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Background and purpose Early-stage Hodgkin lymphoma (HL) is a highly curable disease but the treatment can induce late complications many years later. Irradiation of the healthy heart is inevitable during radiation treatment of mediastinal sites. We developed a novel method to induce a prolonged apnea-like state that can help decrease the dose to organs at risk during radiation therapy. We present the results of the first 8 HL patients treated routinely with percussion assisted radiation therapy (PART) in our clinic. Material and methods We used a newly developed high-frequency non-invasive ventilation system to suppress respiratory motion for prolonged periods and push the heart away from the treated volume. Results All 8 patients were able to rapidly learn the technique and had an advantage to be treated by PART. We lowered the mean heart dose by an average of 3 Gy with similar target coverage compared to a classical free breathing treatment plan. They were all treated for 15 radiotherapy sessions by PART without any notable side effects. Conclusions Percussion assisted radiation therapy can be used routinely to reduce the dose to the heart in Hodgkin lymphoma.

The Gamma Knife ® planning software (TMR 10, Elekta Instruments, AB, Sweden) affords two ways of defining the skull volume, the "historical" one using manual measurements (still perform in some centers) and the new one using image-based skull contours. Our objective was to assess the potential variation of the dose delivery calculation using consecutively in the same patients the two above-mentioned techniques. We included in this self-case-control study, 50 patients, treated with GKRS between July 2016 and January 2017 in Lausanne University Hospital, Switzerland, distributed among four groups: convexity targets (n = 18), deep-seated targets (n = 13), vestibular schwannomas (n = 11), and trigeminal neuralgias (n = 8). Each planning was performed consecutively with the 2 skull definition techniques. For each treatment, we recorded the beam-on time (min), target volume coverage (%), prescription isodose volume (cm 3 ), and maximal dose (Gy) to the nearest organ at risk if relevant, according to each of the 2 skull definition techniques. The image-based contours were performed using CT scan segmentation, based upon a standardized windowing for all patients. The median difference in beam-on time between manual measures and image-based contouring was + 0.45 min (IQR; 0.2-0.6) and was statistically significant (p < 0.0001), corresponding to an increase of 1.28% beam-on time per treatment, when using image-based contouring. The target location was not associated with beam-on time variation (p = 0.15). Regarding target volume coverage (p = 0.13), prescription isodose volume (p = 0.2), and maximal dose to organs at risk (p = 0.85), no statistical difference was reported between the two skull contour definition techniques. The beam-on time significantly increased using image-based contouring, resulting in an increase of the total dose delivery per treatment with the new TMR 10 algorithm. Other dosimetric parameters did not differ significantly. This raises the question of other potential impacts. One is potential dose modulation that should be performed as an adjustment to new techniques developments. The second is how this changes the biologically equivalent dose per case, as related to an increased beam on time, delivered dose, etc., and how this potentially changes the radiobiological effects of GKRS in an individual patient.

Highlights • The first curative management of symptomatic cardiac metastasis of a lung cancer using SBRT. • A CR was obtained and no further specific treatment was needed., Although cardiac metastases (CM) are more common than primary cardiac malignant tumors, they remain a rare localization of metastatic cancer. Until recently, CM were surgically treated as a palliative approach because of a lack of ablative solutions even for oligometastatic patients. Technological advances in radiation therapy (RT) in thoracic oncology have led to high precision delivery that enlarged the indications for stereotactic body radiotherapy (SBRT). To date, there are limited reports of cardiac SBRT for CM. Herein, we report a cardiac SBRT performed in curative intent for a lung cancer patient metastatic to the heart.

Purpose Helical tomotherapy (HT) has been recently introduced in the neoadjuvant treatment of locally advanced rectal cancer. Aim of this study is to report the toxicity and local control rates of a large series of locally advanced rectal cancer patients treated with neoadjuvant chemotherapy and HT under daily image guidance followed by surgery. Methods Data from 117 locally advanced rectal cancer patients treated at two Swiss Radiotherapy departments were collected and analyzed. Radiotherapy consisted of 45 Gy (1.8 Gy/fraction, 5 fractions/week delivered in 5 weeks) to the regional pelvic lymph nodes. Seventy patients also received a simultaneous integrated boost (SIB) up to 50 Gy to the tumor and involved nodes (2 Gy/fraction, 5 fractions/week delivered in 5 weeks). Chemotherapy consisted of capecitabine 825 mg/m2, twice daily, during the irradiation days. After a median interval of 59 days [95% confidence interval (CI) 53–65 days), all patients underwent surgery. Results Median follow-up was 45 months (range 4–90 months). The overall rate of acute grade 2–4 toxicity was 18.8% (n = 22). Four patients (3.4%) presented a grade 3 dermatitis (n = 1) or diarrhea (n = 3), and 1 (0.8%) demonstrated grade 4 rectal toxicity. No patients presented with grade ≥ 3 hematologic toxicity. Six patients (5.1%) had late grade 3 gastrointestinal toxicity. The 4-year local control rate was 88.4% (95% CI 87.5–88.5%). Conclusions Neoadjuvant chemoradiotherapy delivered with HT under daily image guidance is well tolerated and shows a high 4-year local control rates.

Ventricular tachycardia (VT) caused by myocardial scaring bears a significant risk of mortality and morbidity. Antiarrhythmic drug therapy (AAD) and catheter ablation remain the cornerstone of VT management, but both treatments have limited efficacy and potential adverse effects. Stereotactic body radiotherapy (SBRT) is routinely used in oncology to treat non-invasively solid tumors with high precision and efficacy. Recently, this technology has been evaluated for the treatment of VT. This review presents the basic underlying principles, proof of concept, and main results of trials and case series that used SBRT for the treatment of VT refractory to AAD and catheter ablation.

Background and purpose: Adjuvant radiation therapy (RT) of the whole breast (WB) is still the standard treatment for early breast cancer. A variety of radiation techniques is currently available according to different delivery strategies. This study aims to provide a comparison of six treatment planning strategies commonly adopted for breast-conserving adjuvant RT and to use the Pareto concept in an attempt to assess the degree of plan optimization. Materials and methods: Two groups of six left- and five right-sided cases with different dose prescriptions were involved (22 patients in total). Field-in-Field (FiF), two and four Fields static-IMRT (sIMRT-2f and sIMRT-4f), Volumetric-Modulated-Arc-Therapy (VMAT), Helical Tomotherapy (HT) and Static-Angles Tomotherapy (TomoDirect™ – TD) were planned. Dose volume constraints were taken from the RTOG protocol 1005. Pareto fronts were built for a selected case to evaluate the reliability of the plan optimization process. Results: The best target dose coverage was observed for TD able to improve significantly (p

Schwannomas involving the occulomotor cranial nerves (CNs; III, IV and VI), can be disabling, due to the associated diplopia and decreased quality of life and are extremely rare. We evaluated the role of Gamma Knife surgery (GKS) in these cases. Five patients with CN IV and VI schwannomas (three and two, respectively) were treated in Lausanne University Hospital between 2010 and 2015. Four benefitted from upfront GKS and one from a combined approach (planned subtotal resection followed by GKS), due to a large preoperative tumour volume (size, 3 × 2 × 2.5 cm; volume, 7.9 ml), with symptomatic mass effect and oedema, as well as an entrapement cyst at the brainstem interface, in a young patient. Neuro-ophtalmological evaluation was performed at baseline and during each follow-up time-point. A systematic literature review is presented and compared to the present report. The mean follow-up was 44.4 months (12–54). Initial clinical presentation was diplopia in four cases and cavernous sinus syndrome in one. The marginal dose was 12 Gy in all cases. The mean target volume was 1.51 cm3 (0.086–5.8). The mean prescription isodose volume (PIV) was 1.71 cm3 (0.131–6.7). At last follow-up, all patients presented with disappearance of the baseline symptoms. Tumour control was achieved in 100%, with decrease in volume in all cases. The systematic review analysed 11 peer-reviewed studies, with a total of 35 patients. For uniformly reported CN VI, the mean marginal radiation dose ranged between 12 and 12.5 Gy, with disappearance of symptoms in 12.5%, improvement in 31.25%, stabilisation in 6.25%, worsening in 12.5%. Tumour volume decreased in all cases. Our data suggest that first intention GKS is a safe and effective option for patients with small to medium size oculomotor schwannomas, providing a high rate of clinical alleviation and tumour control. When the initial tumour volume is too large for first intention GKS, a combined approach with planned subtotal resection followed by GKS can be performed, with favourable and comparable outcomes as in upfront GKS.

Objective Glossopharyngeal neuralgia (GPN) is a very rare condition, affecting the patient’s quality of life. We report our experience in drug-resistant, idiopathic GPN, treated with Gamma Knife radiosurgery (GKRS), in terms of safety and efficiency, on a very long-term basis. Methods The study was opened, self-controlled, non-comparative and bicentric (Marseille and Lausanne University Hospitals). Patients treated with GKRS between 2003 and 2015 (models C, 4C and Perfexion) were included. A single 4-mm isocentre was positioned in the cisternal portion of the glossopharyngeal nerve, with a targeting based both on magnetic resonance imaging (MRI) and computed tomography (CT). The mean maximal dose delivered was 81.4 ± 6.7 Gy (median = 85 Gy, range = 60–90 Gy at the 100% isodose line). Results Twenty-one patients (11 women, 10 men) benefited from 25 procedures. The mean follow-up period was 5.2 ± 3 years (range = 0.9–12.1 years). Seventeen (81%) were initially pain-free after GKRS. At three months, six months and one year after radiosurgery, the percentage of patients with good outcome (BNI classes I to IIIA) was 87.6%, 100% and 81.8%, respectively. Ten cases (58.8%) from the initial pain-free ones had a recurrence, after a mean period of 13.6 ± 10.4 months (range = 3.1–36.6 months). Only three patients (14.2%) had recurrences (two for each one of them) requiring further surgeries. Three patients underwent a second GKRS procedure; one case needed a third GKRS. The former procedures were performed at 7, 17, 19 and 30 months after the first one, respectively. Furthermore, two patients needed additional interventions. At last follow-up, 17 cases (80.9%) were still pain-free without medication. The actuarial pain relief without new surgery was 83%. A transient complication (paraesthesia of the edge of the tongue) was seen in one case (4.8%). Conclusion GKRS is a valuable, minimally invasive, surgical alternative for idiopathic GPN, with a very high short- and long-term efficacy and without permanent complications. A quality imaging, including T2 CISS/Fiesta MRI and bone CT acquisitions for good visualisation of the nerve and the other bony anatomic landmarks, is essential for targeting accuracy and successful therapy.

Stereotactic body radiotherapy (SBRT) is an emerging non-invasive treatment in the management of ventricular tachycardia (VT). We report here an intensive care patient suffering from an electrical storm due to incessant VT, unresponsive to catheter ablation and anti-arrhythmic drugs, showing an immediate and durable response to electrophysiology-guided cardiac SBRT.

OBJECTIVEVestibular schwannomas (VSs) represent a common indication of Gamma Knife surgery (GKS). While most studies focus on the long-term morbidity and adverse radiation effects (AREs), none describe the acute clinical AREs that might appear on a short-term basis. These types of events are investigated, and their incidence, type, and outcomes are reported in the present paper.METHODSThe included patients were treated between July 2010 and March 2016, underwent at least 6 months of follow-up, and presented with a disabling symptom during the first 6 months after GKS that affected their quality of life. The timing of appearance, as well as the type of main symptom and outcome, were noted. The prescribed dose was 12 Gy at the margin.RESULTSThirty-five (22%) of 159 patients who fulfilled the inclusion criteria had acute clinical AREs. The mean followup period was 30 months (range 6–49.2 months). The mean time of appearance was 37.9 days (median 31 days; range 3–110 days). In patients with de novo symptoms, the more frequent symptoms were vertigo (n = 4; 11.4%) and gait disturbance (n = 3; 8.6%). The exacerbation of a preexisting symptom was more frequently related to hearing loss (n = 10; 28.6%), followed by gait disturbance (n = 7; 20%) and vertigo (n = 3, 8.6%). In the univariate logistic regression analysis, the following factors were statistically significant: age (p = 0.002; odds ratio [OR] 0.96), hearing at baseline by Gardner-Robertson (GR) class (p = 0.006; OR 0.21), pure tone average at baseline (p = 0.006; OR 0.97), and Koos grade at baseline (with Koos Grade I used as a reference) (for Koos Grade II, OR 0.17 and p = 0.002; for Koos Grade III, OR 0.42 and p = 0.05). The following were not statistically significant but showed a tendency toward significance: the number of isocenters (p = 0.06; OR 0.94) and the maximal dose received by the cochlea (p = 0.07; OR 0.74). Fractional polynomial regression analysis showed a nonlinear relationship between the outcome and the radiation dose rate (minimum reached at a cutoff of 2.5 Gy/minute) and the maximal vestibular dose (maximum reached at a cutoff of 8 Gy), but the small sample size precludes a detailed analysis of the former. The clinical acute AREs disappeared in 32 (91.4%) patients during the first 6 months after appearance. Permanent and somewhat disabling morbidity was found in 3 cases (1.9% from the whole series): 1 each with complete hearing loss (GR Class I before and V after), hemifacial spasm (persistent but alleviated), and dysgeusia.CONCLUSIONSAcute effects after radiosurgery for VS are not rare. They concern predominantly de novo vertigo and gait disturbance and the exacerbation of preexistent hearing loss. In de novo vestibular symptoms, a vestibular dose of more than 8 Gy is thought to play a role. In most cases, none of these effects are permanent, and they will ultimately improve or disappear with steroid therapy. Permanent AREs remain very rare.

International audience; INTRODUCTION : Stereotactic radiosurgery (SRS) is increasingly used as a minimally invasive alternative in many neurosurgical conditions, including benign and malignant tumors, vascular malformations, and functional procedures. As for any surgical procedure, strict safety guidelines and checklists are necessary to avoid errors and the inherent unnecessary complications. With regard to the former, other groups have already reported human and/or technical errors. We describe our safety checklist for Gamma Knife radiosurgical procedures.METHODS : We describe our checklist protocol after an experience gained over 1500 radiosurgical procedures, using Gamma Knife radiosurgery, performed over a period of 8 years, while employing the same list of items. Minor implementation has been performed over time to address some safety issues that could be improved.RESULTS : Two types of checklist are displayed. One is related to the indications when a specific tissue volume is irradiated, including tumors or vascular disorders. The second corresponds to functional disorders, such as when the dose is prescribed to one specific point. Using these checklists, no human error had been reported during the past 8 years of practice in our institution.CONCLUSION : The use of a safety checklist for SRS procedures promotes a zero-tolerance attitude for errors. This can lower the complications and is of major help in promoting multidisciplinary cooperation. We highly recommend the use of such tool, especially in the context of the increased use of SRS in the neurosurgical field.

Objective To perform planned subtotal resection followed by gamma knife surgery (GKRS) in a series of patients with large vestibular schwannoma (VS), aiming at an optimal functional outcome for facial and cochlear nerves. Methods Patient characteristics, surgical and dosimetric features, and outcome were collected prospectively at the time of treatment and during the follow-up. Results A consecutive series of 32 patients was treated between July 2010 and June 2016. Mean follow-up after surgery was 29 months (median 24, range 4–78). Mean presurgical tumor volume was 12.5 cm3 (range 1.47–34.9). Postoperative status showed normal facial nerve function (House–Brackmann I) in all patients. In a subgroup of 17 patients with serviceable hearing before surgery and in which cochlear nerve preservation was attempted at surgery, 16 (94.1%) retained serviceable hearing. Among them, 13 had normal hearing (Gardner–Robertson class 1) before surgery, and 10 (76.9%) retained normal hearing after surgery. Mean duration between surgery and GKRS was 6.3 months (range 3.8–13.9). Mean tumor volume at GKRS was 3.5 cm3 (range 0.5–12.8), corresponding to mean residual volume of 29.4% (range 6–46.7) of the preoperative volume. Mean marginal dose was 12 Gy (range 11–12). Mean follow-up after GKRS was 24 months (range 3–60). Following GKRS, there were no new neurological deficits, with facial and hearing functions remaining identical to those after surgery in all patients. Three patients presented with continuous growth after GKRS, were considered failures, and benefited from the same combined approach a second time. Conclusion Our data suggest that large VS management, with planned subtotal resection followed by GKRS, might yield an excellent clinical outcome, allowing the normal facial nerve and a high level of cochlear nerve functions to be retained. Our functional results with this approach in large VS are comparable with those obtained with GKRS alone in small- and medium-sized VS. Longer term follow-up is necessary to fully evaluate this approach, especially regarding tumor control.

Background: The purpose of our report is to describe an innovative system used for mandibular immobilization during Gamma Knife surgery (GKS) procedures. It is based on an approach originally developed in Marseille in extracranial lesions, close to or involving the mandible, which may imply a certain degree of movement during the therapeutic image acquisitions and/or GKS treatment. Methods: The maxillofacial surgeon applied bone titanium self-tapping monocortical screws (4; 2 mm diameter, 10 mm length) between roots of the teeth in the fixed gingiva (upper and lower maxillae) the day before GKS (local anesthesia, 5-10 min time). Two rubber bands were sufficient for the desired tension required to undergo GKS. We further proceeded with application of the Leksell stereotactic G frame and carried out the usual GKS procedure. Results: The mean follow-up period was 2.3 years (range 0.6-3). Three patients have been treated with this approach: 2 cases with extracranial trigeminal schwannomas involving the mandibular branch, with decrease in tumor size on MR follow-up; 1 case with residual paracondylian mandibular arteriovenous malformation following partial embolization, completely obliterated at 7 months (digital subtraction angiography programmed 1 year after treatment). Conclusions: Jaw immobilization appears to be a quick, minimally invasive, safe and accurate adjunctive technique to enhance GKS targeting precision.

We report the first known instance of the clinical use of 99mTc-mebrofenin hepatobiliary scintigraphy (HBS) for the optimization of radiotherapy treatment planning and for the follow-up of acute toxicity in a patient undergoing stereotactic body radiation therapy for hepatocellular carcinoma. In our experience, HBS allowed the identification and the sparing of more functioning liver areas, thus potentially reducing the risk of radiation-induced liver toxicity.

416 Objectives Gastrin releasing peptide receptors (GRPr) are specifically overexpressed in human prostate cancer. High affinity radiolabeled GRPr-antagonists are in clinical trials for PET imaging and have also shown promise for radionuclide treatment of prostate cancer. There currently exists no imaging modality that can accurately measure prostate cancer treatment response after radiation therapy (RT). The goal of this study is to examine a novel dual-label GRPr-antagonist to monitor prostate cancer treatment response to RT and androgen deprivation therapy (ADT). Methods We used an IRDye650 (LI-COR; Absorption Max 648nm, Emission Max 665nm) and DOTA-conjugated GRPr antagonist, HZ220 (DOTA-Lys(IRDye650)-PEG4-[D-Phe6, Sta13]-BN(6-14)NH2) developed by our group to study the expression of GRPr during radiotherapy. Experiments were performed in three cell lines: PC3 (strong GRPr expression, androgen receptor [AR] negative), VCAP (strong GRPr, AR positive), and LNCAP (weak GRPr, AR positive). Cells were exposed to 3Gy or 10Gy of external beam RT (Shepherd Mark I Irradiator, source Cs137, 1.67Gy/min), and uptake of HZ220 measured via flow cytometry at 0-48 hours after RT. For combined RT and ADT, cells were pre-treated for 48 hours with 10-80uM of bicalutamide and then treated with RT. GRPr expression was assessed by the mean fluorescence of the cells on flow cytometry after incubation with 100uM HZ220 in 2% fetal bovine serum in Ca++/Mg++ free PBS for 20 minutes at 37C. GRPr specificity of staining was confirmed by incubation with HZ220 in the presence of an excess of another GRPr antagonist, PETASIN. Cell viability was assessed by DAPI staining. Results In PC3, VCAP, and LNCAP cells, there was no significant alteration of GRPr expression in DAPI-negative cells at 0, 1, 6, 12, 24, 36, and 48 hours after exposure to 3Gy or 10Gy of external beam radiation treatment. These findings were confirmed with Western blots of whole cell protein lysates. Additionally, analysis of non-viable cells showed no significant altered GRPr expression at the same time points. In AR positive cell lines LNCAP and VCAP, there was no significant alteration of GRPr expression after pretreatment with 10-80uM bicalutamide, a nonsteroidal antiandrogen. Radiotherapy reduced percent of maximum mean cell viability to 97.3% (LNCAP), 93.9% (PC3), and 90.9% (VCAP) in the studied cell lines. In the AR positive cell lines VCAP and LNCAP, addition of bicalutamide decreased cell viability by an additional 5.5% and 4.1%, respectively. Conclusions Our data suggest a remarkable stability in expression of GRPR after exposure to high and low dose RT, with or without ADT. This is in contrast to other prostate cancer molecular imaging agents that have either specific or nonspecific change in expression after RT or ADT exposure. This makes GRPR a highly attractive target for prostate cancer imaging as its expression is proportional to cell viability after RT or radionuclide treatment. Further steps include confirming results in murine prostate xenograft models after labeling HZ220 with 68Ga.

Aims and Background To report the dosimetric data and clinical outcomes of patients with advanced neoplasm of the paranasal sinuses and nasal cavity, treated by three-dimensional conformal radiotherapy. Methods Between 2000 and 2005, 31 consecutive patients were treated for locally advanced tumors of paranasal sinuses and nasal cavity. The primary tumor was located as follows: maxillary sinus 15 (48.4%); ethmoid sinus 10 (32.3%); nasal cavity 6 (19.3%). The patients were separated in two groups according to the modality of treatment: group Aincluded 21 patients treated with postoperative three-dimensional conformal radiotherapy with or without chemotherapy; group B included 10 patients treated with radical three-dimensional conformal radiotherapy with or without chemotherapy. The median radiation dose to the planning target volume was 60 Gy (range, 56–63) for patients who underwent complete surgical resection and 68 Gy (range, 64–70) for those who did not have tumor resection or patients with residual disease. Results The median follow-up was 42 months. Five-year local tumor control and overall survival actuarial rates were 74% and 72%, respectively, in the postoperative setting, 20% and 25%, respectively, with the primary radiotherapy. Local recurrence was the most common site of failure. No patient developed radio-induced blindness; 4 patients underwent enucleation as part of radical surgery. Dosimetric data are reported. Conclusions The local control rate for these tumors remains low. The prognosis depends on localization, tumor stage and treatment modality. Three-dimensional conformal radiotherapy reduces the risk on optical pathways but does not modify outcome.

Background: Gamma Knife surgery (GKS) for vestibular schwannomas (VS) has a long-term clinical and scientific track record. After a period of de-escalation of dose prescription, results show a high rate of tumor control with improvement of clinical outcome (less than 1% facial palsy, 50-70% hearing preservation). Currently, there is controversial data about the active early treatment of intracanalicular (Koos I) VS. Methods: We prospectively analyzed 208 VS, focusing on 42 Koos I patients treated with GKS as first intention in Lausanne University Hospital, between July 2010 and February 2015. We concentrated on patient, tumor, and dosimetric characteristics. Special attention was given on the dose to the cochlea and its impact in maintaining serviceable hearing. Results: The mean follow-up period was 1.7 years (range 0.6-4.2). Twenty-six (61.9%) were females and 16 (38.1%) males. Preoperative serviceable hearing was present in 33 (78.57%) patients. The mean maximal diameter was 7.7 (5-10). The median target volume at the moment of GKS was 90 mm3 (range 17-317). The median prescription isodose volume was 118 mm3 (range 37-603). The median marginal dose administrated was 12 Gy (range 11-12). The median number of shots was 2 (range 1-9). The median isodose prescription was 50% (range 45-80%). The median maximal dose received by the cochlea in patients in GR class 1 and 2 was 4.2 Gy (mean 4.4 Gy, range 1.8-7.6). Our preliminary results showed 98% tumor control, with 30% shrinkage on MRI. The actuarial probability of keeping the same audition class for those with functional hearing at GKS was 80% at 3 years; the probability of keeping a functional hearing was more than 90%. A paraclinical evolution (on MRI and/or audiometry) at the time diagnosis, before GKS, was associated with a less good prognosis (p

Introduction The management of large lesions of the skull base, such as vestibular schwannomas (VS) is challenging. Microsurgery remains the main treatment option. Combined approaches (planned subtotal resection followed by gamma knife surgery (GKS) for residual tumor long-term control) are being increasingly considered to reduce the risk of neurological deficits following complete resection. The current study aims to prospectively evaluate the safety-efficacy of combined approach in patients with large VS. Materials and methods We present our experience with planned subtotal resection followed by gamma knife surgery (GKS) in a consecutive a series of 20 patients with large vestibular schwannomas, treated between 2009 and 2014 in Lausanne University Hospital, Switzerland. Clinical and radiological data and audiograms were prospectively collected for all patients, before and after surgery, before and after GKS, at regular intervals, in dedicated case-report forms. Additionally, for GKS, dose-planning parameters were registered. Results Twenty patients (6 males and 14 females) with large VS had been treated by this approach. The mean age at the time of surgery was 51.6 years (range 34.4–73.4). The mean presurgical diameter was 36.7 (range 26.1–45). The mean presurgical tumor volume was 15.9 cm3 (range 5 34.9). Three patients (15%) needed a second surgical intervention because of high volume of the tumor remnant considered too large for a safe GKS. The mean follow-up after surgery was 27.2 months (range 6–61.3). The timing of GKS was decided on the basis of the residual tumor shape and size following surgery. The mean duration between surgery and GKS was 7.6 months (range 4 13.9, median 6 months). The mean tumor volume at the time of GKS was 4.1 cm3 (range 0.5–12.8). The mean prescription isodose volume was 6.3 cm3 (range 0.8–15.5). The mean number of isocenters was 20.4 (range 11–31) and the mean marginal prescription dose was 11.7 Gy (range 11–12). We did not have any major complications in our series. Postoperative status showed normal facial nerve function (House-Brackmann grade I) in all patients. Six patients with useful pre-operative hearing (GR class 1) underwent surgery with the aim to preserve cochlear nerve function; of these patients, 5 (83.3%) of them remained in GR class 1 and one (16.7%) lost hearing (GR class 5). Two patients having GR class 3 at baseline remained in the same GR class, but the tonal audiometry improved in one of them during follow-up. Eleven patients (57.8%) were in GR class 5 preoperatively; one patient improved hearing after surgery, passing to GR class 3 postoperatively. Following GKS, there were no new neurological deficits, with facial and hearing function remaining identical to that after surgery. Conclusion Our data suggest that planned subtotal resection followed by GKS has an excellent clinical outcome with respect to retaining facial and cochlear nerve function. This represents a paradigm shift of the treatment goals from a complete tumor excision perspective to that of a surgery designed to preserve neural functions. As long-term results emerge, this approach of a combined treatment (microsurgery and GKS) will most probably become the standard of care in the management of large vestibular schwanomma.

Background and purpose To report our clinical experience in planning and delivering total marrow irradiation (TMI) after total body irradiation (TBI) in patients with relapsed acute leukemia undergoing an allogeneic stem-cell transplant (SCT). Materials and Methods Patients received conventional TBI as 2 Gy BID/day for 3 days boosted the next day by TMI (2 Gy in a single fraction) and followed by cyclophosphamide (Cy) 60 mg/kg for 2 days. While TBI was delivered with linear accelerator, TMI was performed with helical tomotherapy (HT). Results Fifteen patients were treated from July 2009 till May 2010, ten with acute myeloid leukemia, and five with acute lymphoid leukemia. At the time of radiotherapy eight patients were in relapse and seven in second or third complete remission (CR) after relapse. The donor was a matched sibling in 7 cases and an unrelated donor in 8 cases. Median organ-at-risk dose reduction with TMI ranged from 30% to 65% with the largest reduction (-50%–65%) achieved for brain, larynx, liver, lungs and kidneys. Target areas (bone marrow sites and spleen in selected cases) were irradiated with an optimal conformity and an excellent homogeneity. Follow-up is short ranging from 180 to 510 days (median 310 days). However, tolerance was not different from a conventional TBI-Cy. All patients treated with TBI/TMI reached CR after SCT. Three patients have died (2 for severe GvHD, 1 for infection) and 2 patients showed relapsed leukemia. Twelve patients are alive with ten survivors in clinical remission of disease. Conclusions This study confirms the clinical feasibility of using HT to deliver TMI as selective dose boost modality after TBI. For patients with advanced leukemia targeted TMI after TBI may be a novel approach to increase radiation dose with low risk of severe toxicity.

Introduction Gamma knife surgery (GKS) for vestibular schwannomas (VS) has a long-term clinical and scientific track record. After a period of de-escalation of dose prescription, results show a high rate of tumor control with improvement of clinical outcome (less than 1% facial palsy, 50–70% hearing preservation). Regis et al. (J Neurosurg 2013;119 Suppl.:105-11) suggested recently that proactive GKS management in intracanalicular tumors is better than a « wait and see » strategy when hearing is still useful at the time of diagnosis. Materials and methods Based on these previous findings, we prospectively analyzed 190 vestibular schwannomas (VS), treated with GKS as first intention over a period of 4 years (2010–2014). We concentrated on patient, tumor and dosimetric characteristics. Special attention was given on the dose to the cochlea and its impact in maintaining serviceable hearing. Results The mean follow-up period was 1.3 years (range 0.6–3.6). Preoperative serviceable hearing was present in 63.11% patients. The mean maximal diameter was 15.1 mm (range 5–29.5). The size and volume of the tumor corresponded to Koos grade I, II, III and IV in 15.9%, 34.8%, 45.4% and 3.8% of the cases, respectively. The mean target volume was 1.24 cm3 (0.017–7.8). The mean prescription isodose volume was 1.6 cc (0.032-8.5). The mean marginal dose was 12 Gy (11-12). The mean maximal dose received by the cochlea in patients with GR class 1 and 2 was 4.1 Gy (1.5–7.6). Our preliminary neuroradiological follow-up shows 97% tumor control, with 45% shrinkage. Patients presenting with GR class 1 and class 2 at baseline retained serviceable hearing in 85% of cases. Among the patients with a follow-up of at least one year, those with Koos I tumors had the highest probability to maintain identical level of hearing after GKS. Conclusion Our preliminary data suggest that Koos I patients should be treated early with GKS, before tumor growth and/or hearing deterioration, as they have the highest probability of hearing preservation.