conclusions regarding the effects of delaying radiotherapy (RT) in GBM patients. We present a systematic review and meta-analysis to address the effect of delayed RT on the overall survival (OS) of GBM patients.

METHODS

A systematic search retrieved 19 retrospective studies published between 1975 and 2014 reporting on the waiting time (WT) to RT for GBM patients. The meta-analysis was performed by converting WT to RT studies intervals into a regression coefficient (β) and standard error expressing the effect size on OS per week of delay.

RESULTS

Data required to calculate the effect size on OS per week of delay were available for 12 studies (5212 patients). A non-adjusted model and a meta-regression model based on well-recognized prognostic factors were performed. No association between WT to RT, per week of delay, and OS was found (HR=0.98; 95% CI 0.90-1.08; p=0.70). The meta-regression adjusted for prognostic factors weighted by the inverse-variance (1/SE(2)) showed no clear evidence of the effect of WT to RT, per week of delay, on OS.

CONCLUSIONS

This meta-analysis, despite limitations, provided no evidence of a true effect on OS by delaying RT in GBM patients.

Initial care and outcome of glioblastoma multiforme patients in 2 diverse health care scenarios in Brazil: does public versus private health care matter?

BACKGROUND

The aim of this study was to describe the epidemiological and survival features of patients with glioblastoma multiforme treated in 2 health care scenarios--public and private--in Brazil.

METHODS

We retrospectively analyzed clinical, treatment, and outcome characteristics of glioblastoma multiforme patients from 2003 to 2011 at 2 institutions.

RESULTS

The median age of the 171 patients (117 public and 54 private) was 59.3 years (range, 18-84). The median survival for patients treated in private institutions was 17.4 months (95% confidence interval, 11.1-23.7) compared with 7.1 months (95% confidence interval, 3.8-10.4) for patients treated in public institutions (P < .001). The time from the first symptom to surgery was longer in the public setting (median of 64 days for the public hospital and 31 days for the private institution; P = .003). The patients at the private hospital received radiotherapy concurrent with chemotherapy in 59.3% of cases; at the public hospital, only 21.4% (P < .001). Despite these differences, the institution of treatment was not found to be an independent predictor of outcome (hazard ratio, 1.675; 95% confidence interval, 0.951-2.949; P = .074). The Karnofsky performance status and any additional treatment after surgery were predictors of survival. A hazard ratio of 0.010 (95% confidence interval, 0.003-0.033; P < .001) was observed for gross total tumor resection followed by radiotherapy concurrent with chemotherapy.

CONCLUSIONS

Despite obvious disparities between the hospitals, the medical assistance scenario was not an independent predictor of survival. However, survival was directly influenced by additional treatment after surgery. Therefore, increasing access to resources in developing countries like Brazil is critical.

Outcome of cerebral arteriovenous malformations after linear accelerator reirradiation

Background:

The aim of this study was to evaluate the clinical outcome of patients undergoing single-dose reirradiation using the Linear Accelerator (LINAC) for brain arteriovenous malformations (AVM).

Methods:

A retrospective study of 37 patients with brain AVM undergoing LINAC reirradiation between April 2003 and November 2011 was carried out. Patient characteristics, for example, gender, age, use of medications, and comorbidities; disease characteristics, for example, Spetzler–Martin grading system, location, volume, modified Pollock–Flickinger score; and treatment characteristics, for example, embolization, prescription dose, radiation dose–volume curves, and conformity index were analyzed. During the follow-up period, imaging studies were performed to evaluate changes after treatment and AVM cure. Complications, such as edema, rupture of the blood–brain barrier, and radionecrosis were classified as symptomatic and asymptomatic.

Results:

Twenty-seven patients underwent angiogram after reirradiation and the percentage of angiographic occlusion was 55.5%. In three patients without obliteration, AVM shrinkage made it possible to perform surgical resection with a 2/3 cure rate. A reduction in AVM nidus volume greater than 50% after the first procedure was shown to be the most important predictor of obliteration. Another factor associated with AVM cure was a prescription dose higher than 15.5 Gy in the first radiosurgery. Two patients had permanent neurologic deficits. Factors correlated with complications were the prescription dose and maximum dose in the first procedure.

Conclusion:

This study suggests that single-dose reirradiation is safe and feasible in partially occluded AVM. Reirradiation may not benefit candidates whose prescribed dose was lower than 15.5 Gy in the first procedure and initial AVM nidus volume did not decrease by more than 50% before reirradiation.

Waiting time to radiotherapy as a prognostic factor for glioblastoma patients in a scenario of medical disparities

Objective To evaluate the effect of waiting time (WT) to radiotherapy (RT) on overall survival (OS) of glioblastoma (GBM) patients as a reliable prognostic variable in Brazil, a scenario of medical disparities. Method Retrospective study of 115 GBM patients from two different health-care institutions (one public and one private) in Brazil who underwent post-operative RT. Results Median WT to RT was 6 weeks (range, 1.3-17.6). The median OS for WT ≤ 6 weeks was 13.5 months (95%CI , 9.1-17.9) and for WT > 6 weeks was 14.2 months (95%CI, 11.2-17.2) (HR 1.165, 95%CI 0.770-1.762; p = 0.470). In the multivariate analysis, the variables associated with survival were KPS (p < 0.001), extent of resection (p = 0.009) and the adjuvant treatment (p = 0.001). The KPS interacted with WT to RT (HR 0.128, 95%CI 0.034-0.476; p = 0.002), showing that the benefit of KPS on OS depends on the WT to RT. Conclusion No prognostic impact of WT to RT could be detected on the OS. Although there are no data to ensure that delays to RT are tolerable, we may reassure patients that the time-length to initiate treatment does not seem to influence the control of the disease, particularly in face of other prognostic factors.

Ototoxicity evaluation in medulloblastoma patients treated with involved field boost using intensity-modulated radiation therapy (IMRT): a retrospective review

BACKGROUND

Ototoxicity is a known side effect of combined radiation therapy and cisplatin chemotherapy for the treatment of medulloblastoma. The delivery of an involved field boost by intensity modulated radiation therapy (IMRT) may reduce the dose to the inner ear when compared with conventional radiotherapy. The dose of cisplatin may also affect the risk of ototoxicity. A retrospective study was performed to evaluate the impact of involved field boost using IMRT and cisplatin dose on the rate of ototoxicity.

METHODS

Data from 41 medulloblastoma patients treated with IMRT were collected. Overall and disease-free survival rates were calculated by Kaplan-Meier method Hearing function was graded according to toxicity criteria of Pediatric Oncology Group (POG). Doses to inner ear and total cisplatin dose were correlated with hearing function by univariate and multivariate data analysis.

RESULTS

After a mean follow-up of 44 months (range: 14 to 72 months), 37 patients remained alive, with two recurrences, both in spine with CSF involvement, resulting in a disease free-survival and overall survival of 85.2% and 90.2%, respectively.Seven patients (17%) experienced POG Grade 3 or 4 toxicity. Cisplatin dose was a significant factor for hearing loss in univariate analysis (p < 0.03). In multivariate analysis, median dose to inner ear was significantly associated with hearing loss (p < 0.01). POG grade 3 and 4 toxicity were uncommon with median doses to the inner ear bellow 42 Gy (p < 0.05) and total cisplatin dose of less than 375 mg/m2 (p < 0.01).

CONCLUSIONS

IMRT leads to a low rate of severe ototoxicity. Median radiation dose to auditory apparatus should be kept below 42 Gy. Cisplatin doses should not exceed 375 mg/m2.

Glioblastoma: approach to treat elderly patients

Treating elderly cancer patients is a challenge for oncologists, especially considering the several therapeutic modalities in glioblastoma. Extensive tumor resection offers the best chance of local control. Adequate radiotherapy should always be given to elderly patients if they have undergone gross total resection and have maintained a good performance status. Rather than being ruled out, chemotherapy should be considered, and temozolomide is the chosen drug. A comprehensive geriatric assessment is a valuable tool to help guiding treatment decisions in elderly patients with glioblastoma.

Comparison of conformal and intensity modulated radiation therapy techniques for treatment of pelvic tumors. Analysis of acute toxicity

Background

This retrospective analysis reports on the comparative outcome of acute gastrointestinal (GI) and genitourinary (GU) toxicities between conformal radiation therapy (CRT) and intensity modulated radiation therapy (IMRT) techniques in the treatment of patients with pelvic tumors.

Methods

From January 2002 to December 2008, 69 patients with pelvic tumors underwent whole pelvic CRT and 65 underwent whole pelvic IMRT to treat pelvic lymph nodes and primary tumor regions. Total dose to the whole pelvis ranged from 50 to 50.4 Gy in 25 to 28 daily fractions. Chemotherapy (CT) regimen, when employed, was based upon primary tumor. Acute GI and GU toxicities were graded by RTOG/EORTC acute radiation morbidity criteria.

Results

Absence of GI symptoms during radiotherapy (grade 0) was more frequently observed in the IMRT group (43.1% versus 8.7; p < 0.001) and medication for diarrhea (Grade 2) was more frequently used in the CRT group (65.2% versus 38.5%; p = 0.002). Acute GI grade 1 and 3 side effects incidence was similar in both groups (18.5% versus 18.8%; p = 0.95 and 0% versus 7.2%; p = 0.058, respectively). Incidence of GU toxicity was similar in both groups (grade 0: 61.5% versus 66.6%, p = 0.54; grade 1: 20% versus 8.7%, p = 0.06; grade 2: 18.5% versus 23.5%, p = 0.50 and grade 3: 0% versus 1.5%, p > 0.99).

Conclusions

This comparative case series shows less grade 2 acute GI toxicity in patients treated with whole pelvic IMRT in comparison with those treated with CRT. Incidence of acute GU toxicity was similar in both groups.

Intensity modulated radiotherapy for localized prostate cancer: rigid compliance to dose-volume constraints as a warranty of acceptable toxicity?

BACKGROUND

To report the toxicity after intensity modulated radiotherapy (IMRT) for patients with localized prostate cancer, as a sole treatment or after radical prostatectomy.

METHODS

Between August 2001 and December 2003, 132 patients with prostate cancer were treated with IMRT and 125 were evaluable to acute and late toxicity analysis, after a minimum follow-up time of one year. Clinical and treatment data, including normal tissue dose-volume histogram (DVH) constraints, were reviewed. Gastro-intestinal (GI) and genito-urinary (GU) signs and symptoms were evaluated according to the Radiation Therapy Oncology Group (RTOG) toxicity scales. Median prescribed dose was 76 Gy. Median follow-up time was of 26.1 months.

RESULTS

From the 125 patients, 73 (58.4%) presented acute Grade 1 or Grade 2 GI and 97 (77.2%) presented acute Grade 1 or Grade 2 GU toxicity. Grade 3 GI acute toxicity occurred in only 2 patients (1.6%) and Grade 3 GU acute toxicity in only 3 patients (2.4%). Regarding Grade 1 and 2 late toxicity, 26 patients (20.8%) and 21 patients (16.8%) presented GI and GU toxicity, respectively. Grade 2 GI late toxicity occurred in 6 patients (4.8%) and Grade 2 GU late toxicity in 4 patients (3.2%). None patient presented any Grade 3 or higher late toxicity. Non-conformity to DVH constraints occurred in only 11.2% of treatment plans. On univariate analysis, no significant risk factor was identified for Grade 2 GI late toxicity, but mean dose delivered to the PTV was associated to higher Grade 2 GU late toxicity (p = 0.042).

CONCLUSION

IMRT is a well tolerable technique for routine treatment of localized prostate cancer, with short and medium-term acceptable toxicity profiles. According to the data presented here, rigid compliance to DHV constraints might prevent higher incidences of normal tissue complication.