Bashir

The dosimetric quality of brachytherapy implants in patients with small prostate volume depends on the experience of the brachytherapy team

PURPOSE To investigate the dosimetric outcome of brachytherapy in patients with small prostate volume (PV). METHODS AND MATERIALS Forty-three patients with small PV (<25 cm(3)) as determined using transrectal ultrasound and 120 patients with non-small PV (>25 cm(3)) that had received (125)I seed implants were reviewed in a retrospective cohort study. Implantations were performed under transrectal ultrasound guidance, and the prescription dose was 145 Gy. A CT and MRI scan of the pelvis were performed 1 month after implantation for dosimetric study. RESULTS Compared with non-small PV patients, patients with small PV experienced larger 1-month edema (p<0.001); lower dose to 90% (the isodose enclosing 90% of PV and representing a minimum dose to that volume of the prostate [D(90)]) of the prostate (p=0.03); higher intracapsular seed density (p<0.001); and were less likely to achieve D(90)>or=140 Gy (p=0.013) in a postimplant dosimetric study. The number of patients with D(90)<140 Gy decreased steadily in both subsets of patients as the implant program matured (odds ratio=0.56 per year, p<0.001), but the small prostate group exhibited more improvement compared with the non-small prostate patients over the same time period. Multivariate analysis revealed that brachytherapy team experience rather than the size of prostate was a more important predictive factor of implant quality (p<0.001). CONCLUSIONS This single institution experience demonstrated a significant learning curve in the initial years of a prostate brachytherapy program, especially for patients with small prostates. A small prostate itself is not a contraindication of brachytherapy. The quality of implant for patients with small prostates depends more on the skill of the brachytherapy team.

Small Cell Cancer of the Bladder and Prostate: A Retrospective Review from a Tertiary Cancer Center

Background: Genitourinary small cell cancer (GUSCC) is a rare malignancy. Most of the published data on how to manage this malignancy is based on institutional experience. We undertook the current retrospective review to determine the outcome of the patients with GUSCC treated at CancerCare Manitoba, Canada over a period of 18 years. Methods: The Manitoba Cancer Registry was used to identify patients with a confirmed pathological diagnosis of small cell cancer (SCC) of the bladder or prostate between January 1, 1995, and October 31, 2013. Results: There were 42 patients identified, 28 bladder SCC (17 limited, 11 extensive stage) and 14 prostate SCC (one limited, 12 extensive, and one unknown stage). The median age was 70.7 years. There were 22 patients who were treated with chemotherapy and radiation, five received radiation only, four received chemo only, nine did not receive any treatment, one patient had surgery only, and one had surgery and radiation. The median and one-year overall survival for all patients was 10.7 months and 43%. The median and one-year overall survival of SCC of the bladder was 55.1 months and 71% for the limited stage and 10.1 months and 36% for the extensive stage. The median and one-year overall survival for extensive stage SCC of the prostate was 4.1 months and 17%. There was only one patient with limited stage SCC of the prostate who did not receive any treatment and died of progressive disease 11 months from diagnosis. Conclusions: Our findings suggest that patients with limited stage SCC of the bladder can have a surprisingly good outcome with multimodality treatment. The outcome of the patients with extensive stage SCC of the bladder and prostate remains dismal and optimal therapeutic options have yet to be determined.

Comparison of 7th and 8th editions of the UICC/AJCC TNM staging for non-small cell lung cancer in a non-metastatic North American cohort undergoing primary radiation treatment

BACKGROUND We compared the performance of 7th and 8th edition of the Union for International Cancer Control (UICC) / American Joint Committee on Cancer (AJCC) TNM staging for non-small cell lung cancer (NSCLC) in non-metastatic (stage I-III) North American cohort undergoing primary radiation treatment. METHODS Newly diagnosed NSCLC between (Jan 2011 - Dec 2014) were screened through a Canadian Provincial Cancer Registry. Clinico-radiologically and pathologically confirmed non-metastatic NSCLC undergoing primary radiation treatment were included. Kaplan-Meier methods, Cox proportional hazard regression and Akaike information criterion (AIC) were applied to evaluate discriminatory ability and prognostic performance of 7th and 8th edition of staging systems. RESULTS In this cohort of 295 patients, 8th edition stages IA3, IB, IIA, IIB, IIIA, IIIB, and IIIC showed progressive increase in the hazard ratio compared to best stage IA2 (8th edition IA3 vs IA2: HR 1.72; IB vs IA2: HR 2.04; IIA vs IA2: HR 2.66; IIB vs IA2: HR 2.91; IIIA vs IA2: HR 3.38; IIIB vs IA2: HR 3.62 and IIIC vs IA2: HR 8.22). In a multivariate model, 8th edition stage grouping had smaller AIC of 2342.08 compared to 7th edition 2349.55, confirming better performance. International Association for the Study of Lung Cancer (IASLC) map based nodal categorization N1, N2 and N3, showed good survival and hazard discrimination over stage N0 (1.39, 1.48 and 2.16 respectively). CONCLUSION In an independent cohort of non-metastatic NSCLC undergoing primary radiation treatment, improved performance of 8th edition UICC/AJCC staging system over 7th edition was observed.

Targeting the Tumor: Assessing the Impact of Bladder Volume and Position on Accuracy of Radiation Delivery for Patients with Bladder Cancer

Context Daily variations in bladder size and position can negatively impact the ability to accurately deliver radiation. Aims We attempted to quantify how bladder volumes and positions change over the course of radiotherapy for muscle invasive bladder cancer and the planning target volume (PTV) margins required to account for such changes. Methods and material Cone-beam computed tomography (CT) images of 28 patients during their first, second, and third fractions and weekly thereafter were acquired. Bladders were contoured and the volume, centre of mass, and the maximal positions were recorded and compared to the planning CT scan. Statistical analysis Bladder parameters were analysed using regression analysis examining for time trends and correlation to the patient, tumour, or treatment-related factors. Results There was great variability in the mean bladder volumes during the radiotherapy courses (154.17 +/- 129.38 cm3). There were no statistically significant trends for volume changes. Deviations in bladder positions were seen but were small in magnitude. No patient factors were identified which could help predict bladder changes clinically. Bladder variability resulted in a high percentage of fractions (39.6%) in which part of the bladder was outside the PTV. Calculated PTV margins (for 90% of the population to receive 95% of the prescription dose) were 1.48 cm right, 1.15 cm left, 2.13 cm posterior, 1.52 cm anterior, 2.23 cm superior, and 0.52 cm inferior. Conclusions Because of random bladder changes, a significant number of fractions were treated in which the clinical target volume (CTV) fell outside of the PTV. Methods to minimize the amount of CTV that is missed on a fraction to fraction basis should be explored.