Harmonization of proton treatment planning for head and neck cancer using pencil beam scanning: first report of the IPACS collaboration group.

Background and purpose: A collaborative network between proton therapy (PT) centres in Trento in Italy, Poland, Austria, Czech Republic and Sweden (IPACS) was founded to implement trials and harmonize PT. This is the first report of IPACS with the aim to show the level of harmonization that can be achieved for proton therapy planning of head and neck (sino-nasal) cancer.Methods: CT-data sets of five patients were included. During several face-to-face and online meetings, a common treatment planning protocol was developed. Each centre used its own treatment planning system (TPS) and planning approach with some restrictions specified in the treatment planning protocol. In addition, volumetric modulated arc therapy (VMAT) photon plans were created.Results: For CTV1, the average Dmedian was 59.3 ± 2.4 Gy(RBE) for protons and 58.8 ± 2.0 Gy(RBE) for VMAT (aim was 56 Gy(RBE)). For CTV2, the average Dmedian was 71.2 ± 1.0 Gy(RBE) for protons and 70.6 ± 0.4 Gy(RBE) for VMAT (aim was 70 Gy(RBE)). The average D2% for the spinal cord was 25.1 ± 8.5 Gy(RBE) for protons and 47.6 ± 1.4 Gy(RBE) for VMAT. The average D2% for chiasm was 46.5 ± 4.4 Gy(RBE) for protons and 50.8 ± 1.4 Gy(RBE) for VMAT, respectively. Robust evaluation was performed and showed the least robust plans for plans with a low number of beams.Discussion: In conclusion, several influences on harmonization were identified: adherence/interpretation to/of the protocol, available technology, experience in treatment planning and use of different beam arrangements. In future, all OARs that should be included in the optimization need to be specified in order to further harmonize treatment planning.

Mesenteric ischemia after capecitabine treatment in rectal cancer and resultant short bowel syndrome is not an absolute contraindication for radical oncological treatment.

BACKGROUND: Thrombotic events, arterial or venous in origin, still remain a source of substantial morbidity and mortality in cancer patients. The propensity for their development in oncology patients is partially a consequence of the disease itself and partially a result of our attempts to treat it. One of the rarest and deadliest thromboembolic complications is arterial mesenteric ischemia. The high mortality rate is caused by its rarity and by its non-specific clinical presentation, both of which make early diagnosis and treatment difficult. Hence, most diagnoses and treatments occur late in the course of the disease. The issue survivors of arterial mesenteric ischemia may face is short bowel syndrome, which has become a chronic condition after the introduction of parenteral nutrition at home. CASE REPORT: We present a 73-year-old rectal cancer patient who developed acute arterial mesenteric thrombosis at the beginning of the pre-operative radiochemotherapy. Almost the entire length of his small intestine, except for the proximal 50 cm of it, and the ascending colon had to be resected. After multiorgan failure his condition improved, and he was able to successfully complete radical treatment (preoperative radiotherapy and surgery) for the rectal carcinoma, despite developing short bowel syndrome (SBS) and being dependent upon home-based parenteral nutrition to fully cover his nutritional needs. CONCLUSIONS: Mesenteric ischemia and resultant short bowel syndrome are not absolute contraindications for radical oncological treatment since such patients can still achieve long-term remission.

Carbon Ion Dose Constraints in the Head and Neck and Skull Base: Review of MedAustron Institutional Protocols.

BACKGROUND: Dose constraints are of paramount importance for the outcome of any radiotherapy treatment. In this article, we report dose-volume constraints as well as currently used fractionation schedules for carbon ion radiotherapy as applied in MedAustron (Wiener Neustadt, Austria). MATERIALS AND METHODS: For fractionation schedules, both German and Japanese regimes were used. From the clinical experience of National Institute of Radiological Sciences (Chiba, Japan) and Heidelberg Ion Therapy (Heidelberg, Germany; formerly GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany) and the work by colleagues in Centro Nazionale Adroterapia Oncologica (Pavia, Italy) recalculating the dose from the microdosimetric kinetic model to the local effect model, we have set the dose constraints for critical organs of the head and neck area. Where no clinical data was available, an educated guess was made, based on data available from photon and proton series. RESULTS: We report the constraints for the optic nerve and chiasm, brainstem, spinal cord, cochlea, brain parenchyma, salivary gland, eye and adnexa, and mandibular/maxillary bone; constraints are grouped based on a fractionation scheme (German versus Japanese) and the risk of toxicity (safe, low to middle, and middle to high). CONCLUSION: We think validation of dose constraints should present a relevant part of the activity of any carbon ion radiotherapy facility, and we anticipate future multicentric, joint evaluations.

The EPTN consensus-based atlas for CT- and MR-based contouring in neuro-oncology.

PURPOSE: To create a digital, online atlas for organs at risk (OAR) delineation in neuro-oncology based on high-quality computed tomography (CT) and magnetic resonance (MR) imaging. METHODS: CT and 3 Tesla (3T) MR images (slice thickness 1 mm with intravenous contrast agent) were obtained from the same patient and subsequently fused. In addition, a 7T MR without intravenous contrast agent was obtained from a healthy volunteer. Based on discussion between experienced radiation oncologists, the clinically relevant organs at risk (OARs) to be included in the atlas for neuro-oncology were determined, excluding typical head and neck OARs previously published. The draft atlas was delineated by a senior radiation oncologist, 2 residents in radiation oncology, and a senior neuro-radiologist incorporating relevant available literature. The proposed atlas was then critically reviewed and discussed by European radiation oncologists until consensus was reached. RESULTS: The online atlas includes one CT-scan at two different window settings and one MR scan (3T) showing the OARs in axial, coronal and sagittal view. This manuscript presents the three-dimensional descriptions of the fifteen consensus OARs for neuro-oncology. Among these is a new OAR relevant for neuro-cognition, the posterior cerebellum (illustrated on 7T MR images). CONCLUSION: In order to decrease inter- and intra-observer variability in delineating OARs relevant for neuro-oncology and thus derive consistent dosimetric data, we propose this atlas to be used in photon and particle therapy. The atlas is available online at www.cancerdata.org and will be updated whenever required.

Radiation dose constraints for organs at risk in neuro-oncology; the European Particle Therapy Network consensus.

PURPOSE: For unbiased comparison of different radiation modalities and techniques, consensus on delineation of radiation sensitive organs at risk (OARs) and on their dose constraints is warranted. Following the publication of a digital, online atlas for OAR delineation in neuro-oncology by the same group, we assessed the brain OAR-dose constraints in a follow-up study. METHODS: We performed a comprehensive search to identify the current papers on OAR dose constraints for normofractionated photon and particle therapy in PubMed, Ovid Medline, Cochrane Library, Embase and Web of Science. Moreover, the included articles' reference lists were cross-checked for potential studies that met the inclusion criteria. Consensus was reached among 20 radiation oncology experts in the field of neuro-oncology. RESULTS: For the OARs published in the neuro-oncology literature, we summarized the available literature and recommended dose constraints associated with certain levels of normal tissue complication probability (NTCP) according to the recent ICRU recommendations. For those OARs with lacking or insufficient NTCP data, a proposal for effective and efficient data collection is given. CONCLUSION: The use of the European Particle Therapy Network-consensus OAR dose constraints summarized in this article is recommended for the model-based approach comparing photon and proton beam irradiation as well as for prospective clinical trials including novel radiation techniques and/or modalities.

Radiotherapy With 4 Gy × 5 Versus 3 Gy × 10 for Metastatic Epidural Spinal Cord Compression: Final Results of the SCORE-2 Trial (ARO 2009/01).

PURPOSE: To compare short-course radiotherapy (RT) (4 Gy × 5) to longer-course RT (3 Gy × 10) for metastatic epidural spinal cord compression (MESCC). PATIENTS AND METHODS: Two-hundred three patients with MESCC and poor to intermediate expected survival were randomly assigned to 4 Gy × 5 in 1 week (n = 101) or 3 Gy × 10 in 2 weeks (n = 102). Patients were stratified according to ambulatory status, time developing motor deficits, and primary tumor type. Seventy-eight and 77 patients, respectively, were evaluable for the primary end point, 1-month overall response regarding motor function defined as improvement or no further progression of motor deficits. Other study end points included ambulatory status, local progression-free survival, and overall survival. End points were evaluated immediately after RT and at 1, 3, and 6 months thereafter. RESULTS: At 1 month, overall response rates regarding motor function were 87.2% after 4 Gy × 5 and 89.6% after 3 Gy × 10 (P = .73). Improvement rates were 38.5% and 44.2%, respectively, no further progression rates 48.7% and 45.5%, respectively, and deterioration rates 12.8% and 10.4%, respectively (P = .44). Ambulatory rates at 1 month were 71.8% and 74.0%, respectively (P = .86). At other times after RT, the results were also not significantly different. Six-month local progression-free survival was 75.2% after 4 Gy × 5 and 81.8% after 3 Gy × 10 (P = .51); 6-month overall survival was 42.3% and 37.8% (P = .68). CONCLUSION: Short-course RT with 4 Gy × 5 was not significantly inferior to 3 Gy × 10 in patients with MESCC and poor to intermediate expected survival.

A new instrument for estimation of survival in elderly patients irradiated for metastatic spinal cord compression from breast cancer.

BACKGROUND: Elderly patients become more important in oncology. In this group, personalized treatment approaches taking into account survival prognoses and comorbidities play a major role. Predictive instruments are necessary to estimate the survival of elderly cancer patients. The importance of separate instruments for different tumor entities has been recognized. In this study, an instrument was generated to estimate the survival of elderly patients developing metastatic spinal cord compression (MSCC) from breast cancer. METHODS: In 218 elderly patients (age ≥65 years) irradiated for MSCC from breast cancer, nine factors were evaluated for survival: fractionation regimen, age, time from breast cancer diagnosis to RT of MSCC, visceral metastases, other bone metastases, time developing motor deficits, pre-radiotherapy ambulatory status, number of involved vertebrae, and Eastern Cooperative Oncology Group (ECOG) performance score. Factors significantly associated with survival in the Cox regression analysis were included in the prognostic instrument. Scores for each factor were calculated by dividing the 6-months survival rates by 10. The sums of these scores represented the patients' scores. RESULTS: On multivariate analyses, visceral metastases (p < 0.001), time developing motor deficits (p < 0.001), ambulatory status (p < 0.001), number of involved vertebrae (p = 0.032), and ECOG performance score (p < 0.001) were significant and included in the prognostic instrument. Based on the patients' scores, three groups were designed: 18-27 points, 28-39 points and 40-42 points. Six-months survival rates were 4, 62 and 100%, respectively (p < 0.001). CONCLUSIONS: This new instrument contributes to personalized treatment in elderly patients with MSCC from breast cancer by predicting an individual patient's survival prognosis.

Single-Fraction Versus 5-Fraction Radiation Therapy for Metastatic Epidural Spinal Cord Compression in Patients With Limited Survival Prognoses: Results of a Matched-Pair Analysis.

PURPOSE: This study compared single-fraction to multi-fraction short-course radiation therapy (RT) for symptomatic metastatic epidural spinal cord compression (MESCC) in patients with limited survival prognosis. METHODS AND MATERIALS: A total of 121 patients who received 8 Gy × 1 fraction were matched (1:1) to 121 patients treated with 4 Gy × 5 fractions for 10 factors including age, sex, performance status, primary tumor type, number of involved vertebrae, other bone metastases, visceral metastases, interval between tumor diagnosis and MESCC, pre-RT ambulatory status, and time developing motor deficits prior to RT. Endpoints included in-field repeated RT (reRT) for MESCC, overall survival (OS), and impact of RT on motor function. Univariate analyses were performed with the Kaplan-Meier method and log-rank test for in-field reRT for MESCC and OS and with the ordered-logit model for effect of RT on motor function. RESULTS: Doses of 8 Gy × 1 fraction and 4 Gy × 5 fractions were not significantly different with respect to the need for in-field reRT for MESCC (P=.11) at 6 months (18% vs 9%, respectively) and 12 months (30% vs 22%, respectively). The RT regimen also had no significant impact on OS (P=.65) and post-RT motor function (P=.21). OS rates at 6 and 12 months were 24% and 9%, respectively, after 8 Gy × 1 fraction versus 25% and 13%, respectively, after 4 Gy × 5 fractions. Improvement of motor function was observed in 17% of patients after 8 Gy × 1 fraction and 23% after 4 Gy × 5 fractions, respectively. CONCLUSIONS: There were no significant differences with respect to need for in-field reRT for MESCC, OS, and motor function by dose fractionation regimen. Thus, 8 Gy × 1 fraction may be a reasonable option for patients with survival prognosis of a few months.