How much survival benefit is necessary for breast cancer patients to opt for adjuvant chemotherapy? Results from a Chilean survey.

Background: Breast cancer (BC) is the leading cause of cancer death in Chilean women. Adjuvant chemotherapy decreases recurrence and death from BC. The recommendation to indicate chemotherapy is complex.

Intensity-modulated radiotherapy versus radical prostatectomy in patients with localized prostate cancer: long-term follow-up.

Background: The objective of this work was to assess the overall survival, cause-specific survival and biochemical failure-free survival of a contemporary cohort of patients with localized prostate cancer (PCa) treated with intensity-modulated radiation therapy (IMRT) or radical prostatectomy (RP).

Methods: We did a retrospective cohort study of our institution's registry of patients undergoing either IMRT or RP between January 1999 and March 2010, and assessed Prostate Specific Antigen (PSA), age at diagnosis, Gleason score, and digital rectal examination. Two groups were separated according to RP or IMRT treatment and these groups were in turn divided into risk groups according to the D'Amico classification.

Bone marrow stromal cells modulate mouse ENT1 activity and protect leukemia cells from cytarabine induced apoptosis.

Background: Despite a high response rate to chemotherapy, the majority of patients with acute myeloid leukemia (AML) are destined to relapse due to residual disease in the bone marrow (BM). The tumor microenvironment is increasingly being recognized as a critical factor in mediating cancer cell survival and drug resistance. In this study, we propose to identify mechanisms involved in the chemoprotection conferred by the BM stroma to leukemia cells.

[Postoperative radio-chemotherapy in locally advanced gastric cancer].

Background: Overall 5 years survival for surgically excised gastric cancer is 30%. Adjuvant treatment may improve the surgical results.

Aim: To assess treatment results and toxicity in patients with surgically excised gastric cancer, treated with adjuvant radiotherapy and concomitant continuous 5-Fluorouracil (5-FU).

Comparison between measured and calculated dynamic wedge dose distributions using the anisotropic analytic algorithm and pencil-beam convolution.

We used the two available calculation algorithms of the Varian Eclipse 7.3 three-dimensional (3D) treatment planning system (TPS), the anisotropic analytic algorithm (AAA) and pencil-beam convolution (PBC), to compare measured and calculated two-dimensional enhanced dynamic wedge (2D EDW) dose distributions, plus implementation of the dynamic wedge into the TPS. Measurements were carried out for a 6-MV photon beam produced with a Clinac 2300C/D linear accelerator equipped with EDW, using ionization chambers for beam axis measurements and films for dose distributions.

Commissioning and quality assurance for intensity modulated radiotherapy with dynamic multileaf collimator: experience of the Pontificia Universidad Católica de Chile.

The objective of this paper is to present our experience in the commissioning and quality assurance (QA) for intensity modulated radiotherapy (IMRT) using dynamic multileaf collimator (dMLC), sliding window technique. Using Varian equipment solution, the connectivity and operation between all IMRT chain components was checked. Then the following test were done: stability of leaf positioning and leaf speed, sensitivity to treatment interruptions (acceleration and deceleration), evaluation of standard field patterns, stability of dMLC output, segmental dose accuracy check, average leaf transmission, dosimetric leaf separation, effects of lateral disequilibrium between adjacent leaves in dose profiles and multiple carriage field verification.