A dedicated cloud system for real-time upfront quality assurance in pediatric radiation therapy.

PURPOSE: Pediatric radiotherapy (RT) is a highly specialized field, requiring great experience to delineate correctly tumor targets and organs at risk. To reduce treatment failures related to planning inaccuracies and to obtain robust clinical results despite the limited numbers of enrolled pediatric patients, the SIOP PNET5MB clinical trial on medulloblastoma requires a real-time, pre-radiation review of the RT treatment (craniospinal irradiation and boost plan) under the direct responsibility of the national coordinator center. Here we describe the centralized radiotherapy quality assurance (QA) program developed in Italy for this purpose. METHODS: Using the software package VODCA (MSS, Hagendorn, Switzerland, www.vodca.ch ), we developed a cloud platform able to handle computed tomography (CT) images and RT objects and to support the complete workflow required by the review process in the context of the SIOP PNET5 trial. RESULTS: All Italian centers participating in the PNET5 trial adopted the proposed QA system. 24 patients were successfully enrolled and reviewed. For 15 patients (62.5%), one or more plan revisions were requested for the craniospinal irradiation plan and for 11 patients (45.8%) plan revisions were requested for the boost. RT was delivered after the plan was centrally approved for all enrolled patients. So far, in Italy, no patients have been excluded from PNET5 due to dosimetric incompliance to the protocol or for exceeding the RT starting time limit. CONCLUSION: The cloud platform successfully supported the trial workflow, producing official review documents. This efficient QA was crucial to guarantee optimized treatments and protocol compliance for all pediatric patients enrolled in the SIOP protocol.

Adjuvant intraoperative radiotherapy for selected breast cancers in previously irradiated women: Evidence for excellent feasibility and favorable outcomes.

BACKGROUND: The present report provides preliminary outcomes with intraoperative radiotherapy delivered to women with breast cancer included in a re-irradiation program. MATERIALS AND METHODS: From October 2010 to April 2014, thirty women were included in a re-irradiation protocol by exploiting IORT technique. The median time between the two irradiations was 10 years (range 3-50). All patients underwent conservative surgery, sentinel lymph node excision and IORT with electron beam delivered by a mobile linear accelerator. Primary endpoint was esthetic result and consequential/late toxicity; secondary endpoints were local control (LC), disease free survival (DFS) and overall survival (OS). RESULTS: With a median follow up of 47 months (range 10-78), we analyzed 29 patients (1 lost at follow up). Twenty-seven patients (90%) had presented breast cancer local relapse or a new primary cancer in the same breast after a previous conservative surgery plus radiation treatment; three patients (10%) had previously received irradiation with mantle field for Hodgkin Lymphoma. Esthetic result was excellent in 3 pts (10%), good in 12 pts (41%), fair in 8 pts (28%) and poor in 6 pts (21%). 12 (41%) patients showed subcutaneous fibrosis at the last follow-up. LC, DFS and OS at five years was 92.3%, 86.3% and 91.2%, respectively. CONCLUSION: Although we analyzed a small number of patients, our results are satisfactory and this approach is feasible even if it could not be considered the standard treatment. Further clinical trials exploring IORT are needed to identify possible subgroups of patients that might be suitable for this type of approach.

Dosimetric Comparison Between Proton and Photon Radiation Therapies for Pediatric Neuroblastoma.

Purpose: The aim of this study is to determine the most beneficial radiation treatment technique for pediatric patients with thoracic and abdominal neuroblastoma (NBL), through a dosimetric comparison between photon Volumetric Modulated Arc Therapy and proton Intensity-Modulated Proton Therapy treatment plans. Materials and Methods: A retrospective analysis was conducted on a multicentre case series of 19 patients with thoracic and/or abdominal NBL who underwent radiation therapy, following the recommendations of the European protocol for high-risk NBL (HR-NBL2/SIOPEN). The prescribed dose was 21.6 Gy in 12 fractions (1.8 Gy/fraction) delivered over the preoperative disease volume. The dose volume histograms were analyzed for each patient, and a Wilcoxon signed-rank test with a significance level of 0.01 was employed to assess statistical differences between the dosimetric parameters investigated. Two homogeneity indices (HI and newHI) were compared to evaluate the uniformity in dose, delivered to the adjacent vertebrae (VBs_Adj). Results: Both radiation techniques conform to the protocol regarding CTV/PTV coverage for every location. Proton therapy resulted in statistically significant dose sparing for the heart and lungs in supradiaphragmatic locations and for the contralateral kidney, liver, spleen, and bowel in subdiaphragmatic locations. For both techniques, sparing the non-adjacent vertebrae (VBs_NAdj) results more challenging, although promising results were obtained. Furthermore, the dose delivered to the VBs_Adj was not statistically different, in terms of homogeneity, for the 2 radiation techniques that both met the protocol's requirements. Conclusion: This dosimetric analysis highlights the potential of protons to reduce radiation dose to healthy tissue. These findings apply to all the investigated patients, regardless of primary tumor location, making proton therapy a valuable option for the treatment of neuroblastoma. However, a multidisciplinary assessment of each case is essential to ensure the selection of the most effective and suitable treatment modality.

One-to-one comparison between digital spot compression view and digital breast tomosynthesis.

OBJECTIVE: To assess if digital breast tomosynthesis (DBT) is at least equal to digital spot compression view (DSCV). METHODS: Following institutional approval and written informed consent, both DBT and DSCV were obtained in women with a screening abnormality. The diagnostic accuracy of DBT and DSCV was evaluated by two radiologists of varying experience (Reader1 and Reader2). RESULTS: 52 consecutive recalled women without calcification (mean age: 51 ± 12 years) underwent DSCV and DBT. Overall sensitivity was equal for both techniques (100% [95% CI, 91-100%] for DBT and 100% [95% CI, 91-100%] for DSCV). Overall specificity was higher for DBT (100% [95%CI, 91-100%]) than for DSCV (94% [95% CI, 91-100%]). Specificity for DSCV was higher for Reader1 (95% [95% CI, 91-100%]). Reader2 had lower values of specificity (92% [95% CI, 90-92%]). On DSCV, three and two false positives were recorded by Reader2 and Reader1, respectively. Overall, the area under the curve (AUC) was greater for DBT (AUC = 1) than for DSCV (AUC = 0.963). The mean difference between the two techniques was not significantly different (P = 0.43). CONCLUSION: In this dataset, diagnostic accuracy of digital breast tomosynthesis is at least equal to that of digital spot compression. KEY POINTS: • Digital spot compression views (DSCVs) are often needed in breast screening programmes. • Digital breast tomosynthesis (DBT) now offers an alternative to DSCV • In recalls without calcification, DBT was at least equally accurate as DSCVs • DBT has a lower mean glandular dose than DSCVs • Thus DBT has the potential to help reduce the recall rate.

Mammographic density estimation: one-to-one comparison of digital mammography and digital breast tomosynthesis using fully automated software.

OBJECTIVE: To compare breast density on digital mammography and digital breast tomosynthesis using fully automated software. METHODS: Following institutional approval and written informed consent from all participating women, both digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) were obtained. Breast percentage density was calculated with software on DBT and FFDM. RESULTS: Fifty consecutive patients (mean age, 51 years; range, 35-83 years) underwent both FFDM and DBT. Using a method based on the integral curve, breast density showed higher results on FFDM (68.1 ± 12.1 for FFDM and 51.9 ± 6.5 for DBT). FFDM overestimated breast density in 16.2% (P < 0.0001). Using a method based on maximum entropy thresholding, breast density showed higher results on FFDM (68.1 ± 12.1 for FFDM and 51.9 ± 6.5 for DBT). FFDM overestimated breast density in 11.4% (P < 0.0001). There was a good correlation among BI-RADS categories on a four-grade scale and the density evaluated with DBT and FFDM (r = 0.54, P < 0.01 and r = 0.44, P < 0.01). CONCLUSION: Breast density appeared to be significantly underestimated on digital breast tomosynthesis. KEY POINTS: Breast density is considered to be an independent risk factor for cancer Density can be assessed on full-field digital mammography and digital breast tomosynthesis Objective automated estimation of breast density eliminates subjectivity Automated estimation is more accurate than BI-RADS quantitative evaluation Breast density may be significantly underestimated on digital breast tomosynthesis.

Ten Daily Fractions for Whole Breast Cancer Irradiation: Long Term Results.

BACKGROUND/AIM: To report the feasibility and oncological outcomes in breast cancer patients treated with a short hypofractionated radiotherapy schedule. PATIENTS AND METHODS: We evaluated 380 breast cancer patients treated with ten daily fractions of radiotherapy up to 39 Gy on tumor bed. Primary endpoint was local relapse rate (LRR). Secondary endpoints were overall survival (OS) and metastasis-free survival (MFS). RESULTS: The median follow up was 5.0 years. Two- and 5-year LRR rates were 0.2 and 2%, respectively. Two- and 5-year MFS rates were 96.1% and 90.5%, respectively. Two and 5-year OS rates were 97.4% and 95%, respectively. CONCLUSION: This short schedule may represent an alternative option to standard mild hypofractionated radiotherapy in breast cancer patients due to its excellent feasibility and very low recurrence rate.

Tumor Size-driven Dose of Intraoperative Radiotherapy for Breast Cancer: 18 Gy Versus 21 Gy.

AIM: To test whether a reduced total single dose of 18 Gy of intraoperative radiotherapy with electrons (IORT) may be tailored to safely treat patients in comparison with the standard dose of 21 Gy. (NCT01276938). PATIENTS AND METHODS: From October 2009 to December 2011, 199 females affected by breast cancer were treated with conservative surgery and IORT with two different exclusive doses, 18 or 21 Gy. RESULTS: The median follow-up was 91 months (16-104 months). Sixty-five patients (pT1a\b, pN0\mic, pMx, G1-G3) received 18 Gy and 134 patients (pT1c\2, pN0\mic, pMx, G1-G3) received 21 Gy. No significant difference in local recurrence-free survival or overall survival was detected in the 18 Gy-treated arm versus that treated with 21 Gy: 96.9% vs. 96.3%, p=0.72, and 96.9% vs. 95.5%, p=0.82, respectively at 5 years. CONCLUSION: The lower dose of 18 Gy achieved excellent results in terms of local toxicity and local control in early breast cancer.

Moderate hypofractionated radiotherapy after prostatectomy for cancer patients: toxicity and clinical outcome.

Background: After radical prostatectomy (RP) radiotherapy (RT) plays a role, both as adjuvant or salvage treatment. If negative features are present such as extracapsular extension, seminal vesicle invasion, lymph invasion, and positive surgical margins, RT after RP reduces the risk of recurrence, although it is associated with an increased risk of acute and late toxicities. An intensified RT delivered in a shortened time could improve clinical outcome and be safely combined with hormonal therapy (HT). The aim of this study was to determine the acute and late toxicities associated with hypofractionated RT and to assess the impact of the addition of HT to RT in high-risk prostate cancer (PC) patients on overall response and toxicity. Materials and methods: Sixty-four PC patients undergoing RP were included in this retrospective study. All patients were recommended to receive adjuvant or salvage RT. Prescription doses were 62.5 Gy in 25 fractions to prostate bed, 56.25 Gy in 25 fractions to seminal vesicles bed, and 50 Gy in 25 fractions to pelvis if indicated. HT was administered to patients with additional adverse pathologic features including Gleason score >7, prostate-specific antigen >20 ng/mL before surgery, or prostate-specific antigen with rapid doubling time after relapse or nodal involvement. After completion of RT, patients were observed after 4 weeks, and then followed-up every 3-6 months. Acute and late toxicities were assessed using Common Terminology Criteria for Adverse Events v4 and Radiation Therapy Oncology Group scale, respectively. Results: For acute toxicity, only grade 1 gastrointestinal and genitourinary toxicities were detected in 17% and 11% of patients, respectively. As regards late toxicity, only 5% of the patients developed grade 1 gastrointestinal adverse event; grade 1, grade 2, and grade 3 genitourinary toxicity was recorded in 5%, 3.3%, and 3.3% of patients, respectively. Two and 5 years overall survival were 98% and 96%, respectively. The curves stratified for treatment show a slight difference between patients receiving RT or RT+HT, but the differences did not reach statistical significance (p=0.133). Conclusion: In patients with PC undergoing RP, hypofractionated RT may contribute to achieve a high overall survival with an acceptable toxicity profile. Combination of RT and HT is also well tolerated and efficacious.

Comparison of Local Recurrence Among Early Breast Cancer Patients Treated With Electron Intraoperative Radiotherapy vs Hypofractionated Photon Radiotherapy an Observational Study.

PURPOSE: To evaluate local recurrence (LR) in women with early breast cancer (BC) who underwent intraoperative radiation therapy with electrons particles (IORT-E) or adjuvant hypofractionated external radiotherapy (HYPOFX). MATERIALS AND METHODS: We retrospectively analyzed 470 patients with early BC treated at our center from September 2009 to December 2012. 235 women were treated with breast-conserving surgery and immediate IORT-E (21 Gy/1 fraction) while 235 patients underwent wide excision followed by hypofractionated whole-breast irradiation. Radiotherapy modality was chosen according to an individualized decision based on tumor features, stage, technical feasibility, age, and acceptance to be enrolled in the IORT-E group. RESULTS: After a median follow-up of 6 years, we observed 8 (3.4%) and 1 (0.42%) LR in the IORT-E and in the HYPOFX group (p = 0.02), respectively. The two groups differed in the prevalence of clinical characteristics (p < 0.05): age, tumor size, surgical margins, receptors, ki67, and histology. 4 and 1 woman in the IORT-E and HYPOFX group died of BC, respectively (p = 0.167). OS and DFS hazard ratio [HR] were 2.14 (95% IC, 1.10-4.15) and 2.09 (95% IC, 1.17-3.73), respectively. CONCLUSION: Our comparison showed that IORT-E and HYPOFX are two effective radiotherapy modalities after conservative surgery in early BC. However, at 6 years a significant higher rate of LR occurred in patients submitted to IORT-E with respect to HYPOFX. This finding may be correlated to some subsets of patients who, depending on the biological characteristics of the BC, may be less suitable to IORT-E.

Neuroendocrine late effects after tailored photon radiotherapy for children with low grade gliomas: Long term correlation with tumour and treatment parameters.

PURPOSE: To evaluate neuroendocrine late effects in paediatric patients with low grade glioma (LGG) who underwent radiotherapy. METHODS AND MATERIAL: We performed a retrospective evaluation of 40 children with LGG treated from July 2002 to January 2015 with external radiotherapy. Tumour locations were cerebral hemisphere (n=2); posterior fossa (n=15); hypothalamic-pituitary axis (HPA, n=15); spine (n=5). Three patients presented a diffuse disease. We looked for a correlation between endocrine toxicity and tumour and treatment parameters. The impact of some clinical and demographic factors on endocrinal and neuro toxicity was evaluated using the log-rank test. RESULTS: The median follow-up was 52months (range: 2-151). Median age at irradiation was 6. The dose to the HPA was significantly associated with endocrine toxicity (P value=0.0190). Patients who received chemotherapy before radiotherapy and younger patients, showed worse performance status and lower IQ. The 5-year overall survival (OS) and progression free survival (PFS) rates were 94% and 73.7%, respectively. CONCLUSION: Radiotherapy showed excellent OS and PFS rates and acceptable late neuroendocrine toxicity profile in this population of LGG patients treated over a period of 13years. In our experience, the dose to the HPA was predictive of the risk of late endocrine toxicity.

Use of parallel-plate ionization chambers in reference dosimetry of NOVAC and LIAC® mobile electron linear accelerators for intraoperative radiotherapy: a multi-center survey.

PURPOSE: LIAC® and NOVAC are two mobile linear accelerators dedicated to intraoperative radiation therapy (IORT), generating electron beams in the energy range of 3-12 MeV. Due to high dose-per-pulse (up to 70 mGy per pulse), in 2003 the Italian National Institute of Health (ISS) stated that "for the measure of dose to water in reference conditions, ionization chambers cannot be employed and no published dosimetry protocol can be used". As a consequence, ferrous sulphate (or, alternatively alanine) dosimetry was recommended. Based on a retrospective multi-center survey, a comparison with ferrous sulphate dosimetry is now used to validate the parallel-plate ionization chambers for reference dosimetry of NOVAC and LIAC. METHODS: The IAEA TRS-398 dosimetry protocol was applied except for the reference irradiation setup and the determination of the ion-recombination correction factor ks . Moreover the depth of maximum dose (R100 ) instead of zref as measurement depth was chosen by the majority of centers, thus implying a renormalization of the beam-quality correction factor kQ,Qo , based on water-air stopping power ratios. Regarding the ks determination, a previously published method, independent of ferrous sulphate dosimetry, was adopted. All the centers participating in this study had used both ferrous sulphate dosimeters and ionization chambers in water phantoms for dosimetry under reference conditions. RESULTS: The mean percentage difference between ionization chambers and ferrous sulphate dosimetry was -0.5% with a dispersion of 3.9% (2σ). Moreover, the uncertainty analysis allowed the agreement between ionization chambers and ferrous sulphate dosimetry to be verified. These results did not show any significant dependence on electron energy, thus indirectly confirming kQ,Qo renormalization. The results from the centers using zref as the measurement depth were similar to the other data, but further focused studies could aim at investigating possible dependences of the dose differences on the chosen reference depth. CONCLUSION: The present study confirms that parallel-plate ionization chambers can properly and accurately substitute ferrous sulphate detectors in reference dosimetry of LIAC and NOVAC mobile linear accelerators. Therefore, we hope that the most commonly used protocols for reference dosimetry in external-beam radiotherapy will be updated in order to provide guidance in the calibration of electron beams from linear accelerators dedicated to IORT, so that users may benefit from specific, authoritative and up-to-date recommendations.

Hypofractionated irradiation of infra-supraclavicular lymph nodes after axillary dissection in patients with breast cancer post-conservative surgery: impact on late toxicity.

BACKGROUND: The aim of the present work was to analyse the impact of mild hypofractionated radiotherapy (RT) of infra-supraclavicular lymph nodes after axillary dissection on late toxicity. METHODS: From 2007 to 2012, 100 females affected by breast cancer (pT1- T4, pN1-3, pMx) were treated with conservative surgery, Axillary Node Dissection (AND) and loco-regional radiotherapy (whole breast plus infra-supraclavicular fossa). Axillary lymph nodes metastases were confirmed in all women. The median age at diagnosis was 60 years (range 34-83). Tumors were classified according to molecular characteristics: luminal-A 59 pts (59%), luminal-B 24 pts (24%), basal-like 10 pts (10%), Her-2 like 7 pts (7%). 82 pts (82%) received hormonal therapy, 9 pts (9%) neo-adjuvant chemotherapy, 81pts (81%) adjuvant chemotherapy. All patients received a mild hypofractionated RT: 46 Gy in 20 fractions 4 times a week to whole breast and infra-supraclavicular fossa plus an additional weekly dose of 1,2 Gy to the lumpectomy area. The disease control and treatment related toxicity were analysed in follow-up visits. The extent of lymphedema was analysed by experts in Oncological Rehabilitation. RESULTS: Within a median follow-up of 50 months (range 19-82), 6 (6%) pts died, 1 pt (1%) had local progression disease, 2 pts (2%) developed distant metastasis and 1 subject (1%) presented both. In all patients the acute toxicity was mainly represented by erythema and patchy moist desquamation. At the end of radiotherapy 27 pts (27%) presented lymphedema, but only 10 cases (10%) seemed to be correlated to radiotherapy. None of the patients showed a severe damage to the brachial plexus, and the described cases of paresthesias could not definitely be attributed to RT. We did not observe symptomatic pneumonitis. CONCLUSIONS: Irradiation of infra-supraclavicular nodes with a mild hypofractionated schedule can be a safe and effective treatment without evidence of a significant increase of lymphedema appearance radiotherapy related.

Image guided hypofractionated radiotherapy by helical tomotherapy for prostate carcinoma: toxicity and impact on Nadir PSA.

AIM: To evaluate the toxicity of a hypofractionated schedule for primary radiotherapy (RT) of prostate cancer as well as the value of the nadir PSA (nPSA) and time to nadir PSA (tnPSA) as surrogate efficacy of treatment. MATERIAL AND METHODS: Eighty patients underwent hypofractionated schedule by Helical Tomotherapy (HT). A dose of 70.2 Gy was administered in 27 daily fractions of 2.6 Gy. Acute and late toxicities were graded on the RTOG/EORTC scales. The nPSA and the tnPSA for patients treated with exclusive RT were compared to an equal cohort of 20 patients treated with conventional fractionation and standard conformal radiotherapy. RESULTS: Most of patients (83%) did not develop acute gastrointestinal (GI) toxicity and 50% did not present genitourinary (GU) toxicity. After a median follow-up of 36 months only grade 1 of GU and GI was reported in 6 and 3 patients as late toxicity. Average tnPSA was 30 months. The median value of nPSA after exclusive RT with HT was 0.28 ng/mL and was significantly lower than the median nPSA (0.67 ng/mL) of the conventionally treated cohort (P = 0.02). CONCLUSIONS: Hypofractionated RT schedule with HT for prostate cancer treatment reports very low toxicity and reaches a low level of nPSA that might correlate with good outcomes.

'In vivo' average glandular dose evaluation: one-to-one comparison between digital breast tomosynthesis and full-field digital mammography.

We analysed 300 patients X rayed with digital breast tomosynthesis (DBT), full-field digital mammography (FFDM) and 'COMBO' (single view both in FFDM and DBT in a single breast compression)-Hologic Selenia Dimension-W/Rh-Ag-Al: three different anode-filter combinations-automatic exposure control modalities. Examination parameter data collection (EPDC) and 'in vivo' dosimetry using metal oxide semiconductor field effect transistor (MOSFET) were utilised to determine and compare entrance skin air kerma (ESAK) and average glandular dose (AGD) from a radioprotection viewpoint in the DBT and COMBO modalities. MOSFET has been tested to be introduced in clinical routine. EPDC of DBT underlines increase in ESAK and AGD compared with FFDM (p < 0.05). The mean percentage increase was 34 % (+17 %) in ESAK and 46 % (+16 %) in AGD. In the COMBO modality, the mean percentage increase in ESAK was 162 % (+41 %) and in AGD was 202 % (+61 %). Differences between MOSFET measurement and calculated values were <8 % for breasts thicker than 30 mm; otherwise, the errors are >15 %. DBT increases ESAK and AGD, due to the 3D acquisition modality. MOSFET may be considered in DBT as a routine check.

Ablative or palliative stereotactic body radiotherapy with helical tomotherapy for primary or metastatic lung tumor.

AIM: To evaluate the feasibility and outcomes of stereotactic body radiotherapy (SBRT) by helical tomotherapy (HT) for patients with primary or secondary lung cancer. PATIENTS AND METHODS: Between March 2009 and January 2012, 56 patients were selected as candidates for the study and were divided into two subgroups. The ablative SBRT group included 27 patients with T1-T2 non-small cell lung cancer who received four to five large-dose fractions in two weeks and the palliative SBRT group included 29 patients with lung metastases treated with eight lower-dose fractions in four weeks. RESULTS: No differences in acute toxicities were found between different fractionation schemes with different overall treatment times. Actuarial local control at 24 months was better for the ablative group (69.6%) than for the palliative one (40.4%) (p=0.0019). CONCLUSION: HT-based SBRT was feasible and well-tolerated. Local control was satisfactory for patients treated with ablative SBRT but unsatisfactory for those treated with palliative SBRT. Outcomes also suggest the use of ablative SBRT fractionation for palliative intent.

On-line optimization of intraoperative electron beam radiotherapy of the breast.

PURPOSE: To optimize the dose delivery to the breast lumpectomy target treated with intraoperative electron beam radiotherapy (IOERT). MATERIALS AND METHODS: Two tools have been developed in our MU calculation software NEMO X to improve the dose homogeneity and the in-vivo dosimetry effectiveness for IOERT treatments. Given the target (tumor bed) thickness measured by the surgeon, NEMO X can provide auto dose normalization to cover 95% of the target volume with 95% of the prescription dose (PD) and a "best guess" of the expected dosimeter dose (EDD) for a deep seated in-vivo dosimeter. The tools have been validated with the data of 91 patients treated with IOERT on a LIAC mobile accelerator. In-vivo dosimetry has been performed with microMOSFETs positioned on the shielding disk inserted between the tumor bed and the chest wall. RESULTS: On average the auto normalization showed to provide better results if compared to conventional normalization rules in terms of mean target dose (|MTD-PD|/PD ≤ 5% in 95% vs. 53% of pts) and V107 percentage (left angle bracket V107 right angle bracket =19% vs. 32%). In-vivo dosimetry MOSFET dose (MD) showed a better correlation with the EDD guessed by our tool than just by assuming that EDD=PD (|MD-EDD|/EDD ≤ 5% in 57 vs. 26% of pts). CONCLUSIONS: NEMO X provides two useful tools for the on-line optimization of the dose delivery in IOERT. This optimization can help to reduce unnecessary large over-dosage regions and allows introducing reliable action levels for in-vivo dosimetry.

Advances in the implementation of helical tomotherapy-based total marrow irradiation with a novel field junction technique.

Given the limitations in the travel ability of the helical tomotherapy (HT) couch, total marrow irradiation (TMI) has to be split in 2 segments, with the lower limbs treated with feet first orientation. The aim of this work is to present a planning technique useful to reduce the dose inhomogeneity resulting from the matching of the 2 helical dose distributions. Three HT plans were generated for each of the 18 patients enrolled. Upper TMI (UTMI) and lower TMI (LTMI) were planned onto the whole-body computed tomography (CT) and on the lower-limb CT, respectively. A twin lower TMI plan (tLTMI) was designed on the whole-body CT. Agreement between LTMI and tLTMI plans was assessed by computing for each dose-volume histogram (DVH) structure the γ index scored with 1% of dose and volume difference thresholds. UTMI and tLTMI plans were summed together on the whole-body CT, enabling the evaluation of dose inhomogeneity. Moreover, a couple of transition volumes were used to improve the dose uniformity in the abutment region. For every DVH, a number of points >99% passed the γ analysis, validating the method used to generate the twin plan. The planned dose inhomogeneity at the junction level resulted within ±10% of the prescribed dose. Median dose reduction to organs at risk ranged from 30-80% of the prescribed dose. Mean conformity index was 1.41 (range 1.36-1.44) for the whole-body target. The technique provided a "full helical" dose distribution for TMI treatments, which can be considered effective only if the dose agreement between LTMI and tLTMI plans is met. The planning of TMI with HT for the whole body with adequate dose homogeneity and conformity was shown to be feasible.

Focus on the actual clinical target volume irradiated with intraoperative radiotherapy for breast cancer.

AIM: Intraoperative radiotherapy (IORT) has been investigated as an exclusive adjuvant treatment option for early-stage breast cancer (BC). We analysed our experience on the technical aspects of this innovative approach in terms of identification of breast volume actually to be treated during IORT. PATIENTS AND METHODS: A total of 315 patients at low risk of breast cancer recurrence underwent IORT as exclusive treatment after breast-conservative surgery. To evaluate the breast volume actually irradiated with IORT, we considered a sample of eight patients, chosen retrospectively as having enough clips to identify the tumour bed and IORT site in computed-tomography (CT). The clinical target volume (CTV) was assessed for each patient with two different methods: the first, cc-IORT, was considered during surgery according to the chosen collimator diameter and glandular thickness, while the second, cc-CT, was evaluated through computed-tomography performed after surgery. The cc-CT CTV was obtained by contouring the cc-IORT on the CT section on the basis of the clips placed by the surgeon on the resection margins. RESULTS: In our experience, the 5-cm (50%) and the 6-cm (36%) diameter collimators have been the ones, used the most. The diameter of the collimator used did not appear to adversely affect the satisfactory aesthetic result. The comparison between CTVs showed that glandular breast volume contoured with CT (cc-CT) appeared to be three fold larger than the target identified at surgery and included in the area of chosen collimator (cc-IORT). CONCLUSION: The actual volume of breast gland irradiated with the IORT procedure appears to be larger than expected. This may be due to the area being prepared for IORT by placing tissue compactly.

Adjuvant hypofractionated radiotherapy with weekly concomitant boost for women with early breast cancer: the clinical experience at Genoa university.

UNLABELLED: The aim of this investigation was to evaluate the feasibility of a shortened whole-breast irradiation schedule with a concomitant boost delivered to the tumor bed once-a-week in patients with early breast cancer submitted to conservative surgery. PATIENTS AND METHODS: Patients with pT1 and pT2 M0 carcinoma of the breast were selected. The basic course consisted of 4600 cGy to the whole breast in 20 fractions, 4 times a week, for 5 weeks. Once a week, a concomitant boost of 120 cGy was delivered to the lumpectomy area. RESULTS: From March 2007 to August 2008, we assessed this radiotherapy schedule in 377 patients. According to the RTOG/EORTC Toxicity Criteria, at treatment completion, 85% of patients showed G0-1, 12% G2 and 3% G3 skin toxicity. At 24 months, late toxicity was G0 in 92%, G1 in 7% and G2 in 1%; cosmesis was excellent or good in 95% of patients. To date, at a median follow-up of 33 months, no patient has yet experienced local relapse. CONCLUSION: A shortened whole-breast irradiation schedule with a weekly concomitant boost may be an alternative option with acceptable toxicity and excellent cosmesis.