Sequential magnetic resonance imaging of cervical cancer: the predictive value of absolute tumor volume and regression ratio measured before, during, and after radiation therapy.

Background: The objectives of this study were to investigate outcome prediction by measuring absolute tumor volume and regression ratios using serial magnetic resonance imaging (MRI) during radiation therapy (RT) for cervical cancer and to develop algorithms capable of identifying patients at risk of a poor therapeutic outcome.

Methods: Eighty patients with stage IB2 through IVA cervical cancer underwent 4 MRI scans: before RT (MRI1), during RT at 2 to 2.5 weeks (MRI2) at 4 to 5 weeks (MRI3), and 1 to 2 months after RT (MRI4).

Predicting outcomes in cervical cancer: a kinetic model of tumor regression during radiation therapy.

Applications of mathematical modeling can improve outcome predictions of cancer therapy. Here we present a kinetic model incorporating effects of radiosensitivity, tumor repopulation, and dead-cell resolving on the analysis of tumor volume regression data of 80 cervical cancer patients (stages 1B2-IVA) who underwent radiation therapy. Regression rates and derived model parameters correlated significantly with clinical outcome (P < 0.

Ultra-early predictive assay for treatment failure using functional magnetic resonance imaging and clinical prognostic parameters in cervical cancer.

Background: The authors prospectively evaluated magnetic resonance imaging (MRI) parameters quantifying heterogeneous perfusion pattern and residual tumor volume early during treatment in cervical cancer, and compared their predictive power for primary tumor recurrence and cancer death with the standard clinical prognostic factors. A novel approach of augmenting the predictive power of clinical prognostic factors with MRI parameters was assessed.

Methods: Sixty-two cervical cancer patients underwent dynamic contrast-enhanced (DCE) MRI before and during early radiation/chemotherapy (2-2.

Predicting control of primary tumor and survival by DCE MRI during early therapy in cervical cancer.

Purpose: To assess the early predictive power of MRI perfusion and volume parameters, during early treatment of cervical cancer, for primary tumor control and disease-free-survival.

Materials And Methods: Three MRI examinations were obtained in 101 patients before and during therapy (at 2-2.5 and 4-5 weeks) for serial dynamic contrast enhanced (DCE) perfusion MRI and 3-dimensional tumor volume measurement.

Translating response during therapy into ultimate treatment outcome: a personalized 4-dimensional MRI tumor volumetric regression approach in cervical cancer.

Purpose: To assess individual volumetric tumor regression pattern in cervical cancer during therapy using serial four-dimensional MRI and to define the regression parameters' prognostic value validated with local control and survival correlation.

Methods And Materials: One hundred and fifteen patients with Stage IB(2)-IVA cervical cancer treated with radiation therapy (RT) underwent serial MRI before (MRI 1) and during RT, at 2-2.5 weeks (MRI 2, at 20-25 Gy), and at 4-5 weeks (MRI 3, at 40-50 Gy).

Synergistic effects of hemoglobin and tumor perfusion on tumor control and survival in cervical cancer.

Purpose: The tumor oxygenation status is likely influenced by two major factors: local tumor blood supply (tumor perfusion) and its systemic oxygen carrier, hemoglobin (Hgb). Each has been independently shown to affect the radiotherapy (RT) outcome in cervical cancer. This study assessed the effect of local tumor perfusion, systemic Hgb levels, and their combination on the treatment outcome in cervical cancer.

CNS germinomas: what is the best treatment strategy?

CNS germ cell tumors are rare primary brain malignancies. Germinomas comprise approximately two-thirds of CNS germ cell tumors. Owing to their radiosensitivity, radiotherapy has been used to treat patients with CNS germinomas, with favorable treatment outcomes.

Hypofractionation regimens for stereotactic radiotherapy for large brain tumors.

Purpose: To investigate equivalent regimens for hypofractionated stereotactic radiotherapy (HSRT) for brain tumor treatment and to provide dose-escalation guidance to maximize the tumor control within the normal brain tolerance.

Methods And Materials: The linear-quadratic model, including the effect of nonuniform dose distributions, was used to evaluate the HSRT regimens. The alpha/beta ratio was estimated using the Gammaknife stereotactic radiosurgery (GKSRS) and whole-brain radiotherapy experience for large brain tumors.

What is the best adjuvant treatment for very young patients with medulloblastoma?

The standard treatment for medulloblastoma is surgery followed by adjuvant chemotherapy and external beam radiotherapy to the craniospinal axis and posterior fossa. However, in very young children, craniospinal irradiation has a more significant detrimental effect in terms of neurocognitive function and growth. This article reviews the different strategies used for very young patients with medulloblastoma.

Serial therapy-induced changes in tumor shape in cervical cancer and their impact on assessing tumor volume and treatment response.

Objective: The purpose of this study was to evaluate the patterns and distribution of tumor shape and its temporal change during radiation therapy (RT) in cervical cancer and the effect of tumor configuration changes on the correlation between region of interest (ROI)-based and diameter-based MRI tumor measurement.

Materials And Methods: Serial MRI examinations (T1-weighted and T2-weighted images) were performed in 60 patients (age range, 29-75 years; mean, 53.3 years) with advanced cervical cancer (stages IB2-IVB/recurrent) who were treated with RT at four time points: start of RT, during RT (at 2-2.

Interobserver variation in cervical cancer tumor delineation for image-based radiotherapy planning among and within different specialties.

Radiation therapy for cervical cancer involves a team of specialists, including diagnostic radiologists (DRs), radiation oncologists (ROs), and medical physicists (MPs), to optimize imaging-based radiation therapy planning. The purpose of the study was to investigate the interobserver variations in tumor delineation on MR images of cervical cancer within the same and among different specialties. Twenty MRI cervical cancer studies were independently reviewed by two DRs, two ROs, and two MPs.

Brachytherapy management of the retroverted uterus using ultrasound-guided implant applicator placement.

Purpose: Patients with a retroverted uterus present a dilemma for brachytherapy in gynecologic malignancies because of the challenges of the procedure and the risk of uterine perforation. The purpose of this study was to evaluate the efficacy and outcome of ultrasound-guided brachytherapy applicator placement and intraoperative uterine anteversion in patients with gynecologic malignancies, who have a retroverted uterus.

Methods And Materials: Thirty-three brachytherapy insertions were performed in 18 patients with retroverted uterus (cervical cancer, 17; vaginal cancer, 1).

Does prone positioning reduce small bowel dose in pelvic radiation with intensity-modulated radiotherapy for gynecologic cancer?

Purpose: Intensity-modulated radiotherapy (IMRT) has been shown to reduce the radiation dose to small bowel in pelvic RT in gynecology patients. Prone positioning has also been used to decrease small bowel dose by displacement of small bowel from the RT field in these patients. The purpose of this study was to determine whether the combination of both IMRT and prone positioning on a belly board can reduce small bowel dose further in gynecologic cancer patients undergoing pelvic RT.

Pitfalls of radiation survey after brachytherapy implant removal preceding Tl-201 study.

An unexpected elevated postimplant radiation survey is described in an elderly patient with an interstitial low-dose-rate iridium-192 (Ir-192) needle implant for endometrial cancer. The elevated activity was related to prolonged clearance of Tl-201 from a cardiac study that had been performed 7 days earlier. The Tl-201 accumulated in the soft tissue, particularly the colon, resulting in increased survey readings over the abdomen and raising concern that an Ir-192 source remained within the patient.