Timing of Surgery and Social Determinants of Health Related to Pathologic Complete Response after Total Neoadjuvant Therapy for Rectal Adenocarcinoma: Retrospective Study of National Cancer Database.

Total neoadjuvant therapy (TNT) for rectal adenocarcinoma (RAC) involves multi-agent chemotherapy and radiation before definitive surgery. Previous studies of the rest period (time between radiation and surgery) and pathologic complete response (pCR) have produced mixed results. The objective of this study was to evaluate the relationship between the rest period and pCR.

Volumetric Modulated Arc Therapy Enabled Total Body Irradiation (VMAT-TBI): Six-year Clinical Experience and Treatment Outcomes.

Total body irradiation is an important part of the conditioning regimens frequently used to prepare patients for allogeneic hematopoietic stem cell transplantation (SCT). Volumetric-modulated arc therapy enabled total body irradiation (VMAT-TBI), an alternative to conventional TBI (cTBI), is a novel radiotherapy treatment technique that has been implemented and investigated in our institution. The purpose of this study is to (1) report our six-year clinical experience in terms of treatment planning strategy and delivery time and (2) evaluate the clinical outcomes and toxicities in our cohort of patients treated with VMAT-TBI.

Review of Biological Effects of Acute and Chronic Radiation Exposure on .

Knowledge regarding complex radiation responses in biological systems can be enhanced using genetically amenable model organisms. In this manuscript, we reviewed the use of the nematode, (), as a model organism to investigate radiation's biological effects. Diverse types of experiments were conducted on , using acute and chronic exposure to different ionizing radiation types, and to assess various biological responses.

Effect of chemoradiation on the size of the thyroid gland.

We aimed to evaluate changes in thyroid gland size during the treatment of malignancies outside the head and neck with chemotherapy and/or external beam radiation. We performed a retrospective review of records of adult patients treated at our institution with external beam radiation to the chest and/or chemotherapy with taxanes, alkylating agents, and/or a topoisomerase II inhibitor. Neck and chest computed tomography (CT) images were used to calculate thyroid gland volume before and after therapy, using Vitrea software or the volumetric ellipsoid method.

Margin-Free Fractionated Stereotactic Radiation Therapy for Pediatric Brain Tumors.

Purpose: Conventional radiation therapy (RT) to pediatric brain tumors exposes a large volume of normal brain to unwarranted radiation causing late toxicity. We hypothesized that in well demarcated pediatric tumors lacking microscopic extensions, fractionated stereotactic RT (SRT), without target volume expansions, can reduce high dose normal tissue irradiation without affecting local control.

Methods And Materials: Between 2008 and 2017, 52 pediatric patients with brain tumors were treated using the CyberKnife (CK) with SRT in 180 to 200 cGy per fraction.

Phase II trial of hippocampal-sparing whole brain irradiation with simultaneous integrated boost for metastatic cancer.

Background: Advanced radiotherapeutic treatment techniques limit the cognitive morbidity associated with whole-brain radiotherapy (WBRT) for brain metastasis through avoidance of hippocampal structures. However, achieving durable intracranial control remains challenging.

Methods: We conducted a single-institution single-arm phase II trial of hippocampal-sparing whole brain irradiation with simultaneous integrated boost (HSIB-WBRT) to metastatic deposits in adult patients with brain metastasis.

A Phase 2 Clinical Trial of SABR Followed by Immediate Vertebroplasty for Spine Metastases.

Purpose: To determine the pain response and prevention of vertebral compression fractures (VCFs) after single-fraction stereotactic ablative radiation therapy (SABR) in conjunction with immediate vertebroplasty for spine metastases.

Methods And Materials: Patients with localized spine metastases free from VCF associated with loss of vertebral height with a pain score ≥4 using the visual analog scale were enrolled. Spine SABR was performed with 20 Gy delivered to the gross disease and 14 Gy to the contiguous bone marrow in a single fraction.

Multistage stereotactic radiosurgery for large cerebral arteriovenous malformations using the Gamma Knife platform.

Purpose: Radiosurgery is an established technique to treat cerebral arteriovenous malformations (AVMs). Obliteration of larger AVMs (> 10-15 cm or diameter > 3 cm) in a single session is challenging with current radiosurgery platforms due to toxicity. We present a novel technique of multistage stereotactic radiosurgery (SRS) for large intracranial arteriovenous malformations (AVM) using the Gamma Knife system.

Phantom-to-clinic development of hypofractionated stereotactic body radiotherapy for early-stage glottic laryngeal cancer.

The purpose of this study was to commission and clinically test a robotic stereotactic delivery system (CyberKnife, Sunnyvale, CA) to treat early-stage glottic laryngeal cancer. We enrolled 15 patients with cTis-T2N0M0 carcinoma of the glottic larynx onto an institutional review board (IRB)-approved clinical trial. Stereotactic body radiotherapy (SBRT) plans prescribed 45 Gy/10 fractions to the involved hemilarynx.

Automatic metastatic brain tumor segmentation for stereotactic radiosurgery applications.

The objective of this study is to develop an automatic segmentation strategy for efficient and accurate metastatic brain tumor delineation on contrast-enhanced T1-weighted (T1c) magnetic resonance images (MRI) for stereotactic radiosurgery (SRS) applications. The proposed four-step automatic brain metastases segmentation strategy is comprised of pre-processing, initial contouring, contour evolution, and contour triage. First, T1c brain images are preprocessed to remove the skull.

Remote location interstitial brachytherapy with patient stabilization and subsequent transport to an outpatient center for treatment is safe and effective for the treatment of gynecologic malignancies.

Purpose: Interstitial brachytherapy is an essential component of definitive treatment for locally advanced gynecological malignancies. Although many outpatient centers are capable of delivering the radiation component of brachytherapy, they are not associated with an operative center for implant placement, limiting the ability to deliver appropriate care. In this study, we report on our experience with noncolocated implant placement and radiation delivery, and the impact of patient stabilization improvements on patient safety.

Pre-treatment factors associated with detecting additional brain metastases at stereotactic radiosurgery.

The number of brain metastases identified on diagnostic magnetic resonance imaging (MRI) is a key factor in consideration of stereotactic radiosurgery (SRS). However, additional lesions are often detected on high-resolution SRS-planning MRI. We investigated pre-treatment clinical characteristics that are associated with finding additional metastases at SRS.

Stereotactic radiation therapy of renal cancer inferior vena cava tumor thrombus.

Renal Cell Carcinoma (RCC) is a common malignancy world-wide that is rising in incidence. Up to 10% of RCC patients present with inferior vena cava (IVC) tumor thrombus (IVC-TT). Although surgery is the only treatment with proven efficacy for IVC-TT, the surgical management of advanced (level III and IV) IVC-TT is difficult with high morbidity and mortality, and offers a poor survival outcome.

Advanced MR imaging of peripheral nerve sheath tumors including diffusion imaging.

Peripheral nerve sheath tumors (PNSTs) are neoplasms derived from neoplastic Schwann cells or their precursors. Whereas benign PNSTs are relatively common and considered curable lesions, their malignant counterparts are rare but highly aggressive and require early diagnosis and treatment. MR imaging has been the modality of choice for noninvasive evaluation of PNSTs.

Phase II trial of stereotactic body radiation therapy combined with erlotinib for patients with limited but progressive metastatic non-small-cell lung cancer.

Purpose: Patients with stage IV non-small-cell lung cancer (NSCLC) who progress through first-line therapy have poor progression-free survival (PFS) and overall survival (OS), most commonly failing in original sites of gross disease. Cytoreduction with stereotactic body radiation therapy (SBRT) may help systemic agents delay relapse.

Patients And Methods: Patients in our single arm phase II study had stage IV NSCLC with no more than six sites of extracranial disease who failed early systemic chemotherapy and were able to receive SBRT and concurrent erlotinib until disease progression.

A retrospective analysis of tumor volumetric responses to five-fraction stereotactic radiotherapy for paragangliomas of the head and neck (glomus tumors).

Background: Skull base paragangliomas (SBP) are locally expansile tumors that can be treated with stereotactic radiotherapy with favorable results. This report describes the results of 31 patients with SBP treated with CyberKnife radiotherapy delivering a total dose of 25 Gray in five fractions.

Methods: All patients treated with five-fraction CyberKnife radiotherapy at a single institution were identified between 2007 and 2013.

Total skin electron beam radiation in a pediatric patient with leukemia cutis: a case report.

Leukemia cutis, a form of extramedullary leukemia involving the skin, is a poor prognostic marker and indicator of imminent hematologic relapse and chemotherapeutic resistance in leukemia patients. Although total skin electron beam radiotherapy is commonly recommended for patients with leukemia cutis, its role and effectiveness remains unclear. Here we describe a 19-month-old infant with acute myelogenous leukemia first diagnosed at 15 months of age.

Dosimetric and motion analysis of margin-intensive therapy by stereotactic ablative radiotherapy for resectable pancreatic cancer.

Background: The retroperitoneal margin is a common site of positive surgical margins in patients with resectable pancreatic cancer. Preoperative margin-intensive therapy (MIT) involves delivery of a single high dose of ablative radiotherapy (30 Gy) focused on this surgically inaccessible margin, utilizing stereotactic techniques in an effort to reduce local failure following surgery. In this study, we investigated the motion of regional organs at risk (OAR) utilizing 4DCT, evaluated the dosimetric effects of abdominal compression (AC) to reduce regional motion, and compared various planning techniques to optimize MIT.

Stereotactic body radiation therapy for thoracic cancers: recommendations for patient selection, setup and therapy.

Advanced technologies have facilitated the development of stereotactic body radiation therapy (SBRT) programs capable of delivering ablative radiation doses for the control of lung cancers. To date, experience with these programs has been highly favorable, as reflected in the results of careful clinical trials. The medically inoperable lung cancer patient, lacking more effective options, has served as the initial clinical base to test SBRT; the therapeutic outcomes have confirmed a significant role for this approach.

Stereotactic body radiation therapy: normal tissue and tumor control effects with large dose per fraction.

Stereotactic body radiation therapy (SBRT) is a potent noninvasive means of administering high radiation doses to demarcated tumor deposits in extracranial locations. The treatments use image guidance and related advanced treatment delivery technologies for the purpose of escalating the radiation dose to the tumor, while sharply minimizing the radiation doses to surrounding normal tissues. The local tumor control outcomes for SBRT have been higher than any previously published for the radiotherapy of frequently occurring carcinomas.

Phase I dose-escalation study of stereotactic body radiotherapy in patients with hepatic metastases.

Purpose: To identify a tolerable and effective dose for 5-fraction stereotactic body radiotherapy for hepatic metastases.

Methods: Patients were enrolled onto three dose-escalation cohorts: 30 Gy in 3 fractions, 50 Gy in 5 fractions, and 60 Gy in 5 fractions. Eligible patients had one to five hepatic metastases, ability to spare a critical hepatic volume (volume receiving <21 Gy) of 700 ml, adequate baseline hepatic function, no concurrent antineoplastic therapy, and a Karnofsky performance score of ≥60.

Four-dimensional computed tomography scan analysis of tumor and organ motion at varying levels of abdominal compression during stereotactic treatment of lung and liver.

Purpose: To investigate the effectiveness of different abdominal compression levels on tumor and organ motion during stereotactic body radiotherapy of lower lobe lung and liver tumors using four-dimensional (4D)-CT scan analysis.

Methods And Materials: Three 4D-CT scans were acquired for 10 patients first using with no compression and then compared with two different levels of abdominal compression. The position of the tumor and various organs were defined at the peak inspiratory and expiratory phases and compared to determine the maximum motion.

Stereotactic body radiation therapy for early-stage non-small-cell lung cancer.

Stereotactic body radiation therapy has emerged as a novel oncologic therapy and experience with the use of stereotactic body radiation therapy for the treatment of early-stage non-small-cell lung cancer has grown over the last 10 years. This article reviews the radiobiologic, physical/technical and clinical aspects of stereotactic body radiation therapy for early-stage non-small-cell lung cancer. The literature is also reviewed.

Role of stereotactic radiosurgery and fractionated stereotactic radiotherapy in pediatric brain tumors.

Brain tumors are the most common solid tumor in childhood. Surgery and/or fractionated radiotherapy are conventional treatment modalities. Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) are advanced radiation therapy techniques that have been frequently used in adults with brain tumors but they are less frequently used in pediatric patients.

Lung cancer: a model for implementing stereotactic body radiation therapy into practice.

Primary and metastatic tumors to the lung have been principle targets for the noninvasive high-doseper- fraction treatment programs now officially called stereotactic body radiation therapy (SBRT). Highly focused treatment delivery to moving lung targets requires accurate assessment of tumor position throughout the respiratory cycle. Measures to account for this motion, either by tracking (chasing), gating, or inhibition (breath hold and abdominal compression) must be employed in order to avoid large margins of error that would expose uninvolved normal tissues.