Longer time to testosterone recovery impacts favorably on outcomes for prostate cancer following androgen deprivation and radiotherapy.

PURPOSE: To evaluate the impact of sustained hypogonadism after androgen deprivation therapy (ADT) associated with radiotherapy in prostate cancer (PCa) patients with biochemical relapse-free survival (bRFS). METHODS: A retrospective cohort analysis of 213 consecutive PCa patients referred for radiotherapy plus ADT was carried out. Follow-up times including time to testosterone recovery (TTR) and bRFS were calculated from the end of ADT. Univariate and multivariate Cox regression analyses predicting bRFS were used. The optimal cutoffs for TTR and duration of ADT were determined using the maximally selected rank statistics (MSRS). RESULTS: After a median follow-up of 104 months, 18 patients relapsed among those who had recovered testosterone levels and 9 among those who did not. Median ADT duration was 36 months. The optimal cutoff for TTR was determined using MSRS. TTR >48 months was significantly associated with better bRFS (logrank, p < 0.0027). Five-year bRFS was 100% for >48 months vs. 85% for <48 months. TTR was the only significant variable for bRFS in multivariate Cox analysis. CONCLUSION: Our data show an association between longer TTR and bRFS values among PCa patients treated with ADT.

Biologically effective dose (BED) value lower than 120 Gy improve outcomes in lung SBRT.

BACKGROUND: Lung SBRT has a well-defined role in the treatment of patients with early stage non-small cell lung cancer who are not surgical candidates or refuse surgery. Biologically effective dose (BED) of greater than or equal to 100 Gy has been recommended. However, optimal fractionation remains unclear. Our objective was analyze patients treated with lung SBRT in our institution and evaluate outcomes according prescribed dose. PATIENTS AND METHODS: One hundred nine patients with early non-small cell lung cancer and treated with lung SBRT were retrospectively analyzed. Differences between dose received, local control, and survival were evaluated. For comparison of BEDs, the prescribed dose for SBRT was stratified according to two groups: high (BED > 120 Gy) and low (BED < 120 Gy). RESULTS: A relationship between mortality and total dose (54.7 Gy ± 4.8) was observed. Significantly worse survival was observed for patients with higher total doses (p < 0.003). It was found that patients receiving BED > 120 had increased mortality compared to patients receiving BED < 120 (p = 0.021). It was observed mean dose/fraction 12.6 Gy/f was a protective factor and decreased the probability of death. CONCLUSION: Our data suggest that mean total dose lower 54 and a calculated BED < 120 Gy is the optimal. Further prospective data are needed to confirm these results and determine the optimal dose fractionation scheme as a function of tumor size and location of volume.

Dosimetric comparison of volumetric-arc therapy versus sliding window intensity-modulated radiotherapy in postoperative treatment for primary soft tissue sarcoma of the thigh.

AIM: Intensity-modulated radiotherapy (IMRT) has demonstrated improved local control in extremity soft tissue sarcoma (STS) after limb-sparing surgery compared with three-dimensional conformal radiation therapy. Our purpose was to evaluate sliding-window IMRT (SW-IMRT) and volumetric arc therapy (VMAT) in planning target volume (PTV) coverage and dose to organs-at-risk (OAR). METHODS: Sixteen patients undergoing postoperative RT for lower extremity STS were included. For each patient, one VMAT plan and one SW-IMRT plan were proposed. Both were evaluated using cumulative dose-volume histogram data for OAR and PTVs. Prescribed dose was 66 Gy (2 Gy/fraction) to PTV1 and 56 Gy (1.69 Gy/fraction) to PTV2. OARs contoured were femur, neurovascular bundle, minimum tissue corridor, normal tissue outside PTV2, joint and genitalia. T-Student test was performed. RESULTS: Eleven male (69%) and five female patients (31%) were analyzed. Mean age was 60 years. Both techniques showed optimal target coverage, conformity index (CI) and homogeneity index (HI). VMAT PTV2 CI was 1.13 (mean) ± 0.08 (standard deviation) versus 1.19 ± 0.10 SW-IMRT PTV2 CI (P < 0.05). VMAT PTV1 HI was 0.09 ± 0.01 versus 0.08 ± 0.01 SW-IMRT PTV1 HI (P < 0.05). Regarding OARs, VMAT delivered lower dose to femur, genitalia, normal tissue outside PTV2 and joints. SW-IMRT spared tissue corridor mean dose (10.4 Gy ± 6.8 Gy) versus (14.7 ± 6.5 Gy) VMAT (P < 0.05). CONCLUSIONS: Both techniques achieved great conformity, homogeneity and coverage of PTV. VMAT produced lower dose to OARS and SW-IMRT was superior in sparing dose to normal-tissue-corridor, which could reduce risk of lymphedema.

Does postoperative irradiation improve survival in early-stage endometrial cancer?

Endometrial cancer is the most common gynecological cancer in developed countries. Postoperative irradiation has been shown to lower locoregional relapses among high-intermediate risk endometrial cancer patients. In addition, vaginal cuff brachytherapy has demonstrated similar control to external beam radiotherapy but with lower toxicity. Although randomized trials have failed to translate that into better overall survival, reports from large databases, such as the National Cancer Database and the Surveillance, Epidemiology, and End Results database, have shown evidence of a statistical relationship between postoperative irradiation and survival in the intermediate- and high-risk groups. This review will address the risk groups that have led the therapeutic decisions and then we will review the clinical results accordingly. Special attention will be paid to the survival results based on the data presented through an analysis of the large databases that suggest a possible survival benefit.

Do Patients Feel Well Informed in a Radiation Oncology Service?

Information received by cancer patients has gained importance in recent decades. The aim of this study was to evaluate the perception of information received by oncological patients in a radiotherapy department and to measure the importance of the other information sources. A cross-sectional study was conducted, evaluating patients who received radiotherapy. All the patients were asked two questionnaires: the EORTC QLQ-INFO26 module evaluating their satisfaction with received information, and a questionnaire analyzing other sources of information search. One hundred patients between 27 and 84 years were enrolled. Breast cancer (26 %) was the commonest cancer. Patients felt better informed about the medical tests and secondly about the performed treatment. The younger patients were those who were more satisfied with the information received and patients with no formal education felt less satisfied, with statistically significant differences. Patients did not seek external information; at the most, they asked relatives and other people with cancer. Patients were satisfied with the received information, although a high percentage would like more information. In general, patients did not search for external information sources. Age and educational level seem to influence in the satisfaction with the received information.

Vaginal cuff brachytherapy in endometrial cancer - a technically easy treatment?

Endometrial cancer (EC) is one of the most common gynecological cancers among women in the developed countries. Vaginal cuff is the main location of relapses after a curative surgical procedure and postoperative radiation therapy have proven to diminish it. Nevertheless, these results have not translated into better survival results. The preeminent place of vaginal cuff brachytherapy (VCB) in the postoperative treatment of high- to intermediate-risk EC was given by the PORTEC-2 trial, which demonstrated a similar reduction in relapses with VCB than with external beam radiotherapy (EBRT), but VCB induced less late toxicity. As a result of this trial, the use of VCB has increased in clinical practice at the expense of EBRT. A majority of the clinical reviews of VCB usually address the risk categories and patient selection but pay little attention to technical aspects of the VCB procedure. Our review aimed to address both aspects. First of all, we described the risk groups, which guide patient selection for VCB in clinical practice. Then, we depicted several technical aspects that might influence dose deposition and toxicity. Bladder distension and rectal distension as well as applicator position or patient position are some of those variables that we reviewed.

Analysing the integration of MR images acquired in a non-radiotherapy treatment position into the radiotherapy workflow using deformable and rigid registration.

AIM: Our aim was to analyse the feasibility of integrating an MRI acquired in a non-radiotherapy set-up into the prostate cancer radiotherapy workflow. MATERIAL AND METHODS: The MRIs of 15 prostate cancer patients, acquired with a flat table-top (MRI-flat), and with a curved tabletop (MRI-curve) were analysed. MRIs were rigidly (RIR) and non-rigidly registered (DIR) with CT images. The prostate and rectum were contoured in each image set and translated to the CT, and IMRT plans were computed taking into account structural changes after RIR and DIR (P-flatRIR, P-curveRIR and P-curveDIR). In addition the P-curveDIR was overlaid with RIR structures. Spatial overlap parameters and dose-volume histogram metrics were generated. RESULTS: No significant differences were observed among P-flatRIR and P-curveRIR or P-flatRIR and P-curveDIR. Median gamma-values: P-curveRIR, 95.3%; P-curveDIR, 96%, translated-P-curveDIR, 95%. DVH metrics for translated-P-curveDIR were: Dmin, 64.5Gy; Dmean, 70.06Gy; V95%, 100%. No statistically significant differences were found in the dosimetric MRI-flatDIR values. CONCLUSIONS: The dosimetric reproduction of treatment position image following image registration of non-radiotherapy set-up images suggests that it is feasible to integrate these images into the radiotherapy workflow.

Rectal contrast increases rectal dose during vaginal cuff brachytherapy.

PURPOSE: To evaluate the impact of rectal dose on rectal contrast use during vaginal cuff brachytherapy (VCB). METHODS AND MATERIALS: A retrospective review of gynecology patients who received some brachytherapy fractions with and without rectal contrast was carried out. Rectal contrast was instilled at the clinician's discretion to increase rectal visibility. Thirty-six pairs of CT scans in preparation for brachytherapy were analyzed. Pairs of CTs were segmented and planned using the same parameters. The rectum was always defined from 1 cm above the cylinder tip up to 1.5 cm below the last activated dwell source position. An individual plan was computed at every VCB fraction. A set of values (Dmax, D(0.1cc), D(1cc), and D(2cc)) derived from dose-volume histograms were extracted and compared according to the rectal status. RESULTS: Rectal volume was 26.7% larger in the fractions with rectal contrast. Such an increase in volume represented a significant increase from 7.7% to 10.4% in all parameters analyzed except Dmax dose-volume histogram. CONCLUSIONS: Avoiding rectal contrast is a simple way of decreasing the rectal dose parameters of VCB, which would mean a better therapeutic ratio. Results also suggest that action directed at maintaining the rectum empty might have the same effect.

Dosimetric analysis of rectal filling on rectal doses during vaginal cuff brachytherapy.

PURPOSE: Several studies have analyzed the effect of bladder filling during vaginal cuff brachytherapy (VCB), but the effect of rectum filling has not been studied. We sought to evaluate the effects of rectal volume on rectal doses during postoperative VCB. METHODS AND MATERIALS: Brachytherapy planning CT scans (334 sets) obtained from 92 consecutive patients treated with VCB were resegmented (bladder and rectum) and replanned retrospectively using the same parameters to homogenize data and improve analysis. Rectal volume and a set of values derived from dose-volume histograms (DVHs) were extracted (maximal dose [Dmax], D0.1cc, D1cc, and D2cc). Univariate and multivariate analyses were carried out to evaluate the association between rectal volume and DVH metrics after adjusting for other clinical factors. RESULTS: A positive significant correlation was observed between rectal volume correlated and Dmax, D0.1cc, D1cc, and D2cc. Multiple linear regression models found that rectal volume, cylinder angle position, and cylinder diameter variables correlated significantly with the different DVH parameters analyzed. These variables explained the 14.5% and 18% of variance on regression models. CONCLUSIONS: Larger rectal volumes are associated with higher rectal dose parameters during VCB fractions. Prospective studies are needed to investigate whether these data are linked to differences in rectal toxicity.

Body Mass Index and Doses at Organs at Risk in a Mediterranean Population Treated with Postoperative Vaginal Cuff Brachytherapy.

PURPOSE: Association between body mass index (BMI) and doses in organs at risk during postoperative vaginal cuff brachytherapy (VCB) treatment has not been evaluated. The aim of this study was to analyse the impact of BMI on the dose delivered to bladder and rectum during high-dose-rate VCB using computed tomography (CT) scans at every fraction. MATERIALS AND METHODS: A retrospective analysis of 220 planning CT sets derived from 59 patients was conducted. Every planning CT was re-segmented and re-planned under the same parameters. Rectum and bladder dose-volume histogram values (D0.1cc, D1cc, and D2cc) were extracted and evaluated. The mean values for all applications per patient were calculated and correlated with BMI, as well as other factors influencing rectal and bladder doses. Multiple regression analysis performed to model organ at risk dose-volume parameters. RESULTS: According to World Health Organization (WHO), 6.8% of patients were normal, 35.6% were overweight, and 57.6% were class I obese. Median rectal doses were 133.5%, 110.9%, and 99.3% for D0.1cc, D1cc, and D2cc, respectively. The corresponding median bladder doses were 96.2%, 80.6%, and 73.3%, respectively. BMI did not show significant association with rectal doses. However, BMI did show a significant association with evaluated bladder dose metrics (D0.1cc, r=-0.366, p=0.004; D1cc, r=-0.454, p < 0.001; D2cc, r=-0.451, p < 0.001). BMI was retained in the multivariate regression models (D0.1cc, p=0.004; D1cc, p < 0.001; D2cc, p=0.001). CONCLUSION: In this group of Mediterranean, overweight, and moderately obese patients, BMI showed association with lower bladder dose values, but not with rectal doses.

Tension pneumocephalus related to radiotherapy for nasopharyngeal carcinoma.

Introduction. Tension pneumocephalus (TP) is a very rare complication related to radiotherapy for nasopharyngeal carcinoma (NPC). Case Presentation. A 46-year-old man was admitted to the hospital with an altered mental status and aqueous rhinorrhea for several hours of evolution. The computed tomography (CT) scan showed TP, a defect in the skull base and nasocranial fistula. The patient was receiving a second course of radiotherapy for local relapse. With medical treatment the patient recovered neurological status but died two days later. Discussion. In our knowledge, only 4 cases with similar characteristics have been reported in the literature. This is the first case report of TP during radiotherapy. TP was an abrupt and rapid process with neurological impairment for hours of evolution without suspicious osteoradionecrosis (OR) in previous scan images. The defect in the skull base could be due to a rapid disappearance of the tumor. The appearance of aqueous rhinorrhea and neurological symptoms must be viewed as signs of alarm.

How air influences radiation dose deposition in multiwell culture plates: a Monte Carlo simulation of radiation geometry.

Radiation of experimental culture cells on plates with various wells can cause a risk of underdosage as a result of the existence of multiple air-water interfaces. The objective of our study was to quantify this error in culture plates with multiple wells. Radiation conditions were simulated with the GAMOS code, based on the GEANT4 code, and this was compared with a simulation performed with PENELOPE and measured data. We observed a slight underdosage of ∼ 4% on the most superficial half of the culture medium. We believe that this underdosage does not have a significant effect on the dose received by culture cells deposited in a monolayer and adhered to the base of the wells.

Mejora en el control local en mujeres jóvenes con cáncer de mama precoz añadiendo una sola fracción de braquiterapia de alta tasa de dosis / Improved local control in young women with early-stage breast cancer by adding a single fraction of high-dose-rate brachytherapy

Objetivo. Evaluar la eficacia de la braquiterapia con iridio-192 de alta tasa de dosis con una sola fracción como sobreimpresión después de irradiar la mama en mujeres de hasta 45 años. Pacientes y métodos. Se estudiaron 167 pacientes consecutivas con tumores T1-2, entre 26-45 años, sometidas a cirugía conservadora con bordes libres y radioterapia (46-50 Gy) por carcinoma de mama infiltrante entre 1999 y 2008. Se realizó implante con agujas metálicas paralelas bajo anestesia local y sedación de forma ambulatoria. La quimioterapia se utilizó en el 85% (66% adyuvante, 19% neoadyuvante) y la hormonoterapia en el 77%. Se administró una dosis única de 7 Gy con braquiterapia de alta tasa de dosis (fast-boost). Resultados. El seguimiento mediano fue de 69 meses. Ocho pacientes recayeron en el lecho o en el margen tumoral con un control actuarial local de 95,6% a 10 años (tasa de recaída 4,4%). Hubo una recaída en otro cuadrante, por tanto, el control local en la mama fue de 94,1%. Las pacientes hasta 40 años recayeron en la mama en un 6,9% a los 10 años. Ventidós pacientes desarrollaron metástasis. La supervivencia libre de enfermedad y global fue de 85,5 y 92%, respectivamente. Los resultados cosméticos fueron buenos/excelentes en el 97%. La toxicidad aguda y tardía fueron mínimas. Conclusiones. El fast-boost con una sola fracción es una técnica rápida, sencilla y eficaz cuando los márgenes quirúrgicos están libres. El control local en las mujeres jóvenes se ha mejorado respecto a la literatura, por lo que se recomienda la preservación de la mama con este esquema

Objective. To evaluate the effectiveness of a single fraction of high-dose-rate iridium-192 brachytherapy as a boost after irradiation of the breast in women aged 45 or less. Patients and methods. We studied 167 consecutive patients with T1-2 tumors, aged between 26 and 45 years undergoing conservative surgery with free margins and radiotherapy (46-50 Gy) for invasive breast carcinoma between 1999 and 2008. Parallel metal needles were implanted under local anesthesia and sedation on an outpatient basis. Chemotherapy was used in 85% (66% adjuvant and 19% neoadjuvant) and hormonal therapy in 77%. A single 7 Gy-dose of high-dose rate brachytherapy ("fast boost") was administered. Results. The median follow-up was 69 months. In 8 patients, recurrences occurred in the tumor bed or in the margin with an actuarial local control of 95.6% at 10 years (relapse rate 4.4%). There was a relapse in another quadrant and therefore breast control was 94.1%. In patients aged up to 40 years, the breast failure rate was 6.9% at 10 years. Metastases developed in 22 patients. Disease-free survival was 85.5% and overall survival was 92%. Cosmetic results were good or excellent in 97% and acute and late toxicity was minimal. Conclusions. The fast boost technique with a single fraction is fast, simple, and effective when surgical margins are free. Local control in young women has improved compared with prior reports in the literature. Therefore, this technique can be recommended for breast preservation