Quality of Radiotherapy Workforce Training within the USA.

The training, competency requirements and scope of practice of professionals within a radiation oncology department vary across countries. The purpose of this review is to shed light on the current status of radiotherapy training in the USA by discussing current benchmarks for medical residency, physics residency, radiation therapy and dosimetry training programmes. Although there are notable strengths, the US radiotherapy workforce training system also faces several challenges when it comes to standardising education to develop a competent workforce that meets societal needs. Continued efforts are needed at a systemic level to improve training in areas such as brachytherapy and proton therapy, promote research involvement and develop trainees who are equipped to form a competent radiation therapy workforce.

Vaginal high-grade sarcoma in pregnancy.

BACKGROUND: Vaginal cancer is a rare malignancy making up 1-2% of all female genital tract cancers. Among vaginal cancers, sarcomas constitute 2% of malignant vaginal lesions, with leiomyosarcomas being the most common type of sarcoma. There is a paucity of data to guide treatment of vaginal sarcomas. This case report details a patient diagnosed with a gynecologic sarcoma during pregnancy who is subsequently treated for residual vaginal disease in the postpartum period with local resection and adjuvant vaginal brachytherapy. CASE: A 31-year-old gravida 4 para 0 who presented at 22-weeks gestation with vaginal bleeding to an outside hospital and expelled a mass 11 cm in diameter from the vagina during her admission. Findings were consistent with a high grade gynecologic sarcoma. She underwent planned cesarean section at 36 weeks gestational age with uterine pathology showing no sarcoma. At her 3 month postpartum visit she was found to have a 1 cm posterior vaginal wall lesion which was resected and consistent with vaginal sarcoma. She underwent adjuvant brachytherapy. CONCLUSION: This case demonstrates the challenges with obtaining a correct pathological diagnosis for pregnant patients with vaginal sarcoma during pregnancy. Surgical resection with negative margins remains an important treatment component. Given the low incidence of disease occurrence in pregnancy and rare number of cases reported in literature, further elucidation of timing of delivery and adjuvant treatment is warranted.

Establishing the distribution of satellite lesions in intermediate- and high-risk prostate cancer: implications for focused radiotherapy.

BACKGROUND: In focused radiotherapy for prostate cancer (PC), a full dose of radiation is delivered to the index lesion while reduced dose is delivered to the remaining prostate to reduce morbidity. As PC is commonly multifocal, we investigated whether baseline clinical characteristics or multiparametric magnetic resonance imaging (mpMRI) may be useful to predict the actual pathologic distribution of PC in men with intermediate- or high-risk PC, which may better inform how to deliver focused radiotherapy. METHODS: A retrospective single-institutional study was performed on 71 consecutive men with clinically localized, intermediate- or high-risk PC who underwent mpMRI followed by radical prostatectomy (RP) from January 2012 to December 2012. Logistic regression analysis was performed to evaluate preoperative predictors for satellite lesions. Performance characteristics of mpMRI to detect satellite lesions and the extent of prostate disease (one hemi-gland vs both) were also evaluated. RESULTS: In all, 50.7% had satellite lesions on mpMRI. On RP specimen analysis, 66.2% had satellite lesions and 55.3% of these satellite lesions had pathologic Gleason score (pGS)⩾3+4. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for mpMRI detecting a satellite lesion being present in the RP specimen were 59.6%, 66.7%, 77.8%, 45.7% and 62.0%, respectively. The presence of MRI satellite lesions was the only preoperative predictor significantly associated with finding satellite lesions on final pathology (hazard ratio (HR), 2.95, P=0.040). There was agreement in 76.1% of the entire cohort for unilateral vs bilateral disease when incorporating both biopsy and mpMRI information and comparing with the RP specimen. CONCLUSIONS: In intermediate risk or greater PC, only the presence of mpMRI satellite lesions could predict for pathologic satellite lesions. While combining biopsy and mpMRI information may improve preoperative disease localization, the relatively high incidence of bilateral hemi-gland involvement with pGS ⩾7 satellite lesions makes it challenging to appropriately select men eligible for hemi-gland therapy.

Long-term follow-up of prostate cancer patients treated with vaccine and definitive radiation therapy.

BACKGROUND: Vaccine therapy in combination with radiation therapy may improve distant and/or local control in prostate cancer. We present long-term follow-up data on the secondary and exploratory endpoints of safety and biochemical failure, respectively, from patients with clinically localized prostate cancer treated definitively with a poxviral vector-based therapeutic vaccine combined with external beam radiation therapy (EBRT). METHODS: Thirty-six prostate cancer patients received definitive EBRT plus vaccine. A total of 18 patients were treated with adjuvant standard-dose interleukin-2 (S-IL-2) (4 MIU m(-2)) and 18 were treated with very low-dose IL-2 (M-IL-2) (0.6 MIU m(-2)). Seven patients were treated with EBRT alone. Twenty-six patients treated with EBRT plus vaccine returned for follow-up, and we reviewed the most recent labs and clinical notes of the remaining patients. RESULTS: Median follow-up for the S-IL-2, M-IL-2 and EBRT-alone groups was 98, 76 and 79 months, respectively. Actuarial 5-year PSA failure-free probability was 78%, 82% and 86% (P=0.58 overall), respectively. There were no significant differences between the actuarial overall survival and the prostate cancer-specific survival between the two vaccine arms. Of the 26 patients who returned for follow-up, Radiation Therapy Oncology Group grade ≥2 genitourinary (GU) and gastrointestinal (GI) toxicity was seen in 19% and 8%, respectively, with no difference between the arms (P=1.00 and P=0.48 for grade ≥2 GU and GI toxicity, respectively). In all, 12 patients were evaluated for PSA-specific immune responses, and 1 demonstrated a response 66 months post-enrollment. CONCLUSIONS: We demonstrate that vaccine combined with EBRT does not appear to have significant differences with regard to PSA control or late-term toxicity compared with standard treatment. We also found limited evidence of long-term immune response following vaccine therapy.

TU-E-BRA-07: Post-Operative Eye Plaque Imaging Using Tomotherapy MVCT.

PURPOSE: Intra-operative ultrasound is used to verify the positioning of episcleral eye plaques used to treat ocular melanoma. Ultrasound can be ambiguous because of image artifacts, and plaques may shift position after surgery. Ultrasound verification is particularly challenging for anterior tumors. Post-operative imaging could be used to trigger interventions that would prevent local treatment failure. We investigated if, and under what conditions, the Tomotherapy megavoltage computed tomography (MVCT) system could be used to perform post-implantation verification of eye plaque positioning. METHODS: Plaques were placed on a preserved cow's eye, and imaged with the megavoltage CT of a Tomotherapy linear accelerator (Accuray, Sunnyvale, CA). The images were visually and quantitatively assessed to determine if they were of sufficient quality to verify tumor coverage and plaque tilt with respect to the sclera. We used the visibility of the lens as a proxy for visibility of a tumor. To test the utility of hypothetical higher beam current Tomotherapy images, we averaged sequential images of the same setup. RESULTS: The plaque, the lens of the eye, and the globe are visible in the images. The CNR of the lens with respect to the vitreous was 5.6 for a single image. For 10 images averaged, the CNR was 9.2. Estimated dose from a single image was 1.3 cGy (body CTDIvol); even 10 times this dose would be an acceptable image-guidance dose for radiotherapy patients. One limitation of the imaging procedure is the long scan time (up to 240 seconds), during which time any significant patient motion would lead to image artifacts. Human trials on eye plaque patients are planned. CONCLUSIONS: Tomotherapy MVCT imaging could be used to verify tumor coverage and plaque tilt after episcleral plaque implantation. Tumors should be visible in standard Tomotherapy images but higher beam current images would be preferred if available.

SU-E-T-322: A Dosimetric Comparison of PBI Brachytherapy Techniques: SAVI, Contura, and Tube and Button Applicators.

PURPOSE: To evaluate the dosimetry of partial breast irradiation brachytherapy techniques using the Strut Adjusted Volume Implant (SAVI), Contura, and Tube and Button (T&B) applicators. METHODS: A total of 51 breast-cancer patients (23 SAVI, 6 Contura, and 22 T&B) were treated. The target was delineated following NSABP B-39 guidelines. 3D plans were optimized using the Inverse Planning Simulated Annealing algorithm to deliver 3.4 Gy per fraction to the target and minimize dose to organs at risk (OARs). Graphical optimization was then used to fine tune the final dose distribution. The minimum cavity-to-skin distance was measured. Target coverage (V90 and V95) and maximum dose (D0.1cc) to the OARs were evaluated. Dose homogeneity index (DHI = 1-V150/V100) was calculated. RESULTS: The average cavity-to-skin distances were 4.1 mm (0.5-9.6 mm, SAVI) and 11.7 mm (7.1-15.4 mm, Contura). The target-to-skin distance for the T&B cases was 8.7 mm (5.0-13.7 mm). The average V90 and V95 to the target were 96.8% and 94.5% (SAVI), 97.0% and 93.0% (Contura), 98.6% and 97.3% (T&B). The mean D0.1cc to the skin, ribs, and lung was 91.5%, 58.8%, 44.5% (SAVI), 93.1%, 51.3%, 40.5% (Contura), 69.1%, 41.5%, and 31.9% (T&B). The average V150 and V200 to the normal breast tissue were 30.4 cc and 14.9 cc (SAVI), 29.5 cc and 7.3 cc (Contura), 18.3 cc and 7.1 cc (T&B). The average DHI for the SAVI, Contura, and T&B cases was 0.55 (0.50-0.60), 0.70 (0.63-0.78), and 0.76 (0.74-0.79). CONCLUSIONS: All techniques provided clinically acceptable target coverage and dose to the OARs. The SAVI device provided a lower skin dose at close cavity-to-skin distances while providing excellent target coverage. However, the T&B and Contura applicators produced more homogeneous dose distribution (higher DHI) in the target than the SAVI. The correlations between dosimetric properties and follow-up mammogram results are under investigation.

SU-D-213AB-02: Optimal Design of Multichannel Vaginal Cylinder Applicators for High Dose Rate Brachytherapy.

PURPOSE: To determine the optimal location of catheters in multichannel vaginal applicators to appropriately cover the vaginal cuff target and minimize dose to the organs at risk (OARs) and hot spots in the target. METHODS: A new multichannel vaginal applicator with a diameter of 30 mmconsists of a single central catheter and an outer array of eight catheters. A total of 20 plans were generated from 5 patients by using different outer catheter locations at r = 4, 8, and 12 mm. The target was defined as a 5 mmcircumferential shell extending 4 cm in length around the applicator, excluding the bladder, rectum, and bowel. An inverse planning simulated annealing algorithm and graphical optimization was applied to ensure the prescription dose (7.0 Gy per fraction) covered >97% of the target and minimized dose to the OARs. Target coverage (D90 and V100), hot spots (V150 and V200), and OAR doses (D0.1cc, D1cc, and D2cc) from the various catheter placements were compared to single catheter plans. RESULTS: By study design all plans had the same target coverage D90 (105.0- 108.3%) and V100 (97.1-97.2%). The V150 and V200 were 16.1% and 3.4% (r=0mm), 17.3% and 4.2% (r=4mm), 20.1% and 2.2% (r=8mm), and 30.1% and 6.0% (r=12mm). The DO.1cc to the OARs from the various catheter placements at r = 4, 8, and 12 mm was reduced by 4.0%, 8.6%, 11.9% (bladder), 7.4%, 13.2%, and 17.4% (rectum), when compared to the central catheter plans. CONCLUSIONS: Multichannel vaginal applicators provide better dosimetry than single channel applicator. The catheter array located closest to the applicator surface most significantly reduces dose tothe OARs at the expense of larger hot spots in the target. The array in the middle of the applicator radius provides significantly decreased dose to the OARs and gave relatively smaller hot spots.

Long-term survival and PSA control with radiation and immunotherapy for node positive prostate cancer.

We describe a patient with node positive prostate cancer treated with radiation, androgen deprivation, and immunotherapy with long-term overall survival and PSA control. ELISPOT immunoassay studies demonstrated PSA specific T-cells prior to starting vaccine therapy suggesting that this positive response may be related to an improved antitumor immune response of the patient, increased immunogenicity of the tumor, or decreased activation of immune escape pathways. Further evaluation of therapeutic cancer vaccines in combination with radiation and hormonal therapy in the definitive management of prostate cancer is warranted.

Bromocriptine response in normoprolactinemic patients with polycystic ovary disease: a preliminary report.

Recent work has suggested that a central deficiency or defect of dopamine may contribute significantly to the inappropriate gonadotropin secretion commonly associated with polycystic ovary disease. To evaluate this hypothesis, 2.5 to 5 mg of the dopamine agonist bromocriptine was administered daily to patients with polycystic ovary disease. Prolactin (PRL) levels were normal in all cases and there was no evidence of galactorrhea. All patients had failed to conceive while on clomiphene citrate. Seven patients were treated for a total of nine cycles. Ovulation occurred in four cycles, and two of these patients conceived. In five cycles, no ovulation occurred. Among ovulatory cycles, PRL levels declined, but not to undetectable levels. There was also a periovulatory drop in dehydroepiandrosterone sulfate. Levels of luteinizing hormones rose initially and then dropped to below baseline postovulation. Among anovulatory cycles, PRL fell to undetectable levels and dehydroepiandrosterone sulfate was unaffected. Luteinizing hormone levels rose initially and then dropped slightly. In both ovulatory and anovulatory cycles, follicle-stimulating hormone (FSH) levels remained low. These preliminary data suggest: 1) bromocriptine appears capable of altering gonadotropin secretion in polycystic ovary disease, and 2) variable results on ovulation in polycystic ovary disease may reflect the diverse etiology of the pathophysiology of polycystic ovary disease and/or choosing inappropriate dosages of bromocriptine.

Treatment of polycystic ovary disease with chronic low-dose follicle stimulating hormone: biochemical changes and ultrasound correlation.

Pure follicle stimulating hormone (FSH) was administered during six cycles to five patients with "classical" polycystic ovary disease (PCO). Ovulation occurred in four of six cycles, and pregnancy occurred in three of six cycles studied. Luteinizing hormone (LH) levels initially declined slowly. Immediately prior to ovulation there was an exaggerated drop in LH coincidental with an estradiol (E2) rise. This was subsequently followed by a rise in LH above baseline consistent with a preovulatory LH surge. No more than a single dominant, preovulatory follicle was noted in the ovaries of any patient in whom pelvic ultrasound was performed. This study adds further in vivo evidence that FSH is capable of interrupting the self-perpetuating biochemical cycle of PCO in a safe and logical way.

Disappearance of human chorionic gonadotropin following removal of ectopic pregnancy.

A study was undertaken to determine the length of time serum beta-subunit of human chorionic gonadotropin (beta-hCG) could be detected following removal of ectopic pregnancy. Seven patients underwent complete removal of trophoblastic tissue by either salpingectomy or partial resection of the involved fallopian tube. Nine other patients had conservative surgical treatment by either linear salpingostomy or fimbrial expression of the fallopian tube. Serum beta-hCG levels were determined serially in all these patients. The results demonstrate that the initial titer of hCG is a significant factor in determining the length of time that it can be detected in the serum postoperatively. In addition, decreasing titers, conforming to the disappearance curve of hCG, as constructed in this study, are a helpful aid in avoiding further surgery in the group of patients who had a conservative removal of the trophoblastic tissue. Finally, the serum clearance of hCG by radioimmunoassay may take at least up to 24 days after surgery.

Reversal of persistent anovulation in polycystic ovarian disease by administration of chronic low-dose follicle-stimulating hormone.

Low doses of follicle-stimulating hormone (FSH) were administered once daily to two consecutive patients with polycystic ovarian disease (PCOD) for therapy of infertility. Serial blood samples were obtained for gonadotropins and ovarian steroid determinations during the period of FSH administration. Exogenous FSH resulted in an initial and concomitant decrease in serum androstenedione (A), estrone (E1), and luteinizing hormone (LH), with an increase in estradiol (E2) and FSH. Subsequent changes in the above-mentioned hormonal levels were typical of a normal ovulatory cycle, with the exception of FSH, which continued to rise in the second half of the follicular phase. This was attributed to the exogenous administration of FSH. Both patients became pregnant in their first induced ovulatory cycle by administration of chronic low-dose FSH. These preliminary data demonstrate (1) a correction of the biochemical imbalance characteristic of PCOD, (2) successful ovulation induction, and (3) restoration of fertility in PCOD treated with chronic low-dose FSH.