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Aim: To investigate the potential role of an additional magnetic resonance imaging (MRI) examination performed during neoadjuvant chemoradiation therapy (CRT) in the prediction of pathological response in locally advanced rectal cancer (LARC). Material and methods: Forty-eight consecutive patients with LARC underwent neoadjuvant CRT. MRI studies at 1.5 T, including high-resolution T2-weighted sequences that were acquired parallel and perpendicular to the main axis of the tumour were performed before (preMRI), during (midMRI), and 6-8 weeks after the end of CRT (postMRI). Cancer volumes (Vpre, Vmid, Vpost) were drawn manually and the reduction rate calculated (ΔVmid, ΔVpost). According to Rödel's pathological tumour regression grade (TRG), patients were considered non-responders (NR; TRG0-2), partial responders (PR; TRG3), and complete responders (CR; TRG4). Multivariate regression analysis was performed to identify the best MRI predictors of NR, PR, and CR. Results: Twenty-five patients were considered PR (52%), 13 CR (27%), and 10 NR (22%). Tumour shrinkage mainly occurred shortly after CRT (ΔVmid: CR: 80±10% versus PR: 56±19% versus NR: 28±22%, p=2.2×10-16). Vmid, Vpost, ΔVmid, and ΔVpostcorrelated with TRG (p

Purpose: To report on planning and toxicity findings of hypofractionated adjuvant radiotherapy with helical Tomotherapy (HTT) after radical prostatectomy (RP) for prostate carcinoma (pCa). Methods and materials: Fifty consecutive patients submitted to RP for pT2R1/pT3a/pT3b-pN0 pCa were enrolled in a Phase I-II trial to receive 58 Gy/20 fractions (5/week) on tumoral bed. Endpoint was to verify a risk of toxicity and biochemical failure not exceeding that observed in our Institutional 3DCRT, conventionally fractionated series (15 3 patients). Toxicities were graded according the RTOG scoring system. Results: Excellent coverage of PTV and high homogeneity of dose distribution were always achieved. Median follow-up was 25 months. Acute G2-3 RTOG genitourinary (GU) and acute G2 intestinal toxicities were similar (12% vs 15.6% and 4% vs 7%, respectively), while acute G2 proctitis was 0% vs 9% in HTT and 3DCRT group, respectively. Similarly, late Grade >= 2 gastrointestinal sequelae were 0% vs 8.5%. The incidence of late urethral stricture, 8% and 9% in HTT and 3DCRT group, respectively, is comparable to that of RP-only series. Conclusions: Acute toxicity and early late toxicity outcomes of a moderately hypofractionated regimen with HTT post-RP are excellent. A longer follow-up is needed to fully assess the validity of this approach. (c) 2008 Elsevier Ireland Ltd. All rights reserved. Purpose: To report on planning and toxicity findings of hypofractionated adjuvant radiotherapy with helical Tomotherapy (HTT) after radical prostatectomy (RP) for prostate carcinoma (pCa). Methods and materials: Fifty consecutive patients submitted to RP for pT2R1/pT3a/pT3b-pN0 pCa were enrolled in a Phase I-II trial to receive 58 Gy/20 fractions (5/week) on tumoral bed. Endpoint was to verify a risk of toxicity and biochemical failure not exceeding that observed in our Institutional 3DCRT, conventionally fractionated series (15 3 patients). Toxicities were graded according the RTOG scoring system. Results: Excellent coverage of PTV and high homogeneity of dose distribution were always achieved. Median follow-up was 25 months. Acute G2-3 RTOG genitourinary (GU) and acute G2 intestinal toxicities were similar (12% vs 15.6% and 4% vs 7%, respectively), while acute G2 proctitis was 0% vs 9% in HTT and 3DCRT group, respectively. Similarly, late Grade >= 2 gastrointestinal sequelae were 0% vs 8.5%. The incidence of late urethral stricture, 8% and 9% in HTT and 3DCRT group, respectively, is comparable to that of RP-only series. Conclusions: Acute toxicity and early late toxicity outcomes of a moderately hypofractionated regimen with HTT post-RP are excellent. A longer follow-up is needed to fully assess the validity of this approach. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

OBJECTIVE To compare prospective electrocardiogram (ECG)-triggered high-voltage coronary computed tomography (CT) angiography (CTA; 140-kVp P-cCTA) with retrospective ECG-gated standard-voltage cCTA (120-kVp R-cCTA), in patients with coronary stents. METHODS Fifty-two patients with coronary stents were studied with 64-slice multidetector scanner. Ninety-three stents were analyzed: 55 with 140-kVp P-cCTA and 38 with 120-kVp R-cCTA. Image quality (IQ), diagnostic confidence (DC), in-stent assessable lumen, artificial narrowing, and effective radiation dose were compared between techniques. RESULTS Image quality and DC were significantly better for the 140-kVp P-cCTA in comparison with the 120-kVp R-cCTA (IQ, 1.1 ± 0.36 vs 1.7 ± 0.60, respectively; P < 0.00001. Diagnostic confidence: 1.1 ± 0.29 vs 1.5 ± 0.65 respectively; P < 0.0001). In-stent assessable lumen and artificial narrowing were comparable between the techniques. Effective dose was lower for the 140-kVp P-cCTA (6.7 ± 2.07 mSv vs 15.8 ± 6.89 mSv; P < 0.0001). CONCLUSIONS High voltage combined with axial prospective ECG-triggered scan improved IQ and DC in stent cCTA imaging but failed to improve the diameter of in-stent assessable lumen and to reduce the artificial narrowing compared with the 120-kVp R-cCTA. Effective dose was 60% lower for the 140-kVp P-cCTA.

The aim of this investigation was to explore the potential of biological optimization in the case of simultaneous integrated boost on intra-prostatic dominant lesions (DIL) and evaluating the impact of TCP parameters uncertainty. Different combination of TCP parameters (TD50 and γ50 in the Poisson-like model), were considered for DILs and the prostate outside DILs (CTV) for 7 intermediate/high-risk prostate patients. The aim was to maximize TCP while constraining NTCPs below 5% for all organs at risk. TCP values were highly depending on the parameters used and ranged between 38.4% and 99.9%; the optimized median physical doses were in the range 94–116 Gy and 69–77 Gy for DIL and CTV respectively. TCP values were correlated with the overlap PTV-rectum and the minimum distance between rectum and DIL. In conclusion, biological optimization for selective dose escalation is feasible and suggests prescribed dose around 90–120 Gy to the DILs. The obtained result is critically depending on the assumptions concerning the higher radioresistence in the DILs. In case of very resistant clonogens into the DIL, it may be difficult to maximize TCP to acceptable levels without violating NTCP constraints.

Purpose To find correlation between dose-volume histograms (DVHs) of the intestinal cavity (IC) and moderate-severe acute bowel toxicity in men with prostate cancer treated with pelvic nodal irradiation. Methods and Materials The study group consisted of 191 patients with localized prostate cancer who underwent whole-pelvis radiotherapy with radical or adjuvant/salvage intent during January 2004 to November 2007. Complete planning/clinical data were available in 175 of these men, 91 of whom were treated with a conventional four-field technique (50.4 Gy, 1.8 Gy/fraction) and 84 of whom were treated with IMRT using conventional Linac ( n = 26, 50.4 Gy, 1.8 Gy/fraction) or Helical TomoTherapy ( n = 58, 50–54 Gy, 1.8–2 Gy/fraction). The IC outside the planning target volume (PTV) was contoured and the DVH for the first 6 weeks of treatment was recovered in all patients. The correlation between a number of clinical and DVH (V10–V55) variables and toxicity was investigated in univariate and multivariate analyses. The correlation between DVHs for the IC outside the PTV and DVHs for the whole IC was also assessed. Results Twenty-two patients experienced toxicity (3/22 in the IMRT/tomotherapy group). Univariate analyses showed a significant correlation between V20–V50 and toxicity ( p = 0.0002–0.001), with a higher predictive value observed for V40–V50. Previous prostatectomy ( p = 0.066) and abdominal/pelvic surgery ( p = 0.12) also correlated with toxicity. Multivariate analysis that included V45, abdominal/pelvic surgery, and prostatectomy showed that the most predictive parameters were V45 ( p = 0.002) and abdominal/pelvic surgery ( p = 0.05, HR=2.4) Conclusions Our avoidance IMRT approach drastically reduces the incidence of acute bowel toxicity. V40–V50 of IC and, secondarily, previous abdominal/pelvic surgery were the main predictors of acute bowel toxicity.

Purpose To assess setup and organ motion error by means of analysis of daily megavoltage computed tomography (MVCT) of patients treated with hypofractionated helical tomotherapy (71.4–74.2 Gy in 28 fractions). Methods and Materials Data from 21 patients were analyzed. Patients were instructed to empty the rectum carefully before planning CT and every morning before therapy by means of a self-applied rectal enema. The position of the prostate was assessed by means of automatic bone matching (BM) with the planning kilovoltage CT (BM, setup error) followed by a direct visualization (DV) match on the prostate. Deviations between planning and therapy positions referred to BM and BM + DV were registered for the three main axes. In case of a full rectum at MVCT with evident shift of the prostate, treatment was postponed until after additional rectal emptying procedures; in this case, additional MVCT was performed before delivering the treatment. Data for 522 fractions were available; the impact of post-MVCT procedure was investigated for 17 of 21 patients (410 fractions). Results Prostate motion relative to bony anatomy was limited. Concerning posterior-anterior shifts, only 4.9% and 2.7% of fractions showed deviation of 3 mm or greater of the prostate relative to BM without and with consideration of post-MVCT procedures, respectively. Interobserver variability for BM + DV match was within 0.8 mm (1 SD). Conclusions Daily MVCT-based correction is feasible. The BM + DV matching was found to be consistent between operators. Rectal emptying using a daily enema is an efficient tool to minimize prostate motion, even for centers that have not yet implemented image-guided radiotherapy.

Background and Purpose To investigate the impact of Helical Tomotherapy (HT) upon the dose distribution when compared to our routinely delivered 3D conformal radiotherapy (CRT) in the case of patients affected by stage III non-small-cell lung cancer (NSCLC). Material and methods Thirteen stage III inoperable NSCLC patients were scheduled to receive 61.2–70.2 Gy, 1.8 Gy/fraction. Two treatment techniques (HT and CRT) were considered, and in the case of CRT the dose calculation was performed using both the pencil beam (PB) and Anisotropic Analytical Algorithm (AAA) available on the Varian Eclipse planning system. Dose volume constraints for PTV coverage and OAR sparing were assessed for the HT inverse planning with the highest priority upon PTV coverage and spinal cord sparing. The three plans were compared in terms of dose–volume histograms (DVHs) and normal tissue complication probability (NTCP). A statistical analysis was performed using non-parametric Wilcoxon matched pairs tests. Results In CRT the use of a less accurate algorithm (PB) decreased the monitor unit number by 2.4%. HT significantly improved dose homogeneity within PTV compared with CRT_AAA. For lung parenchyma V20–V40 were lower with HT, corresponding to a decrease of 7% in the risk of radiation pneumonitis. The volume of the heart and esophagus irradiated to >45–60 Gy were reduced using HT plans. For eight PTs with an esophagus–PTV overlap >5%, HT significantly reduced both late and acute esophageal complication probability. Conclusions Our findings obtained in stage III NSCLC patients underline that HT guarantees an important sparing of lungs and esophagus, thus HT has the potential to improve therapeutic ratio, when compared with CRT, by means of dose escalation and/or combined treatment strategy. In CRT of locally advanced lung cancers, the use of a more advanced algorithm would give significantly better modeling of target dose and coverage.

PURPOSE: To review planning and image-guidance aspects of more than 3 years experience in the treatment of prostate cancer with Helical Tomotherapy (HT). METHODS AND MATERIALS: Planning issues concerning two Phase I-II clinical studies were addressed: in the first one, 58 Gy in 20 fractions were delivered to the prostatic bed for post-prostatectomy patients: in the second one, a simultaneous integrated boost (SIB) approach was applied for radical treatment, delivering 71.4-74.2 Gy to the prostate in 28 fractions. On-line daily MVCT image guidance was applied: bone match was used for post-operative patients while prostate match was applied for radically treated patients. MVCT data of a large sample of both categories of patients were reviewed. RESULTS: At now, more than 250 patients were treated. Planning data show the ability of HT in creating highly homogeneous dose distributions within PTVs. Organs at risk (OAR) sparing also showed to be excellent. HT was also found to favorably compare to inversely-optimized IMAT in terms of PTVs coverage and dose distribution homogeneity. In the case of pelvic nodes irradiation, a large sparing of bowel was evident compared to 3DCRT and conventional 5-fields IMRT. The analysis of MVCT data showed a limited motion of the prostate (about 5% of the fractions show a deviation > or =3 mm in posterior-anterior direction), due to the careful application of rectal emptying procedures. Based on phantom measurements and on the comparison with intra-prostatic calcification-based match, direct visualization prostate match seems to be sufficiently reliable in assessing shifts > or =3 mm. CONCLUSIONS: HT offers excellent planning solutions for prostate cancer, showing to be highly efficient in a SIB scenario. Daily MVCT information showed evidence of a limited motion of the prostate in the context of rectal filling control obtained by instructing patients in self-administrating a rectal enema.

Purpose In order to explore the potential of helical Tomotherapy in the treatment of head and neck cancers (HNC), a planning study comparing our routinely delivered IMRT technique (dynamic MLC Varian 600CD Linac, inversely optimised by the Helios/Eclipse system) against two different Tomotherapy planning approaches was performed. Materials and methods In the first Tomotherapy plan (TOMO-a), we merely applied the same constraints used for the IMRT-Linac technique; in the second one (TOMO-b), we tried to stress the sparing of parotids and mandible while keeping PTV coverage and spinal cord Dmax similar to their values in the TOMO-a plan. Five patients with locally advanced oropharinx (n=3), hypopharinx (n=1) and larynx (n=1) cancer were considered. For each patient, CTV1 including neck nodes and the tumour was defined and was expanded with a margin of 0.5 cm (PTV1); then, CTV2 including high risk nodes and CTV3 including only T were defined and the corresponding PTV2/PTV3 were defined by a 0.5 cm expansion. IMRT and Tomotherapy planning were optimised to deliver 54 Gy in 30 fractions on PTV1 and 16.2 Gy in 9 fractions on PTV3; in the case a PTV2 was defined, 15 Gy were concomitantly delivered while delivering 16.2 Gy on PTV3. Separated plans for the two phases (Phase 1: first 30 fractions; Phase 2: last 9 fractions) were compared in terms of dose–volume histograms (DVH) and dose statistics on PTVs and OARs. Results When considering Phase 1, Tomotherapy improved the homogeneity of the dose distribution within PTV1 while delivering the same prescribed dose (assessed to be the median dose to PTV): the fraction of PTV1 receiving more than 95% of the prescribed dose (V95%) increased from 90% (IMRT) to 96–97% for Tomotherapy plans. Dmax within PTV1 decreased from 60.3 Gy (IMRT) to 57.4 Gy (TOMO-a) and 58.7 Gy (TOMO-b). Spinal cord Dmax decreased from 31.6 Gy (IMRT) to 26.5 Gy (TOMO-a) and 24.6 Gy (TOMO-b). No attempts to further reduce spinal cord Dmax were done. Mean dose to the parotids decreased from 26.1 Gy (IMRT) to 25.1 Gy (TOMO-a) and 20.8 Gy (TOMO-b). Mandible was significantly better spared with Tomotherapy: mean dose decreased from 34.9 Gy (IMRT) to 34.0 Gy (TOMO-a) and 30.7 Gy (TOMO-b).When considering phase 2, the average gains (TOMO-b vs IMRT) were more modest and depended on the location of PTV2/PTV3. Conclusions Preliminary findings obtained in a sequential approach for HNC suggest that Tomotherapy has the potential to significantly improve the therapeutic ratio with respect to a conventional IMRT delivery method.

An increase of skin dose during head and neck cancer (HNC) radiotherapy is potentially dangerous. Aim of this study was to quantify skin dose variation and to assess the need of planning adaptation (ART) to counteract it.Planning CTs of 32 patients treated with helical tomotherapy (HT) according to a Simultaneous Integrated Boost (SIB) technique delivering 54/66 Gy in 30 fractions were deformably co-registered to MVCTs taken at fractions 15 and 30; in addition, the first fraction was also considered. The delivered dose-of-the-day was calculated on the corresponding deformed images. Superficial body layers (SL) were considered as a surrogate for skin, considering a layer thickness of 2 mm. Variations of SL DVH (∆SL) during therapy were quantified, focusing on ∆SL95% (i.e., 62.7 Gy).Small changes (within ± 1 cc for ∆SL95%) were seen in 15/32 patients. Only 2 patients experienced ∆SL95% 1 cc in at least one of the two monitored fractions. Negative ∆SL95% 1 cc (up to 17 cc) were much more common (15/32 patients). The trend of skin dose changes was mostly detected at the first fraction. Negative changes were correlated with the presence of any overlap between PTV and SL at planning and were explained in terms of how the planning system optimizes the PTV dose coverage near the skin. Acute toxicity was associated with planning DVH and this association was not improved if considering DVHs referring to fractions 15/30.About half of the patients treated with SIB with HT for HNC experienced a skin-sparing effect during therapy; only 6% experienced an increase. Our findings do not support skin-sparing ART, while suggesting the introduction of improved skin-sparing planning techniques.ZWECK: Eine Erhöhung der Hautdosis während der Strahlentherapie von Kopf-Hals-Tumoren (HNC) ist potenziell gefährlich. Das Ziel dieser Studie war es, die Änderung der Hautdosis zu quantifizieren und den Bedarf einer Plananpassung (ART) zu bewerten, um dieser entgegenzuwirken.Planungs-CTs von 32 Patienten, die mittels helikaler Tomotherapie (HT) in einer „Simultaneous Integrated Boost“(SIB)-Technik mit 54/66 Gy bei 30 Fraktionen behandelt wurden, wurden nichtrigide registriert mit MVCTs, die bei Fraktion 15, 30 gefahren wurden; zusätzlich wurde auch die erste Fraktion berücksichtigt. Die verabreichte Tagesdosis wurde auf den entsprechenden deformierten Bildern berechnet. Die äußersten Schichten (SL) wurden als Ersatz für die Haut angesehen, mit einer Schichtdicke von 2 mm. Änderungen der SL-DVH (∆SL) während der Therapie wurden quantifiziert, mit einem Fokus auf ∆SL95 % (d. h. 62,7 Gy).Kleine Änderungen (innerhalb ± 1 cc für ∆SL95 %) ergaben sich bei 15 von 32 Patienten. Bei nur 2 Patienten wurde ein ∆SL95 % 1 cc in mindestens einer der beiden überwachten Fraktionen beobachtet. Negative ∆SL95 % 1 cc (bis zu 17 cc) waren weit häufiger (15 von 32). Der Trend von Hautdosisänderungen wurde zumeist bei der ersten Fraktion festgestellt. Negative Änderungen korrelierten mit der Anwesenheit einer Überlappung von PTV und SL bei der Planung und wurden dahingehend erklärt, wie das Planungssystem die PTV-Dosisabdeckung in der Nähe der Haut optimiert. Eine akute Toxizität war auf das Planungs-DVH zurückzuführen; dies wurde unter Berücksichtigung von DVH bei Fraktion 15 bzw. 30 nicht verbessert.Bei etwa der Hälfte der Patienten, die in SIB-Technik mittels HT für HNC behandelt wurden, ergab sich eine Hautschonung während der Therapie; nur 6 % erfuhren einen Anstieg. Unsere Erkenntnisse unterstützen keine hautschonende Plananpassung (ART), schlagen jedoch die Einführung verbesserter hautschonender Planungstechniken vor.

Background and Purpose: The topotherapy technique was recently suggested as a robust alternative to helical radiation delivery for total body irradiation (TBI). It allows to deliver a discrete number of beams with fixed gantry. A Topotherapy-based low-dose TBI technique was optimized and clinically implemented. Materials and methods: TBI delivery was split in two parts: the first treating from the head to half thigh and the second the remaining legs. An in-silico investigation aimed to optimize plan parameters was first carried out on four patients. For the upper plan, field width and pitch were fixed to 5 cm and 0.5: the combined impact of five modulation factor (MF) values and different field configurations (6/8/12 fields) was investigated. For the lower plan, two anterior/posterior beams (field width: 5 cm; pitch: 0.5; MF:1.5) were used. After assessing the optimal technique, set-up/quality assurance/image-guidance procedures were defined and the technique clinically implemented: 23 patients were treated up to now. Results: The best compromise between treatment time and planning target volume (PTV) coverage/homogeneity was found for MF = 1.5 and 8 fields. All clinical plans were automatically optimized using an “ad-hoc” plan template: excellent PTV coverage (PTV95%>98.5%) and homogeneity (median SD:4%) were found with a median beam-on time of 17/9 min for the upper/lower plan. All patients were successfully treated and transplanted. Conclusions: TBI delivered with the topotherapy approach robustly guarantees adequate coverage and dose homogeneity. Semi-automatic clinical plans can be quickly generated and efficiently delivered. Keywords: TBI, TomoDirect, Tomotherapy, Automatic planning

MariX is a research infrastructure conceived for multi-disciplinary studies, based on a cutting-edge system of combined electron accelerators at the forefront of the world-wide scenario of X-ray sources. The generation of X-rays over a large photon energy range will be enabled by two unique X-ray sources: a Free Electron Laser and an inverse Compton source, called BriXS (Bright compact X-ray Source). The X-ray beam provided by BriXS is expected to have an average energy tunable in the range 20–180 keV and intensities between 1011 and 1013 photon/s within a relative bandwidth Δ E / E = 1 –10 % . These characteristics, together with a very small source size ( ~ 20 μ m) and a good transverse coherence, will enable a wide range of applications in the bio-medical field. An additional unique feature of BriXS will be the possibility to make a quick switch of the X-ray energy between two values for dual-energy and K-edge subtraction imaging. In this paper, the expected characteristics of BriXS will be presented, with a particular focus on the features of interest to its possible medical applications.

Purpose: The value of FDG PET-derived parameters in predicting overall survival (OS), local relapse-free survival (LRFS) and distant relapse-free survival (DRFS) in treated patients with malignant pleural mesothelioma (MPM) was evaluated. Methods: This retrospective evaluation included 55 MPM patients treated between March 2006 and February 2015 with FDG PET/CT-guided salvage helical tomotherapy (HTT) after previous surgery plus chemotherapy. Univariate Cox regression analysis was performed to assess the impact of the following FDG PET-derived parameters: biological target volume (BTV), mean and maximum standardized uptake values (SUVmean/max), metabolic tumour volume (MTV) and total lesion glycolysis (TLG), measured using different uptake thresholds (40%, 50% and 60%). Logistic regression was then performed to identify the best FDG PET-derived parameters for selecting patients with poorer survival. Results: The median OS was 9.1months (range 0.0 – 69.6months) after the end of HTT; 54/55 patients were dead at the last follow-up. BTV and TLG40, TLG50 and TLG60 were the most significant predictors of OS (p< 0.005). The median OS was 4.8months in patients with MTV60 >5cm3 and TLG40 >334.4, compared with 13.8months and 16.1months in patients with smaller values, respectively. The median LRFS and DRFS were 6.2months (range 1.2 – 39.4months) and 6.5months (0.0 – 66.4months), respectively. TLG40, TLG50 and TLG60 were significantly correlated with LRFS (p< 0.015). Median DRFS was 6.4months in patients with MTV40 >39.6cm3 and 6.2months in patients with TLG40 >334.4, compared with 17months and 18.8months in patients with smaller values. BTV, TLG40 and MTV40 were also found to be good predictors in patients with poor OS/LRFS/DRFS (median survival times less than the median values). Conclusion: FDG PET-derived parameters effectively discriminated patients with a poor prognosis and may be helpful in the selection of MPM patients for salvage HTT.

Purpose: To explore the association between planning skin dose-volume data and acute cutaneous toxicity after Radio–chemotherapy for Head and Neck (HN) cancer patients. Methods: Seventy HN patients were treated with Helical Tomotherapy (HT) with radical intent (SIB technique: 54/66 Gy to PTV1/PTV2 in 30fr) ± chemotherapy superficial body layer 2 mm thick (SL2) was delineated on planning CT. CTCAE v4.0 acute skin toxicity data were available. Absolute average Dose-Volume Histograms (DVH) of SL2 were calculated for patients with severe (G3) and severe/moderate (G3/G2) skin acute toxicities. Differences against patients with none/mild toxicity (G0/G1) were analyzed to define the most discriminative regions of SL2 DVH; univariable and multivariable logistic analyses were performed on DVH values, CTV volume, age, sex, chemotherapy. Results: Sixty-one % of patients experienced G2/G3 toxicity (rate of G3 = 19%). Differences in skin DVHs were significant in the range 53-68Gy (p-values: 0.005–0.01). V56/V64 were the most predictive parameters for G2/G3 (OR = 1.12, 95%CI = 1.03–1.21, p = 0.001) and G3 (OR = 1.13, 95%CI = 1.01–1.26, p = 0.027) with best cut-off of 7.7cc and 2.7cc respectively. The logistic model for V56 was well calibrated being both, slope and R2, close to 1. Average V64 were 2.2cc and 6cc for the two groups (G3 vs G0-G2 toxicity); the logistic model for V64 was quite well calibrated, with a slope close to 1 and R2 equal to 0.60. Conclusion: SL2 DVH is associated with the risk of acute skin toxicity. Constraining V64 < 3cc (equivalent to a 4x4cm2 skin surface) should keep the risk of G3 toxicity below or around 10%.

The need of a fs-scale pulsed, high repetition rate, X-ray source for time-resolved fine analysis of matter (spectroscopy and photon scattering) in the linear response regime is addressed by the conceptual design of a facility called MariX (Multi-disciplinary Advanced Research Infrastructure for the generation and application of X-rays) outperforming current X-ray sources for the declared scope. MariX is based on the original design of a two-pass two-way superconducting linear electron accelerator , equipped with an arc compressor, to be operated in CW mode (1 MHz). MariX provides FEL emission in the range 0.2–8 keV with 1 0 8 photons per pulse ideally suited for photoelectric effect and inelastic X-ray scattering experiments. The accelerator complex includes an early stage that supports an advanced inverse Compton source of very high-flux hard X-rays of energies up to 180 keV that is well adapted for large area radiological imaging, realizing a broad science programme and serving a multidisciplinary user community, covering fundamental science of matter and application to life sciences, including health at preclinical and clinical level.

Objective To investigate if early variation of PET-derived parameters after concomitant chemoradiotherapy (CRT) predicts overall survival (OS), local relapse free survival (LRFS), distant relapse free survival (DRFS) and progression free survival (PFS) in locally advanced pancreatic cancer (LAPC) patients. Methods Fifty-two LAPC patients (median age: 61 years; range: 35-85) with available FDG PET/CT before and after RT (2-6 months, median: 2) were enrolled from May 2005 to June 2015. The predictive value of the percentage variation of mean/maximum standard uptake value (ΔSUVmean/max), metabolic tumour volume (ΔMTV) and total lesion glycolysis (ΔTLG), estimated considering different uptake thresholds (40-50-60%), was investigated between pre- and post-RT PET. The percentage difference between gastrointestinal cancer-associated antigen (ΔGICA) levels measured at the time of PET was also considered. Log-rank test and Cox regression analysis were performed to assess the prognostic value of considered PET-derived parameters on survival outcomes. Results The median follow-up was 13 months (range: 4-130). At univariate analysis, ΔTLG50 showed borderline significance in predicting OS (P = 0.05) and was the most significant parameter correlated to LRFS and PFS (P = 0.001). Median LRFS was 4 and 33 months if ΔTLG50 was below or above 35% respectively (P = 0.0003); similarly, median PFS was 3 vs 6 months (P = 0.0009). No significant correlation was found between PET-derived parameters and DRFS, while the ΔGICA was the only borderline significant prognostic value for this endpoint (P = 0.05). Conclusion PET-derived parameters predict survival in LAPC patients; in particular, ΔTLG50 is the strongest predictor. The combination of these biochemical and imaging biomarkers is promising in identifying patients at higher risk of earlier relapse.

Aims To report 5 year outcome and late toxicity in prostate cancer patients treated with image-guided tomotherapy with a moderate hypofractionated simultaneous integrated boost approach. Materials and methods In total, 211 prostate cancer patients, 78 low risk, 53 intermediate risk and 80 high risk were treated between 2005 and 2011. Intermediate- and high-risk patients received 51.8 Gy to pelvic lymph nodes and concomitant simultaneous integrated boost to prostate up to 74.2 Gy/28 fractions, whereas low-risk patients were treated to the prostate only with 71.4 Gy/28 fractions. Daily megavoltage computed tomography (MVCT) image guidance was applied. Androgen deprivation was prescribed for a median duration of 6 months for low-risk patients (for downsizing), 12 months for intermediate-risk and 36 months for high-risk patients. The 5 year biochemical relapse-free survival (bRFS), cancer-specific survival (CSS), overall survival and late gastrointestinal and genitourinary CTCAE.v3 toxicity were assessed. The effect of several clinical variables on both outcome and gastrointestinal/genitourinary toxicity was tested by uni- and multivariate Cox regression analyses. Results After a median follow-up of 5 years, the late toxicity actuarial incidence was: genitourinary ≥ grade 2: 20.2%; genitourinary ≥ grade 3: 5.9%; gastrointestinal ≥ grade 2: 17%; gastrointestinal ≥ grade 3: 6.3% with lower prevalence at the last follow-up visit (≥ grade 3: genitourinary: 1.9%; gastrointestinal: 1.9%). Major predictors of ≥ grade 3 genitourinary and gastrointestinal late toxicity were genitourinary acute toxicity ≥ grade 2 (hazard ratio: 4.9) and previous surgery (hazard ratio: 3.4). The overall 5 year bRFS was 93.7% (low risk: 94.6%; intermediate risk: 96.2%; high risk: 91.1%), overall survival and CSS were 88.6% (low risk: 90.5%; intermediate risk: 87.4%; high risk: 87%) and 97.5% (low risk: 98.7%; intermediate risk: 95%; high risk: 94.3%), respectively. Risk classes and androgen deprivation were not significantly correlated with either bRFS, overall survival or CSS. Twelve patients experienced a biochemical relapse but none experienced clinically proven local and/or pelvic recurrence. Conclusion A satisfactory 5 year outcome with an acceptable toxicity profile was observed. The combination of image-guided radiotherapy–intensity-modulated radiotherapy, high equivalent 2 Gy dose (EQD2) with a moderate hypofractionated approach and extensive prophylactic lymph node irradiation also leads to very good outcome in high-risk patients.

Background and Purpose: Head-Neck (HN) patients may experience severe acute skin complications that can cause treatment interruption and increase the risk of late fibrosis. This study assessed a method for accurately monitoring skin dose changes during helical tomotherapy for HN cancer based on deformable image registration of planning computed tomography (CT) and mega-voltage CT (MVCT). Materials and Methods: Planning CTs of nine patients were deformably registered to mid-treatment MVCT (MV15) images resulting in CTdef images. The original plans were recalculated on both CTdef and mid-treatment kilo-voltage CT (CT15) taken as ground truth. Superficial layers (SL) of the body with thicknesses of 2, 3 and 5 mm (SL2, SL3, SL5) were considered as derma surrogates. SL V95%, V97%, V98%, V100%, V102%, V105% and V107% of the prescribed PTV dose were extracted for CT15/CTdef and compared (considering patients with skin dose > 95%). For comparison, doses were calculated directly on the calibrated MVCT and analyzed in the same way. Results: Differences between SL2/SL3/SL5 V95%-V107% in CT15/CTdef were very small: for eight of nine patients the difference between the considered SL2 Vd% computed on CTdef and CT15 was less than 1.4 cm3 for all d%. A larger value was found when using MVCT for skin dose calculation (4.8 cm3 for SL2), although CTdef body contour matched CT15 body with accuracy similar to that of MV15. Conclusions: Deforming the planning CT-to-MVCT was shown to be accurate considering external body contours and skin DVHs. The method was able to accurately identify superficial overdosing. Keywords: Skin dose, DIR, MVCT, Dose of the day, Tomotherapy

PURPOSE: An adaptive concomitant boost (ACB) for the neo-adjuvant treatment of rectal cancer was clinically implemented. In this study population margins M(90,90) considering rectal deformation were derived for 10 consecutive patients treated at 18 × 2.3Gy with Helical Tomotherapy (HT) and prospectively validated on 20 additional patients treated with HT, delivering ACB in the last 6 fractions. METHODS: Sectorial margins M(90,90) of the whole and second treatment parts were assessed for 90% population through a method combining the 90% coverage probability maps of rectal positions (CPC90%) with 3D local distance measurements between the CPC90% and a reference rectal contour. M(90,90) were compared with the margins M(90,90)95%/99%, ensuring CPC90% coverage with 95%/99% confidence level. M(90,90) of the treatment second part were chosen as ACB margins which were clinically validated for each patient by means of %volume missing of CPC5/6 excluded by the ACB margins. RESULTS: The whole treatment M(90,90) ranged between 1.9 mm and 9 mm in the lower-posterior and upper-anterior sectors, respectively. Regarding ACB, M(90,90) were 7 mm in the anterior direction and

Purpose The aim of this study was to test the feasibility and dosimetric accuracy of a method that employs planning CT-to-MVCT deformable image registration (DIR) for calculation of the daily dose for head and neck (HN) patients treated with Helical Tomotherapy (HT). Methods For each patient, the planning kVCT (CTplan) was deformably registered to the MVCT acquired at the 15th therapy session (MV15) with a B-Spline Free Form algorithm using Mattes mutual information (open-source software 3D Slicer), resulting in a deformed CT (CTdef). On the same day as MVCT15, a kVCT was acquired with the patient in the same treatment position (CT15). The original HT plans were recalculated both on CTdef and CT15, and the corresponding dose distributions were compared; local dose differences

Background and purpose Gamma Knife Surgery (GKS) can be an adjunctive option to surgery in the case of pituitary adenomas. The effect of dosimetric variables on the incidence of new anterior pituitary deficits after GKS requires better definition. Materials and methods This retrospective study considered 130 patients with a follow up after GKS >6months. The diagnosis was nonfunctioning pituitary adenoma (NFPA) in 68 patients and secreting pituitary adenoma (SPA) in 62 patients. Median margin dose was 15/25Gy for NFPA and SPA, respectively. The endocrinological median follow-up was 60months. Hypopituitarism was defined as a new pituitary deficit in (at least) one of the three hormonal axes (hypogonadism, hypothyroidism and hypoadrenalism). The predictive value of clinical/dosimetric parameters was tested by univariate/multivariate analyses. Results Sixteen patients (12.3%) showed a new pituitary deficit in one or more axes. Multivariate analysis confirmed that the mean dose to the stalk/pituitary and the amount of healthy tissue within the high dose region were strong independent predictors of pituitary dysfunction; their best cut-off values were around 15.7Gy, 7.3Gy and 1.4cm 3 , respectively. Conclusions Our data showed a dose-dependent incidence of new hormonal deficits after GKS for pituitary adenoma. During planning definition, the risk of hypopituitarism could be reduced using the outlined safe dose–volume values.

The Jacobian of the deformation field of elastic registration between images taken during radiotherapy is a measure of inter-fraction local deformation. The histogram of the Jacobian values (Jac) within an organ was introduced (JVH-Jacobian-volume-histogram) and first applied in quantifying parotid shrinkage. MVCTs of 32 patients previously treated with helical tomotherapy for head-neck cancers were collected. Parotid deformation was evaluated through elastic registration between MVCTs taken at the first and last fractions. Jac was calculated for each voxel of all parotids, and integral JVHs were calculated for each parotid; the correlation between the JVH and the planning dose-volume histogram (DVH) was investigated. On average, 82% (±17%) of the voxels shrinks (Jac1) and 14% (±17%) shows a local compression50% (Jac0.5). The best correlation between the DVH and the JVH was found between V10 and V15, and Jac0.4-0.6 (p0.01). The best constraint predicting a higher number of largely compressing voxels (Jac0.57.5%, median value) was V15 ≥ 75% (OR: 7.6, p = 0.002). Jac and the JVH are promising tools for scoring/modelling toxicity and for evaluating organ/contour variations with potential applications in adaptive radiotherapy.

We developed an efficient technique to auto-propagate parotid gland contours from planning kVCT to daily MVCT images of head-and-neck cancer patients treated with helical tomotherapy. The method deformed a 3D surface mesh constructed from manual kVCT contours by B-spline free-form deformation to generate optimal and smooth contours. Deformation was calculated by elastic image registration between kVCT and MVCT images. Data from ten head-and-neck cancer patients were considered and manual contours by three observers were included in both kVCT and MVCT images. A preliminary inter-observer variability analysis demonstrated the importance of contour propagation in tomotherapy application: a high variability was reported in MVCT parotid volume estimation (p = 0.0176, ANOVA test) and a larger uncertainty of MVCT contouring compared with kVCT was demonstrated by DICE and volume variability indices (Wilcoxon signed rank test, p < 10-4 for both indices). The performance analysis of our method showed no significant differences between automatic and manual contours in terms of volumes (p > 0.05, in a multiple comparison Tukey test), center-of-mass distances (p = 0.3043, ANOVA test), DICE values (p = 0.1672, Wilcoxon signed rank test) and average and maximum symmetric distances (p = 0.2043, p = 0.8228 Wilcoxon signed rank tests). Results suggested that our contour propagation method could successfully substitute human contouring on MVCT images. © 2011 Institute of Physics and Engineering in Medicine.

Purpose/objective Whole pelvis irradiation with IMRT (WPRT–IMRT) after prostatectomy is efficient in reducing acute toxicity: however, a number of patients still experience moderate acute bowel toxicity. Materials and methods Ninety-six patients treated with WPRT–IMRT after prostatectomy with adjuvant or salvage intent were analysed. A number of parameters were individually recovered, including the DVHs of the intestinal cavity outside PTV and of the loops referred to both the WPRT phase and the whole treatment. Correlation between clinical-dosimetric parameters and acute bowel toxicity was investigated by logistic analyses. Best predictive cut-off values for continuous variables were assessed by ROC curves. Results 15/96 (15.6%) Patients experienced grade 2 toxicity (no grade 3). Best dose–volume predictors were the fraction of loops receiving more than 45, 50 and 55Gy (respectively, V45TL⩾50cc, V50TL⩾13cc, V55TL⩾3cc; p -values ranging from 0.005 to 0.027). Age, GU acute toxicity, rectal acute toxicity and time between prostatectomy and IMRT were also predictors of acute bowel toxicity. Multivariate analysis showed that the most predictive independent parameters were age (OR: 1.13; 95%CI: 1.02–1.25; p =0.021) and V50TL (⩾13cc, OR: 8.2; 95%CI: 1.7–40; p =0.009). Conclusions The risk of moderate acute uGI toxicity during WPRT–IMRT for post-operatively treated patients increases with age; the risk is substantially reduced in patients with small overlap between PTV and loops.

Purpose To investigate the role of IMRT in reducing the risk of acute genito-urinary (GU), upper gastrointestinal (uGI) and lower gastrointestinal (lGI) toxicity following whole-pelvis irradiation (WPRT) after radical prostatectomy. Patients and methods 172 consecutive patients with prostate cancer were post-operatively irradiated to the prostatic bed (PB) and pelvic lymph-nodal area with adjuvant ( n =100) or salvage ( n =72) intent. Eighty-one patients underwent three-dimensional conformal (3DCRT) WPRT, while the remaining 91 underwent IMRT (54/91 with helical tomotherapy (HTT); 37/91 with Linac intensity-modulated RT (LinacIMRT)). Results Patients treated with IMRT experienced a decreased risk of acute toxicity. The crude incidence of grade ⩾2 toxicity was GU 12.3% vs. 6.6% ( p =0.19); lGI 8.6% vs. 3.2% ( p =0.14); uGI 22.2% vs. 6.6% ( p =0.004), for 3DCRT and IMRT, respectively. With respect to uGI and lGI, the acute toxicity profile of the HTT patients was even better when compared to that of 3DCRT patients (crude incidence:1.8% and 0.0%, respectively). Treatment interruptions due to uGI toxicity were 11/81 in the 3DCRT group vs. 2/91 in the IMRT group ( p =0.006). Conclusions The risk of acute toxicity following post-operative WPRT delivered by means of IMRT was reduced compared to that of 3DCRT. The most significant reduction concerned uGI, mainly owing to better bowel sparing with IMRT.

BACKGROUND AND PURPOSE:To assess the impact of using MRI and Helical Tomotherapy (HT) compared to 3DCRT and dynamic IMRT on the dose to the penile bulb (PB).MATERIALS AND METHODS:Eight patients diagnosed with prostate cancer entered a treatment protocol including CT and MRI simulation. The prostate apex was defined on both MRI and CT. Treatment plans (HT, Linac-IMRT, 3DCRT and conventional technique), were elaborated on both MRI and CT images. A dose of 71.4Gy (2.55Gy/fraction) was prescribed; it was requested that PTVs be covered by 95% isodose line. The mean dose and V50 of PB were evaluated.RESULTS:PTV-MRI plans reduced PB mean dose and V50 compared to PTV-CT plans. This improvement, deriving also from the treatment modality, was 89% for 3DCRT, 99% for Linac-IMRT and 97% for HT (p

The aim of this paper is to evaluate the risks and doses for the internal contamination of the radiochemistry staff in a high workload medical cyclotron facility. The doses from internal contamination derive from the inhalation of radioactive gas leakage from the cells by personnel involved in the synthesis processes and are calculated from urine sample measurements. Various models are considered for the calculation of the effective committed dose from the analysis of these urine samples, and the results are compared with data obtained from local environmental measurement of the radioactivity released inside the lab.

Purpose To fit the individual biochemical recurrence-free survival (bRFS) data from patients treated with postprostatectomy radiation therapy (RT) with a comprehensive tumor control probability (TCP) model. Methods and Materials Considering pre-RT prostate-specific antigen (PSA) as a surrogate of the number of clonogens, bRFS may be expressed as a function of dose-per-fraction–dependent radiosensitivity (αeff), the number of clonogens for pre-RT PSA = 1 ng/mL (C), and the fraction of patients who relapse because of clonogens outside the treated volume (K), assumed to depend (linearly or exponentially) on pre-RT PSA and Gleason score (GS). Data from 894 node-negative, ≥pT2, pN0 hormone-naive patients treated with adjuvant (n=331) or salvage (n=563) intent were available: 5-year bRFS data were fitted grouping patients according to GS (7:119). Results The median follow-up time, pre-RT PSA, and dose were 72 months, 0.25 ng/mL, and 66.6 Gy (range 59.4-77.4 Gy), respectively. The best-fit values were 0.23 to 0.26 Gy−1and 107for αeffand C for the model considering a linear dependence between K and PSA. Calibration plots showed good agreement between expected and observed incidences (slope: 0.90-0.93) and moderately high discriminative power (area under the curve [AUC]: 0.68-0.69). Cross-validation showed satisfactory results (average AUCs in the training/validation groups: 0.66-0.70). The resulting dose-effect curves strongly depend on pre-RT PSA and GS. bRFS rapidly decreases with PSA: the maximum obtainable bRFS (defined as 95% of the maximum) declined by about 2.7% and 4.5% for each increment of 0.1 ng/mL for GS 0.8-1.0 ng/mL; GS ≥7: PSA >0.3 ng/mL). Early RT should be preferred over delayed RT; the detrimental effect of PSA increase can never be fully compensated by increasing the dose, especially for patients with GS ≥7.

Purpose: Characterizing the changes of PET-positive lymphnodes (PNs) of head-neck cancer patients during image-guided Tomotherapy in order to verify if our clinical margin for PTV boost are adequate. Material and methods: Weekly MVCTs of 30 patients were matched with the planning kVCT (kVCT_pl) on bony anatomy: 42 visible PNs were contoured on kVCT_pl/MVCTs. Intra/inter-observer and inter-modality variability in contouring PNs was evaluated by blind re-delineation. Shrinkage of PNs and center-of-mass (CM) shifts were measured and Van Herk margins for the residual error were estimated. In addition, due to the PNs' shrinkage during therapy, probability coverage maps were considered to estimate the fraction of the high probability contours missed by the clinical PTV (5mm margin); larger margins were tried for PNs showing some missing. Results: MVCTs were adequate for PNs' delineation (DICE=0.85; range=0.79–0.91). Twenty-seven PNs showed a significant volume shrinkage at the end of therapy (median: 71%, range: 27–94%, ρ =−0.93). Time–trend of 3D-CM shift was significant for 38% of PNs (median: 5.1mm at the end of treatment, range: 1.0–8.9). The clinical PTV included 95% of the 90%/100% probability contours in 40/36 (95%/86%) PNs respectively. Van Herk margins (not considering shrinkage) were approximately 7mm for all three main axes. The clinical PTV included 95% of the 90%/100% probability contours in 40/36 (95%/86%) PNs respectively. Conclusions: The residual error relative to PNs after bone match is relatively small; the impact of CM shifts is partially counterbalanced by shrinkage. Our results do not seem to support an extensive use of adaptive re-planning to avoid the missing of PNs in dose-escalated protocols, although more information about the dosimetry impact of the reported changes is warranted.

We investigated the possibility to early identify non-responding patients based on FDG-PET positive lymph nodes (PNs) volume variation assessed with in-room images.Twenty-seven head and neck cancer patients with at least one pre-treatment PNs were retrospectively analyzed; they received 54 Gy, 66 Gy, 69 Gy in 30 fractions on precautionary lymph nodal (N), primary (T) and PET positive (BTV) planning target volumes (PTVs), respectively with Helical TomoTherapy (SIB approach). PNs volume changes during treatment were assessed based on megavoltage computed tomography (MVCT) used for image guidance as ratio between volumes at fractions 10/20/30 and at first fraction. Data on T, N and M relapses (rT, rN, rM) were collected for all patients. The difference of PNs volume changes, during treatment, between patients with versus without relapses was tested (Mann-Whitney test). The impact of shrinkage on the corresponding survival curves (Cox proportional-hazard regression), dividing between no/moderate versus large shrinkage (based on ROC curve best cut-off value) was also investigated.Median follow-up was 27.4 m (3.7-108.9). The numbers for rT, rN, rM were 5, 4, 6, respectively. Differences in PNs shrinkage were found between patients with and without rT/rN at all considered timing [fr 20, rT: 0.56 vs. 1.07 (median), p = 0.06; rN: 0.57 vs. 1.25, p = 0.07]. Differences were lower for rM. Survival curves provide high hazard ratios (HR) between PNs changes and rT/rN at all considered timing [fr 20, rT: best cut-off = 0.58, HR 5.1 (95% CI 0.5-49.4), p = 0.12; rN: best cut-off = 0.98, HR 14.9 (1.6-142.9), p = 0.01].A limited shrinkage of PNs during treatment is associated with poorer outcome in terms of T/N relapses. The early variation of PNs observed on in-room images may provide useful information about the individual response with potential application in guiding an early adaptation of the treatment.

Images taken during and after RT for head and neck cancer have the potential to quantitatively assess xerostomia. Image information may be used as biomarkers of RT effects on parotid glands with significant potential to support adaptive treatment strategies. We investigated the possibility to extract information based on in-room CT images (kVCT, MVCT), acquired for daily image-guided radiotherapy treatment of head-and-neck cancer patients, in order to predict individual response in terms of toxicity. Follow-up MRI images were also used in order to investigate long term parotid gland deformation.

Background Dose escalation and hypofractionation may have a role in postprostatectomy radiotherapy (RT), but at the risk of increasing urinary toxicity. Objective To address predictors of severe (Grade ≥3) late urinary toxicities (LGUTOX3) after postoperative irradiation. Design, setting, and participants A single-institution cohort of 1176 patients treated between 1993 and 2010 with adjuvant or salvage RT was analyzed. A total of 929 patients underwent conventionally fractionated (CF) RT (1.8Gy per fraction; median dose to the prostatic bed: 70.2Gy) with nonconformal RT ( n =169), three-dimensional conformal RT ( n =657), or intensity-modulated RT ( n =103) technique, while 247 patients received hypofractionated helical TomoTherapy (median: 2.50Gy per fraction) at the following doses: 117 patients at 65.8Gy (2.35Gy in 28 fractions), 80 patients at a median of 71.4Gy (2.5–2.6Gy in 28 fractions), and 50 patients at 58Gy in 20 fractions. Total doses were converted into 2 Gy–equivalent doses (EQD2) following the linear quadratic model taking α/β=5. Outcome measurements and statistical analysis Univariable and multivariable Cox regression models tested the relationship between clinicodosimetric variables and the risk of LGUTOX3 retrospectively, graded according to Common Terminology Criteria for Adverse Events v.4.0. Results and limitations After a median follow-up of 98 mo, the 5-yr risk of LGUTOX3 was 6.9% and 18.1% in the CF and hypofractionated cohorts, respectively. At univariable analysis, the risk of LGUTOX3 was predicted by dose per fraction (hazard ratio [HR]: 2.96), acute Grade ≥2 toxicity (HR: 2.37), EQD2, pT4, and year of irradiation. At multivariable analyses, acute Grade ≥2 toxicity and dose per fraction independently predicted LGUTOX3 in the population, while an interaction analysis indicated a predictive role of hypertension in the hypofractionated cohort only. These findings are limited by their retrospective nature. Conclusions In the postprostatectomy setting, the logistic convenience of hypofractionation should be carefully balanced against the risk of severe late urinary sequelae. Patient summary This study investigated the causes of urinary adverse effects after postprostatectomy radiotherapy. Hypofractionation resulted in an increased risk of severe urinary toxicities.

Purpose: To assess the impact on local control and survival of intraoperative radiotherapy (IORT) in resectable pancreatic adenocarcinoma. Methods and Materials: The outcome of 127 patients surgically treated with curative intent combined with IORT was compared with the therapeutic results of 76 patients treated with surgery as exclusive treatment. Results: Operative mortality and morbidity were similar in IORT and no-IORT patients. In 49 patients with locally limited disease (Stage I–II; LLD), IORT (n = 30) reduced the local failure rate and significantly prolonged time to local failure (TTLF), time to failure (TTF), and overall survival (OS) with respect to surgery alone (n = 19). The multivariate analyses, stratifying patients by age, tumor grade, resection margins, chemotherapy, and external-beam radiotherapy use, confirmed the independent impact of IORT on outcome. In patients with locally advanced disease (Stage III–IVA; LAD), IORT had an impact on local failure rate and on TTLF when combined with beam energies of greater than 6 MeV, whereas no effect on TTF and OS was observed. Conclusion: IORT did not increase operative mortality and morbidity and achieved a significant improvement in local control and outcome in patients with LLD. In patients with LAD, beam energies greater than 6 MeV prolonged TTLF.

Background and purpose: Accurate contouring of the clinical target volume (CTV) is a fundamental prerequisite for successful conformal radiotherapy of prostate cancer. The purpose of this study was to investigate intra-and inter-observer variability in contouring prostate (P) and seminal vesicles (SV) and its impact on conformal treatment planning in our working conditions. Materials and methods: Inter-observer variability was investigated by asking five well-trained radiotherapists of contouring on CT images the P and the SV of six supine-positioned patients previously treated with conformal techniques. Short-term intra-observer variability was assessed by asking the radiotherapists to contour the P and SV of one patient for a second time, just after the first contouring. The differences among the inserted volumes were considered for both intra-and inter-observer variability. Regarding intra-observer variability, the differences between the two inserted contours were estimated by taking the relative differences in correspondence to the CT slices on BEV plots (antero-posterior and left-right beams). Concerning inter-observer variability, the distances between the internal and external envelopes of the inserted contours (named projected diagnostic uncertainties or PDUs) and the distances from the mean inserted contours (named mean contour distances or MCDs) were measured from BEV plots (i.e. parallel to the CT slices). Results: Intra-observer variability was relatively small (the average percentage variation of the volume was similar to 5%; SD of the differences measured on BEV plots within 1.8 mm). Concerning inter-observer variability, the percentage SD of the inserted volumes ranged from 10 to 18%. Differences equal to 1 cm in the cranio-caudal extension of P + SV were found in four out of six patients. The largest interobserver variability was found when considering the anterior margin in the left-right beam of P top (MCD = 7.1 mm, 1 SD). Relatively high values for MCDs were also found for P bottom, for the posterior and lateral margins of P top (2.6 and 3.1 mm, respectively, 1 SD) and for the anterior margin of SV (2.8 mm, 1 SD). Relatively small values were found for P central (from 1.4 to 2.0 mm, 1 SD) and the posterior margin of SV (1.5 mm, 1 SD). Conclusions: The application of larger margins taking inter-observer variability into account should be taken into consideration for the anterior and the lateral margins of SV and P top and for the lateral margin of P. The impact of short-term intra-observer variability does not seem to be relevant. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.

Background and purpose: Comparing some isocentric coplanar techniques for conformal irradiation of prostate and seminal vesicles. Materials and methods: Five conformal techniques have been considered: (A) a 3-fields technique with an antero-posterior (AP) field and two lateral (LAT-LAT) 30 degrees wedged fields; (B) a 3-fields technique with an AP field and two oblique posterior (OBL) 15 degrees wedged fields with relative weights of 0.8, 1 and 1, respectively; (C) a 4-fields technique (AP-PA and LAT-LAT); (D) a 6-fields technique (LAT-LAT and four OBL at gantry angles 45 degrees, 135 degrees, 235 degrees and 315 degrees) with all the fields having the same weight; (E) the same 6-fields technique with lateral fields double-weighted with respect to the oblique fields. The conformal plans have been simulated on 12 consecutive patients (stages B and C) by using our 3D treatment planning system (Cadplan 2.7). The contours of the rectum, the bladder and the left femoral head were outlined together with the clinical target volume (CTV) which included the prostate and the seminal vesicles. A margin of 10 mm was added to define the planning target volume (PTV) through automatic volume expansion. Then a 7 mm margin between the PTV and block edges was added to take the beam penumbra into account. Dose distributions were normalised to the isocentre and the reference dose was considered to be 95% of the isocentre dose. Dose-volume histograms and dose statistics of the rectum, the bladder and the left femoral head were collected for all plans. For the rectum and the bladder the mean dose (Dm) and the fraction of volume receiving a dose higher than the reference dose (V95) were compared. For the femoral head, the mean dose together with the fraction of volume receiving a dose higher than 50% (V50) were compared. Results: Differences among the techniques have been found for all three considered organs at risk. When considering the rectum, technique A is better than the others both when considering Dm and V95 (P = 0.002), while technique D is the worst when considering Dm (P < 0.002) and is also worse than techniques A, E (P = 0.002) and C (P = 0.003) when considering V95. Technique E is the best when considering the bladder mean dose (P = 0.002 against A and D, P < 0.01 against B and C) and technique C is the worst (P < 0.012). No relevant differences were found for the bladder V95. in the femoral heads, techniques A and E are worse than B, C and D (P < 0.003) when considering Dm and V50. Moreover, techniques B and D are better than C (P < 0.004) when considering V50. Conclusions: There is no technique that is absolutely better than the others. Technique A gives the best sparing of the rectum; the bladder is better spared with technique E. These results are reached with a worse sparing of the femoral heads which should be carefully taken into account. (C) 1997 Elsevier Science Ireland Ltd.

Background and purpose Hypofractionated radiotherapy (RT) of pancreatic adenocarcinoma is limited by the tolerance of adjacent normal tissues. A better understanding of the influence of dosimetric variables on the rate of toxicity after RT must be considered an important goal. Methods and materials Sixty-one patients with histologically proven locally advanced disease (LAPD) were analyzed. The therapeutic strategy consisted of induction chemotherapy (ChT) followed by concurrent chemoradiotherapy (CRT). In 39 out of 61 patients the target volume was based on a four-dimensional CT (4D-CT) procedure. Delivered dose was 44.25Gy in 15 fractions to PTV 2 , which consisted of pancreatic tumor and regional lymph nodes considered radiologically involved; 23 out of 61 patients received a simultaneous integrated boost (SIB) to a tumor sub-volume infiltrating the great abdominal vessels (PTV 1 ) with dose in the range of 48–58Gy. RT was delivered with Helical Tomotherapy. Dose–volume histograms (DVHs) of target volumes and organs at risk (OARs) were collected for analysis. The predictive value of clinical/dosimetric parameters was tested by univariate/multivariate analyses. Results The crude incidence of acute gastrointestinal (GI) grade 2 toxicity was 33%. The 12-month actuarial rate of "anatomical" (gastro-duodenal mucosa damage) toxicity was 13% (95% CI: 4–22%). On univariate analysis, several stomach and duodenum DVH endpoints are predictive of toxicity after moderately hypofractionated radiotherapy. Multivariate analysis confirmed that baseline performance status and the stomach V 20 [%] were strong independent predictors of acute GI grade ⩾2 toxicity. The high-dose region of duodenum DVH ( V 45 [%]; V 40 [%]) was strongly correlated with grade ⩾2 "anatomical" toxicity; the best V 40 [%] and V 45 [%] cut-off values were 16% and 2.6% respectively. Conclusion Regarding dosimetric indices, stomach V 20 [%] correlates with a higher rate of acute toxicity; more severe acute and late anatomical toxicities are related to the high dose region of duodenum DVH.

Purpose To investigate the feasibility of preoperative adaptive radiochemotherapy by delivering a concomitant boost to the residual tumor during the last 6 fractions of treatment. Methods and Materials Twenty-five patients with T3/T4N0 or N+ rectal cancer were enrolled. Concomitant chemotherapy consisted of oxaliplatin 100 mg/m 2 on days −14, 0, and +14, and 5-fluorouracil 200 mg/m 2 /d from day −14 to the end of radiation therapy (day 0 is the start of radiation therapy). Radiation therapy consisted of 41.4 Gy in 18 fractions (2.3 Gy per fraction) with Tomotherapy to the tumor and regional lymph nodes (planning target volume, PTV) defined on simulation CT and MRI. After 9 fractions simulation CT and MRI were repeated for the planning of the adaptive phase: PTV adapt was generated by adding a 5-mm margin to the residual tumor. In the last 6 fractions a boost of 3.0 Gy per fraction (in total 45.6 Gy in 18 fractions) was delivered to PTV adapt while concomitantly delivering 2.3 Gy per fraction to PTV outside PTV adapt . Results Three patients experienced grade 3 gastrointestinal toxicity; 2 of 3 showed toxicity before the adaptive phase. Full dose of radiation therapy, oxaliplatin, and 5-fluorouracil was delivered in 96%, 96%, and 88% of patients, respectively. Two patients with clinical complete response (cCR) refused surgery and were still cCR at 17 and 29 months. For the remaining 23 resected patients, 15 of 23 (65%) showed tumor regression grade 3 response, and 7 of 23 (30%) had pathologic complete response; 8 (35%) and 12 (52%) tumor regression grade 3 patients had ≤5% and 10% residual viable cells, respectively. Conclusions An adaptive boost strategy is feasible, with an acceptable grade 3 gastrointestinal toxicity rate and a very encouraging tumor response rate. The results suggest that there should still be room for further dose escalation of the residual tumor with the aim of increasing pathologic complete response and/or cCR rates.

Seed embolisation to the lung is a possible risk following permanent prostate brachytherapy. The purpose of this work is to analyse a seed migration case and to suggest methods to reduce such occurrences. With this aim, the clinical history of the patient who experienced seed migration, the implant technique and the pre- and post-plan procedures have been investigated. The massive seed migration has been detected in the patient by means of a pelvic X-ray and a CT-scan of the thorax. The use of loose seeds, the implant technique and the presence of unfavourable anatomical characteristics, have been recognised as possible causes of this event. The use of linked seeds embedded in vicryl sutures for the peripheral portions of prostate, and the development of an implant technique based on both transverse and longitudinal ultrasound guidance are proposed in order to reduce seed migration.

PURPOSE: Measuring parotid density changes in patients treated with IMRT for head-neck cancer (HNC) and assessing correlation with treatment-related parameters. PATIENTS AND MATERIALS: Data of 84 patients treated with IMRT for different HNC were pooled from three institutions. Parotid deformation and average Hounsfield number changes (?HU) were evaluated through MVCT (with Helical Tomotherapy) or diagnostic kVCT images taken at the treatment start/end. Parotids were delineated in the first image and propagated to the last using a previously validated algorithm based on elastic registration. The correlation between ?HU and several treatment-related parameters was tested; then, logistic uni- and multi-variate analyses taking "large" ?HU as end-point were carried out. Due to the better image quality, analyses were repeated considering only kVCT data. RESULTS: ?HU was negative in 116/168 parotids (69%; for kVCT patients: 72/92, 78%). The average ?HU was significantly different from zero (-7.3, 0.20-0.25HU/fraction, p

Purpose To compare helical tomotherapy (HT) and intensity modulated proton therapy (IMPT) on early stage prostate cancer treatments delivered with simultaneous integrated boost (SIB) in moderate hypofractionation. Material/methods Eight patients treated with HT were replanned with two-field IMPT (2fIMPT) and five-field IMPT (5fIMPT), using a small pencil beam size (3 mm sigma). The prescribed dose was 74.3 Gy in 28 fractions on PTV1 (prostate) and PTV2 (proximal seminal vesicles), 65.5 Gy on PTV3 (distal seminal vesicles) and on the overlap between rectum and PTVs. Results IMPT and HT achieved similar target coverage and dose homogeneity, with 5fIMPT providing the best results. The conformity indexes of IMPT were significantly lower for PTV1+2 and PTV3. Above 65 Gy, HT and IMPT were equivalent in the rectum, while IMPT spared the bladder and the penile bulb from 0 to 70 Gy. From 0 up to 60 Gy, IMPT dosimetric values were (much) lower for all OARs except the femur heads, where HT was better than 2fIMPT in the 25–35 Gy dose range. OARs mean doses were typically reduced by 30–50% by IMPT. NTCPs for the rectum were within 1% between the two techniques, except when the endpoint was stool frequency, where IMPT showed a small (though statistically significant) benefit. Conclusions HT and IMPT produce similar dose distributions in the target volume. The current knowledge on dose–effect relations does not allow to quantify the clinical impact of the large sparing of IMPT at medium-to-low doses.

There has been growing interest in investigating both the in vitro and in vivo detection of optical photons from a plethora of beta emitters using optical techniques. In this paper we have investigated an alpha particle induced fluorescence signal by using a commercial CCD-based small animal optical imaging system. The light emission of a 241 Am source was simulated using GEANT4 and tested in different experimental conditions including the imaging of in vivo tissue. We believe that the results presented in this work can be useful to describe a possible mechanism for the in vivo detection of alpha emitters used for therapeutic purposes. C 2011 Society of Photo-Optical

Purpose Assessing predictors of acute bowel toxicity after whole-pelvis irradiation (WPRT) Image-guided Tomotherapy with simultaneous integrated boost on prostate/prostate bed. Methods and materials In the period March 2005–April 2009, 178 patients were treated with radical or adjuvant/salvage intent with WPRT Tomotherapy. Median dose to the pelvic nodes was 51.8Gy/28 fractions while concomitantly delivering 65.5–74.2Gy to prostate/prostatic bed. The impact of many anatomical and clinical parameters on ⩾Grade 2 acute bowel toxicity was investigated by logistic analyses. Results Only 15/178 patients (8.4%) experienced Grade 2 toxicity (none Grade 3). Main predictors at univariate analysis were nodal CTV (CTVN⩾380cc; OR: 3.7, p =0.017), treatment duration ( p =0.006) and Grade 2 acute rectal toxicity (OR: 6.5, p =0.015). A multivariate analysis including only pre-treatment variables revealed an independent role of CTVN and age; if including treatment-related factors the best predictors were age, treatment duration and Grade 2 rectal toxicity. This last was correlated with the overlap between PTVN and loops (OVPN⩾51cc; OR: 14.4, p =0.0003) that is representative of the volume of loops receiving the prescribed dose (51.8Gy, 1.85Gy/fr). Conclusions Acute bowel toxicity after WPRT Tomotherapy is mild, relatively rare and associated to larger CTVN and older age. While efforts to further reduce it do not appear to be relevant, the pre-treatment assessment of "high-risk" patients may help physicians in better managing symptoms. A prospective validation would be very important in confirming these results and in better refining dose-volume bowel effects including symptoms milder that the ones here investigated and retrospectively assessed.

to study the impact of the 4DCT imaging technique on radiotherapy planning for pancreatic carcinoma. To evaluate the possibility of IMRT/IGRT to increase the dose to PTV subvolume.contrast-enhanced 4DCT scans of 15 patients (PTs) with unresectable pancreatic cancer were acquired. A 4DCT based PTV (4D-PTV) was created by the convolution of contours and then expanded for geometric uncertainties; a standard PTV (STD-PTV) was derived from a single CTV plus conventional margins. Two 3D conformal treatment (3DCRT) plans and one Helical Tomotherapy (HT) plan were generated with a prescription of 60 Gy. Regarding the 3DCRT plans, the 4D-PTV was considered as the target volume for one, and the STD-PTV for the other; the HT plans were performed only for 4D-PTV. Twelve of 15 PTs were admitted to a Phase I hypofractionated study (15 fractions). The prescribed dose was 44.25 Gy to the 4D-PTV and the PTV subvolume around vascular involvement was boosted from 50 to 55 Gy; before treatment, daily patient position was corrected using MVCT.4D-PTVs were smaller than STD-PTVs with a volume reduction equal to 37%. 3DCRT plans on 4D-PTV showed a significant sparing of most OARs, the use of IMRT allowed a further significant dose reduction. In the Phase I study the PTV subvolume received up to 55 Gy with modest increase in dose to OARs.the 4DCT procedure decreases the overlap between PTV and OARs. HT technique, compared with 3DCRT, allows efficient dose sparing in particular for the duodenum. The IMRT/IGRT approach allows a safe dose escalation to PTV subvolume.

"BACKGROUND\/OBJECTIVES:. To assess the gender influence on radiation dose saving allowed by prospective ECG-triggered MDCT coronary angiography (P-MDCT-CA) in comparison with retrospective ECG-gated MDCT-CA (R-MDCT-CA). The influence of kilovoltage and body mass index on radiation dose and the impact of different parameters on image quality (IQ) and diagnostic confidence (DC), were also determined.. METHODS:. 64-slice MDCT-CA was performed in 176 patients: 66 R-MDCT-CA and 110 P-MDCT-CA. Effective dose was determined using ImpactDose software based on Monte Carlo method. Three point scales were used to assess IQ and DC on a segmental basis.. RESULTS:. Patients were divided into 4 groups according with the examination performed: group A (90 pts, coronary tree assessment with P-MDCT-CA); group B (55 pts, coronary tree assessment with R-MDCT-CA); group C (20 pts, bypass grafts assessment with P-MDCT-CA); and group D (11 pts, bypass grafts assessment with R-MDCT-CA). Effective dose was 68% lower for P-MDCT-CA than R-MDCT-CA for coronary artery studies (Gr. A=4.7±1.69mSv and Gr. B=14.9±4.4mSv; p

To evaluate clinical and physico-dosimetric variables affecting clinical outcome of patients treated with Gamma Knife radiosurgery (GKRS) for brain metastases from non-small cell lung cancer (NSCLC).Between 2001 and 2006, 373 patients (298 men and 75 women, median age 65 years) with brain metastases from NSCLC underwent GKRS. All of them had KPS ≥ 60%, eight or fewer brain metastases, confirmed histopathological diagnosis and recent work-up (3 months). Thirty-five patients belonged to recursive partitioning analysis (RPA) Class I, 307 patients were in RPA Class II, 7 patients were in RPA Class III. Median tumor volume was 3.6 cm(3). Median marginal dose was 22.5 Gy at 50% isodose.; median 10 Gy and 12 Gy isodose volumes were 30.8 cm(3) and 15.8 cm(3), respectively. Follow-up with MRI was performed every 3 months. Overall survival data were collected from internal database, telephone interviews, and identifying registries.Mean follow-up after GKRS was 51 months (range, 6 to 96 months); mean overall survival was 14.2 months. Of 373 patients, 29 were alive at time of writing, 104 had died of cerebral progression, and 176 had died of systemic progression. In 64 cases it was not possible to ascertain the cause. Univariate and multivariate analysis were adjusted for the following: RPA class, surgery, WBRT, age, gender, number of lesions, median tumor volume, median peripheral dose, and 10 Gy and 12 Gy volumes. Identified RPA class and overall tumor volume5 cc were the only two covariates independently predictive of overall survival in patients who died of cerebral progression.Global volume of brain disease should be the main parameter to consider for performing GKRS, which is a first-line therapy for patient in good general condition and controlled systemic disease.

Purpose To assess anatomical, clinical and dosimetric pre-treatment parameters, possibly predictors of parotid shrinkage during radiotherapy of head and neck cancer (HNC). Materials Data of 174 parotids from four institutions were analysed; patients were treated with IMRT, with radical and adjuvant intent. Parotid shrinkage was evaluated by the volumetric difference (Δ V ) between parotid volumes at the end and those at the start of the therapy, as assessed by CT images (MVCT for 40 patients, KVCT for 47 patients). Correlation between Δ V cc/% and a number of dosimetric, clinical and geometrical parameters was assessed. Univariate as well as stepwise logistic multivariate (MVA) analyses were performed by considering as an end-point a Δ V cc/% larger than the median value. Linear models of Δ V (continuous variable) based on the most predictive variables found at the MVA were developed. Results Median Δ V cc/% were 6.95cc and 26%, respectively. The most predictive independent variables of Δ V cc at MVA were the initial parotid volume (IPV, OR: 1.100; p =0.0002) and D mean (OR: 1.059; p =0.038). The main independent predictors of Δ V % at MVA were age (OR: 0.968; p =0.041) and V 40 (OR: 1.0338; p =0.013). Δ V cc and Δ V % may be well described by the equations: Δ V cc=−2.44+0.076 D mean (Gy)+0.279 IPV (cc) and Δ V %=34.23+0.192 V 40 (%)−0.2203 age (year). The predictive power of the Δ V cc model is higher than that of the Δ V % model. Conclusions IPV/age and D mean/ V 40 are the major dosimetric and clinical/anatomic predictors of Δ V cc and Δ V %. Δ V cc and Δ V % may be well described by bi-linear models including the above-mentioned variables.

To optimise image-guided radiotherapy (IGRT) approaches in set-up error correction for hypofractionated adjuvant treatment of prostate cancer using helical tomotherapy (HT).HT unit provides megavoltage - CT (MVCT) imaging capability for daily patient set-up. The intrinsic uncertainty of the available image registration techniques was first investigated on a pelvic phantom. To optimise different set-up correction strategies, MVCT data of 37 patients treated with 58 Gy delivered in 20 fractions were analyzed. 620 MVCT images were globally available for the analysis. Daily on-line set-up correction without any action level was applied for 27/37 patients. The residual and the effective set-up error were assessed. For 10/37 patients an off-line correction strategy with an action level was applied.Phantom measurements showed an intrinsic uncertainty in MVCT imaging and registration around 0.6 mm (+/-0.5 mm) for each of the three main axes. The minimum value of the residual systematic error was found at 7th-10th session, with values between 0.7 and 1.1 mm (1 SD); a systematic residual error2 mm for all directions was in any case found at 3rd-4th session. This result was also confirmed by the effective systematic set-up error analysis, with a minimum value within 1.5mm nearly at the 4th or 5th fraction.Although the minimum systematic residual error is reached at 7th-10th treatment session, the effective systematic set-up error analysis confirmed that an off-line correction at the 4th fraction without any action level may be a robust compromise with a large sparing of time and resources compared to on-line correction.

Purpose To report planning and acute toxicity data of the first 60 patients treated within a Phase I–II study with moderate hypofractionation by image-guided helical tomotherapy. Methods and Materials Various clinical target volumes (CTVs) were defined: CTV1—pelvic nodes; CTV2—upper portion of seminal vesicles; CTV3—lower portion of SV; CTV4—prostate; overlap between planning target volume (PTV) 4 and rectum. Different doses to each PTV were simultaneously delivered in 28 fractions. For 31 low-risk patients: 56.0, 61.6, and 71.4 Gy for PTV2–4, respectively; for 20 intermediate-risk patients: 51.8, 61.6, 65.5, and 74.2 Gy for PTV1–4, respectively; for 9 high-risk patients: 51.8 and 65.5 Gy for PTV1–2 and 74.2 Gy for PTV3–4. For all patients, the dose to overlap was 65.5 Gy. Results The mean fraction of rectum receiving more than 65 Gy (V65) and rectal Dmax were 10% and 70.8 Gy respectively. In cases of pelvic node irradiation, the intestinal cavity (outside PTV) receiving > 45 and 50 Gy was 86 and 12 cc, respectively. A homogeneous dose distribution within each PTV was guaranteed. Acute genitourinary toxicity according to RTOG scoring system was as follows: 21/60 (35%) Grade 1, 12/60 (20%) Grade 2, 2/60 (3%) Grade 3. Acute rectal toxicities were: 18/60 (30%) Grade 1. Twelve (20%) patients showed Grade 1 upper intestinal toxicity (uGI). No patients experienced ≥ Grade 2 acute rectal or uGI side effects. Conclusions This study shows excellent results with regard to acute toxicity. Further research is necessary to assess definitive late toxicity and tumor control outcome.

PURPOSE: To compare intensity-modulated proton therapy (IMPT) and helical tomotherapy (HT) treatment plans for nasopharynx cancer using a simultaneous integrated boost approach. METHODS AND MATERIALS: The data from 6 patients who had previously been treated with HT were used. A three-beam IMPT technique was optimized in the Hyperion treatment planning system, simulating a "beam scanning" technique. HT was planned using the tomotherapy treatment planning system. Both techniques were optimized to simultaneously deliver 66 Gy in 30 fractions to planning target volume (PTV1; GTV and enlarged nodes) and 54 Gy to PTV2 subclinical, electively treated nodes. Normal tissue complication probability calculation was performed for the parotids and larynx. RESULTS: Very similar PTVs coverage and homogeneity of the target dose distribution for IMPT and HT were found. The conformity index was significantly lower for protons than for photons (1.19 vs. 1.42, respectively). The mean dose to the ipsilateral and contralateral parotid glands decreased by 6.4 Gy and 5.6 Gy, respectively, with IMPT. The volume of mucosa and esophagus receiving > or =20 Gy and > or =30 Gy with IMPT was significantly lower than with HT. The average volume of larynx receiving > or =50 Gy was significantly lower with HT, while for thyroid, it was comparable. The volume receiving > or =30, > or =20, and > or =10 Gy in total body volume decreased with IMPT by 14.5%, 19.4%, and 23.1%, respectively. The normal tissue complication probability for the parotid glands was significantly lower with IMPT for all sets of parameters; however, we also estimated an almost full recovery of the contralateral parotid with HT. The normal tissue complication probability for the larynx was not significantly different between the two irradiation techniques. CONCLUSION: Excellent target coverage, homogeneity within the PTVs, and sparing of the organs at risk were reached with both modalities. IMPT allows for better sparing of most organs at risk at medium-to-low doses.

Adenoid cystic carcinoma, also called cylindroma, is the second most common histological type of tracheal malignancy but represents 1% of all respiratory tract cancers. We report a case of a 59-year-old patient submitted to an incomplete resection of the trachea and subsequently treated with adjuvant tomotherapy. There have been no reports in the literature regarding intensity-modulated radiation therapy with linac or tomotherapy systems in adenoid cystic carcinoma of the trachea. The present clinical case demonstrates the feasibility of adjuvant intensity-modulated radiation therapy techniques for optimizing the dose coverage of the tumor bed while sparing surrounding normal tissues. A dosimetric comparison between the tomotherapy plan and a 3-dimensional conformal radiotherapy plan is also reported. We demonstrate that tomotherapy permits an increase in the dose per fraction without important acute adverse effects. At 24 months’ follow-up, our patient shows no evidence of disease with negative histological findings.