Person:

Efstathiou, Jason

Purpose

To quantify daily variations in the anatomy of patients undergoing radiation therapy for prostate carcinoma, to estimate their effect on dose distribution, and to evaluate the effectiveness of current standard planning and set-up approaches employed in proton therapy.

Methods

We used series of CT data, which included the pre-treatment scan, and between 21 and 43 in-room scans acquired on different treatment days, from 10 patients treated with intensity-modulated radiation therapy at Morristown Memorial Hospital. Variations in femur rotation angles, thickness of subcutaneous adipose tissue, and physical depth to the distal surface of the prostate for lateral beam arrangement were recorded. Proton dose distributions were planned with the standard approach. Daily variations in the location of the prescription iso-dose were evaluated.

Results

In all 10 datasets, substantial variation was observed in the lateral tissue thickness (standard deviation of 1.7–3.6 mm for individual patients, variations of over 5 mm from the planning CT observed in all series), and femur rotation angle (standard deviation between 1.3–4.8°, with the maximum excursion exceeding 10° in 6 out of 10 datasets). Shifts in the position of treated volume (98% iso-dose) were correlated with the variations in the lateral tissue thickness.

Conclusions

Analysis suggests that, combined with image-guided set-up verification, the range compensator expansion technique prevents loss of dose to target due to femur rotation and soft tissue deformation, in the majority of cases. Anatomic changes coupled with the uncertainties of particle penetration in tissue restrict possibilities for margin reduction in proton therapy of prostate cancer.

The NCI Bladder Cancer Task Force convened a Clinical Trials Planning Meeting (CTPM) Workshop focused on Novel Therapeutics for Non-Muscle Invasive Bladder Cancer (NMIBC). Meeting attendees included a broad and multi-disciplinary group of clinical and research stakeholders and included leaders from NCI, FDA, National Clinical Trials Network (NCTN), advocacy and the pharmaceutical and biotech industry. The meeting goals and objectives were to: 1) create a collaborative environment in which the greater bladder research community can pursue future optimally designed novel clinical trials focused on the theme of molecular targeted and immune-based therapies in NMIBC; 2) frame the clinical and translational questions that are of highest priority; and 3) develop two clinical trial designs focusing on immunotherapy and molecular targeted therapy. Despite successful development and implementation of large Phase II and Phase III trials in bladder and upper urinary tract cancers, there are no active and accruing trials in the NMIBC space within the NCTN. Disappointingly, there has been only one new FDA approved drug (Valrubicin) in any bladder cancer disease state since 1998. Although genomic-based data for bladder cancer are increasingly available, translating these discoveries into practice changing treatment is still to come. Recently, major efforts in defining the genomic characteristics of NMIBC have been achieved. Aligned with these data is the growing number of targeted therapy agents approved and/or in development in other organ site cancers and the multiple similarities of bladder cancer with molecular subtypes in these other cancers. Additionally, although bladder cancer is one of the more immunogenic tumors, some tumors have the ability to attenuate or eliminate host immune responses. Two trial concepts emerged from the meeting including a window of opportunity trial (Phase 0) testing an FGFR3 inhibitor and a second multi-arm multi-stage trial testing combinations of BCG or radiotherapy and immunomodulatory agents in patients who recur after induction BCG (BCG failure).

The 10th Annual Bladder Cancer Think Tank was hosted by the Bladder Cancer Advocacy Network and brought together a multidisciplinary group of clinicians, researchers, representatives and Industry to advance bladder cancer research efforts. Think Tank expert panels, group discussions, and networking opportunities helped generate ideas and strengthen collaborations between researchers and physicians across disciplines and between institutions. Interactive panel discussions addressed a variety of timely issues: 1) data sharing, privacy and social media; 2) improving patient navigation through therapy; 3) promising developments in immunotherapy; 4) and moving bladder cancer research from bench to bedside. Lastly, early career researchers presented their bladder cancer studies and had opportunities to network with leading experts.

Radical cystectomy with extended pelvic lymph-node dissection, associated with neo-adjuvant chemotherapy, remains the standard of care for advanced, non-metastatic muscle-invasive bladder cancer (MIBC). Loco-regional control is a key factor in the outcome of patients since it is related to overall survival (OS), disease-free survival (DFS) and cause-specific survival. The risk of loco-regional recurrence (LRR) is correlated to pathological factors as well as the extent of the lymphadenectomy. In addition, neither pre- nor post-operative chemotherapy have shown a clear impact on LRR-free survival. Several recent publications have led to the development of a nomogram predicting the risk of LRR, in order to identify patients most likely to benefit from adjuvant radiotherapy. Given the high risk of LRR for selected patients and improvements in radiation techniques that can reduce toxicity, there is a growing interest in adjuvant radiotherapy; international cooperative groups have come together to provide the rationale in favor of adjuvant radiotherapy. Clinical trials in order to reduce the risk of pelvic relapse are opened based on this optimizing patient selection. The aim of this critical literature review is to provide an overview of the rationale supporting the studies of adjuvant radiation for patients with pathologic high-risk MIBC.

Background. Three-quarters of cancer deaths occur in resource-limited countries, and delayed presentation contributes to poor outcome. In Botswana, where more than half of cancers arise in HIV-infected individuals, we sought to explore predictors of timely oncology care and evaluate the hypothesis that engagement in longitudinal HIV care improves access. Methods. Consenting patients presenting for oncology care from October 2010 to September 2014 were interviewed and their records were reviewed. Cox and logistic models were used to examine the effect of HIV and other predictors on time to oncology care and presentation with advanced cancer (stage III or IV). Results. Of the 1,146 patients analyzed, 584 (51%) had HIV and 615 (54%) had advanced cancer. The initial clinic visit occurred a mean of 144 days (median 29, interquartile range 0–185) after symptom onset, but subsequent mean time to oncology care was 406 days (median 160, interquartile range 59–653). HIV status was not significantly associated with time to oncology care (adjusted hazard ratio [aHR] 0.91, 95% confidence interval [CI] 0.79–1.06). However, patients who reported using traditional medicine/healers engaged in oncology care significantly faster (aHR 1.23, 95% CI 1.09–1.40) and those with advanced cancer entered care earlier (aHR 1.48, 95% CI 1.30–1.70). Factors significantly associated with advanced cancer included income <$50 per month (adjusted odds ratio [aOR] 1.35, 95% CI 1.05–1.75), male sex (aOR 1.45, 95% CI 1.12–1.87), and pain as the presenting symptom (aOR 1.39, 95% CI 1.03–1.88). Conclusion. Longitudinal HIV care did not reduce the substantial delay to cancer treatment. Research focused on reducing health system delay through coordination and navigation is needed. Implications for Practice: The majority (54%) of patients in this large cohort from Botswana presented with advanced-stage cancer despite universal access to free health care. Median time from first symptom to specialized oncology care was 13 months. For HIV-infected patients (51% of total), regular longitudinal contact with the health system, through quarterly doctor visits for HIV management, was not successful in providing faster linkages into oncology care. However, patients who used traditional medicine/healers engaged in cancer care faster, indicating potential for leveraging traditional healers as partners in early cancer detection. New strategies are urgently needed to facilitate diagnosis and timely treatment of cancer in low- and middle-income countries.

Background: The purpose of this study was to demonstrate the feasibility of physician driven planning in intensity modulated radiotherapy (IMRT) with a multicriteria optimization (MCO) treatment planning system and template based plan optimization. Exploiting the full planning potential of MCO navigation, this alternative planning approach intends to improve planning efficiency and individual plan quality. Methods: Planning was retrospectively performed on 12 brain tumor and 10 post-prostatectomy prostate patients previously treated with MCO-IMRT. For each patient, physicians were provided with a template-based generated Pareto surface of optimal plans to navigate, using the beam angles from the original clinical plans. We compared physician generated plans to clinically delivered plans (created by dosimetrists) in terms of dosimetric differences, physician preferences and planning times. Results: Plan qualities were similar, however physician generated and clinical plans differed in the prioritization of clinical goals. Physician derived prostate plans showed significantly better sparing of the high dose rectum and bladder regions (p(D1) < 0.05; D1: dose received by 1% of the corresponding structure). Physicians’ brain tumor plans indicated higher doses for targets and brainstem (p(D1) < 0.05). Within blinded plan comparisons physicians preferred the clinical plans more often (brain: 6:3 out of 12, prostate: 2:6 out of 10) (not statistically significant). While times of physician involvement were comparable for prostate planning, the new workflow reduced the average involved time for brain cases by 30%. Planner times were reduced for all cases. Subjective benefits, such as a better understanding of planning situations, were observed by clinicians through the insight into plan optimization and experiencing dosimetric trade-offs. Conclusions: We introduce physician driven planning with MCO for brain and prostate tumors as a feasible planning workflow. The proposed approach standardizes the planning process by utilizing site specific templates and integrates physicians more tightly into treatment planning. Physicians’ navigated plan qualities were comparable to the clinical plans. Given the reduction of planning time of the planner and the equal or lower planning time of physicians, this approach has the potential to improve departmental efficiencies.

Abstract Purpose In SBRT for prostate cancer, higher fractional dose to the rectum is a major toxicity concern due to using smaller PTV margin and hypofractionation. We investigate the dosimetric impact on rectum using endorectal balloon (ERB) in prostate SBRT. Materials and Methods Twenty prostate cancer patients were included in a retrospective study, ten with ERB and 10 without ERB. Optimized SBRT plans were generated on CyberKnife MultiPlan for 5 × 7.25 Gy to PTV under RTOG‐0938 protocol for early‐stage prostate cancer. For the rectum and the anterior half rectum, mean dose and percentage of volumes receiving 50%, 80%, 90%, and 100% prescription dose were compared. Results: Using ERB, mean dose to the rectum was 62 cGy (P = 0.001) lower per fraction, and 50 cGy (P = 0.024) lower per fraction for the anterior half rectum. The average V50%, V80%, V90%, and V100% were lower by 9.9% (P = 0.001), 5.3% (P = 0.0002), 3.4% (P = 0.0002), and 1.2% (P = 0.005) for the rectum, and lower by 10.4% (P = 0.009), 8.3% (P = 0.0004), 5.4% (P = 0.0003), and 2.1% (P = 0.003) for the anterior half rectum. Conclusions: Significant reductions of dose to the rectum using ERB were observed. This may lead to improvement of the rectal toxicity profiles in prostate SBRT.