MR-LINAC, a New Partner in Radiation Oncology: Current Landscape.

Technological advances in radiation oncology are oriented towards improving treatment precision and tumor control. Among these advances, magnetic-resonance-image-guided radiation therapy (MRgRT) stands out, with technological advances to deliver targeted treatments adapted to a tumor's anatomy on the day while minimizing incidental exposure to organs at risk, offering an unprecedented therapeutic advantage compared to X-ray-based IGRT delivery systems. This new technology changes the traditional workflow in radiation oncology and requires an evolution in team coordination to administer more precise treatments. Once implemented, it paves the way for newer indication for radiation therapy to safely deliver higher doses than ever before, with better preservation of healthy tissues to optimize patient outcomes. In this narrative review, we assess the technical aspects of the novel linear accelerators that can deliver MRgRT and summarize the available published experience to date, focusing on oncological results and future challenges.

Relación entre marcadores hematológicos y la respuesta patológica completa al tratamiento neoadyuvante en cáncer de recto localmente avanzado / Relationship between haematological markers and patological complete response to neoadjuvant treatment in locally advanced rectal cancer

INTRODUCCIÓN: Múltiples marcadores hematológicos de inflamación pueden tener relación con un peor pronóstico en los pacientes oncológicos. PROPÓSITO: Este estudio evaluó si los cambios en marcadores hematológicos antes y después del tratamiento quimio-radioterápico (QT-RT) en cáncer de recto pueden estar asociados con la respuesta patológica completa. MATERIAL Y MÉTODO: Se revisaron retrospectivamente las historias clínicas de 140 pacientes con cáncer de recto que recibieron tratamiento radioterápico neoadyuvante seguido de resección quirúrgica fueron revisados retrospectivamente. Se realizó analítica completa antes y después del tratamiento QT-RT. Se evaluaron leucocitos, hemoglobina, neutrófilos, linfocitos, monocitos, ratio neutrófilo-linfocitos (NLR), ratio plaqueta-linfocitos (PLR) y ratio linfocitos-monocitos (LMR). RESULTADOS: La respuesta patológica completa fue de 17,5%. Los marcadores hematológicos tuvieron una disminución significativa tras el tratamiento de QT-RT (p < 0,05), sin embargo en nuestro análisis no se relacionó con la respuesta patológica completa, salvo el PLR (p = 0,027). CONCLUSIÓN: Los marcadores hematológicos antres y después del tratamiento neoadyuvante no predicen la respuesta tumoral tras QT-RT en este estudio. Sin embargo una muestra mayor puede presentar resultados estadísticamente signifiacativos, especialmente con los monocitos

INTRODUCTION: Multiple haematological markers of inflammation might be related with poor prognosis in oncological patients. PURPOSE: This study evaluated whether changes of haematological markers before and after chemo-radiotherapy treatment in rectal cancer might be associated to pathological complete response. MATERIAL AND METHODS: Medical records of 140 patients with rectal cancer who received neoadjuvant radiotherapy followed by surgical resection were retrospectively review. Complete bloods counts (CBC) was measured days before and after period of RT. We assessed white blood cells count (WBC), hemoglobin levels (Hb), neutrophils count, lymphocytes count, monocytes count, neutrophil-to-lymphocye ratio (NLR), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR). RESULTS: The overall rate of pCR was 17,5%. Hematological markers had a statistically significant decrease after CRT treatment (p < 0,05), however in our analysis they do not predict complete pathological response. CONCLUSION: Haematological markers before and after neoadjuvant treatment do not predict tumor responses in this study. However, a larger sample can show statistically significant results, especially in monocytes ratio

Quimioradioterapia en cáncer de recto y tasa de respuesta patológica / Chemoradiotherapy in rectal cancer and pathological response

INTRODUCCIÓN: El tratamiento neoadyuvante con radioterapia y quimioterapia radiosensibilizante en el cáncer de recto localmente avanzado (CRLA) disminuye significativamente las tasas de recurrencia local. Por tanto el objetivo de este estudio es analizar la respuesta patológica completa (RPC) y parcial (RPP) tras el tratamiento neoadyuvante con quimioradioterapia en pacientes con CRLA. MATERIAL Y MÉTODO: Se realizó un estudio descriptivo, retrospectivo en pacientes con diagnóstico de CRLA desde enero 2016 a diciembre 2018 en el Servicio de Oncología-Radioterápica del Hospital Universitario La Paz. Se incluyeron 140 pacientes. Un grupo de pacientes (92,9%) se trató con radioterapia 3D conformada con una dosis de 45Gy sobre pelvis y una sobreimpresión de 5,4Gy sobre tumor primario y otro grupo (7,1%) se trató con radioterapia con técnica volumétrica y en arcoterapia (VMAT) guiado por imagen (IGRT) con una dosis de 53,7Gy en pelvis con sobreimpresión concurrente al tumor. La dosis de capecitabina oral fue de 850mg/m2 dos veces al día durante el tratamiento. Todos los pacientes fueron reevaluados con resonancia magnética (RM) post-neoadyuvancia. Los pacientes se operaron entre 6-8 semanas tras quimioradioterapia. RESULTADOS: Se obtuvo una RPC de 17,1% y RPP de 80,1% con una tasa global de downstaging de 31,8%. CONCLUSIÓN: Se concluye que la quimioradioterapia neoadyuvante es un tratamiento seguro con aceptables tasas de control local en los pacientes con CRLA

INTRODUCTION: Neoadjuvant treatment with radiotherapy and radiosensitizing chemotherapy in locally advanced rectal cancer (LARC) significantly decreases local recurrence rates. Therefore the objective of this study is to analyze the pathological complete response (PCR) and partial response (PPR) of neoadjuvant treatment with exclusive chemoradiotherapy in patients with locally advanced rectal cancer. MATERIAL AND METHOD: It has been made a study descriptive, retrospective in a cohort of patients with LARC in the January 2016 to December 2018 period in the Radiation-Oncology Department of Hospital Universitario La Paz. 140 patients were included. A group of patients (92,9%) received treatment with radiotherapy 3D conformed technique with a dose administered the 45 Gy on pelvis and a boost of 5,4 Gy on tumor and other group (7,1%) received treatment with volumetric archotherapy radiotherapy (VMAT) guided by image (IGRT) with a dose administered of 53,7% on pelvis with concurrent boost and. The dose of capecitabine was 850 mg/m2, twice a day during the treatment. The patients were re-evaluated with post-neoadjuvant MRI. Patients were operated 6 to 8 weeks post chemoradiotherapy. RESULTS: CPR was obtained of 17,1% and pPR of 80,1% with a global rate downstaging of 31,8%. CONCLUSION: It concludes that chemoradiotherapy neoadjuvant is a safe treatment with acceptable rates of local control in patients with LARC

Segmentation improvement through denoising of PET images with 3D-context modelling in wavelet domain.

Positron emission tomography (PET) images have been incorporated into the radiotherapy process as a powerful tool to assist in the contouring of lesions, leading to the emergence of a broad spectrum of automatic segmentation schemes for PET images (PET-AS). However, not all proposed PET-AS algorithms take into consideration the previous steps of image preparation. PET image noise has been shown to be one of the most relevant affecting factors in segmentation tasks. This study demonstrates a nonlinear filtering method based on spatially adaptive wavelet shrinkage using three-dimensional context modelling that considers the correlation of each voxel with its neighbours. Using this noise reduction method, excellent edge conservation properties are obtained. To evaluate the influence in the segmentation schemes of this filter, it was compared with a set of Gaussian filters (the most conventional) and with two previously optimised edge-preserving filters. Five segmentation schemes were used (most commonly implemented in commercial software): fixed thresholding, adaptive thresholding, watershed, adaptive region growing and affinity propagation clustering. Segmentation results were evaluated using the Dice similarity coefficient and classification error. A simple metric was also included to improve the characterisation of the filters used for induced blurring evaluation, based on the measurement of the average edge width. The proposed noise reduction procedure improves the results of segmentation throughout the performed settings and was shown to be more stable in low-contrast and high-noise conditions. Thus, the capacity of the segmentation method is reinforced by the denoising plan used.

Dosimetric evaluation of 3-D conformal and intensity-modulated radiotherapy for breast cancer after conservative surgery.

BACKGROUND: Breast cancers are becoming more frequently diagnosed at early stages with improved long term outcomes. Late normal tissue complications induced by radiotherapy must be avoided with new breast radiotherapy techniques being developed. The aim of the study was to compare dosimetric parameters of planning target volume (PTV) and organs at risk between conformal (CRT) and intensity-modulated radiation therapy (IMRT) after breast-conserving surgery. MATERIALS AND METHODS: A total of 20 patients with early stage left breast cancer received adjuvant radiotherapy after conservative surgery, 10 by 3D-CRT and 10 by IMRT, with a dose of 50 Gy in 25 sessions. Plans were compared according to dose-volume histogram analyses in terms of PTV homogeneity and conformity indices as well as organs at risk dose and volume parameters. RESULTS: The HI and CI of PTV showed no difference between 3D-CRT and IMRT, V95 gave 9.8% coverage for 3D-CRT versus 99% for IMRT, V107 volumes were recorded 11% and 1.3%, respectively. Tangential beam IMRT increased volume of ipsilateral lung V5 average of 90%, ipsilateral V20 lung volume was 13%, 19% with IMRT and 3D-CRT respectively. Patients treated with IMRT, heart volume encompassed by 60% isodose (30 Gy) reduced by average 42% (4% versus 7% with 3D-CRT), mean heart dose by average 35% (495 cGy versus 1400 cGy with 3D-CRT). In IMRT minimal heart dose average is 356 cGy versus 90 cGy in 3D-CRT. CONCLUSIONS: IMRT reduces irradiated volumes of heart and ipsilateral lung in high-dose areas but increases irradiated volumes in low-dose areas in breast cancer patients treated on the left side.

Case of lung carcinoma revealed by vulvar metastasis associated with systemic scleroderma and literature review.

UNLABELLED: Metastatic carcinoma to the vulva is rare, where the incidence is believed to be between 5% and 8%. However, malignant tumors have been described in 3-11% of systemic scleroderma (SSc) cases. We report the case of one patient, a 66-year-old postmenopausal woman, whose medical history was marked with rheumatic vascular disease (systemic scleroderma) since 1993 without muscular, renal, cardiac lesions or HTA (arterial hypertension) and without tobacco history. The woman presented with a new vulvar mass of the right labia in December 2011 that had progressively enlarged in size. CT scan of the abdominopelvic region demonstrated a lobular mass of the right labia with central necrosis, 7 cm on the wide axis, and the rectum and the vaginal wall were normal. No inguinal or iliac lymphadenopathy was noted. An outpatient excisional biopsy revealed a poorly differentiated malignant tumor suggestive of carcinoma. IHC: CK7+/CK20-, estrogen receptors-, AE 1 AE 3+, vimentine+, S100-, Desmina-, CD34-, KI 67: 20%. The thoracic scan revealed a large mass of 4 cm × 3 cm in the right lung base with right paratracheal lymphadenopathy 3 cm × 2 cm. A bronchoscopy revealed discrete stenosis of the mediastinal portion of the right bronchial tree. The bronchial biopsy also revealed poorly differentiated lung carcinoma, non-small cell, which was identical with the vulvar tumor. CONCLUSION: The presence of the single lung lesion with only one lymphadenopathy paratracheal with pathological and immunohistochemical (IHC) profile similar to the vulvar lesion, and a particular IHC profile with CK7+ and CK20- was detected - that is more specific to the primitive pulmonary cancer, and the presence of only one sarcoma marker vementine+, desmine and actine-. Also the presence of KI 67: 20%, predicted the proliferative and great metastatic power of the lung tumor was observed. Additionally, lung cancer was the most frequent type and may develop in scleroderma as reported in most studies. This allows to conclude for primitive lung carcinoma revealed with vulvar metastasis after elimination of the possibility of vulvar sarcoma. The patient was treated by chemotherapy (Taxol/Platin) with partial response from the lung after 3 cycles and palliative radiotherapy in the vulva with a good response. This case described primary lung carcinoma associated with scleroderma, revealed by a vulvar metastasis, which may be related to the aggressiveness of lung cancer when the lung fibrosis follow-up is not performed well to detect early the development of lung tumors in the patient with systemic scleroderma.

Le carcinome métastatique de la vulve est rare, son incidence est estimé entre 5% et 8%. D'autre part les tumeurs malignes ont été décrite dans 3-11% de la sclérodermie systémique (ScS) cas. Nous rapportons le cas d'une patiente, 66 ans ménopausée, ses antécédents médicaux ont été marquée par une maladie vasculaire rhumatismale (sclérodermie systémique) depuis 1993 sans atteintes musculaires, rénales, cardiaques ou HTA (hypertension artérielle) et sans histoiretabagique. La patiente a représenté une masse vulvaire de la lèvre droite de la vulve en Décembre 2011, qui avait progressivement augmenté de taille. La tomodensitométrie abdomino-pelvienne a montré une masse lobulaire de la lèvre droite avec une nécrose centrale, 7 cm l'axe le plus large, le rectum et la paroi vaginale étaient normale. Aucune adénopathie inguinale ou iliaque a été noté. Une biopsie-exérèse ambulatoire a révélé une tumeur maligne peu différenciée suggérant un cancer. IHC: CK7+/CK20−, récepteurs des oestrogènes−, AE 1 AE 3+, vimentine+, S100−, Desmina−, CD34−, KI 67: 20%. Le scanner thoracique a révélé une grosse masse de 4 × 3 cm au niveau de la base du poumon droit avec lymphadénopathie paratrachéaux droite de 3 × 2 cm. Une bronchoscopie a révélé: une sténose de la partie médiastinale de l'arbre bronchique droit. Et la biopsie bronchique a révélé un carcinome du poumon peu différencié, non à petites cellules, ce qui était identique à la tumeur vulvaire. CONCLUSION: La présence de la lésion pulmonaire unique avec un seul lymphadénopathie paratrachéal avec à l'anatomopathologie et immunohistochimie (IHC) un profil similaire à la lésion vulvaire, et le profil IHC particulier avec CK7+ et CK20− qui sont plus spécifiques au cancer primitif pulmonaire, et la présence d'un seul marqueur de sarcome vementine+, desmine et actine−. Aussi la présence de KI 67: 20%, qui prédit le grand pouvoir prolifératif et métastatique de la tumeur pulmonaire. En plus le cancer du poumon est le type de cancer le plus fréquent qui peut se développer chez les patients sclérodermiques dans la plupart des études. Ces arguments ont permis de conclure au carcinome primitif du poumon révélé par des métastases vulvaire après élimination de la possibilité de sarcome vulvaire. Traités par chimiothérapie (Taxol/Platin) avec une réponse partielle au niveau du poumon après 3 cycles et radiothérapie palliative de la vulve avec une bonne réponse. Ce cas décrit un carcinome primitif du poumon associé à une sclérodermie systémique, révélé par une métastase vulvaire, qui peut être lié à l'agressivité du cancer pulmonaire lorsque le bon suivi de la fibrose pulmonaire n'est pas effectué pour le dépistage précoce des tumeurs pulmonaires développées chez des patients suivis pour sclérodermie systémique.

Epidemiology and prevalence of oropharyngeal candidiasis in Spanish patients with head and neck tumors undergoing radiotherapy treatment alone or in combination with chemotherapy.

OBJECTIVE: To describe the oropharyngeal candidiasis (OPC) prevalence in Spanish patients with head and neck cancer undergoing radiotherapy, alone or combined with chemotherapy. Secondary objectives were to determine the prevalence of Candida species colonization, and to explore whether different Candida species colonizing the oral cavity and the treatment were associated with a higher prevalence of OPC. METHODS: This is an observational, cross-sectional, multicentre study, conducted in Spanish radiation oncology units. Patients were diagnosed with head and neck cancer and started a radiotherapy treatment alone or combined with chemotherapy at the moment of their inclusion (N = 92). RESULTS: The OPC prevalence was 26 %. The identification of colonizing pathogens was performed in 49 patients, and Candida albicans was the dominant yeast (69 %), while non-albicans Candida was only found in 15 patients (31 %). Patients with C. albicans colonization had a significant higher prevalence of OPC compared to patients colonized by non-albicans Candida (p = 0.0273), but no difference was found regarding the OPC prevalence in patients receiving only radiotherapy compared to patients with both radiotherapy and chemotherapy treatments. CONCLUSIONS: Our data represent a step further in the knowledge of Candida species present in Spanish patients with head and neck tumors under radiation therapy. This is an essential step to manage the prophylaxis and treatment of OPC, since it might lead to severe clinical complications causing treatment interruption and, thus, representing a reduction in anti-tumor efficacy.

Prevention of urinary tract infections in palliative radiation for vertebral metastasis and spinal compression: a pilot study in 71 patients.

PURPOSE: To assess the impact of bladder instillations of hyaluronic acid (HA) on the prevalence of urinary tract infection (UTI) in patients receiving emergency radiotherapy for metastatic spinal cord compression. METHODS AND MATERIALS: Patients were recruited consecutively at one center and assigned to usual care (UC) (n = 34, mean age 62.2 years) or UC with once-weekly HA instillation (UC + HA) (Cystistat: 40 mg in 50 mL phosphate-buffered saline) (n = 37; mean age, 63.1 years). All patients had an indwelling catheter and received radiotherapy. UTI status was assessed at baseline and during hospitalization. RESULTS: At baseline, patient groups were comparable, except for the prevalence of UTI at baseline, which was 11.8% and 0% in the UC and UC + HA patients, respectively (p = 0.0477). During hospitalization, 76.5% (vs. 11.8% at baseline, p < 0.0001) of the UC patients had a UTI compared with 13.5% (vs. 0% at baseline, p = 0.0541) of the UC + HA patients (p < 0.0001). Both groups were hospitalized for similar periods (19.8 days [UC] vs. 18.5 days, p = 0.4769) and received equivalent radiotherapy sessions (4.6 [UC] vs. 5.8 sessions, p = 0.2368). CONCLUSIONS: Patients receiving UC + HA had a 5.7-fold decrease in UTI prevalence over the hospitalization period compared to UC patients, suggesting that bladder instillations of HA effectively prevent UTI in patients with indwelling catheters receiving radiotherapy for nerve compression.

Heparin and low molecular weight heparin decrease nitric oxide production by human polymorphonuclear cells

Background. Heparin and heparin derivatives with low anticoagulant activity exhibit a wide spectrum of biological functions affecting adhesion, activation and trafficking of luekocytes. Methods. We investigated the in vitro effect of heparin and low molecular weight heparin derivative (LMWH) on nitric oxide (NO) production by human polymorphonuclear leukocytes (PMN). Results. N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated NO production was significantly decreased by heparin at doses of 0.5 and 5 µg/mL, while LMWH was only effective at doses of 50 and 200 µg/mL by means of a mechanism not related to No synthase (NOS) activity. Conclusions. These results support the hypothesis that heparin and LMWH derivatives may offet therapeutic benefit for inflammatory diseases where No plays a protagonic role