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1.
Anticancer Res ; 41(7): 3589-3595, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34230155

RESUMO

BACKGROUND/AIM: Curing local recurrence of rectal cancer (LRRC) is difficult with conventional photon radiotherapy. Proton beam therapy (PBT) on the other hand, has unique physical characteristics that permit higher doses to LRRC while minimizing side effects on surrounding organs. However, the efficacy of PBT on controlling rectal cancer recurrence has not yet been reported. This study aimed to evaluate clinical outcomes and toxicities of PBT for LRRC. PATIENTS AND METHODS: Clinical outcomes were retrospectively evaluated for 12 patients with 13 total lesions that had received PBT for LRRC at our institute. RESULTS: The median follow-up period from the initiation of PBT was 35.6 months. The 3-year local control, progression-free survival and overall survival rates were 80.2%, 10.4% and 73.8%, respectively. Median survival time was 67.1 months. There were no severe acute or late adverse events. CONCLUSION: PBT could be a safe and effective treatment method for LRRC.


Assuntos
Recidiva Local de Neoplasia/radioterapia , Neoplasias Retais/radioterapia , Adulto , Idoso , Quimiorradioterapia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Intervalo Livre de Progressão , Terapia com Prótons/métodos , Dosagem Radioterapêutica , Neoplasias Retais/mortalidade , Estudos Retrospectivos , Taxa de Sobrevida
2.
J Appl Clin Med Phys ; 22(7): 27-35, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34231945

RESUMO

PURPOSE: Prostate patients with positive lymph node margins receive an initial course of 45 Gy to the planning target volume (PTV) comprised of prostate, seminal vesicles, and lymph nodes with a 1-cm margin. The prostate is localized via implanted fiducial markers before each fraction is delivered using portal-imaging. However, the pelvic lymph nodes are affixed to the bony anatomy and are not mobile in concert with the prostate. The aim of this study was to determine whether a significant difference in pelvic lymph node coverage exists between planned and delivered external beam therapy treatments for these patients. METHODS: The recorded prostate motions were gathered for 19 patients; conjointly the pelvic lymph node motions were determined by manual registration of the bony anatomy in the kV-images. The difference between the prostate and the bony anatomy coordinates was input into Eclipse as field shifts to represent the deviation in planned vs delivered pelvic lymph node coverage. RESULTS: Structure volume at V(100) was recorded for each patient for two structures: summed pelvic lymph nodes (LN CTV) and pelvic lymph nodes +1 cm margin (LN PTV) to express their contribution to the PTV. For the LN PTV, the average difference between the planned coverage and calculated delivered coverage was 3.5%, with a paired t-test value of P = 0.005. Based upon bony anatomy registration, 26% of patients received less than 95% dose coverage using V(100) criteria for LN PTV. Dose value differences between the two plans at minimum were 6.96 ± 6.23 Gy, at mean were 0.54 ± 0.40 Gy, and at maximum were 0.10 ± 0.29 Gy. For the LN CTV, the average difference between the planned coverage and calculated delivered coverage was 1%, with a paired t-test value of P = 0.53. CONCLUSIONS: The results indicate a significant difference exists between the planned coverage and calculated delivered coverage for the LN PTV. There was no significant difference found for the LN CTV. We conclude that lymph node motion must be considered with the prostate motion when aligning patients before each fraction.


Assuntos
Neoplasias da Próstata , Radioterapia de Intensidade Modulada , Humanos , Linfonodos , Masculino , Pelve/diagnóstico por imagem , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
3.
Int J Mol Sci ; 22(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199667

RESUMO

Nanoparticles (NPs) with a high atomic number (Z) are promising radiosensitizers for cancer therapy. However, the dependence of their efficacy on irradiation conditions is still unclear. In the present work, 11 different metal and metal oxide NPs (from Cu (ZCu = 29) to Bi2O3 (ZBi = 83)) were studied in terms of their ability to enhance the absorbed dose in combination with 237 X-ray spectra generated at a 30-300 kVp voltage using various filtration systems and anode materials. Among the studied high-Z NP materials, gold was the absolute leader by a dose enhancement factor (DEF; up to 2.51), while HfO2 and Ta2O5 were the most versatile because of the largest high-DEF region in coordinates U (voltage) and Eeff (effective energy). Several impacts of the X-ray spectral composition have been noted, as follows: (1) there are radiation sources that correspond to extremely low DEFs for all of the studied NPs, (2) NPs with a lower Z in some cases can equal or overcome by the DEF value the high-Z NPs, and (3) the change in the X-ray spectrum caused by a beam passing through the matter can significantly affect the DEF. All of these findings indicate the important role of carefully planning radiation exposure in the presence of high-Z NPs.


Assuntos
Cobre/uso terapêutico , Nanopartículas Metálicas/uso terapêutico , Neoplasias/radioterapia , Radiossensibilizantes/uso terapêutico , Bismuto/química , Bismuto/uso terapêutico , Cobre/química , Relação Dose-Resposta a Droga , Humanos , Nanopartículas Metálicas/química , Método de Monte Carlo , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Óxidos/química , Óxidos/uso terapêutico , Radiossensibilizantes/química , Dosagem Radioterapêutica
4.
Clinics (Sao Paulo) ; 76: e2769, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34231708

RESUMO

OBJECTIVES: To explore the effect of tumor and normal lung volumes on lung volume-dose parameters in patients with non-small-cell lung cancer (NSCLC) who had undergone intensity-modulated radiation therapy (IMRT). METHODS: The clinical data of 208 patients with NSCLC who underwent radical IMRT between June 2014 and June 2018 were retrospectively analyzed. A regression model curve was used to evaluate the effect of tumor and normal lung volumes on normal lung relative volumes receiving greater than 5 and 20 Gy (V5, V20), on mean lung dose (MLD), and on absolute volumes spared from greater than 5 and 20 Gy (AVS5, AVS20). RESULTS: The V5, V20, and MLD of the bilateral lung were fitted to a quadratic equation curve with the change in tumor volume, which increased initially and then decreased when the tumor volume increased. The V5, V20, and MLD of the lung reached their apex when the tumor volumes were 288.07, 341.69, and 326.83 cm3, respectively. AVS5 and AVS20 decreased in a logarithmic curve with an increase in tumor volume. The V5, V20, and MLD of the small normal lung volume group were all significantly higher than those of the large normal lung volume group (p<0.001, p=0.004, p=0.002). However, the AVS5 and AVS20 of the small normal lung volume group were all significantly lower than those of the large normal lung volume group (p<0.001). CONCLUSION: The effects of tumor volume and normal lung volume on dose-volume parameters should be considered. AVS5 is an important supplementary dose limitation parameter for patients whose tumor volume exceeds a certain boundary value (approximately 300 cm3).


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Radioterapia de Intensidade Modulada , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Humanos , Pulmão/diagnóstico por imagem , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Medidas de Volume Pulmonar , Dosagem Radioterapêutica , Estudos Retrospectivos
5.
World J Surg Oncol ; 19(1): 214, 2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34271911

RESUMO

BACKGROUND: The radiation-induced lung injury (RILI) in patients with advanced non-small cell lung cancer (NSCLS) is very common in clinical settings; we aimed to evaluate the risk factors of RILI in NSCLS patients, to provide insights into the treatment of NSCLS. METHODS: NSCLC patients undergoing three-dimensional conformal radiotherapy (3D-CRT) in our hospital from June 1, 2018, to June 30, 2020, were included. The characteristics and treatments of RILI and non-RILI patients were analyzed. Logistic regression analyses were conducted to assess the risk factors of RILI in patients with NSCLC. RESULTS: A total of 126 NSCLC patients were included; the incidence of RILI in NSCLC patients was 35.71%. There were significant differences in diabetes, smoke, chronic obstructive pulmonary disease (COPD), concurrent chemotherapy, radiotherapy dose, and planning target volume (PTV) between the RILI group and the non-RILI group (all P < 0.05). Logistic regression analyses indicated that diabetes (OR 3.076, 95%CI 1.442~5.304), smoke (OR 2.745, 95%CI 1.288~4.613), COPD (OR 3.949, 95%CI 1.067~5.733), concurrent chemotherapy (OR 2.072, 95%CI 1.121~3.498), radiotherapy dose ≥ 60 Gy (OR 3.841, 95%CI 1.932~5.362), and PTV ≥ 396 (OR 1.247, 95%CI 1.107~1.746) were the independent risk factors of RILI in patients with NSCLC (all P < 0.05). CONCLUSIONS: RILI is commonly seen in NSCLS patients; early targeted measures are warranted for patients with those risk factors; future studies with larger sample sizes and different areas are needed to further elucidate the influencing factors of RILI in the treatment of NSCLS.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Lesão Pulmonar , Neoplasias Pulmonares , Radioterapia Conformacional , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Humanos , Neoplasias Pulmonares/radioterapia , Prognóstico , Dosagem Radioterapêutica , Radioterapia Conformacional/efeitos adversos , Fatores de Risco
7.
Int J Mol Sci ; 22(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208396

RESUMO

Non-small cell lung cancer (NSCLC) continues to be the leading cause of cancer death worldwide. Recently, targeting molecules whose functions are associated with tumorigenesis has become a game changing adjunct to standard anti-cancer therapy. As evidenced by the results of preclinical and clinical investigations, whole-body irradiations (WBI) with X-rays at less than 0.1-0.2 Gy per fraction can induce remissions of various neoplasms without inciting adverse side effects of conventional chemo- and radiotherapy. In the present study, a murine model of human NSCLC was employed to evaluate for the first time the anti-neoplastic efficacy of WBI combined with inactivation of CTLA-4, PD-1, and/or HSP90. The results indicate that WBI alone and in conjunction with the inhibition of the function of the cytotoxic T-lymphocyte antigen-4 (CTLA-4) and the programmed death-1 (PD-1) receptor immune checkpoints (ICs) and/or heat shock protein 90 (HSP90) markedly reduced tumorigenesis in mice implanted by three different routes with the syngeneic Lewis lung cancer cells and suppressed clonogenic potential of Lewis lung carcinoma (LLC1) cells in vitro. These results were associated with the relevant changes in the profile of pro- and anti-neoplastic immune cells recruited to the growing tumors and the circulating anti- and pro-inflammatory cytokines. In contrast, inhibition of the tested molecular targets used either separately or in combination with each other did not exert notable anti-neoplastic effects. Moreover, no significant synergistic effects were detected when the inhibitors were applied concurrently with WBI. The obtained results supplemented with further mechanistic explanations provided by future investigations will help design the effective strategies of treatment of lung and other cancers based on inactivation of the immune checkpoint and/or heat shock molecules combined with low-dose radiotherapy.


Assuntos
Proteínas de Choque Térmico/metabolismo , Proteínas de Checkpoint Imunológico/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/radioterapia , Transplante de Neoplasias , Dosagem Radioterapêutica , Irradiação Corporal Total , Animais , Células Clonais , Pulmão/patologia , Contagem de Linfócitos , Linfócitos do Interstício Tumoral , Macrófagos/patologia , Camundongos Endogâmicos C57BL , Ensaio Tumoral de Célula-Tronco
8.
Int J Mol Sci ; 22(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34208417

RESUMO

In the present study, we analyze the nuclear magnetic resonance (NMR) blood serum metabolic profiles of 106 head and neck squamous cell carcinoma (HNSCC) patients during radio (RT) and concurrent radio-chemotherapy (CHRT). Four different fractionation schemes were compared. The blood samples were collected weekly, from the day before the treatment until the last week of CHRT/RT. The NMR spectra were acquired on A Bruker 400 MHz spectrometer at 310 K and analyzed using multivariate methods. Seven metabolites were found significantly to be altered solely by radiotherapy: N-acetyl-glycoprotein (NAG), N-acetylcysteine, glycerol, glycolate and the lipids at 0.9, 1.3 and 3.2 ppm. The NMR results were correlated with the tissue volumes receiving a particular dose of radiation. The influence of the irradiated volume on the metabolic profile is weak and mainly limited to sparse correlations with the inflammatory markers, creatinine and the lymphocyte count in RT and the branched-chain amino-acids in CHRT. This is probably due to the optimal planning and delivery of radiotherapy improving sparing of the surrounding normal tissues and minimizing the differences between the patients (caused by the tumor location and size).


Assuntos
Neoplasias de Cabeça e Pescoço/sangue , Neoplasias de Cabeça e Pescoço/radioterapia , Espectroscopia de Ressonância Magnética , Metabolômica , Dosagem Radioterapêutica , Adulto , Idoso , Análise Discriminante , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Feminino , Humanos , Análise dos Mínimos Quadrados , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas
9.
BMJ Case Rep ; 14(7)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34253513

RESUMO

The treatment of local recurrence of nasopharyngeal carcinoma (NPC) is challenging, and the role of reirradiation is controversial regarding the high risk for severe toxicity. Stereotactic body radiotherapy (SBRT) is a high-precision radiation technique that can spare surrounding normal tissues. Studies have demonstrated the high activity and low toxicity of both SBRT and anti-programmed-cell-death-1 immune checkpoint inhibitors for head and neck cancers. There has been preclinical and clinical evidence suggesting synergy between radiotherapy and checkpoint inhibitors. We report two patients with locally recurrent unresectable rT4 NPC both involving the retro-orbital areas. They received the same treatment with low-dose SBRT (28 Gy in 5 fractions) and pembrolizumab, and showed a remarkable tumour response without untoward radiation toxicity. SBRT plus an immune checkpoint inhibitor may provide a new treatment option for locally recurrent NPC. We propose further investigation with a formal clinical trial.


Assuntos
Neoplasias Nasofaríngeas , Radiocirurgia , Humanos , Carcinoma Nasofaríngeo/tratamento farmacológico , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/radioterapia , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/radioterapia , Recidiva Local de Neoplasia/cirurgia , Dosagem Radioterapêutica , Terapia de Salvação
10.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 46(6): 615-619, 2021 Jun 28.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34275930

RESUMO

OBJECTIVES: To compare 2 dynamic conformal arc plans based on the high dose rate flattening filter free (FFF) beams, and to evaluate the dosimetric differences. METHODS: A total of 20 patients with early peripheral non-small cell lung cancer were selected, and 2 dynamic conformal arc plans were designed in the Eclipse 10.0 treatment planning system (TPS). One of them was based on tumor-center (T-DCA), and the other was based on iso-center (Iso-DCA). Both plans were created by using the Truebeam linear accelerator, based on 6 MV FFF photons with a dose rate at 1 400 monitor unit (MU)/min. All patients received the prescribed dose of 4 800 cGy in 4 fractions (1 200 cGy/fraction). Target coverage and organ at risk limits were planned and designed according to the Radiation Therapy Oncology Group (RTOG) Criteria, and were compared between the T-DCA and the Iso-DCA plans. RESULTS: There was no significant difference in the target coverage between the T-DCA and Iso-DCA plans (P>0.05). Conformal index and homogeneity index had no significant differences (both P>0.05), but the percentage of the maximum dose in any direction 2 cm away from the planned target area (D2 cm) and the ratio of the volume wrapped by the isodose line of 50% prescription dose to the volume of the planned target area (R50%) showed significant differences (both P<0.05). The MU of the Iso-DCA plan was increased by 21% compared with that of the T-DCA plan. Except the maximum dose of spinal cord and esophagus, there was no significant difference in the other dosimetric parameters of the organs at risk between the T-DCA and the Iso-DCA plans (all P>0.05). CONCLUSIONS: The dose fall-off of Iso-DCA plan is better than T-DCA plan, but the T-DCA plan is consistently superior in sparing dose to spinal cord and esophagus, and the T-DCA plan has fewer MU.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Radiocirurgia , Radioterapia de Intensidade Modulada , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Humanos , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/cirurgia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
11.
Acta Oncol ; 60(8): 1045-1053, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34107847

RESUMO

BACKGROUND: Radiotherapy (RT) planning for cervical cancer patients entails the acquisition of both Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). Further, molecular imaging by Positron Emission Tomography (PET) could contribute to target volume delineation as well as treatment response monitoring. The objective of this study was to investigate the feasibility of a PET/MRI-only RT planning workflow of patients with cervical cancer. This includes attenuation correction (AC) of MRI hardware and dedicated positioning equipment as well as evaluating MRI-derived synthetic CT (sCT) of the pelvic region for positioning verification and dose calculation to enable a PET/MRI-only setup. MATERIAL AND METHODS: 16 patients underwent PET/MRI using a dedicated RT setup after the routine CT (or PET/CT), including eight pilot patients and eight cervical cancer patients who were subsequently referred for RT. Data from 18 patients with gynecological cancer were added for training a deep convolutional neural network to generate sCT from Dixon MRI. The mean absolute difference between the dose distributions calculated on sCT and a reference CT was measured in the RT target volume and organs at risk. PET AC by sCT and a reference CT were compared in the tumor volume. RESULTS: All patients completed the examination. sCT was inferred for each patient in less than 5 s. The dosimetric analysis of the sCT-based dose planning showed a mean absolute error (MAE) of 0.17 ± 0.12 Gy inside the planning target volumes (PTV). PET images reconstructed with sCT and CT had no significant difference in quantification for all patients. CONCLUSIONS: These results suggest that multiparametric PET/MRI can be successfully integrated as a one-stop-shop in the RT workflow of patients with cervical cancer.


Assuntos
Neoplasias do Colo do Útero , Feminino , Humanos , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Tomografia Computadorizada por Raios X , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/radioterapia
12.
Br J Radiol ; 94(1123): 20210214, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34111955

RESUMO

OBJECTIVE: To develop and evaluate a practical automatic treatment planning method for intensity-modulated radiation therapy (IMRT) in cervical cancer cases. METHODS: A novel algorithm named as Optimization Objectives Tree Search Algorithm (OOTSA) was proposed to emulate the planning optimization process and achieve a progressively improving IMRT plan, based on the Eclipse Scripting Application Programming Interface (ESAPI). 30 previously treated cervical cancer cases were selected from the clinical database and comparison was made between the OOTSA-generated plans and clinical treated plans and RapidPlan-based (RP) plans. RESULTS: In clinical evaluation, compared with plan scores of the clinical plans and the RP plans, 22 and 26 of the OOTSA plans were considered as clinically improved in terms of plan quality, respectively. The average conformity index (CI) for the PTV in the OOTSA plans was 0.86 ± 0.01 (mean ± 1 standard deviation), better than those in the RP plans (0.83 ± 0.02) and the clinical plans (0.71 ± 0.11). Compared with the clinical plans, the mean doses of femoral head, rectum, spinal cord and right kidney in the OOTSA plans were reduced by 2.34 ± 2.87 Gy, 1.67 ± 2.10 Gy, 4.12 ± 6.44 Gy and 1.15 ± 2.67 Gy. Compared with the RP plans, the mean doses of femoral head, spinal cord, right kidney and small intestine in the OOTSA plans were reduced by 3.31 ± 1.55 Gy, 4.25 ± 3.69 Gy, 1.54 ± 2.23 Gy and 3.33 ± 1.91 Gy, respectively. In the OOTSA plans, the mean dose of bladder was slightly increased, with 2.33 ± 2.55 Gy (versus clinical plans) and 1.37 ± 1.74 Gy (vs RP plans). The average elapsed time of OOTSA and clinical planning were 59.2 ± 3.47 min and 76.53 ± 5.19 min. CONCLUSION: The plans created by OOTSA have been shown marginally better than the manual plans, especially in preserving OARs. In addition, the time of automatic treatment planning has shown a reduction compared to a manual planning process, and the variation of plan quality was greatly reduced. Although improvement on the algorithm is warranted, this proof-of-concept study has demonstrated that the proposed approach can be a practical solution for automatic planning. ADVANCES IN KNOWLEDGE: The proposed method is novel in the emulation strategy of the physicists' iterative operation during the planning process. Based on the existing optimizers, this method can be a simple yet effective solution for automated IMRT treatment planning.


Assuntos
Algoritmos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada , Neoplasias do Colo do Útero/radioterapia , Adulto , Feminino , Humanos , Órgãos em Risco , Dosagem Radioterapêutica , Estudos Retrospectivos , Carga Tumoral
13.
Br J Radiol ; 94(1123): 20210012, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34111959

RESUMO

OBJECTIVES: To investigate the efficacy of a schedule of low-dose radiotherapy (LDRT) with 4 Gy (2 Gy x 2) in a cohort of unselected MALT or MZL patients. METHODS: We retrospectively collected all patients receiving LDRT, either for cure or palliation, for a stage I-IV histologically proven MALT or MZL between 2016 and 2020. Response to LDRT was evaluated with the Lugano criteria. Local control (LC), distant relapse-free survival (DRFS), progression-free survival (PFS) and overall survival (OS) were stratified for treatment intent (curative vs palliative) and estimated by the Kaplan-Meier product-limit. RESULTS: Among 45 consecutively enrolled patients with a median age of 68 years (range 22-86), 26 (58%) were female. Thirty-one patients (69%) with a stage I-II disease received LDRT as first line therapy and with a curative intent. Overall response rate was 93%, with no significant difference among curative and palliative intent. With a median follow-up of 18 months, LC, DRFS, PFS and OS at 2 years were 93, 92, 76 and 91%, respectively, in the overall population. Patients receiving curative LDRT had a better PFS at 2 years (85% vs 54%, p < 0.01) compared to patients receiving palliative treatment. LDRT was well tolerated in all patients, without any significant acute or chronic side-effect. CONCLUSIONS: LDRT is effective and well tolerated in patients affected with MALT or nodal MZL, achieving high response rates and durable remission at 2 years. ADVANCES IN KNOWLEDGE: This study shows the efficacy of LDRT in the treatment of MALT and MZL.


Assuntos
Linfoma de Zona Marginal Tipo Células B/radioterapia , Dosagem Radioterapêutica , Adulto , Feminino , Humanos , Linfoma de Zona Marginal Tipo Células B/mortalidade , Linfoma de Zona Marginal Tipo Células B/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Cuidados Paliativos , Estudos Retrospectivos , Taxa de Sobrevida
14.
Br J Radiol ; 94(1123): 20210473, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34111967

RESUMO

OBJECTIVES: The aim of this work was to evaluate the operation of the 1600SRS detector and to develop a calibration procedure for verifying the dose delivered by a single isocenter stereotactic radiosurgery (SRS) treatment of small multiple brain metastases (BM). METHODS: 14 clinical treatment cases were selected with the number of BM ranging from 2 to 11. The dosimetric agreement was investigated between the calculated and the measured dose by an OCTAVIUS 1600SRS array detector in an OCTAVIUS 4D phantom equipped with dedicated SRS top. The cross-calibration procedure deviated from the manufacturer's as it applied field sizes and dose rates corresponding to the volumetric modulated arc therapy segments in each plan. RESULTS: Measurements with a plan specific cross-calibration showed mean ± standard deviation (SD) agreement scores for cut-off values 50%, 80%, 95%, of 98.6 ± 1.7%, 96.5 ± 4.6%, 97.3 ± 4.4% for the 6 MV plans respectively, and 98.6 ± 1.5%, 96.6 ± 4.0% 96.4 ± 6.3%, for the 6 MV flattening filter free (FFF) plans respectively. Using the default calibration procedure instead of the plan specific calibration could lead to a combined systematic dose offset of 4.1% for our treatment plans. CONCLUSION: The 1600SRS detector array with the 4D phantom offers an accurate solution to perform routine quality assurance measurements of single isocenter SRS treatments of multiple BM. This work points out the necessity of an adapted cross-calibration procedure. ADVANCES IN KNOWLEDGE: A dedicated calibration procedure enables accurate dosimetry with the 1600SRS detector for small field single isocenter SRS treatment of multiple brain metastases for a large amount of BM.


Assuntos
Neoplasias Encefálicas/radioterapia , Radiocirurgia/normas , Algoritmos , Calibragem , Humanos , Imagens de Fantasmas , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
15.
In Vivo ; 35(4): 2313-2319, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34182511

RESUMO

BACKGROUND/AIM: Non-melanoma skin cancers (NMSC) are the most common neoplasms worldwide and their incidence has been proven to increase in recent years and their treatment should aim at cancer cure as well as cosmetic and functional results. The aim of the study was to report the results of our mono-institutional series of high-dose-rate radiotherapy (cHDR-RT) in NMSC, based on a homogenous technique and two different treatment schedules. PATIENTS AND METHODS: All patients affected by NMSC who were consecutively evaluated and treated at our Interventional Oncology Center from October 2018 to August 2020, were included. Patients underwent cHDR-RT using flap applicators and remotely afterloaded Ir-192 sources. RESULTS: Overall, 51 patients were treated for a total of 67 lesions. Local control (LC) and disease-specific survival (DSS) were 94.0% and 100%, respectively. Grade 1, grade 2, grade 3 and grade 4 acute toxicity rates were 24.6%, 3.5%, 3.5%, and 0.0%, respectively. The cosmetic results were graded as excellent/good, fair, and poor in 73.7%, 19.3%, and 7.0%. CONCLUSION: cHDR-RT of NMSC is an effective alternative to surgery due to excellent outcomes both in terms of local control and aesthetic results especially in the face.


Assuntos
Braquiterapia , Neoplasias Cutâneas , Estética , Humanos , Dosagem Radioterapêutica , Neoplasias Cutâneas/radioterapia
16.
Rozhl Chir ; 100(4): 180-185, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34182760

RESUMO

INTRODUCTION: The purpose of this study was to compare the radiation dose to organs at risk for deep-inspiration breath hold (DIBH) and free-breathing (FB) radiotherapy in patients with lef-sided breast cancer undergoing adjuvant radiotherapy after partial mastectomy.  Methods: One hundred patients with left-sided breast cancer underwent DIBH and FB planning computed tomography scans, and the 2 techniques were compared. Dose-volume histograms were analyzed for heart, left anterior descending coronary artery (LAD), and left lung.  Results: Radiation dose to heart, LAD, and left lung was significantly lower for DIBH than for free breathing plans. The median mean heart dose for DIBH technique in comparison with FB was 1.21 Gy, and 3.22 Gy respectively; for LAD, 4.67 versus 24.71 Gy; and for left lung 8.32 Gy versus 9.99 Gy.  Conclusion: DIBH is an effective technique to reduce cardiac and lung radiation exposure.


Assuntos
Neoplasias da Mama , Neoplasias Unilaterais da Mama , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Suspensão da Respiração , Feminino , Humanos , Mastectomia , Mastectomia Segmentar , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Neoplasias Unilaterais da Mama/diagnóstico por imagem , Neoplasias Unilaterais da Mama/radioterapia , Neoplasias Unilaterais da Mama/cirurgia
17.
Crit Rev Oncol Hematol ; 163: 103396, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34146680

RESUMO

The aim of this work is to summarize and evaluate the current status of knowledge on flattening filter free (FFF) beams and their applications in stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT). A PubMed search was undertaken in order to identify relevant publications using FFF and stereotactic radiotherapy as keywords. On a clinical aspect, lung tumors treated with FFF SBRT show promising results in terms of local control and overall survival with acute toxicities consistent with those that occur with standard radiotherapy. Beside lung, SBRT is suitable for different anatomical sites such as liver, prostate, cervix, etc. offering similar results: reduced treatment time, good tumor control and mild acute toxicities. Regarding brain tumors, the employment of SRS with FFF beams significantly reduces treatment time and provides notable normal tissue sparing due to the sharp dose fall-off outside the tumor.


Assuntos
Neoplasias Pulmonares , Radiocirurgia , Radioterapia de Intensidade Modulada , Feminino , Humanos , Neoplasias Pulmonares/cirurgia , Masculino , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Tecnologia
18.
Medicine (Baltimore) ; 100(25): e26390, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34160420

RESUMO

ABSTRACT: Hepatocellular carcinoma (HCC) involving the inferior vena cava rarely occurs, but its prognosis is extremely poor, with no established treatment to date. This study aimed to analyze the clinical outcome and toxicity of radiotherapy (RT) targeting inferior vena cava tumor thrombus (IVCTT) in HCC patients.From November 2011 to July 2020, medical record of 19 HCC patients who were treated with RT for IVCTT was retrospectively reviewed. RT was delivered using 3-dimensional conformal radiation therapy, intensity-modulated radiation therapy, and stereotactic body radiation therapy. The median radiation dose was 50 Gy (range, 45-55.8 Gy) for intensity-modulated radiation therapy and three-dimensional conformal radiotherapy. Stereotactic body radiation therapy was performed in 5 patients, for a total of 32 Gy in 4 fractions.The median follow-up duration was 8.1 months (range, 3.3-26.5 months). The median overall survival was 9.4 months (range, 3.7-26.5 months), and the 1-year overall survival rate was 37.1%. Eight of 19 patients (42.1%) had extrahepatic metastasis at the start of RT. Six of 11 patients (54.5%) who did not have extrahepatic metastasis at the start of RT showed extrahepatic metastasis after RT. The major cause of death was progression of extrahepatic metastasis (11 patients, 57.9%). The overall response rate of IVCTT for RT was 84.2%, and the local control rate at the time of the last follow-up was 89.4%. After RT, the most common first progression site was the lungs (9 patients, 47.4%). Most toxicities were grade 1 to 2 gastrointestinal (26.3%) and liver enzyme elevation (68.4%). Three patients occurred pulmonary embolism after RT later than 5 months after.RT is a feasible and safe local therapy for IVCTT, with favorable tumor control and acceptable toxicity. Extrahepatic metastasis is the major progression pattern and a leading cause of death in patients treated with RT. The combination of effective systemic therapy with RT may have to be considered.


Assuntos
Carcinoma Hepatocelular/radioterapia , Neoplasias Hepáticas/radioterapia , Veia Cava Inferior/patologia , Trombose Venosa/radioterapia , Adulto , Idoso , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Progressão da Doença , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Fígado/irrigação sanguínea , Fígado/diagnóstico por imagem , Fígado/patologia , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Prognóstico , Intervalo Livre de Progressão , Radiocirurgia/efeitos adversos , Dosagem Radioterapêutica , Radioterapia Conformacional/efeitos adversos , Radioterapia de Intensidade Modulada/efeitos adversos , Critérios de Avaliação de Resposta em Tumores Sólidos , Estudos Retrospectivos , Taxa de Sobrevida , Tomografia Computadorizada por Raios X , Veia Cava Inferior/diagnóstico por imagem , Trombose Venosa/diagnóstico , Trombose Venosa/etiologia , Trombose Venosa/patologia
19.
J Appl Clin Med Phys ; 22(7): 147-154, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34101334

RESUMO

PURPOSE: The purpose of the current study was threefold: (a) investigate the impact of the variations (errors) in spot sizes in robustly optimized pencil beam scanning (PBS) proton-based stereotactic body radiation therapy (SBRT) lung plans, (b) evaluate the impact of spot sizes and position errors simultaneously, and (c) assess the overall effect of spot size and position errors occurring simultaneously in conjunction with either setup or range errors. METHODS: In this retrospective study, computed tomography (CT) data set of five lung patients was selected. Treatment plans were regenerated for a total dose of 5000 cGy(RBE) in 5 fractions using a single-field optimization (SFO) technique. Monte Carlo was used for the plan optimization and final dose calculations. Nominal plans were normalized such that 99% of the clinical target volume (CTV) received the prescription dose. The analysis was divided into three groups. Group 1: The increasing and decreasing spot sizes were evaluated for ±10%, ±15%, and ±20% errors. Group 2: Errors in spot size and spot positions were evaluated simultaneously (spot size: ±10%; spot position: ±1 and ±2 mm). Group 3: Simulated plans from Group 2 were evaluated for the setup (±5 mm) and range (±3.5%) errors. RESULTS: Group 1: For the spot size errors of ±10%, the average reduction in D99% for -10% and +10% errors was 0.7% and 1.1%, respectively. For -15% and +15% spot size errors, the average reduction in D99% was 1.4% and 1.9%, respectively. The average reduction in D99% was 2.1% for -20% error and 2.8% for +20% error. The hot spot evaluation showed that, for the same magnitude of error, the decreasing spot sizes resulted in a positive difference (hotter plan) when compared with the increasing spot sizes. Group 2: For a 10% increase in spot size in conjunction with a -1 mm (+1 mm) shift in spot position, the average reduction in D99% was 1.5% (1.8%). For a 10% decrease in spot size in conjunction with a -1 mm (+1 mm) shift in spot position, the reduction in D99% was 0.8% (0.9%). For the spot size errors of ±10% and spot position errors of ±2 mm, the average reduction in D99% was 2.4%. Group 3: Based on the results from 160 plans (4 plans for spot size [±10%] and position [±1 mm] errors × 8 scenarios × 5 patients), the average D99% was 4748 cGy(RBE) with the average reduction of 5.0%. The isocentric shift in the superior-inferior direction yielded the least homogenous dose distributions inside the target volume. CONCLUSION: The increasing spot sizes resulted in decreased target coverage and dose homogeneity. Similarly, the decreasing spot sizes led to a loss of target coverage, overdosage, and degradation of dose homogeneity. The addition of spot size and position errors to plan robustness parameters (setup and range uncertainties) increased the target coverage loss and decreased the dose homogeneity.


Assuntos
Neoplasias Pulmonares , Terapia com Prótons , Radiocirurgia , Radioterapia de Intensidade Modulada , Humanos , Pulmão/diagnóstico por imagem , Pulmão/cirurgia , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/cirurgia , Órgãos em Risco , Prótons , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Estudos Retrospectivos
20.
J Appl Clin Med Phys ; 22(7): 155-164, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34145732

RESUMO

A first-time survey across 15 cancer centers in Ontario, Canada, on the current practice of patient-specific quality assurance (PSQA) for intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) delivery was conducted. The objectives were to assess the current state of PSQA practice, identify areas for potential improvement, and facilitate the continued improvement in standardization, consistency, efficacy, and efficiency of PSQA regionally. The survey asked 40 questions related to PSQA practice for IMRT/VMAT delivery. The questions addressed PSQA policy and procedure, delivery log evaluation, instrumentation, measurement setup and methodology, data analysis and interpretation, documentation, process, failure modes, and feedback. The focus of this survey was on PSQA activities related to routine IMRT/VMAT treatments on conventional linacs, including stereotactic body radiation therapy but excluding stereotactic radiosurgery. The participating centers were instructed to submit answers that reflected the collective view or opinion of their department and represented the most typical process practiced. The results of the survey provided a snapshot of the current state of PSQA practice in Ontario and demonstrated considerable variations in the practice. A large majority (80%) of centers performed PSQA measurements on all VMAT plans. Most employed pseudo-3D array detectors with a true composite (TC) geometry. No standard approach was found for stopping or reducing frequency of measurements. The sole use of delivery log evaluation was not widely implemented, though most centers expressed interest in adopting this technology. All used the Gamma evaluation method for analyzing PSQA measurements; however, no universal approach was reported on how Gamma evaluation and pass determination criteria were determined. All or some PSQA results were reviewed regularly in two-thirds of the centers. Planning related issues were considered the most frequent source for PSQA failures (40%), whereas the most frequent course of action for a failed PSQA was to review the result and decide whether to proceed to treatment.


Assuntos
Radiocirurgia , Radioterapia de Intensidade Modulada , Canadá , Humanos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
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