Radioterapia estereotáctica

La radioterapia con técnica estereotáctica es una modalidad de radioterapia externa que utiliza un sistema de coordenadas tridimensionales independientes del paciente para la localización precisa de la lesión. También se caracteriza porque los haces de irradiación son altamente conformados, precisos y convergentes sobre la lesión que hacen posible la administración de dosis muy altas de radioterapia sin incrementar la irradiación de los órganos o estructuras sanas adyacentes. Cuando el procedimiento se realiza en una sesión de tratamiento se denomina radiocirugía y si se administra en varias sesiones se denomina radioterapia estereotáctica. Se precisa de sistemas de fijación e inmovilización del paciente especiales (guías o marcos estereotácticos) y dispositivos de radioterapia capaces de generar haces muy conformados (acelerador lineal, gammaknife, cyberknife, tomoterapia, ciclotrones). La radioterapia estereotáctica moderna utiliza marcas radioopacas intratumorales o sistemas de imágenes de TAC incluidos en el dispositivo de irradiación, que permiten una precisa localización de las lesiones móviles en cada sesión de tratamiento. Además, los avances tecnológicos hacen posible coordinar los movimientos de la lesión en la respiración con la unidad de radioterapia (gaiting y tracking) de forma que pueden estrecharse al máximo los márgenes y por lo tanto excluir un mayor volumen de tejido sano La radiocirugía está indicada principalmente en lesiones cerebrales benignas o malignas menores de 3-4 centímetros (malformaciones arteriovenosas, neurinomas, meningiomas, metástasis cerebrales) y la radioterapia estereotáctica se administra fundamentalmente en tumores de localización extracraneal que requieran una alta conformación y precisión como cáncer precoz de pulmón inoperable y metástasis hepáticas.Stereotactic radiotherapy is an external radiation modality that uses a system of three dimensional references independent of the patient to achive a precise location of the lesion. Stereotactic radiotherapy generate highly conformal, precisely focused radiation beams to administer very high doses of radiation without increasing the radiation to healthy surrounding organs or structures. When the procedure is carried out in one treatment session the procedure is termed radiosurgery, and when the treatment is administered in several fractions, the radiation modality is termed stereotactic radiotherapy. Special systems of patient immobilization (guides or stereotactic frames) are required together with radiotherapy devices capable of generating conformal beams (lineal accelerator, gammaknife, cyberknife, tomotherapy, cyclotrons). Modern stereotactic radiotherapy techniques employ intratumoural radio-opaque fiducials or CT image systems included in the irradiation device, which make possible a precise location of mobile lesions in each treatment session. Besides, technological advances permit breathing synchronized radiation (gating and tracking) for maximum tightening of margins and excluding a greater volume of healthy tissue. Radiosurgery is mainly indicated in benign or malign cerebral lesions less than 3-4 centimetres (arteriovenous malformations, neurinomas, meningiomas, cerebral metastases) and stereotactic radiotherapy is basically administered in tumours of extracraneal location that require high conformation and precision, such as inoperable early lung cancer and liver metastasis

Hypofractionated radiation therapy and temozolomide in patients with glioblastoma and poor prognostic factors. A prospective, single-institution experience

Background: Hypofractionated radiation therapy is a feasible and safe treatment option in elderly and frail patients with glioblastoma. The aim of this study was to evaluate the effectiveness of hypofractionated radiation therapy with concurrent temozolomide in terms of feasibility and disease control in primary glioblastoma patients with poor prognostic factors other than advanced age, such as post-surgical neurological complications, high tumor burden, unresectable or multifocal lesions, and potential low treatment compliance due to social factors or rapidly progressive disease. Material and methods: GTV included the surgical cavity plus disease visible in T1WI-MRI, FLAIR-MRI and in the MET-uptake. The CTV was defined as the GTV plus 1.5-2 cm margin; the PTV was the CTV+0.3 cm margin. Forty, fourty-five, and fifty grays in 15 fractions were prescribed to 95% of PTV, CTV, and GTV, respectively. Treatment was delivered using IMRT or the VMAT technique. Simultaneously, 75 mg/m2/day of temozolomide were administered. Results: Between January 2010 and November 2017, we treated a total of 17 patients. The median age at diagnosis was 68-years; median KPS was 50-70%. MGMT-methylation status was negative in 5 patients, and 8 patients were IDH-wildtype. Eight of 18 patients were younger than 65-years. Median tumor volume was 26.95cc; median PTV volume was 322cc. Four lesions were unresectable; 6 patients underwent complete surgical resection. Median residual volume was 1.14cc. Progression-free survival was 60% at 6 months, 33% at 1-year and 13% at 2-years (median OS = 7 months). No acute grade 3-5 toxicities were documented. Symptomatic grade 3 radiation necrosis was observed in one patient. Conclusions: Patients with poor clinical factors other than advanced age can be selected for hypofractionated radiotherapy. The OS and PFS rates obtained in our series are similar to those in patients treated with standard fractionation, assuring good treatment adherence, low rates of toxicity and probable improved cost-effectiveness

Intensity-modulated radiation therapy (IMRT) vs. 3D conformal radiotherapy (3DCRT) in locally advanced rectal cancer (LARC): dosimetric comparison and clinical implications

Purpose: To compare target dose distribution, comformality, normal tissue avoidance, and irradiated body volume (IBV) in 3DCRT using classic anatomical landmarks (c3DCRT), 3DCRT fitting the PTV (f3DCRT), and intensitymodulated radiation therapy (IMRT) in patients with locally advanced rectal cancer (LARC). Materials and methods: Fifteen patients with LARC underwent c3DCRT, f3DCRT, and IMRT planning. Target definition followed the recommendations of the ICRU reports No. 50 and 62. OAR (SB and bladder) constraints were D5 ≤ 50 Gy and Dmax < 55 Gy. PTV dose prescription was defined as PTV95 ≥ 45 Gy and PTVmin ≥ 35 Gy. Target coverage was evaluated with the D95, Dmin, and Dmax. Target dose distribution and comformality was evaluated with the homogeneity indices (HI) and Conformity Index (CI). Normal tissue avoidance of OAR was evaluated with the D5 and V40. IBV at 5 Gy (V5), 10 Gy (V10), and 20 Gy (V20) were calculated. Results: The mean GTV95, CTV95, and PTV95 doses were significantly lower for IMRT plans. Target dose distribution was more inhomogeneous after IMRT planning and 3DCRTplans had significantly lower CI. The V40 and D5 values for OAR were significantly reduced in the IMRT plans .V5 was greater for IMRT than for f3DCRT planning (p < 0.05) and V20 was smaller for IMRT plans(p < 0.05). Conclusions: IMRT planning improves target conformity and decreases irradiation of the OAR at the expense of increased target heterogeneity. IMRT planning increases the IBV at 5 Gy or less but decreases the IBV at 20 Gy or more

Radioterapia estereotáctica

La radioterapia con técnica estereotáctica es una modalidad de radioterapia externa que utiliza un sistema de coordenadas tridimensionales independientes del paciente para la localización precisa de la lesión. También se caracteriza porque los haces de irradiación son altamente conformados, precisos y convergentes sobre la lesión que hacen posible la administración de dosis muy altas de radioterapia sin incrementar la irradiación de los órganos o estructuras sanas adyacentes. Cuando el procedimiento se realiza en una sesión de tratamiento se denomina radiocirugía y si se administra en varias sesiones se denomina radioterapia estereotáctica. Se precisa de sistemas de fijación e inmovilización del paciente especiales (guías o marcos estereotácticos) y dispositivos de radioterapia capaces de generar haces muy conformados (acelerador lineal, gammaknife, cyberknife, tomoterapia, ciclotrones). La radioterapia estereotáctica moderna utiliza marcas radioopacas intratumorales o sistemas de imágenes de TAC incluidos en el dispositivo de irradiación, que permiten una precisa localización de las lesiones móviles en cada sesión de tratamiento. Además, los avances tecnológicos hacen posible coordinar los movimientos de la lesión en la respiración con la unidad de radioterapia (gaiting y tracking) de forma que pueden estrecharse al máximo los márgenes y por lo tanto excluir un mayor volumen de tejido sano La radiocirugía está indicada principalmente en lesiones cerebrales benignas o malignas menores de 3-4 centímetros (malformaciones arteriovenosas, neurinomas, meningiomas, metástasis cerebrales) y la radioterapia estereotáctica se administra fundamentalmente en tumores de localización extracraneal que requieran una alta conformación y precisión como cáncer precoz de pulmón inoperable y metástasis hepáticas.Stereotactic radiotherapy is an external radiation modality that uses a system of three dimensional references independent of the patient to achive a precise location of the lesion. Stereotactic radiotherapy generate highly conformal, precisely focused radiation beams to administer very high doses of radiation without increasing the radiation to healthy surrounding organs or structures. When the procedure is carried out in one treatment session the procedure is termed radiosurgery, and when the treatment is administered in several fractions, the radiation modality is termed stereotactic radiotherapy. Special systems of patient immobilization (guides or stereotactic frames) are required together with radiotherapy devices capable of generating conformal beams (lineal accelerator, gammaknife, cyberknife, tomotherapy, cyclotrons). Modern stereotactic radiotherapy techniques employ intratumoural radio-opaque fiducials or CT image systems included in the irradiation device, which make possible a precise location of mobile lesions in each treatment session. Besides, technological advances permit breathing synchronized radiation (gating and tracking) for maximum tightening of margins and excluding a greater volume of healthy tissue. Radiosurgery is mainly indicated in benign or malign cerebral lesions less than 3-4 centimetres (arteriovenous malformations, neurinomas, meningiomas, cerebral metastases) and stereotactic radiotherapy is basically administered in tumours of extracraneal location that require high conformation and precision, such as inoperable early lung cancer and liver metastasis

Id1 and Id3 co-expression correlates with clinical outcome in stage III-N2 non-small cell lung cancer patients treated with definitive chemoradiotherapy

A correlation between Id1 and Id3 protein expression is observed. Id1 and Id3 co-expression seems associated with a poor clinical outcome in patients with locally advanced NSCLC treated with definitive chemoradiotherapy

Patterns and management of distant failure in locally advanced rectal cancer a cohort study

Purpose To determine the long-term outcomes of locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiation (CRT) and surgery, and to analyze the management and survival once distant failure has developed. Methods Data from LARC patients treated from 2000 to 2010 were retrospectively reviewed. CRT protocols were based on fluoropirimidines ± oxaliplatin. Follow-up consisted of physical examination, carcinoembryonic antigen levels, and chest-abdominal-pelvic CT scan. Results The study included 228 patients with a mean age of 59 years. Forty-eight (21.1 %) patients had distant recurrence and 6 patients (2.6 %) had local recurrence. Median follow-up was 49 months. The 5- and 10-year actuarial disease free survival was 75.3 and 65.0 %, respectively. The 5- and 10-year actuarial overall survival (OS) was 89.6 and 71.2 %, respectively. Patients were classified as having liver (14 patients) or lung (27 patients) relapse according to the organ firstly metastasized. The variables significantly associated by univariate Cox analysis to survival were the achievement of an R0 metastases resection and the Köhne risk index, while the metastatic site showed a statistical trend. By multivariate Cox analysis, the only variable associated with survival was a R0 resection (HR = 16.3, p < 0.001). Median OS for patients undergoing a R0 resection was 73 months (95 % CI 67.8–78.2) compared to 25 months (95 % CI 5.47–44.5) in those non-operated patients (p < 0.001). Conclusions Combined treatment for LARC obtains a 5-year OS rounding 90 %. Follow-up based on thoracic-abdominal CT scan allows an early diagnosis of metastatic lesions. Surgical resection of metastases, regardless of their location, greatly increases the patient’s survival rate

Repeated stereotactic radiosurgery for recurrent brain metastases: An effective strategy to control intracranial oligometastatic disease

Due to improvements in systemic therapies and longer survivals, cancer patients frequently present with re- current brain metastases (BM). The optimal therapeutic strategies for limited brain relapse remain undefined. We analyzed tumor control and survival in patients treated with salvage focal radiotherapy in our center. Thirty- three patients with 112 BM received salvage stereotactic radiosurgery (SRS) or fractionated stereotactic radio- therapy (FSRT) for local or regional recurrences. Local progression was observed in 11 BM (9.8 %). After 1 year, 72 % of patients were free of distant brain failure, and the 2-year overall survival (OS) was 37.7 %. No increase in toxicity or neurologically related deaths were observed. The 2- and 3-year whole brain radiation therapy free survival (WFS) rates were 92.9 % and 77.4 %, respectively. Hence, focal radiotherapy is a feasible salvage of recurrent BM in selected group of patients with limited brain disease, achieving a maintained intracranial control and less neurological toxicity

Hypofractionated radiation therapy and temozolomide in patients with glioblastoma and poor prognostic factors. A prospective, single-institution experience

Background: Hypofractionated radiation therapy is a feasible and safe treatment option in elderly and frail patients with glioblastoma. The aim of this study was to evaluate the effectiveness of hypofractionated radiation therapy with concurrent temozolomide in terms of feasibility and disease control in primary glioblastoma patients with poor prognostic factors other than advanced age, such as post-surgical neurological complications, high tumor burden, unresectable or multifocal lesions, and potential low treatment compliance due to social factors or rapidly progressive disease. Material and methods: GTV included the surgical cavity plus disease visible in T1WI-MRI, FLAIR-MRI and in the MET-uptake. The CTV was defined as the GTV plus 1.5-2 cm margin; the PTV was the CTV+0.3 cm margin. Forty, fourty-five, and fifty grays in 15 fractions were prescribed to 95% of PTV, CTV, and GTV, respectively. Treatment was delivered using IMRT or the VMAT technique. Simultaneously, 75 mg/m2/day of temozolomide were administered. Results: Between January 2010 and November 2017, we treated a total of 17 patients. The median age at diagnosis was 68-years; median KPS was 50-70%. MGMT-methylation status was negative in 5 patients, and 8 patients were IDH-wildtype. Eight of 18 patients were younger than 65-years. Median tumor volume was 26.95cc; median PTV volume was 322cc. Four lesions were unresectable; 6 patients underwent complete surgical resection. Median residual volume was 1.14cc. Progression-free survival was 60% at 6 months, 33% at 1-year and 13% at 2-years (median OS = 7 months). No acute grade 3-5 toxicities were documented. Symptomatic grade 3 radiation necrosis was observed in one patient. Conclusions: Patients with poor clinical factors other than advanced age can be selected for hypofractionated radiotherapy. The OS and PFS rates obtained in our series are similar to those in patients treated with standard fractionation, assuring good treatment adherence, low rates of toxicity and probable improved cost-effectiveness