AimTo evaluate the possible role of dosimetric parameters according Normal Tissue Complication Probability (NTCP) model as predictive of late toxicity and cosmesis in hypofractionated whole-breast three-dimensional conformal radiotherapy.Patients and methodsA retrospective analysis on 215 consecutive early breast cancer patients treated with breast conserving surgery and adjuvant hypofractionated whole-breast radiotherapy (according the Ontario Canadian trial), with a 6 years median follow-up was conducted. To assess the impact of 10%–20% dose hotspots on different percent values of planning target volume (PTV) of the breast, we retrospectively employed the NTCP model of Lyman. PTV breast (PTVbr), V110 were identified. For statistical analysis the χ2 and paired t-test were used to find a correlation between late skin and subcutaneous toxicity and cosmetic outcome with dosimetrical parameters Multivariate analysis was performed with the aim to assess independently the impact of dosimetric and clinical parameters on late toxicity and cosmesis using Pearson’s covariance.ResultsLate skin toxicity was recorded in 47/215 (22%); and G3 toxicity occurred in 11 patients (5%). Cosmesis with excellent–good score was found in 172 patients (80%) while fair–poor score was found in 43 patients (20%). In univariate χ2 analysis the V110 >10% of the PTV breast significantly correlated with higher toxicity (P<0.005, OR 9.60 [CI 3.89–23.72]). Cosmesis related to V110 >10% and PTV breast volume over 1,300 cc was significant at multivariate analysis (P<0.005, OR 6.07 [CI 2.36–15.59]).ConclusionTo safely use one of the most important whole-breast hypofractionated radiotherapy schedules, we found some predictive paramaters on the basis of NTCP model by Lyman. These parameters may be useful in selection of elegible patients.

Radiation therapy represents an important approach in the therapeutic management of children and adolescents with malignant tumors and its application with modern techniques – including Proton Beam Therapy (PBT) – is of great interest. In particular, potential radiation-induced injuries and secondary malignancies – also associated to the prolonged life expectancy of patients – are still questions of concern that increase the debate on the usefulness of PBT in pediatric treatments. This paper presents a literary review of current applications of PBT in non-Central Nervous System pediatric tumors (such as retinoblastoma, Hodgkin Lymphoma, Wilms tumor, bone and soft tissues sarcomas). We specifically reported clinical results achieved with PBT and dosimetric comparisons between PBT and the most common photon-therapy techniques. The analysis emphasizes that PBT minimizes radiation doses to healthy growing organs, suggesting for reduced risks of late side-effects and radiation-induced secondary malignancies. Extended follow up and confirms by prospective clinical trials should support the effectiveness and long-term tolerance of PBT in the considered setting.

Background and PurposeVolumetric modulated arc radiotherapy (RT) has become pivotal in the treatment of prostate cancer recurrence (RPC) to optimize dose distribution and minimize toxicity, thanks to the high-precision delineation of prostate bed contours and organs at risk (OARs) under multiparametric magnetic resonance (mpMRI) guidance. We aimed to assess the role of pre-treatment mpMRI in ensuring target volume coverage and normal tissue sparing.Material and MethodsPatients with post-prostatectomy RPC eligible for salvage RT were prospectively recruited to this pilot study. Image registration between planning CT scan and T2w pre-treatment mpMRI was performed. Two sets of volumes were outlined, and DWI images/ADC maps were used to facilitate precise gross tumor volume (GTV) delineation on morphological MRI scans. Two rival plans (mpMRI-based or not) were drawn up.ResultsTen patients with evidence of RPC after prostatectomy were eligible. Preliminary data showed lower mpMRI-based clinical target volumes than CT-based RT planning (p = 0.0003): median volume difference 17.5 cm3. There were no differences in the boost volume coverage nor the dose delivered to the femoral heads and penile bulb, but median rectal and bladder V70Gy was 4% less (p = 0.005 and p = 0.210, respectively) for mpMRI-based segmentation.ConclusionsmpMRI provides high-precision target delineation and improves the accuracy of RT planning for post-prostatectomy RPC, ensures better volume coverage with better OARs sparing and allows non-homogeneous dose distribution, with an aggressive dose escalation to the GTV. Randomized phase III trials and wider datasets are needed to fully assess the role of mpMRI in optimizing therapeutic strategies.

Background: Skin metastases from pancreatic neuroendocrine carcinoma (PNEC) are rare and their palliative treatment is challenging. We report our experience in the multimodal management of one of the few reported cases of metastatic PNEC with multiple visceral and subcutaneous secondary lesions, focusing on the effectiveness of palliative radiotherapy for skin metastases. Case presentation: A 61-years old woman affected by a metastatic PNECwith subcutaneous growing and bleeding secondary lesions (at the scalp, right scapular region and at the back of the left thoracic wall, respectively) obtained a successful control of visceral metastases with the use of chemotherapy and an unexpected local response of her skin metastases with palliative radiotherapy. In particular, two subsequent radiation treatments were performed using different fractionation schedules (30 Gy in 10 fractions and 20 Gy in 5 fractions, respectively). Both radiation treatments were well-tolerated and patient's quality of life was improved. Local response was maintained until patient's deaththat occurred due to cachexia. Conclusions: The presented case highlights the effectiveness and the good tolerance of radiotherapy in the treatment of subcutaneous metastases; nevertheless, further knowledge of the optimal local palliative approach for PNEC metastatic sites is necessary. The experience gained in this work is the occasion to encourage a routine integrated multidisciplinary team management of metastatic PNECs because of their clinical complexity. The aim is to guarantee the optimization of the care with personalized and more effective systemic and local treatmentsalso including supportive cares and treatment-related side effects management.

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