Development and clinical introduction of automated radiotherapy treatment planning for prostate cancer.

To develop an automated radiotherapy treatment planning and optimization workflow to efficiently create patient specifically optimized clinical grade treatment plans for prostate cancer and to implement it in clinical practice. A two-phased planning and optimization workflow was developed to automatically generate 77Gy 5-field simultaneously integrated boost intensity modulated radiation therapy (SIB-IMRT) plans for prostate cancer treatment. A retrospective planning study (n = 100) was performed in which automatically and manually generated treatment plans were compared. A clinical pilot (n = 21) was performed to investigate the usability of our method. Operator time for the planning process was reduced to <5 min. The retrospective planning study showed that 98 plans met all clinical constraints. Significant improvements were made in the volume receiving 72Gy (V72Gy) for the bladder and rectum and the mean dose of the bladder and the body. A reduced plan variance was observed. During the clinical pilot 20 automatically generated plans met all constraints and 17 plans were selected for treatment. The automated radiotherapy treatment planning and optimization workflow is capable of efficiently generating patient specifically optimized and improved clinical grade plans. It has now been adopted as the current standard workflow in our clinic to generate treatment plans for prostate cancer.

Cervical dysplasia and associated risk factors in a juvenile detainee population.

STUDY OBJECTIVE: Canada has licensed a human papilloma virus (HPV) vaccine for adolescent females, with the goal of decreasing the incidence of HPV infection and associated cervical cancer. This study identifies the juvenile detainee population as a high-risk group for HPV infection and therefore an important target for primary prevention. DESIGN: A retrospective chart review. SETTING: Sundance Juvenile Detention Center, Kingston, Ontario, Canada. PARTICIPANTS: Female detainees admitted between 2003 and 2006. MAIN OUTCOME MEASURES: Papanicolaou (Pap) test results, sexually transmitted infection (STI) rates, and associated risk factors were collected from 119 charts. RESULTS: Of 57 recorded Pap smears, 46 (80.7%) were normal, 5 (8.8%) were reported as atypical squamous cells of unknown significance, and 6 (10.5%) were reported as low-grade squamous intraepithelial lesion. Of the women tested, 4% were positive for gonorrhea, 10% for chlamydia, 32% for bacterial vaginosis, and 5% for trichomonas; none were positive for syphilis. Of the girls, (91) (77%) had negative HIV and hepatitis B tests, two girls were hepatitis-C-positive, three had clinical evidence of genital herpes, and one showed evidence of pelvic inflammatory disease. There were 75 (63%) girls who reported sexual activity; 87% of them used contraception or protection of some kind, albeit inconsistently. Of these young females, 12 (10%) had engaged in prostitution and 13 (11%) had allegedly been raped or sexually assaulted. CONCLUSIONS: Female juvenile detainees in Kingston, Ontario, have higher rates of STIs, associated risk factors, and abnormal Pap tests than the general female adolescent population. This new information confirms that this population is at risk for HPV infection and subsequent cervical cancer.

Osmotic lysis of tumor spill in ovarian cancer: a murine model.

OBJECTIVE: Our purpose was to determine, in the murine model, whether human ovarian cancer cells injected intraperitoneally are subject to osmotic lysis by peritoneal lavage with sterile water, thereby decreasing the establishment of peritoneal implants. STUDY DESIGN: Preliminary experiments on six nude mice determined that the injection of 20 million cells of the SKOV-3 cell line reliably leads to the establishment of intraperitoneal tumor xenografts in the mice within 60 days. Four other nude mice functioned as sham controls undergoing peritoneal lavage with 3 to 4 ml of saline solution or sterile water to determine any adverse effects from the lavage alone. Subsequently, 36 nude (nu/nu) mice were injected intraperitoneally with 1 ml of the SKOV-3 cell line at a concentration of 20 million cells per milliliter. Alternate mice then underwent intraperitoneal lavage with either 3 to 4 ml of normal saline solution (control group) or sterile water (study group). The mice were followed up until tumor growth caused a moribund status or until 60 days after injection and then were killed. At necropsy the number and size of tumor nodules were recorded, and each mouse was assigned a composite tumor score. Statistical comparison used the X2 or Fisher's exact test for discrete variables. Time to failure analysis used the Kaplan-Meier method. RESULTS: Tumor growth occurred in 35 of 36 (97%) of the mice during the study period. In the first 30 days 89% of the saline solution group grew clinically visible tumor compared with 55% of the water group (p = 0.03). Ascites developed more frequently in the water group than in the saline solution group. The median tumor scores at death were significantly higher for the water group versus the saline solution group. Survival time, as determined by the time from injection until moribund status, was worse for the water group (p = 0.002). CONCLUSIONS: Intraperitoneal lavage with sterile water did not offer protection against the establishment of xenografts after the intraperitoneal injection of human ovarian cancer cells in the nude mouse model.