Dosimetric effect of photon beam energy on volumetric modulated arc therapy treatment plan quality due to body habitus in advanced prostate cancer.

PURPOSE: The purpose of this study was to dosimetrically compare 6- and 10-MV photon beam energies in high-risk prostate cancer patients of various body habitus using a volumetric modulated arc therapy (VMAT) radiation delivery technique. The objectives of the study were to evaluate whether dosimetric differences exist and to investigate whether differences are dependent on patient body habitus. METHODS AND MATERIALS: Forty patients with various body habitus who had previously received treatment to the prostate and pelvic lymph nodes with VMAT techniques were chosen. Patients were planned in the Pinnacle(3) treatment planning system with double or triple SmartArc plans with 6- and 10-MV photon energies. All patients were optimized with the same planning objectives and normalized such that 95% of the planning target volume (PTV) received the prescription dose. Patients were evaluated for PTV and organ at risk (OAR) parameters for the bladder, rectum, small bowel, penile bulb, and sigmoid colon. Metrics used for comparison were D2%, D98%, homogeneity, conformity, and dose falloff for the PTV and D(2%), D(mean), V(80%), V(60%), and V(40%) for OARs. Statistical differences were evaluated with a paired-sample Wilcoxon signed rank test with a significance level of .05. RESULTS: For the PTV, there were no statistically significant differences in D(mean), D(2cc), conformation number, and homogeneity index values, but the dose falloff parameters, R50 and R25, showed a median improvement of 6.7% (P<.01) and 6.2% (P<.01), respectively, with 10 MV. A correlation between patient anterior-posterior distance (d(AP)) and percentage reduction in R50 of 0.436% per centimeter (P<.01) was determined. For OARs, statistically significant reductions in dose metrics were found in the small bowel and bladder, but increases in the D(2cc) of 3.5% in the penile bulb (P<.01) and 0.2% in the rectum (P=.02) were shown with 10 MV. The use of 10 MV also demonstrated a statistically significant reduction in the total number of monitor units of 15.9% (P<.01) compared with 6 MV. CONCLUSIONS: The study showed that 10 MV provides a faster dose falloff than 6 MV for patients whose prostate and pelvic lymph nodes are treated using a VMAT technique irrespective of body habitus; however, the improvement in dose falloff is dependent on body habitus and increases as the patient body habitus increases.

A virtual fluoroscopy system to verify seed positioning accuracy during prostate permanent seed implants.

PURPOSE: The purpose of this project was to develop a software platform to produce a virtual fluoroscopic image as an aid for permanent prostate seed implants. MATERIALS AND METHODS: Seed location information from a pre-plan was extracted and used as input to in-house developed software to produce a virtual fluoroscopic image. In order to account for differences in patient positioning on the day of treatment, the user was given the ability to make changes to the virtual image. RESULTS: The system has been shown to work as expected for all test cases. CONCLUSION: The system allows for quick (on average less than 10 sec) generation of a virtual fluoroscopic image of the planned seed pattern. The image can be used as a verification tool to aid the physician in evaluating how close the implant is to the planned distribution throughout the procedure and enable remedial action should a large deviation be observed.

Long-term outcome for lymph node-positive prostate cancer.

Although the number of men with lymph node-positive prostate cancer has declined, it is still significant and the challenge remains on how best to treat these patients. Only long-term follow-up can give a true indication of the outcome in prostate cancer. We evaluated our experience in treating lymph node-positive prostate cancer with a median follow-up of 10.2 years. The overall 5-year survival was 78% and the 10-year survival was 56%. Length of tumor control depends on the type of treatment given. Adding androgen ablation improves the duration of control dramatically, although optimal timing is still uncertain.

Treatment options in locally advanced prostate cancer.

Even though the incidence has decreased, locally advanced prostate cancer remains a treatment challenge. Primary androgen ablation remains an option, but must be used judiciously as a high number of patients ultimately progress and die of prostate cancer. Unfortunately, while there is not good data that more aggressive treatment impacts significantly on survival, it does appear that some patients can be rendered free of disease. The failure rate with surgery alone has been high and androgen ablation has been used as a frequent adjunct. The randomized trials completed so far suggest that holding the androgen ablation for failure is as effective for survival. Randomized data with adjuvant radiation shows a significant decrease in biochemical and clinical failure, but a survival advantage is also not yet apparent. Historically, the results of primary radiation have been poor and have been only modestly improved with the addition of androgen ablation. In retrospective studies, favorable results have been achieved with dose escalation utilizing intensity modulated external beam radiation therapy or brachytherapy without the need for androgen ablation.

Long-term follow-up of radiotherapy for prostate cancer.

PURPOSE: To determine the long-term outcome of radiotherapy for prostate cancer. METHODS AND MATERIALS: A total of 136 consecutive patients with prostate cancer underwent primary radiotherapy. All but 4 patients received 6000 cGy to the prostate. The minimal follow-up was 22.9 years. RESULTS: Of the 136 patients, 93 had Stage B (T2), 9 Stage A (T1), and 34 Stage C (T3). Sixty-nine percent of the patients developed recurrence, and 51% of all patients died of prostate cancer. The recurrences developed at a steady state throughout the length of follow-up. One half the recurrences occurred after 10 years, and recurrence was still observed >20 years after treatment. The survival rate at 5, 10, 15, 20, and 25 years was 81%, 59%, 37%, 16%, and 10%, respectively. The recurrence-free survival rate at 25 years was 17%. The median survival for Grade 3-4 patients was 6.3 years and for Grade 1-2 patients was 13.0 years. The median survival for those with T1 tumors was 12.9 years; T2 tumors, 12.4 years; and T3 tumors, 9.5 years. CONCLUSION: Despite favorable early results, with long-term follow-up, patients continued to experience prostate cancer recurrence. Unless they died an intercurrent death, they were highly likely to develop recurrence and die of prostate cancer. The conclusions from treatment studies with <15 years of follow-up should be viewed as preliminary.

Long-term follow-up of radical retropubic prostatectomy for prostate cancer.

OBJECTIVES: The ultimate outcome of patients after radical prostatectomy is often predicted from statistical projections of short-term follow-up. Only actual long-term follow-up can demonstrate true outcome. METHODS: One hundred thirty-one patients underwent retropubic prostatectomy for clinically organ confined prostate cancer and have been followed for a minimum of 22.5 years. Preoperatively, all but 12 had clinically palpable cancer. RESULTS: Overall survival in these patients was similar to an age-matched population, with 65% alive at 15 years, and 23% alive at 25 years. Thirty-seven percent of the patients recurred and 24% of all the patients died of prostate cancer. For patients with pathologically organ confined disease, 27% recurred, while those with extension outside the gland or positive nodes had an 83% recurrence rate. Although, the median time to recurrence was 7 years, recurrences occurred at a steady-state throughout the length of follow-up. Patients with higher grade tumors, even if organ confined, were significantly more likely to recur. CONCLUSIONS: In a cohort of patients treated with radical prostatectomy for predominantly palpable disease, long-term follow-up (79% deceased) reveals that 37% will recur and 24% will die of prostate cancer. Almost half the recurrences occurred after 10 years, indicating that reports with shorter follow-up will underestimate the recurrence rate.

Breast conservation in the treatment of breast cancer: community-based experience.

BACKGROUND: Results of large, randomized studies in the 1980s established wide excision and radiation as an accepted breast cancer treatment approach. We evaluated our initial results with this treatment in the community setting. METHODS: We evaluated the frequency and outcome of breast conservation treatment in 303 women with invasive ductal carcinoma from 1985 to 1995. RESULTS: The frequency of breast conservation treatment increased from 9% during 1985 to 1989 to 24% during 1990 to 1995. With a median follow-up of 4.7 years, there were 19 (6%) ipsilateral recurrences. Metastatic disease occurred in 23 patients (8%). Overall 5-year survival was 95%, and 5-year recurrence-free survival was 90%. Twelve patients died of breast cancer. CONCLUSIONS: Increased use of breast conservation in our community practice parallels the national trend, with similar treatment results. Our findings suggest the successful integration of research-proven innovations into community practice.

Salvage brachytherapy for localized prostate cancer after radiotherapy failure.

OBJECTIVES: To evaluate the effectiveness and morbidity of salvage brachytherapy for locally recurrent or persistent prostate cancer after radiotherapy failure. METHODS: In this retrospective study, 49 patients of median age 73.3 years (range 52.9 to 86.9) with biopsy-proven localized prostate cancer underwent interactive transperineal fluoroscopic-guided and biplane ultrasound-guided brachytherapy with either iodine 125 or palladium 103 after prior radiotherapy failure. Post-treatment follow-up was conducted for a median of 64.1 months (range 26.6 to 96.8) and included clinical assessment of disease status, assays of serum prostate-specific antigen (PSA) levels, and documentation of treatment-related symptoms and complications. Determination of biochemical treatment failure was based on two successive rising PSA values above the post-treatment PSA nadir value. RESULTS: The actuarial rate of local prostate cancer control was 98% (95% confidence interval [CI] 94% to 99%). Actuarial disease-specific survival at 3 and 5 years was 89% (95% CI 73% to 96%) and 79% (95% CI 58% to 91%), respectively. At 3 and 5 years, actuarial biochemical disease-free survival was 48% (95% CI 32% to 63%) and 34% (95% CI 17% to 51%), respectively. Post-treatment PSA nadir was found to be a significant predictor of biochemical disease-free survival. Actuarial biochemical disease-free survival of patients who achieved a PSA nadir less than 0.5 ng/mL was 77% (95% CI 53% to 90%) and 56% (95% CI 25% to 78%) at 3 and 5 years, respectively. Of 49 patients, 23 (47%) achieved a post-treatment PSA nadir less than 0.5 ng/mL. The incidence of serious complications after salvage brachytherapy, such as incontinence and rectal complications, was lower than that reported after other types of salvage procedures. CONCLUSIONS: Interactive transperineal fluoroscopic-guided and biplane ultrasound-guided brachytherapy is a novel, potentially curative salvage modality for patients in whom prior radiotherapy failed. In a population of patients with poor prognosis, this modality was associated with a high rate of local prostate cancer control and a 34% actuarial rate of biochemical disease-free survival at 5 years. The incidence of major complications after salvage brachytherapy appears to be lower than that after other potentially curative salvage procedures, such as radical prostatectomy and cryoablation. Salvage brachytherapy warrants further investigation.

Actuarial disease-free survival after prostate cancer brachytherapy using interactive techniques with biplane ultrasound and fluoroscopic guidance.

PURPOSE: To evaluate the effectiveness and safety of interactive transperineal brachytherapy under biplane ultrasound and fluoroscopic guidance in patients with localized prostate cancer. METHODS AND MATERIALS: Brachytherapy using 125I or 103Pd radioactive seeds either alone or in combination with adjunctive external beam radiotherapy (XRT) was administered to 490 patients at a single institution. Post-treatment follow-up included clinical assessment of disease status, assays of serum prostate-specific antigen (PSA) levels and documentation of treatment-related symptoms and complications. RESULTS: Actuarial disease-free survival at 5 yr was 79% (95% CI, 71-85%), and the 5-yr actuarial rate of local control was 98% (95% CI, 94-99%). Post-treatment PSA nadir and pretreatment PSA level were found to be significant predictors of disease-free survival. In patients with a PSA nadir < 0.5 ng/ml, 5-yr disease-free survival was 93% (95% CI, 84-97%), compared with 25% (95% CI, 5-53%) in patients whose PSA nadir was 0.5-1.0 ng/ml and 15% (95% CI, 3-38) in patients with a PSA nadir > 1.0 ng/ml. Brachytherapy was well tolerated with few post-treatment complications. CONCLUSION: A broad range of patients with localized prostate cancer can benefit from transperineal brachytherapy with minimal morbidity. A post-treatment PSA nadir below 0.5 ng/ml provides a useful prognostic indicator of favorable long-term outcome.

Chromosome 11 abnormalities in Bowen disease of the vulva.

Chromosomal cytogenetic abnormalities are common in tumor cells and are often the basis for more detailed chromosomal mapping of tumor suppressor and oncogenes. Chromosome 11 abnormalities are frequently recognized in various neoplasms. We report a case of Bowen disease (squamous cell carcinoma in situ) of the vulva with an isolated 11p cytogenetic abnormality. A chromosome 11 paint confirmed two copies of chromosome 11 in all analyzed metaphases. An 11p subtelomeric probe confirmed an abnormality of 11p15-->pter indicative of a deletion. Previous studies of invasive vulvar cancers also frequently show 11p cytogenetic abnormalities, but never as an isolated finding. The patient suffered from other diseases that may also be related to this locus. Breakage and p53 studies were normal. It is possible that an 11p abnormality in Bowen's disease is a precursor in the evolution of invasive vulva cancer.

Increasing patient involvement in choosing treatment for early breast cancer.

BACKGROUND: This investigation examined factors affecting patient involvement in consultations to decide local treatment for early breast cancer and the effectiveness of two methods of preconsultation education aimed at increasing patient participation in these discussions. METHODS: Sixty patients with Stage I or II breast cancer (1) were pretested on their knowledge about breast cancer treatment and optimism for the future, (2) were randomly assigned to one of two methods for preconsultation education: interactive multimedia program or brochure, (3) completed knowledge and optimism measures, (4) consulted with a medical oncologist, radiation oncologist, and general surgeon, and (5) completed self-report measures assessing their involvement in the consultations and control over decision-making. The consultations were audiorecorded and analyzed to identify behavioral indicators of patient involvement (question-asking, opinion-giving, and expressing concern) and physician utterances encouraging patient participation. RESULTS: College-educated patients younger than 65 years of age were more active participants in these consultations than were older, less educated patients. In addition, patients showed more involvement when they interacted with physicians who encouraged and facilitated patient participation. The method of education did not affect patient involvement although patients tended to learn more about breast cancer treatment after using the multimedia program than after reading the brochure. CONCLUSIONS: Although patients vary in their expressiveness, physicians may be able to increase patient participation in deciding treatment by using patient-centered behavior. Also, preconsultation education appears to be an effective clinical strategy for helping patients gain an accurate understanding of their treatment options before meeting with physicians.

Definitive therapy for prostate carcinoma: Mayo Clinic results at 15 years after treatment.

Data on long-term follow-up for definitive therapy of prostate cancer are limited, especially for radiation therapy. Either surgery or radiation was used in 322 patients for treatment with curative intent, and follow-up was for a minimum of 15 years. Overall survival was nearly identical to that in age-matched cohort. 5-, 10-, and 15-year recurrence-free survival rates were 77%, 63% and 53%, respectively. Grade and stage were significant prognostic factors for both recurrence and survival. More than 60% of the initial failures were local, and more than 25% of the failures occurred after 10 years. Radiation therapy was used in 137 patients with clinically staged disease. Radical retropubic prostatectomy and perineal prostatectomy were performed in 133 and 44 patients, respectively. In this group, pathological staging was used. Survival rates for surgically treated patients were better than those in the cohort population. In conclusion, overall long-term follow-up demonstrates that definitive treatment does not have an adverse effect on survival from prostate cancer. Local recurrence is a frequent cause of failure. Caution must be used in interpreting any prostate study with less than 10 years of follow-up, because 25% to 50% of the failures occur after that time.

Nephrotic syndrome associated with ant bite.

A 3-year-old child experienced edema of the face and extremities approximately 2 weeks after being stung on the legs, scrotum, and penis by "fire ants" (Solenopsis invicta). After diagnosis of idiopathic minimal-change nephrotic syndrome and treatment with steroids, the edema rapidly disappeared. Follow-up 3 years after his hospitalization showed no recurrence of nephrotic syndrome. We have correlated this case with previously published reports of the causal relationship of allergy to nephrotic syndrome, but we are unaware of any previously published correlation between ant bite and nephrotic syndrome.