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1.
Crit Rev Oncol Hematol ; 169: 103546, 2021 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-34848367

RESUMO

Access to high-quality continuing medical education, particularly in Radiation Oncology, can be challenging in some developing countries due to economic barriers. Despite the current offer of free-access self-educational material, end user training faces a backlog still difficult to overcome. The purpose of this investigation is to report the willingness-to-pay profile of practitioners in Latin America, as a surrogate of quality perception of remote educational resources. Related factors include professional experience and baseline practice confidence levels. Most of practitioners would cover their own expenses, while an increased tendency in less-experienced professionals was observed. However, baseline knowledge confidence levels were not influential in decision making. This report contributes to better know the profile of Latin American professionals, in order to design future educational interventions in the region and bridging the current accessibility gap.

2.
Front Oncol ; 11: 767468, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34926271

RESUMO

Purpose/Objectives: To perform a dosimetric comparison between kilovoltage intraoperative radiotherapy (IORT) and stereotactic radiosurgery (SRS) simulating both deep-inspiration breath-hold (DIBH) and free-breathing (FB) modalities for patients with liver metastases. Methods/Materials: Diagnostic computed tomographies (CT) of patients carrying one or two lesions <4 cm and who underwent surgery were retrospectively screened and randomly selected for the study. For DIBH-SRS, a gross target volume (GTV) plus planning target volume (PTV) were delineated. For FB-SRS, a GTV plus an internal target volume (ITV) and PTV were defined. Accounting for the maximal GTV diameters, a modified GTV (GTV-IORT) was expanded circumferentially to simulate a resection cavity. The best suitable round-applicator size was thereafter selected. All treatment plans were calculated homogeneously to deliver 40 Gy. Doses delivered to organs at risk (OAR) and target volumes were compared for IORT vs. both SRS modalities. Results: Eight patients encompassing 10 lesions were included in the study. The mean liver volume was 2,050.97 cm3 (SD, 650.82), and the mean GTV volume was 12.23 cm3 (SD, 12.62). As for target structures, GTV-IORT [19.44 cm3 (SD, 17.26)] were significantly smaller than both PTV DIBH-SRS [30.74 cm3 (SD, 24.64), p = 0.002] and PTV FB-SRS [75.82 cm3 (SD, 45.65), p = 0.002]. The median applicator size was 3 cm (1.5-4.5), and the mean IORT simulated delivery time was 45.45 min (SD, 19.88). All constraints were met in all modalities. Liver V9.1 showed significantly smaller volumes with IORT [63.39 cm3 (SD, 35.67)] when compared to DIBH-SRS [150.12 cm3 (SD, 81.43), p = 0.002] or FB-SRS [306.13 cm3 (SD, 128.75), p = 0.002]. No other statistical or dosimetrically relevant difference was observed for stomach, spinal cord, or biliary tract. Mean IORT D90 was 85.3% (SD, 6.05), whereas D95 for DIBH-SRS and FB-SRS were 99.03% (SD, 1.71; p = 0.042) and 98.04% (SD, 3.46; p = 0.036), respectively. Conclusion: Kilovoltage IORT bears the potential as novel add-on treatment for resectable liver metastases, significantly reducing healthy liver exposure to radiation in comparison to SRS. Prospective clinical evidence is required to confirm this hypothesis.

3.
Front Oncol ; 11: 759873, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34778080

RESUMO

Purpose: To simulate and analyze the dosimetric differences of intraoperative radiotherapy (IORT) or pre-operative single-fraction stereotactic radiosurgery (SRS) in addition to post-operative external beam radiotherapy (EBRT) in Glioblastoma (GB). Methods: Imaging series of previously treated patients with adjuvant radiochemotherapy were analyzed. For SRS target definition, pre-operative MRIs were co-registered to planning CT scans and a pre-operative T1-weighted gross target volume (GTV) plus a 2-mm planning target volume (PTV) were created. For IORT, a modified (m)GTV was expanded from the pre-operative volume, in order to mimic a round cavity as during IORT. Dose prescription was 20 Gy, homogeneously planned for SRS and calculated at the surface for IORT, to cover 99% and 90% of the volumes, respectively. For tumors > 2cm in maximum diameter, a 15 Gy dose was prescribed. Plan assessment was performed after calculating the 2-Gy equivalent doses (EQD2) for both boost modalities and including them into the EBRT plan. Main points of interest encompass differences in target coverage, brain volume receiving 12 Gy or more (V12), and doses to various organs-at-risk (OARs). Results: Seventeen pre-delivered treatment plans were included in the study. The mean GTV was 21.72 cm3 (SD ± 19.36) and mGTV 29.64 cm3 (SD ± 25.64). The mean EBRT and SRS PTV were 254.09 (SD ± 80.0) and 36.20 cm3 (SD ± 31.48), respectively. Eight SRS plans were calculated to 15 Gy according to larger tumor sizes, while all IORT plans to 20 Gy. The mean EBRT D95 was 97.13% (SD ± 3.48) the SRS D99 99.91% (SD ± 0.35) and IORT D90 83.59% (SD ± 3.55). Accounting for only-boost approaches, the brain V12 was 49.68 cm3 (SD ± 26.70) and 16.94 cm3 (SD ± 13.33) (p<0.001) for SRS and IORT, respectively. After adding EBRT results respectively to SRS and IORT doses, significant lower doses were found in the latter for mean Dmax of chiasma (p=0.01), left optic nerve (p=0.023), right (p=0.008) and left retina (p<0.001). No significant differences were obtained for brainstem and cochleae. Conclusion: Dose escalation for Glioblastoma using IORT results in lower OAR exposure as conventional SRS.

4.
Radiat Oncol ; 16(1): 145, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34348765

RESUMO

BACKGROUND: Hypofractionation is increasingly being applied in radiotherapy for prostate cancer, requiring higher accuracy of daily treatment deliveries than in conventional image-guided radiotherapy (IGRT). Different adaptive radiotherapy (ART) strategies were evaluated with regard to dosimetric benefits. METHODS: Treatments plans for 32 patients were retrospectively generated and analyzed according to the PACE-C trial treatment scheme (40 Gy in 5 fractions). Using a previously trained cycle-generative adversarial network algorithm, synthetic CT (sCT) were generated out of five daily cone-beam CT. Dose calculation on sCT was performed for four different adaptation approaches: IGRT without adaptation, adaptation via segment aperture morphing (SAM) and segment weight optimization (ART1) or additional shape optimization (ART2) as well as a full re-optimization (ART3). Dose distributions were evaluated regarding dose-volume parameters and a penalty score. RESULTS: Compared to the IGRT approach, the ART1, ART2 and ART3 approaches substantially reduced the V37Gy(bladder) and V36Gy(rectum) from a mean of 7.4cm3 and 2.0cm3 to (5.9cm3, 6.1cm3, 5.2cm3) as well as to (1.4cm3, 1.4cm3, 1.0cm3), respectively. Plan adaptation required on average 2.6 min for the ART1 approach and yielded doses to the rectum being insignificantly different from the ART2 approach. Based on an accumulation over the total patient collective, a penalty score revealed dosimetric violations reduced by 79.2%, 75.7% and 93.2% through adaptation. CONCLUSION: Treatment plan adaptation was demonstrated to adequately restore relevant dose criteria on a daily basis. While for SAM adaptation approaches dosimetric benefits were realized through ensuring sufficient target coverage, a full re-optimization mainly improved OAR sparing which helps to guide the decision of when to apply which adaptation strategy.

5.
Radiat Oncol ; 16(1): 127, 2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34246284

RESUMO

We read with great interest the recent review, entitled "Current status and recent advances in resection cavity irradiation of brain metastases". It is a comprehensive summary of currently available techniques for treatment of post-resection cavity in patients with this diagnosis. We would like to complement this manuscript by including intraoperative techniques as other viable approaches in the management of these patients.

6.
Front Oncol ; 11: 664225, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33954116

RESUMO

Purpose: To assess the outcome of radiotherapy (RT) to all PSMA ligand positive metastases for patients with castrate-resistant prostate cancer (mCRPC). Patients and methods: A total of 42 patients developed oligometastatic mCRPC and received PSMA PET-guided RT of all metastases. The main outcome parameters were biochemical progression-free survival (bPFS), and second-line systemic treatment free survival (SST-FS). Results: A total of 141 PSMA ligand-positive metastases were irradiated. The median follow-up time was 39.0 months (12-58 months). During the follow-up five out of 42 (11.9%) patients died of progressive mPCa. Five out of 42 (11.9%) patients showed no biochemical responses and presented with a PSA level ≥10% of the baseline PSA at first PSA level measurement after RT and were classified as non-responders. The median PSA level before RT was 4.79 ng/mL (range, 0.4-46.1), which decreased significantly to a median PSA nadir level of 0.39 ng/mL (range, <0.07-32.8; p=0.002). The median PSA level at biochemical progression after PSMA ligand-based RT was 2.75 ng/mL (range, 0.27-53.0; p=0.24) and was not significantly different (p=0.29) from the median PSA level (4.79 ng/mL, range, 0.4-46.1) before the PSMA ligand-based RT. The median bPFS was 12.0 months after PSMA ligand PET-based RT (95% CI, 11.2-15.8) and the median SST-FS was 15.0 months (95% CI, 14.0-21.5). Conclusion: In well-informed and closely followed-up patients, PSMA PET-guided RT represents a viable treatment option for patients with oligometastatic mCRPC to delay further systemic therapies.

7.
Cancers (Basel) ; 13(3)2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33530293

RESUMO

A retrospective study was performed to assess the outcomes of a single-fraction adjuvant electronic brachytherapy (e-BT) approach for patients with squamous cell conjunctival carcinoma (SCCC). Forty-seven patients with T1-T3 SCCC were included. All patients underwent surgery followed by a single-fraction adjuvant e-BT with a porTable 50-kV device. Depending on margins, e-BT doses ranged between 18 to 22 Gy prescribed at 2 mm depth, resembling equivalent doses in 2 Gy (EQD2) per fraction of 46-66 Gy (α/ß ratio of 8-10 Gy and a relative biological effect (RBE) of 1.3). The median age was 69 (29-87) years. Most tumors were T1 (40.4%) or T2 (57.5%) with a median size of 7 mm (1.5-20). Margins were positive in 40.4% of cases. The median time from surgery to e-BT was nine weeks (0-37). After a median follow-up of 24 (17-40) months, recurrence occurred in only two patients (6 and 7 months after e-BT), yielding a median disease-free survival (DFS) of 24 (6-40) months and DFS at two years of 95.7%. Acute grade 2 conjunctivitis occurred in 25.5%. E-BT is a safe and effective for SCCC treatment, with clinical and logistic advantages compared to classical methods. Longer follow-up and prospective assessment are warranted.

8.
Adv Radiat Oncol ; 6(1): 100593, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33490728

RESUMO

Purpose: This study aimed to investigate, in the setting of neoadjuvant gastric irradiation with integrated boost, whether cone beam computed tomography (CBCT)-based adaptive radiation therapy compared with a defined-filling protocol would be beneficial in terms of feasibility and achieving daily reproducible dose volume indexes of the planning target volume (PTV) and organs at risk (OARs) and workflow. Methods and materials: Planning computed tomography (PCT) and 25 CBCT scans of a previously treated patient were used, and neoadjuvant therapy of gastric carcinoma was simulated offline. PTVs and OARs were defined per the TOPGEAR protocol (PTV: 45 Gy/1.8 Gy), and an integrated boost (gross tumor volume [GTV]: 50.4 Gy/2.016 Gy) was added. The patient followed a filling regimen consisting of 12-hour fasting followed by 200 mL of water intake (2 glasses of water) immediately before irradiation. OARs and PTVs were newly contoured on each CBCT. Nonrigid registration of PCT and CBCT scans was performed. Nonadapted plans were recalculated on each CBCT (R-CBCT). Furthermore, an adapted plan was created for the new anatomy (A-CBCT). Dose parameters and comparison of R-CBCT and A-CBCT for the kidneys, liver, and heart were analyzed using a paired t test. Results: A total of 200 plans for R-CBCT and A-CBCT were obtained. Mean gastric volumes were 277.32 cm3 (±54.40 cm3) in CBCT scans and 519.2 cm3 in PCT. Mean doses to the PTV did not differ meaningfully within the CBCT scans, with an average of 1.54%. The D95 improved in GTV coverage by 5.26% compared with the R-CBCT plan. Mean heart, liver, and right kidney doses were reduced with the A-CBCT plan by 35.74%, 10.71% and 29.47%, respectively. The R- and A-CBCT comparison for GTV and OARs was significantly different in all cases (P < .0001). Conclusions: Adaptive radiation therapy through deformable registration represents an important tool in neoadjuvant gastric irradiation, encompassing daily variability and organ motion, compared with the defined-filling protocol while improving OAR sparing.

9.
Int J Cancer ; 148(7): 1676-1684, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33045097

RESUMO

The aim of the study was to report on the association of trial sponsors with intervention type, treatment intent, recruitment success and reasons to terminate cancer trials. The ClinicalTrials database was searched for interventional Phase 3 cancer trials (01/2006-05/2017). Noncancer studies and ongoing studies were excluded, permanently suspended studies were counted as terminated. Trials were stratified according to sponsors (industry/nonindustry), intervention type, setting (curative/palliative) and intent of intervention (curative/symptom-control/life-extending). We identified 345 terminated trials and 1137 completed studies as a control group. The frequency of premature termination did not differ significantly between sponsors. Time to termination was shorter but recruitment per month prior to termination was higher in industry-sponsored studies (7.0 vs 2.2 patients/month; P < .001). Drug interventions were more common in industry-sponsored, all other interventions in nonindustry-sponsored settings (P < .001). Life-extending palliative interventions occurred more frequently, symptom-control interventions in a curative setting less frequently in industry-sponsored trials (both P < .001). Intervention, setting and intent were not associated with termination in industry-sponsored trials. In nonindustry-sponsored trials, the frequency of drug interventions and life-extending (noncurative) interventions were increased in terminated trials (both P < .05); symptom-control interventions in curative settings occurred more frequently in completed studies. Industry-sponsored trials were more often terminated due to toxicity/inefficacy while lack of accrual occurred more frequently in nonindustry-sponsored trials (P < .01). Interventions, treatment setting/intent and reasons for termination differed between sponsor types. In nonindustry-sponsored trials, drug interventions and life-extending (noncurative) interventions were associated with premature termination and symptom-control interventions (curative setting) were associated with trial completion.


Assuntos
Ensaios Clínicos como Assunto/estatística & dados numéricos , Neoplasias , Projetos de Pesquisa/estatística & dados numéricos , Bases de Dados Factuais , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/mortalidade , Neoplasias/terapia
10.
Med Dosim ; 46(1): 74-79, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32958360

RESUMO

To simulate an early 20th century viral pneumonia radiotherapy treatment using modern fluoroscopy and evaluated it according to current dose guidelines. Monte Carlo was used to assess the dose distribution on an anthropomorphic phantom. Critical organs were: skin, breasts, esophagus, ribs, vertebrae, heart, thymus, and spinal cord. A 100 kVp beam with 3 mm Al HVL, 25 × 25 cm2 posterior-anterior (PA) field and 50 cm source-to-surface distance were simulated. Simulations had a resolution of 0.4 × 0.4 × 0.06 cm3 and a 6% uncertainty. Hundred percent dose was normalized to the skin surface and results were displayed in axial, coronal, and sagittal planes. Dose volume histograms were generated in MATLAB for further analysis. Prescription doses of 0.3, 0.5, and 1.0 Gy were applied to the 15% isodose for organ-dose comparison to current tolerances and potential risk of detriment. Ninety-five and ninety-seven percent of the right and left lung volumes, respectively, were well-covered by the 15% isodose line. For the 0.3, 0.5, and 1.0 Gy prescriptions, the maximum skin doses were 2.9, 4.8, and 9.6 Gy compared to a 2.0 Gy transient erythema dose threshold; left/right lung maximum doses were 1.44/1.46, 2.4/2.4, and 4.8/4.9 Gy compared to a 6.5 Gy pneumonitis and 30 Gy fibrosis thresholds; maximum heart doses were 0.5, 0.9, and 1.8 Gy compared to the 0.5 Gy ICRP-recommendation; maximum spinal cord doses were 1.4, 2.3, and 4.6 Gy compared to 7.0 Gy single fraction dose threshold. Maximum doses to other critical organs were below modern dose thresholds. A 100 kVp PA field could deliver a 0.3 Gy or 0.5 Gy dose without risk of complications. However, a 1.0 Gy dose treatment could be problematic. Critical organ doses could be further reduced if more than one treatment field is used.


Assuntos
Pneumonia , Planejamento da Radioterapia Assistida por Computador , Fluoroscopia , Humanos , Método de Monte Carlo , Dosagem Radioterapêutica
12.
J Contemp Brachytherapy ; 12(5): 480-486, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33299437

RESUMO

Purpose: Radiotherapy is the mainstay in the treatment of locally inoperable tumors. Interstitial electronic needle-based kilovoltage brachytherapy (EBT) could be an economic alternative to high-dose-rate (HDR) brachytherapy or permanent seed implantation (PSI). In this work, we evaluated if locally inoperable tumors treated with PSI at our institution may be suitable for EBT. Material and methods: A total of 10 post-interventional computed tomography (CT) scans of patients, who received PSI and simulated stepping-source EBT applied with Intrabeam system and needle applicator were used. EBT treatment planning software with 3-dimensional image and projection of applicator were applied for designing trajectories and establishing dwell positions. Dwell position doses were summarized, and doses covering 90% of the target volume (D90) achieved with stepping-source EBT were compared to those of PSI. Additionally, conformality of dose distributions and total irradiation time were assessed using conformation number (CN) or conformal index (COIN). Results: In all patients, D90 of EBT exceeded the prescribed dose or D90 of PSI on average by 4.7% or 21.3% relative to the prescribed dose, respectively. Mean number of trajectories was 5.0 for EBT and 6.9 for PSI. Average CN/COIN for EBT was 0.69, with a mean irradiation time of 27.8 minutes for standardized dose of 13 Gy. Conclusions: Stepping-source EBT allowed for a conformal treatment of inoperable interstitial tumors with similar D90. Fewer trajectories were required for EBT in majority of cases.

13.
Phys Med ; 80: 308-316, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33246190

RESUMO

PURPOSE: Image-guided radiation therapy could benefit from implementing adaptive radiation therapy (ART) techniques. A cycle-generative adversarial network (cycle-GAN)-based cone-beam computed tomography (CBCT)-to-synthetic CT (sCT) conversion algorithm was evaluated regarding image quality, image segmentation and dosimetric accuracy for head and neck (H&N), thoracic and pelvic body regions. METHODS: Using a cycle-GAN, three body site-specific models were priorly trained with independent paired CT and CBCT datasets of a kV imaging system (XVI, Elekta). sCT were generated based on first-fraction CBCT for 15 patients of each body region. Mean errors (ME) and mean absolute errors (MAE) were analyzed for the sCT. On the sCT, manually delineated structures were compared to deformed structures from the planning CT (pCT) and evaluated with standard segmentation metrics. Treatment plans were recalculated on sCT. A comparison of clinically relevant dose-volume parameters (D98, D50 and D2 of the target volume) and 3D-gamma (3%/3mm) analysis were performed. RESULTS: The mean ME and MAE were 1.4, 29.6, 5.4 Hounsfield units (HU) and 77.2, 94.2, 41.8 HU for H&N, thoracic and pelvic region, respectively. Dice similarity coefficients varied between 66.7 ± 8.3% (seminal vesicles) and 94.9 ± 2.0% (lungs). Maximum mean surface distances were 6.3 mm (heart), followed by 3.5 mm (brainstem). The mean dosimetric differences of the target volumes did not exceed 1.7%. Mean 3D gamma pass rates greater than 97.8% were achieved in all cases. CONCLUSIONS: The presented method generates sCT images with a quality close to pCT and yielded clinically acceptable dosimetric deviations. Thus, an important prerequisite towards clinical implementation of CBCT-based ART is fulfilled.


Assuntos
Processamento de Imagem Assistida por Computador , Planejamento da Radioterapia Assistida por Computador , Algoritmos , Tomografia Computadorizada de Feixe Cônico , Humanos , Masculino , Radiometria , Dosagem Radioterapêutica
14.
Cancers (Basel) ; 12(9)2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32872216

RESUMO

Background: Radiation-induced dermatitis (RID) is frequent in breast cancer patients undergoing radiotherapy (RT). Spectrophotometry (SP) is an objective and reliable tool for assessing RID severity. Despite intensive research efforts during the past decades, no sustainable prophylactic and treatment strategies have been found. Estimation of new and reevaluation of established risk factors leading to severe RID is therefore of major importance. Methods: 142 early breast cancer patients underwent whole-breast irradiation following breast-conserving surgery. RID was evaluated by physician-assessed Common Terminology Criteria of Adverse Events (CTCAE v4.03). Spectrophotometers provided additional semi quantification of RID using the L*a*b color-space. A total of 24 patient- and treatment-related parameters as well as subjective patient-assessed symptoms were analyzed. Results: Values for a*max strongly correlated with the assessment of RID severity by physicians. Breast volume, initial darker skin, boost administration, and treatment technique were identified as risk factors for severe RID. RID severity positively correlated with the patients' perception of pain, burning, and reduction of everyday activities. Conclusions: Physician-assessed RID gradings correlate with objective SP skin measurements. Treatment technique and high breast volumes were identified as objective and significant predictors of RID. Our data provide a solid benchmark for future studies on RID with objective SP.

15.
Int J Radiat Oncol Biol Phys ; 108(2): 356-361, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32890512

RESUMO

PURPOSE: In February 2020, the COVID-19 pandemic reached the United States. The impact of the pandemic on the US radiation oncology field remains unknown. The American Society for Radiation Oncology surveyed US radiation oncology practice leaders to gauge initial impact and immediate operational responses to the pandemic. METHODS AND MATERIALS: From April 16 to April 30, 2020, the American Society for Radiation Oncology surveyed US radiation oncology practice leaders by email to gauge initial impact and immediate operational responses to the COVID-19 pandemic. RESULTS: Two hundred twenty-two (43%) of 517 leaders responded from community and academic practices (62% and 34%, respectively), hospital-based and free-standing centers (69% and 29%), and metro and rural locations (88% and 12%). Practices reported treating an average of 1086 patients per year in 2019 (range, 0-7900) with an average daily treatment volume of 70 patients (range, 5-400). All practices reported uninterrupted operation. On average, practices were treating 68% of their typical volume (range, 10%-95%), with 92% implementing planned treatment postponement for lower risk patients. An estimated revenue decrease of 20% or more was experienced by 71% of practices. Confirmed COVID-19 patient cases were treated by 39% of practices. Seventy percent experienced staff shortages. Almost all (98%) practices implemented formal operational procedures to protect patients and staff, although personal protective equipment/infection control supply shortages were reported by 78% of practices. Seventy-four percent used telemedicine for virtual follow-up surveillance, and 15% leveraged telemedicine for on-treatment assessment. CONCLUSIONS: The clinical and financial impacts of the COVID-19 pandemic on US radiation oncology were deep and broad. Despite reported shortages in personal protective equipment, declines in revenue, and reduced patient volumes, practices adapted quickly by refining standard processes of care, implementing recommended safety measures, and employing telemedicine to facilitate treatment continuity. Patients with higher risk disease experienced uninterrupted access to care. We plan to continue regular surveying across the lifespan of the pandemic to document the geographic and temporal impact of COVID-19 on the field and its patients.


Assuntos
Infecções por Coronavirus/epidemiologia , Pandemias , Pneumonia Viral/epidemiologia , Radioterapia (Especialidade) , Sociedades Médicas , COVID-19 , Humanos , Corpo Clínico/provisão & distribuição , Telemedicina , Estados Unidos
16.
Int J Radiat Oncol Biol Phys ; 108(2): 374-378, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32890516

RESUMO

PURPOSE: The impact of the COVID-19 pandemic on Latin American radiation therapy services has not yet been widely assessed. In comparison to centers in Europe or the United States, the scarcity of data on these terms might impair design of adequate measures to ameliorate the pandemic's potential damage. The first survey-based analysis revealing regional information is herein presented. METHODS AND MATERIALS: From May 6 to May 30, 2020, the American Society for Radiation Oncology's COVID-19 Survey was distributed across Latin America with support of the local national radiation therapy societies. Twenty-six items, including facility demographic and financial characteristics, personnel and patient features, current and expected impact of the pandemic, and research perspectives, were included in the questionnaire. RESULTS: Complete responses were obtained from 115 (50%) of 229 practices across 15 countries. Only 2.6% of centers closed during the pandemic. A median of 4 radiation oncologists (1-27) and 9 (1-100) radiation therapists were reported per center. The median number of new patients treated in 2019 was 600 (24-6200). A median 8% (1%-90%) decrease in patient volume was reported, with a median of 53 patients (1-490) remaining under treatment. Estimated revenue reduction was 20% or more in 53% of cases. Shortage of personal protective equipment was reported in 51.3% of centers, and 27% reported personnel shortage due to COVID-19. Reported delays in treatment for low-risk entities included early stage breast cancer (42.6%), low-risk status prostate cancer (67%), and nonmalignant conditions (42.6%). Treatment of COVID-19 patients at designated treatment times and differentiated bunkers were reported in 22.6% and 10.4% of centers, respectively. Telehealth initiatives have been started in 64.3% of facilities to date for on-treatment (29.6%) and posttreatment (34.8%) patients. CONCLUSIONS: Regional information regarding COVID-19 pandemic in Latin America may help elucidate suitable intervention strategies for personnel and patients. Follow-up surveys will be performed to provide dynamic monitoring the pandemic's impact on radiation therapy services and adoption of ameliorating measures.


Assuntos
Infecções por Coronavirus/epidemiologia , Pandemias , Pneumonia Viral/epidemiologia , Radioterapia (Especialidade)/estatística & dados numéricos , Inquéritos e Questionários , COVID-19 , Humanos , América Latina
17.
Crit Rev Oncol Hematol ; 154: 103072, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32805497

RESUMO

PURPOSE: To assess the impact of longitudinal telehealth training in stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery (SRS) for clinicians in Latin America. MATERIALS AND METHODS: Professionals from two Peruvian centers received an initial SBRT/SRS on-site training course and subsequently received follow-up telehealth training (interventional group) or not (negative control arm). Twelve live video conference sessions were scheduled. Surveys pre- and post-curriculum measured participants' confidence in seven practical domains of SBRT/SRS, based on Likert scales of 1-5, and post-curriculum surveys assessed educators' experiences. RESULTS: Sixty-one participants were registered, with an average of 24 attendees per session. Pre- and post- surveys were completed by 22 participants. For interventional and negative-control groups, mean changes in Likert scale were satisfactory for the former and remained unmodified for the latter. CONCLUSIONS: Conducting telehealth educational programs via virtual classroom sessions could be a reliable method to augment training for SBRT and SRS.


Assuntos
Radiocirurgia , Telemedicina , Humanos , América Latina , Inquéritos e Questionários
18.
EPMA J ; 11(3): 377-398, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32843908

RESUMO

The Warburg effect is characterised by increased glucose uptake and lactate secretion in cancer cells resulting from metabolic transformation in tumour tissue. The corresponding molecular pathways switch from oxidative phosphorylation to aerobic glycolysis, due to changes in glucose degradation mechanisms known as the 'Warburg reprogramming' of cancer cells. Key glycolytic enzymes, glucose transporters and transcription factors involved in the Warburg transformation are frequently dysregulated during carcinogenesis considered as promising diagnostic and prognostic markers as well as treatment targets. Flavonoids are molecules with pleiotropic activities. The metabolism-regulating anticancer effects of flavonoids are broadly demonstrated in preclinical studies. Flavonoids modulate key pathways involved in the Warburg phenotype including but not limited to PKM2, HK2, GLUT1 and HIF-1. The corresponding molecular mechanisms and clinical relevance of 'anti-Warburg' effects of flavonoids are discussed in this review article. The most prominent examples are provided for the potential application of targeted 'anti-Warburg' measures in cancer management. Individualised profiling and patient stratification are presented as powerful tools for implementing targeted 'anti-Warburg' measures in the context of predictive, preventive and personalised medicine.

19.
Strahlenther Onkol ; 196(12): 1086-1093, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32816059

RESUMO

BACKGROUND: The COVID-19 pandemic outbreak has set the emergency services in developing countries on major alert, as the installed response capacities are easily overwhelmed by the constantly increasing high demand. The deficit of intensive care unit beds and ventilators in countries like Peru is forcing practitioners to seek preventive or early interventional strategies to prevent saturating these chronically neglected facilities. CASE PRESENTATION: A 64-year-old patient is reported after presenting with COVID-19 pneumonia and rapidly progressing to deteriorated ventilatory function. Compassionate treatment with a single 1­Gy dose to the bilateral whole-lung volume was administered, with gradual daily improvement of ventilatory function and decrease in serum inflammatory markers and oxygen support needs, including intubation. No treatment-related toxicity developed. Procedures of transport, disinfection, and treatment planning and delivery are described. CONCLUSION: Whole-lung low-dose radiotherapy seems to be a promising approach for avoiding or delaying invasive respiratory support. Delivered low doses are far from meeting toxicity ranges. On-going prospective trials will elucidate the effectiveness of this approach.


Assuntos
COVID-19/tratamento farmacológico , COVID-19/radioterapia , Antibacterianos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticoagulantes/uso terapêutico , Antivirais/uso terapêutico , COVID-19/sangue , COVID-19/diagnóstico por imagem , COVID-19/terapia , Terapia Combinada , Ensaios de Uso Compassivo , Enoxaparina/uso terapêutico , Humanos , Hidroxicloroquina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Oxigenoterapia , Peru , Planejamento da Radioterapia Assistida por Computador , Trombofilia/tratamento farmacológico , Trombofilia/etiologia , Tomografia Computadorizada por Raios X
20.
J Contemp Brachytherapy ; 12(3): 267-272, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32695199

RESUMO

Purpose: Conjunctival lymphoma represents an uncommon tumor, accounting for 5-10% of total extranodal lymphomas. Although radiotherapy is a frequent treatment option, limited capacities and lack of specialized centers are common problems in Peru, forcing radiation oncologists to apply short courses of radiotherapy. Here, we report a case series of patients treated with a novel single-shot scheme. Additionally, we present a literature review of the current short-course irradiation strategies. Cases presentation: Three cases of conjunctival marginal zone (B-cell) lymphoma (marginal zone lymphoma [MZL]/mucosa-associated lymphoid tissue [MALT]) of the fornix are presented. Following biopsy and sonographic assessment of the lesion thickness, we applied a focused single dose of 14 Gy kilovoltage brachytherapy (prescribed to the maximum thickness of the lesion). Follow-up was scheduled in quarterly intervals. After 28, 31, and 40 months of follow-up, none of the three patients treated exhibited acute or chronic toxicities and remained local or distant disease-free. Conclusions: Single dose kilovoltage brachytherapy was effective and safe in this small cohort of patients. Based on the literature, there is an evidence that local treatment in short-course radiotherapy is effective and should be considered amongst therapeutic options for these patients; however, this novel approach should be evaluated prospectively in a larger cohort.

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