Assessment of Treatment Plan Quality between Flattening Filter and Flattening Filter Free Photon Beam for Carcinoma of the Esophagus with IMRT Technique

Background

As compared to the flattened photon beam, removing the flattening filter (FF) from the head of a gantry decreases the average energy of the photon beam and increases the dose rate, leading to an impact on the quality of treatment plans.

Objective

This study aimed to compare the quality of intensity-modulated radiation therapy (IMRT) treatment plans for esophageal cancer with and without a flattened filter photon beam.

Material and Methods

In this analytical study, 12 patients, who had already been treated with a 6X FF photon beam, were treated based on new IMRT methods using a 6X the flattening filter-free (FFF) photon beam. Both 6X FF IMRT and 6X FFF IMRT plans used identical beam parameters and planning objectives. All plans were evaluated with planning indices and doses for organs at risk (OARs).

Results

Insignificant dose variation was for HI, CI, D_98%, and V_95% between FF and FFF photon beam IMRT plans. FF-based IMRT plan delivered a 15.51 % and 11.27% higher mean dose to both lungs and heart than the FFF plan, respectively. The integral dose (ID) for the heart and lungs was 11.21% and 15.51%, respectively, less in the IMRT plan with an FFF photon beam.

Conclusion

In contrast to the FF photon beam, a filtered photon beam-oriented IMRT plan provides significant OAR sparing without losing the quality of the treatment plan. High monitor units (MUs), low ID, and Beam on Time (BOT) are major highlights of the IMRT plan with FFF beam.

Optimizing multi-modal cancer treatment under 3D spatio-temporal tumor growth

In this paper we introduce a new mixed-integer linear programming (MIP) model that explicitly integrates the spread of cancer cells into a spatio-temporal reaction-diffusion (RD) model of cancer growth, while taking into account treatment effects. This linear but non-convex model appears to be the first of its kind by determining the optimal sequence of the typically prescribed cancer treatment methods-surgery (S), chemotherapy (C), and radiotherapy (R)-while minimizing the newly generated tumor cells for early-stage breast cancer in a unique three-dimensional (3D) spatio-temporal system. The quadratically-constrained cancer growth dynamics and treatment impact formulations are linearized by using linearization as well as approximation techniques. Under the supervision of medical oncologists and utilizing several literature resources for the parameter values, the effectiveness of treatment combinations for breast cancer specified with different sequences (i.e., SRC, SCR, CR, RC) are compared by tracking the number of cancer cells at the end of each treatment modality. Our results provide the optimal dosages for chemotherapy and radiation treatments, while minimizing the growth of new cancer cells.

Multimodal treatment in locally advanced gastric cancer

According to the data of the GLOBOCAN-network of the World Health Organization, there were 952,000 (6.8% of the total) new cases of gastric cancer in 2012, making it the fifth most common malignancy in the world. It represents a substantive change since the very first estimates in 1975 when stomach cancer was the most common neoplasm. More than 70% of cases (677,000 cases) occur in developing countries, and half the world total occurs in Eastern Asia, mainly in China. Gastric cancer is the third leading cause of cancer death in both sexes worldwide (Globocan, Estimated cancer incidence, mortality and prevalence worldwide in 2012, http://globocan.iarc.fr , 2012). Annually, worldwide 723,000 patients die of this tumor entity. Interestingly, a strong change in incidence rates in relation to the anatomical-topographic localization of the primary tumors in the stomach and esophagus has been experienced. While the frequency of proximal gastric carcinoma and adenocarcinoma of the cardiac and subcardiac region in Europe and North America has been constantly rising, distal gastric carcinomas have become less common (Torre et al. in JAMA 65:87-108, 2015). Furthermore, the relative incidence of esophageal adenocarcinoma (mostly localized in the distal esophagus) has strongly increased (Jemal et al. in JAMA 58:71-96, 2008; Crew and Neugut 31:450-464, 2004; Pohl and Welch 97:142-146, 2005).

Large-scale comprehensive immunohistochemical biomarker analyses in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a heterogeneous disease in the sense that the biological behavior is regulated by the activation of various signaling pathways. The aim of this study was to investigate the relationships between the expressions of various targetable proteins and the clinicopathological characteristics of ESCC patients.

METHODS

A total of 286 patients with ESCC who had undergone curative surgical resection without neoadjuvant therapy were enrolled in this study. The protein expressions of EGFR, HER2, MET, IGF1R, FGFR2, p53, and PD-L1 were immunohistochemically evaluated in a tissue microarray analysis. The relationships between the expression statuses of each of the above molecules, and the PD-L1 expression status as well as the clinicopathological characteristics, including the survival outcome were assessed.

RESULTS

The expression frequencies of EGFR, HER2, MET, IGF1R, FGFR2, p53, and PD-L1 were as follows: 90.9, 1.0, 2.4, 71.0, 16.1, 62.9 and 23.4%. The overlapping expressions of two or more receptor tyrosine kinases were observed in 72.0%. MET expression was the only poor prognostic factor of recurrence-free survival [hazard ratio (HR) 1.89, 95% confidence interval (CI) 1.15-3.11]; in contrast, PD-L1 was the only favorable prognostic factor for both recurrence-free survival (HR 0.57, 95% CI 0.38-0.87) and overall survival (HR 0.56, 95% CI 0.35-0.89). No correlation was observed between the expressions of PD-L1 and the other molecules.

CONCLUSIONS

This large cohort study demonstrated that multiple molecules were co-expressed in most of the ESCC cases, suggesting that combining molecular targeted agents for these co-expressed molecules should be considered.

Unravelling the pharmacologic opportunities and future directions for targeted therapies in gastro-intestinal cancers Part 1: GI carcinomas

Until the 1990s, cytotoxic chemotherapy has been the cornerstone of medical therapy for gastrointestinal (GI) cancers. Better understanding of the molecular biology of cancer cell has led to the therapeutic revolution of targeted therapies, i.e. monoclonal antibodies or small molecule inhibitors directed against proteins that are specifically overexpressed or mutated in cancer cells. These agents being more specific to cancer cells were expected to be less toxic than cytotoxic agents. Targeted agents have provided clinical benefit in many GI cancer types. For example, antiangiogenics and anti-EGFR therapies have significantly improved survival of patients affected by metastatic colorectal cancer and have deeply changed the therapeutic strategy in this disease. However, their effects have sometimes been disappointing, due to intrinsic or acquired resistance mechanisms (e.g., RAS mutation for anti-EGFR therapies), or to an activity restricted to some tumour settings (e.g., lack of activity in other cancer types, or on the microscopic residual disease in adjuvant setting). Many studies are negative in overall population but positive in some specific patient subgroups (e.g., trastuzumab in HER2-positive gastric cancer), illustrating the importance of patient selection and early identification of predictive biomarkers of response to these therapies. We propose a comprehensive two-part review providing a panoramic approach of the successes and failures of targeted agents in GI cancers to unravel the pharmacologic opportunities and future directions for these agents in GI oncology. In this first part, we will focus on adenocarcinomas and squamous cell carcinomas, for which targeted therapies are mostly used in combination with chemotherapy.

Eastern Cooperative Oncology Group and American College of Radiology Imaging Network Randomized Phase 2 Trial of Neoadjuvant Preoperative Paclitaxel/Cisplatin/Radiation Therapy (RT) or Irinotecan/Cisplatin/RT in Esophageal Adenocarcinoma: Long-Term Outcome and Implications for Trial Design

PURPOSE

Toxicity, pathologic complete response, and long-term outcomes are reported for the neoadjuvant therapies assessed in a randomized phase 2 Eastern Cooperative Oncology Group and American College of Radiology Imaging Network trial for operable esophageal adenocarcinoma, staged as II-IVa by endoscopy/ultrasonography (EUS).

METHODS AND MATERIALS

A total of 86 eligible patients began treatment. For arm A, preoperative chemotherapy was cisplatin, 30 mg/m(2), and irinotecan, 50 mg/m(2), on day 1, 8, 22, 29 during 45 Gy radiation therapy (RT), 1.8 Gy per day over 5 weeks. Adjuvant therapy was cisplatin, 30 mg/m(2), and irinotecan, 65 mg/m(2) day 1, 8 every 21 days for 3 cycles. Arm B therapy was cisplatin, 30 mg/m(2), and paclitaxel, 50 mg/m(2), day 1, 8, 15, 22, 29 with RT, followed by adjuvant cisplatin, 75 mg/m(2), and paclitaxel, 175 mg/m(2), day 1 every 21 days for 3 cycles. Stratification included EUS stage and performance status.

RESULTS

In arm A, median overall survival was 35 months, and 5-, 6-, and 7-year survival rates were 46%, 39%, and 35%, respectively, whereas for arm B, they were 21 months and 27%, 27%, and 23%, respectively. Median progression- or recurrence-free survival (PFS) was 39.8 months with a 3-year PFS of 50% for arm A and 12.4 months (P=.046) with 3-year PFS of 28% for arm B. Eighty percent of the observed incidents of progression occurred within 19 months. Survival did not differ significantly by EUS and performance status strata.

CONCLUSIONS

Long-term survival was similar for both arms and did not appear superior to results achieved with other standard regimens.