Tolerance of normal tissue to therapeutic irradiation

Salvage treatment using carbon ion radiation in patients with locoregionally recurrent nasopharyngeal carcinoma: Initial results

BACKGROUND

Reirradiation for locoregionally recurrent nasopharyngeal carcinoma (NPC) after a definitive dose of radiotherapy (RT) is challenging and usually associated with severe toxicities. Intensity‐modulated carbon ion RT (IMCT) offers physical/biologic advantages over photon‐based intensity‐modulated RT. Herein, the authors report their initial experience of IMCT in previously irradiated patients with locoregionally recurrent NPC.

METHODS

Patients with locoregionally recurrent, poorly differentiated or undifferentiated NPC who underwent salvage therapy with IMCT at the Shanghai Proton and Heavy Ion Center between May 2015 and August 2017 were included in the current study. The IMCT doses were 50 to 66 Gray equivalent (GyE) (2.0‐3.0 GyE/daily fraction), delivered via raster scanning technology. The 1‐year overall survival, disease‐specific survival, progression‐free survival (PFS), local recurrence‐free survival, regional recurrence‐free survival, and distant metastasis‐free survival were calculated. Univariate and multivariate analyses of PFS were performed to identify possible predictive factors.

RESULTS

Among the 75 patients included, 4 patients, 14 patients, 29 patients, and 28 patients, respectively, had recurrent American Joint Committee on Cancer stage I, stage II, stage III, and stage IVA/B disease. With a median follow‐up of 15.4 months (range, 2.6‐29.7 months), the 1‐year overall survival, disease‐specific survival, PFS, local recurrence‐free survival, regional recurrence‐free survival, and distant metastasis‐free survival rates were 98.1%, 98.1%, 82.2%, 86.6%, 97.9%, and 96.2%, respectively. A higher fraction size of 3 GyE (vs <3 GyE) or a higher biological equivalent dose significantly improved the PFS rate on univariate analysis, but not on multivariate analysis. No patient developed acute toxicity of grade ≥2 during IMCT. Late treatment‐induced severe (grade 3 or 4) toxicities were infrequent, but included mucosal necrosis (9.3%), xerostomia (1.3%), and temporal lobe necrosis (1.3%).

CONCLUSIONS

This initial experience in the first 75 patients with locoregionally recurrent NPC was encouraging. Carbon ion RT could provide promising survival rates with infrequent severe toxicities for patients with locoregionally recurrent NPC. Cancer 2018;124:2427‐37. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

Reirradiation for locoregionally recurrent nasopharyngeal carcinoma after a definitive dose of radiotherapy is challenging and usually associated with severe toxicities. Carbon ion radiotherapy provides promising short‐term survival rates for patients with locoregionally recurrent nasopharyngeal carcinoma, with few treatment‐induced severe adverse effects noted.

Brachial plexopathy after stereotactic body radiation therapy for apical lung cancer: Dosimetric analysis and preliminary clinical outcomes

Purpose

The treatment of apical lung tumors with stereotactic body radiation therapy (SBRT) is challenging due to the proximity of the brachial plexus and the concern for nerve damage.

Methods and materials

Between June 2009 and February 2017, a total of 75 consecutive patients underwent SBRT for T1-T3N0 non-small cell lung cancer involving the upper lobe of the lung. All patients were treated with 4-dimensional computed tomography (CT)-based image guided SBRT to a dose of 40 to 60 Gy in 3 to 5 fractions. For dosimetric analysis, only apical tumors as defined by the location of the tumor epicenter superior to the aortic arch were included. The anatomical brachial plexus was delineated using the Radiation Therapy Oncology Group atlas.

Results

Thirty-one patients with 31 apical lung tumors satisfied the anatomical criteria for inclusion. The median age was 73 years (range, 58-89). The median planning target volume was 26.5 cc (range, 8.2-81.4 cc). The median brachial plexus, brachial plexus maximum dose (Dmax), Dmax per fraction, V22 (cc, 3-4 fractions), V30 (cc, 5 fractions), and biologically effective dose 3 Gy were 15.8 Gy (range, 1.7-66.5 Gy), 3.4 Gy (range, 0.6-14.7 Gy), 0.0 cc (range, 0-0.9 cc), 0.06 cc (range, 0-2.5 cc), and 31.5 Gy (range, 3.3-133.1 Gy), respectively. At a median follow-up of 17 months, the observed incidence of brachial plexopathy was 0%.

Conclusions

There is significant variation in dose to the brachial plexus for patients treated with SBRT for apical lung tumors. Although the incidence of neuropathic symptoms in this series was zero, further attention should be focused on the clinical implications of these findings.

The effect of kidney volume estimation on dosimetry in lutetium-177 DOTATATE therapy

BACKGROUND

The kidneys are the dose-limiting organ in lutetium-177 DOTATATE therapy. Therefore, it is advisable to perform critical organ dosimetry focussed on renal dose in treated patients. A key uncertainty in such dose estimates is the use of standard phantoms to represent the individual patient. The primary aim of this study was to investigate the accuracy of methods for estimating kidney size, and hence absorbed kidney dose, by comparison with individual measurements from computed tomography (CT) imaging.

MATERIALS AND METHODS

Kidney volume was measured using diagnostic CT images for 57 patients who underwent lutetium-177 DOTATATE therapy. Kidney mass was also estimated in two ways: using the standard adult phantoms, as well as through the application of a weight scaling factor to these phantoms and their organs. Dose calculations were performed for each of the three methods using OLINDA/EXM software.

RESULTS

Scaling of the phantom by patient weight gave a more accurate result when compared with the CT gold standard than the standard phantom. The dose difference from the CT method had mean values of 1.4% (SD=22.6%) and 8.4% (SD=21.5%) for scaled and unscaled, respectively. Patient weight was not found to be a good predictor of kidney mass in these patients (r of 0.12 from linear regression analysis).

CONCLUSION

The most accurate method of organ volume estimation would be individual measurements from CT imaging; however, where this is not possible, scaling of organ masses by weight ratio is more accurate than the use of the standard phantom.

Prostate cancer in renal transplant recipients

As patients with end-stage renal disease are receiving renal allografts at older ages, the number of male renal transplant recipients (RTRs) being diagnosed with prostate cancer (CaP) is increasing. Historically, the literature regarding the management of CaP in RTR's is limited to case reports and small case series. To date, there are no standardized guidelines for screening or management of CaP in these complex patients. To better understand the unique characteristics of CaP in the renal transplant population, we performed a literature review of PubMed, without date limitations, using a combination of search terms including prostate cancer, end stage renal disease, renal transplantation, prostate cancer screening, prostate specific antigen kinetics, immuno-suppression, prostatectomy, and radiation therapy. Of special note, teams facilitating the care of these complex patients must carefully and meticulously consider the altered anatomy for surgical and radiotherapeutic planning. Active surveillance, though gaining popularity in the general low risk prostate cancer population, needs further study in this group, as does the management of advance disease. This review provides a comprehensive and contemporary understanding of the incidence, screening measures, risk stratification, and treatment options for CaP in RTRs.

90Y-DOTATOC Dosimetry-Based Personalized Peptide Receptor Radionuclide Therapy

Pretherapy PET with ⁸⁶Y-DOTATOC is considered the ideal dosimetry protocol for ⁹⁰Y-DOTATOC therapy; however, its cost, limited availability, and need for infusion of amino acids to mimic the therapy administration limit its use in the clinical setting. The goal of this study was to develop a dosimetric method for ⁹⁰Y-DOTATOC using ⁹⁰Y-DOTATOC PET/CT and bremsstrahlung SPECT/CT and to determine whether dosimetry-based administered activities differ significantly from standard administered activities. Methods: This was a prospective phase 2 trial of ⁹⁰Y-DOTATOC therapy in patients with somatostatin receptor-positive tumors. ⁹⁰Y-DOTATOC was given in 3 cycles 6-8 wk apart. In the first cycle of therapy, adults received 4.4 GBq and children received 1.85 GBq/m²; the subsequent administered activities were adjusted according to the dosimetry of the preceding cycle so as not to exceed a total kidney dose of 23 Gy and bone marrow dose of 2 Gy. The radiation dose to the kidneys was determined from serial imaging sessions consisting of time-of-flight ⁹⁰Y-DOTATOC PET/CT at 5 h after therapy and ⁹⁰Y-DOTATOC bremsstrahlung SPECT/CT at 6, 24, 48, and 72 h. The PET/CT data were used to measure the absolute concentration of ⁹⁰Y-DOTATOC and to calibrate the bremsstrahlung SPECT kidney clearance data. The radiation dose to the kidneys was determined by multiplying the time-integrated activity (from the fitted biexponential curve of renal clearance of ⁹⁰Y-DOTATOC) with the energy emitted per decay, divided by the mass of the kidneys. Results: The radiation dose to the kidneys per cycle of ⁹⁰Y-DOTATOC therapy was highly variable among patients, ranging from 0.32 to 3.0 mGy/MBq. In 17 (85%) of the 20 adult patients who received the second and the third treatment cycles of ⁹⁰Y-DOTATOC, the administered activity was modified by at least 20% from the starting administered activity. Conclusion: Renal dosimetry of ⁹⁰Y-DOTATOC is feasible using ⁹⁰Y-DOTATOC time-of-flight PET/CT and bremsstrahlung SPECT/CT and has a significant impact on the administered activity in treatment cycles.

Single-institution experience with selective internal radiation therapy (SIRT) for the treatment of unresectable colorectal liver metastases

BACKGROUND

Liver metastases are the commonest cause of death for patients with colorectal cancer. Growing evidence supports the use of selective internal radiation therapy (SIRT) in combination with conventional chemotherapy regimens for liver-only or liver-dominant unresectable metastatic colorectal cancer.

AIMS

To measure and evaluate outcomes of the first 20 consecutive patients with unresectable colorectal liver metastasis selected for SIRT in addition to their chemotherapy at a single Irish institution.

METHODS

Retrospective case series was performed. Patient charts and medical records were reviewed.

RESULTS

All 20 patients (100%) selected for angiographic workup were subsequently successfully treated with radioembolization. All patients were discharged 1 day post-SIRT. At initial imaging evaluation, 12 (60%) had a partial response in their liver, 2 (10%) had stable disease, and 6 (30%) had liver-specific progressive disease. Median follow up was 10 months (range 6-26). At last follow up, 14 (70%) patients were alive and 6 (30%) deceased. Most recent imaging demonstrated 2 (10%) with a complete response, 7 (35%) had a partial response, 2 (10%) had stable disease, and 9 (45%) had progressive disease within their liver. One patient was downstaged to hepatic resection, and one with a complete hepatic response had his primary sigmoid tumor resected 11 months post-SIRT.

CONCLUSIONS

SIRT is a safe and effective therapy for certain patients with unresectable colorectal liver metastases. This case series supports our opinion that selected patients should be offered SIRT in concert with their medical oncologist, concomitant with their chemotherapy. Larger multi-center studies are required to more clearly define the patient groups that will derive most benefit from SIRT.

Evaluation of Stereotactic Radiotherapy of the Resection Cavity After Surgery of Brain Metastases Compared to Postoperative Whole-Brain Radiotherapy (ESTRON)—A Single-Center Prospective Randomized Trial

BACKGROUND

Neurosurgical resection is recommended for symptomatic brain metastases, in oligometastatic patients or for histology acquisition. Without adjuvant radiotherapy, roughly two-thirds of the patients relapse at the resection site within 24 mo, while the risk of new metastases in the untreated brain is around 50%. Adjuvant whole-brain radiotherapy (WBRT) can reduce the risk of both scenarios of recurrence significantly, although the associated neurocognitive toxicity is substantial, while stereotactic radiotherapy (SRT) improves local control at comparably low toxicity.

OBJECTIVE

To compare locoregional control and treatment-associated toxicity for postoperative SRT and WBRT after the resection of 1 brain metastasis in a single-center prospective randomized study.

METHODS

Fifty patients will be randomized to receive either hypofractionated SRT of the resection cavity and single- or multisession SRT of all unresected brain metastases (up to 10 lesions) or WBRT. Patients will be followed-up regularly and the primary endpoint of neurological progression-free survival will be assessed by magnetic resonance imaging (MRI). Quality of life and neurocognition will be assessed in 3-mo intervals using standardized tests and EORTC questionnaires.

EXPECTED OUTCOMES

We expect to show that postoperative SRT of the resection cavity and further unresected brain metastases is a valid means of improving locoregional control over observation at less neurocognitive toxicity than caused by WBRT.

DISCUSSION

The present study is the first to compare locoregional control as well as neurocognitive toxicity for postoperative SRT and WBRT in patients with up to 10 metastases, while utilizing a highly sensitive and standardized MRI protocol for treatment planning and follow-up.

Prospective study to evaluate the safety of the world-first spot-scanning dedicated, small 360-degree gantry, synchrotron-based proton beam therapy system

This is a report of a single-institution prospective study evaluating the safety of a spot-scanning dedicated, small 360-degree gantry, synchrotron-based proton beam therapy (PBT) system. Data collection was performed for 56 patients with 59 treatment sites who received proton beam therapy at Hokkaido University Hospital between March 2014 and July 2015. Forty-one patients were male and 15 were female. The median age was 66 years. The primary lesion sites were prostate (n = 17), bone/soft tissue (n = 10), liver (n = 7), lung (n = 6), central nervous system (n = 5), colon (n = 2), pancreas (n = 2), kidney (n = 2) and others (n = 5). Chemotherapy was administered in 11 patients. The prescribed total dose was from 20 to 76 GyE (Radiobiological equivalent dose, RBE = 1.1), with the median dose of 65 GyE in 4 to 35 fractions. No PBT-related Common Terminology Criteria for Adverse Events Grade 4 or 5 toxicities were observed; the incidence of early PBT-related Grade 4 adverse events was 0% (95% confidence interval 0 to 6.38%). The most common Grade 3 toxicities were hematologic toxicity (12.5%) unlikely to be related to the PBT. One patient developed a left femoral neck fracture (Grade 3) at 14.5 months after PBT for chondrosarcoma of the left pelvis. The pathological findings showed no other malignancies, suggesting that it was possibly related to the PBT. In conclusion, the spot-scanning dedicated, synchrotron-based PBT system is feasible, but further studies on its long-term safety and efficacy are warranted.

Integration of radiobiological modeling and indices in comparative plan evaluation: A study comparing VMAT and 3D-CRT in patients with NSCLC

PURPOSE

The purpose of this article was to generate an algorithm to calculate radiobiological endpoints and composite indices and use them to compare volumetric modulated arc therapy (VMAT) and 3-dimensional conformal radiation therapy (3D-CRT) techniques in patients with locally advanced non-small cell lung cancer.

METHODS AND MATERIALS

The study included 25 patients with locally advanced non-small cell lung cancer treated with 3D-CRT at our center between January 1, 2010, and December 31, 2014. The planner generated VMAT plans using clones of the original computed tomography scans and regions of interest volumes, which did not include the original 3D plans. Both 3D-CRT and VMAT plans were generated using the same dose-volume constraint worksheet. The dose-volume histogram parameters for planning target volume and relevant organs at risk (OAR) were reviewed. The calculation engine was written in the R programming language; the user interface was developed with the "shiny" R Web library. Dose-volume histogram data were imported into the calculation engine and tumor control probability (TCP), normal tissue complication probability (NTCP), composite cardiopulmonary toxicity index (CPTI), morbidity index: MI = ∑_j = 1^{#ofrelevantOARs}(w_j ∗ NTCP_j), uncomplicated TCP (UTCP=TCP∗∏k=1#ofOARs1-NTCP_K100, and therapeutic gain (TG): ie, TG = TCP ∗ (100 - MI) were calculated.

RESULTS

TCP was better with 3D-CRT (12.62% vs 11.71%, P < .001), whereas VMAT demonstrated superior NTCP esophagus (4.45% vs 7.39%, P = .02). NTCP spinal cord (0.001% vs 0.009%, P = .001), and NTCP heart/perfusion defect (44.57% vs 56.42%, P = .016). There was no difference in NTCP lung (6.27% vs 7.62%, P = .221) and NTCP heart/pericarditis (0.001% vs 0.15%, P = .129) between 2 techniques. VMAT showed substantial improvement in morbidity index (11.06% vs. 14.31%, P = 0.01), CPTI (47.59% vs 59.41%, P = .03), TG (P = .035), and trend toward superiority in UTCP (5.89 vs 4.75, P=.057).

CONCLUSION

The study highlights the utility of the radiobiological algorithm and summary indices in comparative plan evaluation and demonstrates benefits of VMAT over 3D-CRT.

Prognostic variables for temporal lobe injury after intensity modulated-radiotherapy of nasopharyngeal carcinoma

To determine predictive factors for temporal lobe injury (TLI) in nasopharyngeal carcinoma patient (NPC) treated with intensity-modulated radiation therapy (IMRT). A total of 695 NPC cases treated with IMRT were retrospectively analyzed. TLI was diagnosed on MRI images. Volume-dose histograms for 870 evaluable temporal lobes were analyzed, and the predictive factors for the occurrence of TLI was evaluated. Receiver operating characteristic curve (ROC) and Logistic regression analysis was used to determine volume-dose parameters that predict temporal lobe injury (TLI). Univariate and multivariate analysis were used to analyze the predictive factors for TLI. The radiation dose-tolerance model of temporal lobe was calculated by logistic dose-response model. The median follow-up time was 73 months. A total of 8.5% patients were diagnosed with TLI. Among all the volume-dose parameters, logistic regression model showed D2cc (the dose Gray delivered to 2 cubic centimeter volume) was an only independent predictive factor. Multivariate analysis showed D2cc of temporal lobe, fraction size of prescription, T stage, and chemotherapy were the independent predictive factors for TLI. Logistic dose-response model has indicated the TD5/5 and TD50/5 of D2cc are 60.3 Gy and 76.9 Gy, respectively. D2cc of temporal lobe, fraction size of prescription, T stage, and chemotherapy were the possible independent predictive factors for TLI after IMRT of NPC. Biologic effective doses (TD5/5 and TD50/5 ) of D2cc are considered to prevent TLI.

Prospective observational study of 177Lu-DOTA-octreotate therapy in 200 patients with advanced metastasized neuroendocrine tumours (NETs): feasibility and impact of a dosimetry-guided study protocol on outcome and toxicity

PURPOSE

Peptide receptor radionuclide therapy in patients with neuroendocrine tumours has yielded promising results. This prospective study investigated the feasibility of dosimetry of the kidneys and bone marrow during therapy and its impact on efficacy and outcome.

METHODS

The study group comprised 200 consecutive patients with metastasized somatostatin receptor-positive neuroendocrine tumours progressing on standard therapy or not suitable for other therapeutic options. A treatment cycle consisted of 7.4 GBq ¹⁷⁷Lu-DOTA-octreotate with co-infusion of a mixed amino acid solution, and cycles were repeated until the absorbed dose to the kidneys reached 23 Gy or there were other reasons for stopping therapy. The Ki-67 index was ≤2% in 47 patients (23.5%), 3-20% in 121 (60.5%) and >20% in 16 (8%).

RESULTS

In 123 patients (61.5%) the absorbed dose to the kidneys reached 23 Gy with three to nine cycles during first-line therapy; in no patient was a dose to the bone marrow of 2 Gy reached. The best responses (according to RECIST 1.1) were a complete response (CR) in 1 patient (0.5%), a partial response (PR) in 47 (23.5%), stable disease (SD) in 135 (67.5%) and progressive disease (PD) in 7 (3.5%). Median progression-free survival was 27 months (95% CI 22-30 months) in all patients, 33 months in those in whom the absorbed dose to the kidneys reached 23 Gy and 15 months in those in whom it did not. Median overall survival (OS) was 43 months (95% CI 39-53 months) in all patients, 54 months in those in whom the absorbed dose to the kidneys reached 23 Gy and 25 months in those in whom it did not. Median OS was 60 months in patients with a best response of PR or CR, 42 months in those with SD and 16 months in those with PD. Three patients (1.5%) developed acute leukaemia, 1 patient (0.5%) chronic leukaemia (unconfirmed) and 30 patients (15%) grade 3 or 4 bone marrow toxicity. Eight patients (4%) developed grade 2 kidney toxicity and one patient (0.5%) grade 4 kidney toxicity.

CONCLUSIONS

Dosimetry-based therapy with ¹⁷⁷Lu-DOTA-octreotate is feasible. Patients in whom the absorbed dose to the kidneys reached 23 Gy had a longer OS than those in whom it did not. Patients with CR/PR had a longer OS than those with SD. Bone marrow dosimetry did not predict toxicity.

Assessing the uncertainty in a normal tissue complication probability difference (∆NTCP): radiation-induced liver disease (RILD) in liver tumour patients treated with proton vs X-ray therapy

Modern radiotherapy technologies such as proton beam therapy (PBT) permit dose escalation to the tumour and minimize unnecessary doses to normal tissues. To achieve appropriate patient selection for PBT, a normal tissue complication probability (NTCP) model can be applied to estimate the risk of treatment-related toxicity relative to X-ray therapy (XRT). A methodology for estimating the difference in NTCP (∆NTCP), including its uncertainty as a function of dose to normal tissue, is described in this study using the Delta method, a statistical method for evaluating the variance of functions, considering the variance-covariance matrix. We used a virtual individual patient dataset of radiation-induced liver disease (RILD) in liver tumour patients who were treated with XRT as a study model. As an alternative option for individual patient data, dose-bin data, which consists of the number of patients who developed toxicity in each dose level/bin and the total number of patients in that dose level/bin, are useful for multi-institutional data sharing. It provides comparable accuracy with individual patient data when using the Delta method. With reliable NTCP models, the ∆NTCP with uncertainty might potentially guide the use of PBT; however, clinical validation and a cost-effectiveness study are needed to determine the appropriate ∆NTCP threshold.

Radiotherapy Controversies and Prospective in Head and Neck Cancer: A Literature-Based Critical Review

In treating head and neck cancer (HNC), the objectives are provided for best functional results and minimal risk of serious complications. The choice of appropriate management depends primarily on specific site and stage of primary tumor at diagnosis. Radiation therapy (RT) with or without concomitant chemotherapy represents a classical treatment option. In this review, we provide an update of recent research strategies to counteract the existing damage caused by RT and highlight clinical trials currently in progress. We discuss the challenges in the evaluation of new stage system and RT-related toxicity onset. We mainly address the deficiencies and the advantages noted in the current treatment era.

Salivary glands regenerate after radiation injury through SOX2-mediated secretory cell replacement

Salivary gland acinar cells are routinely destroyed during radiation treatment for head and neck cancer that results in a lifetime of hyposalivation and co-morbidities. A potential regenerative strategy for replacing injured tissue is the reactivation of endogenous stem cells by targeted therapeutics. However, the identity of these cells, whether they are capable of regenerating the tissue, and the mechanisms by which they are regulated are unknown. Using in vivo and ex vivo models, in combination with genetic lineage tracing and human tissue, we discover a SOX2+ stem cell population essential to acinar cell maintenance that is capable of replenishing acini after radiation. Furthermore, we show that acinar cell replacement is nerve dependent and that addition of a muscarinic mimetic is sufficient to drive regeneration. Moreover, we show that SOX2 is diminished in irradiated human salivary gland, along with parasympathetic nerves, suggesting that tissue degeneration is due to loss of progenitors and their regulators. Thus, we establish a new paradigm that salivary glands can regenerate after genotoxic shock and do so through a SOX2 nerve-dependent mechanism.

Comparison of three and four-field radiotherapy technique and the effect of laryngeal shield on vocal and spinal cord radiation dose in radiotherapy of non-laryngeal head and neck tumors

Introduction: Due to the effect of radiation on both the tumor and the surrounding normal tissues, the side effects of radiation in normal tissues are expected. One of the important complications in the head and neck radiotherapy is the doses reached to the larynx and spinal cord of patients with non-laryngeal head and neck tumors.

Materials and Methods: In this study, CT scan images of 25 patients with non-laryngeal tumors including; lymph nodes, tongue, oropharynx and nasopharynx were used. A three-field and a four-field treatment planning with and without laryngeal shield in 3D CRT technique were planned for each patient. Subsequently, the values of Dmin, Dmean, Dmax and Dose Volume Histogram from the treatment planning system and NTCP values of spinal cord and larynx were calculated with BIOPLAN and MATLAB software for all patients.

Results: Statistical results showed that mean values of doses of larynx in both three and four-field methods were significantly different between with and without shield groups. Comparison of absorbed dose didn’t show any difference between the three and four field methods (P>0.05). Using Shield, just the mean and minimum doses of spinal cord decreased in both three and four fields. The NTCP of the spinal cord and larynx by three and four-field methods with shield in the LKB and EUD models significantly are less than that of the three and four fields without shields, and in the four-field method NTCP of larynx is less than three radiation field.

Conclusion: The results of this study indicate that there is no significant difference in doses reached to larynx and spinal cord between the treatments techniques, but laryngeal shield reduce dose and NTCP values in larynx considerably.

Current status of theranostics in prostate cancer

The aim of this review is to report on the current status of prostate-specific membrane antigen (PSMA)-directed theranostics in prostate cancer (PC) patients. The value of 68Ga-PSMA-directed PET imaging as a diagnostic procedure for primary and recurrent PC as well as the role of evolving PSMA radioligand therapy (PRLT) in castration-resistant (CR)PC is assessed. The most eminent data from mostly retrospective studies currently available on theranostics of prostate cancer are discussed. The current knowledge on 68Ga-PSMA PET/CT implicates that primary staging with PET/CT is meaningful in patients with high-risk PC and that the combination with pelvic multi parametric (mp)MR (or PET/mpMR) reaches the highest impact on patient management. There may be a place for 68Ga-PSMA PET/CT in intermediate-risk PC patients as well, however, only a few data are available at the moment. In secondary staging for local recurrence, 68Ga-PSMA PET/mpMR is superior to PET/CT, whereas for distant recurrence, PET/CT has equivalent results and is faster and cheaper compared to PET/mpMR. 68Ga-PSMA PET/CT is superior to 18F / 11Choline PET/CT in primary staging as well as in secondary staging. In patients with biochemical relapse, PET/CT positivity is directly associated with prostate-specific antigen (PSA) increase and amounts to roughly 50% when PSA is raised to ≤0.5 ng/ml and to ≥90% above 1 ng/ml. Significant clinical results have so far been achieved with the subsequent use of radiolabeled PSMA ligands in the treatment of CRPC. Accumulated activities of 30 to 50 GBq of 177Lu-PSMA ligands seem to be clinically safe with biochemical response and PERCIST/RECIST response in around 75% of patients along with xerostomia in 5-10% of patients as the only notable side effect. On the basis of the current literature, we conclude that PSMA-directed theranostics do have a major clinical impact in diagnosis and therapy of PC patients. We recommend that 68Ga-PSMA PET/CT should be performed in primary staging together with pelvic mpMR in high-risk patients and in all patients for secondary staging, and that PSMA-directed therapy is a potent strategy in CRPC patients when other treatment options have failed. The combination of PSMA-directed therapy with existing therapy modalities (such as 223Ra-chloride or androgen deprivation therapy) has to be explored, and prospective clinical multicenter trials with theranostics are warranted.

Strategies for prediction and mitigation of radiation-induced liver toxicity

Although well described in the 1960s, liver toxicity secondary to radiation therapy, commonly known as radiation-induced liver disease (RILD), remains a major challenge. RILD encompasses two distinct clinical entities, a 'classic' form, composed of anicteric hepatomegaly, ascites and elevated alkaline phosphatase; and a 'non-classic' form, with liver transaminases elevated to more than five times the reference value, or worsening of liver metabolic function represented as an increase of 2 or more points in the Child-Pugh score classification. The risk of occurrence of RILD has historically limited the applicability of radiation for the treatment of liver malignancies. With the development of 3D conformal radiation therapy, which allowed for partial organ irradiation based on computed tomography treatment planning, there has been a resurgence of interest in the use of liver irradiation. Since then, a large body of evidence regarding the liver tolerance to conventionally fractionated radiation has been produced, but severe liver toxicities has continued to be reported. More recently, improvements in diagnostic imaging, radiation treatment planning technology and delivery systems have prompted the development of stereotactic body radiotherapy (SBRT), by which high doses of radiation can be delivered with high target accuracy and a steep dose gradient at the tumor - normal tissue interface, offering an opportunity of decreasing toxicity rates while improving tumor control. Here, we present an overview of the role SBRT has played in the management of liver tumors, addressing the challenges and opportunities to reduce the incidence of RILD, such as adaptive approaches and machine-learning-based predictive models.

Nonmetastatic pancreatic cancer : Improved survival with chemoradiotherapy > 40 Gy after systemic treatment

Purpose

The role of radiotherapy (RT) for nonmetastatic pancreatic cancer is still a matter of debate since randomized control trials have shown inconsistent results. The current retrospective single-institution study includes both resected and unresected patients with nonmetastasized pancreatic cancer. The aim is to analyze overall survival (OS) after irradiation combined with induction chemotherapy.

Patients and methods

Of the 73 patients with nonmetastatic pancreatic cancer eligible for the present analysis, 42 (58%) patients had adjuvant chemoradiotherapy (CRT), while 31 (42%) received CRT as primary treatment. In all, 65 (89%) had chemotherapy at any time before, during, or after RT, and 39 (53%) received concomitant CRT. The median total dose was 50 Gy (range 12–77 Gy), while 61 (84%) patients received >40 Gy.

Results

With a median follow-up of 22 months (range 1.2–179.8 months), 14 (19%) are still alive and 59 (81%) of the patients have died, whereby 51 (70%) were cancer-related deaths. Median OS and the 2‑year survival rate were 22.9 months (1.2–179.8 months) and 44%, respectively. In addition, 61 (84%) patients treated with >40 Gy had a survival advantage (median OS 23.7 vs. 17.3 months, p = 0.026), as had patients with 4 months minimum of systemic treatment (median OS 27.5 vs. 14.3 months, p = 0.0004).

Conclusion

CRT with total doses >40 Gy after induction chemotherapy leads to improved OS in patients with nonmetastatic pancreatic cancer.

Electronic supplementary material

The online version of this article (10.1007/s00066-018-1281-7) contains supplementary material, which is available to authorized users.

Impact of time-related factors on biologically accurate radiotherapy treatment planning

BACKGROUND

The incomplete repair (IR) model expresses the cell repair effect from radiation-induced damage over time, which is given little consideration in actual treatment planning. By incorporating the IR model into the normal tissue complication probability (NTCP), the accuracy and safety of treatment plan evaluations concerning the effect of repair can be improved. This study aims to evaluate the impact of incorporating the IR model into the NTCP by varying time-related factors such as the repair half-time (T_1/2) and the junction-shift sc3hedule in craniospinal irradiation (CSI).

METHODS

CSI was planned retrospectively, and the NTCP of the spinal cord was calculated with the IR model for values of T_1/2 from 1 to 10 h. The NTCP in the case of changing the junction-shift schedule was also examined in the same manner.

RESULTS

The NTCP with the IR model increased with increasing T_1/2, which is prominent for the larger T_1/2. By changing the junction-shift schedule, the NTCP with the IR model decreased when adjacent fields overlapped.

CONCLUSIONS

The IR model is a valuable addition to treatment planning because it enables the NTCP to be evaluated including the effect of repair and differences in scheduling to be reflected in the NTCP. However, these are largely dependent on the value of the T_1/2.

State of the Art Treatment of Spinal Metastatic Disease

Treatment paradigms for patients with spine metastases have evolved significantly over the past decade. Incorporating stereotactic radiosurgery into these paradigms has been particularly transformative, offering precise delivery of tumoricidal radiation doses with sparing of adjacent tissues. Evidence supports the safety and efficacy of radiosurgery as it currently offers durable local tumor control with low complication rates even for tumors previously considered radioresistant to conventional radiation. The role for surgical intervention remains consistent, but a trend has been observed toward less aggressive, often minimally invasive, techniques. Using modern technologies and improved instrumentation, surgical outcomes continue to improve with reduced morbidity. Additionally, targeted agents such as biologics and checkpoint inhibitors have revolutionized cancer care, improving both local control and patient survivals. These advances have brought forth a need for new prognostication tools and a more critical review of long-term outcomes. The complex nature of current treatment schemes necessitates a multidisciplinary approach including surgeons, medical oncologists, radiation oncologists, interventionalists, and pain specialists. This review recapitulates the current state-of-the-art, evidence-based data on the treatment of spinal metastases, integrating these data into a decision framework, NOMS, which integrates the 4 sentinel decision points in metastatic spine tumors: Neurologic, Oncologic, Mechanical stability, and Systemic disease and medical co-morbidities.

Respiratory-gated Proton Beam Therapy for Hepatocellular Carcinoma Adjacent to the Gastrointestinal Tract without Fiducial Markers

The efficacy of proton beam therapy (PBT) for hepatocellular carcinoma (HCC) has been reported, but insertion of fiducial markers in the liver is usually required. We evaluated the efficacy and toxicity of respiratory-gated PBT without fiducial markers for HCC located within 2 cm of the gastrointestinal tract. From March 2011 to December 2015 at our institution, 40 patients were evaluated (median age, 72 years; range, 38-87 years). All patients underwent PBT at a dose of 60 to 80 cobalt gray equivalents (CGE) in 20 to 38 fractions. The median follow-up period was 19.9 months (range, 1.2-72.3 months). The median tumor size was 36.5 mm (range, 11-124 mm). Kaplan-Meier estimates of the 2-year overall survival, progression-free survival, and local tumor control rates were 76%, 60%, and 94%, respectively. One patient (2.5%) developed a grade 3 gastric ulcer and one (2.5%) developed grade 3 ascites retention; none of the remaining patients developed grade >3 toxicities (National Cancer Institute Common Terminology Criteria for Adverse Events ver. 4.0.). This study indicates that PBT without fiducial markers achieves good local control without severe treatment-related toxicity of the gastrointestinal tract for HCC located within 2 cm of the gastrointestinal tract.

Use of expanders for bowel protection in pediatric pelvic tumor radiation therapy: 15 years of tolerance results

PURPOSE

Bowel is often the dose-limiting organ in curative pelvic irradiation because of radiation enteritis when dose exceeds 40 to 45 Gy. To limit radiation enteritis, a silicone tissue-expander prothesis (STEP) connected to a subcutaneous self-sealing valve was prospectively used in children undergoing pelvic or abdominal radiation therapy. This study reports the 15-year long-term outcomes of this prospective series.

METHODS AND MATERIALS

Between 1987 and 2008, 29 children from 3 Paris institutions received pelvic radiation therapy after surgical placement of a STEP in the pelvis. The median prescribed dose was 50.4 Gy (44.1-55 Gy) using 5 daily fractions of 1.8 Gy per week, except for 1 patient receiving 4 fractions of 2.5 Gy per week. The median treatment duration was 40 days (29-49 days). After 2000, computed tomography (CT) conformal 3-dimensional radiation therapy was used, and 12 patients had CT simulation. Four had CT before and after insertion of the STEP, enabling us to compare pre- and postprosthesis insertion bowel dose-volume histograms. Acute and late toxicities were captured using the Radiation Therapy Oncology Group or the National Cancer Institute Common Terminology Criteria for Adverse Events 4.0 scale.

RESULTS

No patient experienced significant perioperative complications. Pre- and post-STEP insertion small bowel dose-volume histograms show significant reductions in small bowel: 51%, 45%, and 64%, respectively, in V₁₀, V₁₅, and V₄₀ (V_x = irradiated volume by x Gy). Twenty-five patients (86%) completed their radiation therapy with no or minimal small bowel toxicity. One patient also treated with neutrons developed delayed grade 4 toxicities. The 15-year complication-free survival for those surviving was 70.3%.

CONCLUSIONS

We report the long-term follow-up of STEP prosthesis insertion in children to reduce the small bowel volume in the radiation field. The acute and long-term tolerances were excellent. The STEP reduced the bowel dose over 40 Gy by 64%.

Dose-response curves for MRI-detected radiation-induced temporal lobe reactions in patients after proton and carbon ion therapy: Does the same RBE-weighted dose lead to the same biological effect?

PURPOSE

To derive the dose-response curve for temporal lobe reactions (TLRs) after proton therapy and to compare the resulting relative biological effectiveness (RBE)-weighted tolerance doses based on an RBE of 1.1 with published values for carbon ions, which were calculated by the two versions of the local effect model (LEM I or IV).

METHODS AND MATERIALS

62 patients treated with protons for skull base tumors were analyzed for TLRs using magnetic resonance imaging. Within the mean follow-up time of 38 months, TLRs were observed in six patients. Dose-response curves based on the RBE-weighted maximum dose, excluding the 1 cm³-volume with the highest dose, were derived and compared to previously published dose-response curves for carbon ions, which were obtained using LEM I or IV, respectively.

RESULTS

The dose-response curves for protons and LEM I were found to be almost identical while the curve of LEM IV was shifted toward higher doses. The resulting tolerance doses at the 5% effect level were 68.2_+2.7^-5.6, 68.6_+3.0^-3.9 and 78.3_+3.8^-5.0 Gy (RBE), respectively.

CONCLUSIONS

The RBE-weighted dose prescription for protons leads to the same RBE-weighted dose-response curve for TLR as the one for LEM I-based carbon ions, while LEM IV predicts clinically significant higher tolerance doses.

Mathematical Modelling for Patient Selection in Proton Therapy

Proton beam therapy (PBT) is still relatively new in cancer treatment and the clinical evidence base is relatively sparse. Mathematical modelling offers assistance when selecting patients for PBT and predicting the demand for service. Discrete event simulation, normal tissue complication probability, quality-adjusted life-years and Markov Chain models are all mathematical and statistical modelling techniques currently used but none is dominant. As new evidence and outcome data become available from PBT, comprehensive models will emerge that are less dependent on the specific technologies of radiotherapy planning and delivery.

Strategic application of radiotherapy for hepatocellular carcinoma

With increasing clinical use, radiotherapy (RT) has been considered reliable and effective method for hepatocellular carcinoma (HCC) treatment, depending on extent of disease and patient characteristics. RT for HCC can improve therapeutic outcomes through excellent local control, downstaging, conversion from unresectable to resectable status, and treatments of unresectable HCCs with vessel invasion or multiple intrahepatic metastases. In addition, further development of modern RT technologies, including image-guided radiotherapy (IGRT), intensity-modulated radiotherapy (IMRT), and stereotactic body radiotherapy, has expanded the indication of RT. An essential feature of IGRT is that it allows image guidance therapy through in-room images obtained during radiation delivery. Compared with 3D-conformal RT, distinctions of IMRT are inverse treatment planning process and use of a large number of treatment fields or subfields, which provide high precision and exquisitely conformal dose distribution. These modern RT techniques allow more precise treatment by reducing inter- and intra-fractional errors resulting from daily changes and irradiated dose at surrounding normal tissues. More recently, particle therapy has been actively investigated to improve effectiveness of RT. This review discusses modern RT strategies for HCC, as well as optimal selection of RT in multimodal approach for HCC.

Radiotherapeutic factors affecting the incidence of developing hypothyroidism after radiotherapy for head and neck squamous cell cancer

PURPOSE

The purpose of this study is to determine radiotherapy (RT) dose-volumetric threshold of radiation-induced hypothyroidism (HT) in head and neck squamous cell carcinoma (HNSCC) patients.

PATIENTS AND METHODS

The diagnosis of HT in 78 HNSCC patients treated with RT was based on a thyroid stimulating hormone (TSH) level greater than the maximum value of laboratory range. In all patients, dose-volumetric parameters were analyzed according to their relation to development of HT, and thyroid volumes spared from doses ≥10, 20, 30, 40 and 50 Gy (V10, V20, V30, V40 and V50) were analyzed from the dose volume histograms (DVHs).

RESULTS

Median follow-up duration was 31 months. At the end of study, 33 patients (42.3%) developed HT and the cumulative incidence of HT was 24.6%, 36.5% and 42.3% at one, two and three years, respectively. V30 of 42.1% (P = 0.005) was defined as dose-volumetric threshold of radiation-induced HT in HNSCC patients. Our analysis showed that V30 separates patients into low- and high-risk groups; the incidence of radiation-induced HT in the group with V30 < 42.1% and V30 ≥ 42.1% was 29.4% and 71.4%, respectively (P = 0.002).

CONCLUSIONS

The V30 may predict risk of developing HT after RT for HNSCC patients. V30 of 42.1%, defined as dose-volumetric threshold of radiation-induced HT, can be useful in treatment planning of HNSCC patients.

Treatment outcome for locally advanced non-small-cell lung cancer using TomoDirect plan and its characteristics compared to the TomoHelical plan

Introduction

TomoDirect (TD) is an intensity‐modulated radiotherapy system that uses a fixed gantry angle instead of the rotational beam delivery used in the TomoHelical (TH) system. This study was performed (1) to evaluate the treatment outcome of the TD plan for locally advanced non‐small‐cell lung cancer (NSCLC) and (2) to compare the characteristics of TD plans with those of TH plans.

Methods

Twenty‐one patients with NSCLC were treated using the TD system. The prescribed dose was 40 Gy/20 Fx for the initial planning target volume (PTV), which included the gross tumour volume (GTV) and lymph node regions. A boost plan of 20 Gy/10 Fx was then applied, focusing on the GTV. For the planning study, matched TH plans of 40 Gy for the initial PTV were created for each patient, to meet the same dosimetric constraints specified in the TD plans.

Results

The 2‐year overall survival, progression‐free survival and local control rates were 47%, 45% and 74% respectively. Grade 2 treatment‐related pneumonitis occurred in three (14%) patients. The planning study comparing TD and TH showed that dose distribution to GTV and PTV were not significantly different. The lung V5 Gy was lower in the TD plans than TH plans (46.4 ± 5.4 vs. 52.3 ± 8.5), while the V20 Gy was higher (26.2 ± 4 vs. 24 ± 4.3). The TD plans had a significantly shorter treatment time than TH plans (4.5 ± 1.3 min vs. 9.8 ± 1.5 min).

Conclusions

TD is a clinically acceptable treatment option for NSCSL. The quality of the TD and TH plans are comparable.

[Hypofractionated radiotherapy for glioblastoma: changing the radiation treatment paradigm]

Hypofractionation has the dual advantage of increased cell death with a higher dose per fraction and a reduced effect of accelerated tumor cell repopulation due to a shorter overall treatment time. However, the potential advantage may be offset by increased toxicity in the late-responding neural tissues. Recently, investigators have attempted delivering radical doses of HFRT by escalating the dose in the immediate vicinity of the enhancing tumor and postoperative surgical cavity and reported reasonable outcomes with acceptable toxicity levels. Three different studies of high-dose HFRT have reported on the paradoxical phenomenon of improved survival in patients developing radiation necrosis at the primary tumor site. The toxicity criteria of RTOG and EORTC have defined clinically or radiographically suspected radionecrosis as Grade 4 toxicity. However, most patients diagnosed with radiation necrosis in the above studies remained asymptomatic. Furthermore, the probable association with improved survival would strongly argue against adopting a blind approach for classifying radiation necrosis as Grade 4 toxicity. The data emerging from the above studies is encouraging and strongly argues for further research. However, the majority of these studies are predominantly retrospective or relatively small single-arm prospective series that add little to the overall quality of evidence. Notwithstanding the above limitations, HFRT appears to be a safe and feasible strategy for glioblastoma patients.

Fitting NTCP models to bladder doses and acute urinary symptoms during post-prostatectomy radiotherapy

BACKGROUND

To estimate the radiobiological parameters of three popular normal tissue complication probability (NTCP) models, which describe the dose-response relations of bladder regarding different acute urinary symptoms during post-prostatectomy radiotherapy (RT). To evaluate the goodness-of-fit and the correlation of those models with those symptoms.

METHODS

Ninety-three consecutive patients treated from 2010 to 2015 with post-prostatectomy image-guided intensity modulated radiotherapy (IMRT) were included in this study. Patient-reported urinary symptoms were collected pre-RT and weekly during treatment using the validated Prostate Cancer Symptom Indices (PCSI). The assessed symptoms were flow, dysuria, urgency, incontinence, frequency and nocturia using a Likert scale of 1 to 4 or 5. For this analysis, an increase by ≥2 levels in a symptom at any time during treatment compared to baseline was considered clinically significant. The dose volume histograms of the bladder were calculated. The Lyman-Kutcher-Burman (LKB), Relative Seriality (RS) and Logit NTCP models were used to fit the clinical data. The fitting of the different models was assessed through the area under the receiver operating characteristic curve (AUC), Akaike information criterion (AIC) and Odds Ratio methods.

RESULTS

For the symptoms of urinary urgency, leakage, frequency and nocturia, the derived LKB model parameters were: 1) D50 = 64.2Gy, m = 0.50, n = 1.0; 2) D50 = 95.0Gy, m = 0.45, n = 0.50; 3) D50 = 83.1Gy, m = 0.56, n = 1.00; and 4) D50 = 85.4Gy, m = 0.60, n = 1.00, respectively. The AUC values for those symptoms were 0.66, 0.58, 0.64 and 0.64, respectively. The differences in AIC between the different models were less than 2 and ranged within 0.1 and 1.3.

CONCLUSIONS

Different dose metrics were correlated with the symptoms of urgency, incontinence, frequency and nocturia. The symptoms of urinary flow and dysuria were poorly associated with dose. The values of the parameters of three NTCP models were determined for bladder regarding four acute urinary symptoms. All the models could fit the clinical data equally well. The NTCP predictions of urgency showed the best correlation with the patient reported outcomes.

Respiratory motion during 90Yttrium PET contributes to underestimation of tumor dose and overestimation of normal liver tissue dose

Background Yttrium-90 dosimetry after radioembolization is reliant on accurate quantitative imaging of the microsphere deposition. Previous studies have focused on the correction of geometrical resolution effects. Purpose To uncover additional effects of respiratory motion. Material and Methods Mathematical models describing spherical tumors were formed and two blurring effects, limited geometrical resolution and respiratory motion, were simulated. The virtual images were used as basis for dose volume histogram estimations by convolving the radioactivity representations with a dose point kernel. Results For respiratory motion only, the largest errors were found for the smallest tumors and/or tumors with heterogeneous distribution of yttrium-90 microspheres. The deviations in max dose and dose to 25% and 50% of the tumor volume were estimated at 20-40%, 10-30%, and 0-30%, respectively. Additional blurring from geometrical resolution increased the errors to 55-75%, 50-60%, and 25-60%, respectively. Conclusion Respiratory motion contributes to underestimation of tumor dose and overestimation of normal tissue dose.

Relationship between Eustachian tube dysfunction and otitis media with effusion in radiotherapy patients

OBJECTIVE

This study evaluated the relationship between radiation and Eustachian tube dysfunction, and examined the radiation dose required to induce otitis media with effusion.

METHODS

The function of 36 Eustachian tubes in 18 patients with head and neck cancer were examined sonotubometrically before, during, and 1, 2 and 3 months after, intensity-modulated radiotherapy. Patients with an increase of 5 dB or less in sound pressure level (dB) during swallowing were categorised as being in the dysfunction group. Additionally, radiation dose distributions were assessed in all Eustachian tubes using three dose-volume histogram parameters.

RESULTS

Twenty-two of 25 normally functioning Eustachian tubes before radiotherapy (88.0 per cent) shifted to the dysfunction group after therapy. All ears that developed otitis media with effusion belonged to the dysfunction group. The radiation dose threshold evaluation revealed that ears with otitis media with effusion received significantly higher doses to the Eustachian tubes.

CONCLUSION

The results indicate a relationship between radiation dose and Eustachian tube dysfunction and otitis media with effusion.

Improving oncoplastic breast tumor bed localization for radiotherapy planning using image registration algorithms

Knowledge about tumor bed localization and its shape analysis is a crucial factor for preventing irradiation of healthy tissues during supportive radiotherapy and as a result, cancer recurrence. The localization process is especially hard for tumors placed nearby soft tissues, which undergo complex, nonrigid deformations. Among them, breast cancer can be considered as the most representative example. A natural approach to improving tumor bed localization is the use of image registration algorithms. However, this involves two unusual aspects which are not common in typical medical image registration: the real deformation field is discontinuous, and there is no direct correspondence between the cancer and its bed in the source and the target 3D images respectively. The tumor no longer exists during radiotherapy planning. Therefore, a traditional evaluation approach based on known, smooth deformations and target registration error are not directly applicable. In this work, we propose alternative artificial deformations which model the tumor bed creation process. We perform a comprehensive evaluation of the most commonly used deformable registration algorithms: B-Splines free form deformations (B-Splines FFD), different variants of the Demons and TV-L¹ optical flow. The evaluation procedure includes quantitative assessment of the dedicated artificial deformations, target registration error calculation, 3D contour propagation and medical experts visual judgment. The results demonstrate that the currently, practically applied image registration (rigid registration and B-Splines FFD) are not able to correctly reconstruct discontinuous deformation fields. We show that the symmetric Demons provide the most accurate soft tissues alignment in terms of the ability to reconstruct the deformation field, target registration error and relative tumor volume change, while B-Splines FFD and TV-L¹ optical flow are not an appropriate choice for the breast tumor bed localization problem, even though the visual alignment seems to be better than for the Demons algorithm. However, no algorithm could recover the deformation field with sufficient accuracy in terms of vector length and rotation angle differences.

Rapid recovery of vision following early intervention with fractionated stereotactic radiotherapy for optic nerve sheath meningioma

Purpose

To report the outcomes of early intervention with fractionated stereotactic radiotherapy (FSRT) in a patient with primary optic nerve sheath meningioma (ONSM).

Patient and methods

A male patient in his early 40s underwent 5-beam FSRT at a prescribed dose of 50 Gy in 25 fractions over 35 days. The patient had an 11-month history of progressive visual impairment at the time of FSRT.

Results

On day 14 of treatment, the patient reported early improvement in his vision. Two weeks after the completion of FSRT, his left eye visual acuity and field recovered completely. However, the tumor regressed only slightly in the 2 years of follow-up.

Conclusion

Early intervention with FSRT for optic nerve sheath meningioma resulted in a rapid response and complete improvement of visual impairment.

Stage III-IV Sinonasal and Nasal Cavity Carcinoma Treated with Three-Dimensional Conformal Radiotherapy

Aims and Background

To report the dosimetric data and clinical outcomes of patients with advanced neoplasm of the paranasal sinuses and nasal cavity, treated by three-dimensional conformal radiotherapy.

Methods

Between 2000 and 2005, 31 consecutive patients were treated for locally advanced tumors of paranasal sinuses and nasal cavity. The primary tumor was located as follows: maxillary sinus 15 (48.4%); ethmoid sinus 10 (32.3%); nasal cavity 6 (19.3%). The patients were separated in two groups according to the modality of treatment: group Aincluded 21 patients treated with postoperative three-dimensional conformal radiotherapy with or without chemotherapy; group B included 10 patients treated with radical three-dimensional conformal radiotherapy with or without chemotherapy. The median radiation dose to the planning target volume was 60 Gy (range, 56–63) for patients who underwent complete surgical resection and 68 Gy (range, 64–70) for those who did not have tumor resection or patients with residual disease.

Results

The median follow-up was 42 months. Five-year local tumor control and overall survival actuarial rates were 74% and 72%, respectively, in the postoperative setting, 20% and 25%, respectively, with the primary radiotherapy. Local recurrence was the most common site of failure. No patient developed radio-induced blindness; 4 patients underwent enucleation as part of radical surgery. Dosimetric data are reported.

Conclusions

The local control rate for these tumors remains low. The prognosis depends on localization, tumor stage and treatment modality. Three-dimensional conformal radiotherapy reduces the risk on optical pathways but does not modify outcome.

Three-Dimensional Conformal Radiotherapy, Temozolomide Chemotherapy, and High-Dose Fractionated Stereotactic Boost in a Protocol-Driven, Postoperative Treatment Schedule for High-Grade Gliomas

Aims and background

No available scientific report deals with high-dose (≥70 Gy) radiotherapy plus temozolomide chemotherapy (TMZ CHT) in high-grade gliomas. The survival results of a protocol-driven, postoperative treatment schedule are reported here to contribute to the discussion on this issue.

Methods and study design

Uniform criteria were prospectively adopted for case selection during the period 1993–2006 in the management of 123 patients, and we progressively introduced three-dimensional conformal radiotherapy (3D-CRT, 60 Gy), TMZ CHT and a high-dose (70 Gy) stereotactic boost (HDSRT) in the treatment schedule. Palliative radiotherapy was delivered by whole brain irradiation (WBI, 50 Gy) for bulky tumors, whereas radical irradiation was performed with 3D-CRT throughout the study period. Two periods of accrual are considered: 36 patients were treated before 31 December 1999 (29.25%) and 87 (70.75%) after 1 January 2000. This subdivision was due to the implementation of HDSRT hardware and TMZ CHT from January 2000.

Results

The median overall survival was 13 months and the 1-, 2- and 3-year survival rates were 53%, 19.5% and 11.6%, respectively. The differences in survival related to the treatment variables were highly significant, both in univariate and multivariate analysis. The median survival and 1-, 2- and 3-year survival rates in the palliative WBI group were 9.75 months and 37%, 2%, and 0%, respectively; in the 3D-CRT group 17.25 months and 64%, 34%, and 15%, respectively; in the TMZ CHT concomitant with radiotherapy group 20 months and 61%, 39%, and 21%, respectively; in the TMZ CHT concomitant with and sequential to radiotherapy group 25.75 months and 84%, 54%, and 26%, respectively, and in the HDSRT group 22 months and 72%, 48%, and 37%, respectively. No symptomatic radiation necrosis occurred in any of the groups.

Conclusions

The results reported here are generally better than those reported in the literature. The selection of patients on the basis of favorable prognostic factors and suitability to the currently available, aggressive postoperative treatment resources can be the mainstay for improving therapeutic results. In particular, the new treatment option reported here (HDSRT in association with TMZ CHT) proved to be safe and effective in obtaining a relatively favorable outcome.

The Technique of Intensity-Modulated Radiotherapy in the Treatment of Cholangiocarcinoma

Aims and background

Conventional radiotherapy in inoperable cholangiocarcinoma is limited by radiotolerance of the surrounding tissues. The aim of our dosimetric study was an evaluation of intensity-modulated radiotherapy in the treatment of inoperable bile duct carcinoma.

Methods

Four patients with inoperable cholangiocarcinoma treated by self-expandable stent placed to the biliary tree and radiotherapy were studied. The rotational technique, conformal 3D BOX technique and intensity-modulated radiotherapy plan were compared. Dose volume histograms and the normal tissue complication probability concept were used for comparison. The stent was used for target motion verification.

Results

The intensity-modulated radiotherapy plans showed favorable dose distribution in planning target volume and remarkable sparing of organs at risk.

Conclusions

The intensity-modulated radiotherapy technique in bile duct carcinomas deserves further research and clinical evaluation.

Using Intensity-Modulated Radiotherapy to Spare the Kidney in a Patient with Seminoma and a Solitary Kidney: A Case Report

Aims and background

Radiotherapy-related kidney injury is multifactorial and influenced by radiation dose-volume distributions, patient-related factors, and chemotherapy. Traditional radiation parameters for the kidney are based on pre-intensity-modulated radiotherapy (IMRT) data and focus on limiting the volume receiving high dose. We report a case of testicular seminoma with paraaortic adenopathy in a patient with a solitary kidney treated with radiotherapy.

Methods

A comparison was performed for IMRT and two 3D-conformal techniques. In our case, IMRT reduced the volume of kidney receiving high dose but increased the volume receiving low dose.

Results

Given the lack of data for suggesting that large renal volumes treated to low doses would cause excess toxicity, the consensus opinion was to proceed with IMRT. The patient tolerated treatment well without evidence of radiotherapy-related kidney injury.

Conclusions

As patients are treated with increasingly complex techniques such as IMRT, understanding low dose effects and monitoring low dose parameters may become clinically important.

Dosimetric and clinical predictors of radiation-induced lung toxicity in esophageal carcinoma

Aims and background

Radiation-induced lung toxicity occurs frequently in patients with esophageal carcinoma. This study aims to evaluate the clinical and three-dimensional dosimetric parameters associated with lung toxicity after radiotherapy for esophageal carcinoma.

Methods and study design

The records of 56 patients treated for esophageal carcinoma were reviewed. The Radiation Therapy Oncology Group criteria for grading of lung toxicity were followed. Spearman's correlation test, the chi-square test and logistic regression analyses were used for statistical analysis.

Results

Ten of the 56 patients developed acute toxicity. The toxicity grades were grade 2 in 7 patients and grade 3 in 3 patients; none of the patients developed grade 4 or worse toxicity. One case of toxicity occurred during radiotherapy and 9 occurred 2 weeks to 3 months after radiotherapy. The median time was 2.0 months after radiotherapy. Fourteen patients developed late irradiated lung injury, 3 after 3.5 months, 7 after 9 months, and 4 after 14 months. Radiographic imaging demonstrated patchy consolidation (n = 5), atelectasis with parenchymal distortion (n = 6), and solid consolidation (n = 3). For acute toxicity, the irradiated esophageal volume, number of fields, and most dosimetric parameters were predictive. For late toxicity, chemotherapy combined with radiotherapy and other dosimetric parameters were predictive. No obvious association between the occurrence of acute and late injury was observed.

Conclusions

The percent of lung tissue receiving at least 25 Gy (V25), the number of fields, and the irradiated length of the esophagus can be used as predictors of the risk of acute toxicity. Lungs V30, as well as chemotherapy combined with radiotherapy, are predictive of late lung injury.

Epidural and intramedullary spinal metastasis: clinical features and role of fractionated radiotherapy

Metastases involving the spinal epidural space and cord parenchyma are major sources of neurological impairment and decreased quality of life in cancer patients. Herein we review the clinical manifestations, pathophysiology, importance of early diagnosis and initiation of treatment, and role of fractionated radiotherapy of these disorders.

Phase 1 Study of High-Specific-Activity I-131 MIBG for Metastatic and/or Recurrent Pheochromocytoma or Paraganglioma

CONTEXT

No therapies are approved for the treatment of metastatic and/or recurrent pheochromocytoma or paraganglioma (PPGL) in the United States.

OBJECTIVE

To determine the maximum tolerated dose (MTD) of high-specific-activity I-131 meta-iodobenzylguanidine (MIBG) for the treatment of metastatic and/or recurrent PPGL.

DESIGN

Phase 1, dose-escalating study to determine the MTD via a standard 3 + 3 design, escalating by 37 MBq/kg starting at 222 MBq/kg.

SETTING

Three centers.

PATIENTS

Twenty-one patients were eligible, received study drug, and were evaluable for MTD, response, and toxicity.

INTERVENTION

Open-label use of high-specific-activity I-131 MIBG therapy.

MAIN OUTCOME MEASURES

Dose-limiting toxicities, adverse events, radiation absorbed dose estimates, radiographic tumor response, biochemical response, and survival.

RESULTS

The MTD was determined to be 296 MBq/kg on the basis of two observed dose-limiting toxicities at the next dose level. The highest mean radiation absorbed dose estimates were in the thyroid and lower large intestinal wall (each 1.2 mGy/MBq). Response was evaluated by total administered activity: four patients (19%), all of whom received >18.5 GBq of study drug, had radiographic tumor responses of partial response by Response Evaluation Criteria in Solid Tumors. Best biochemical responses (complete or partial response) for serum chromogranin A and total metanephrines were observed in 80% and 64% of patients, respectively. Overall survival was 85.7% at 1 year and 61.9% at 2 years after treatment. The majority (84%) of adverse events were considered mild or moderate in severity.

CONCLUSIONS

These findings support further development of high-specific-activity I-131 MIBG for the treatment of metastatic and/or recurrent PPGL at an MTD of 296 MBq/kg.

UK Consensus on Normal Tissue Dose Constraints for Stereotactic Radiotherapy

Six UK studies investigating stereotactic ablative radiotherapy (SABR) are currently open. Many of these involve the treatment of oligometastatic disease at different locations in the body. Members of all the trial management groups collaborated to generate a consensus document on appropriate organ at risk dose constraints. Values from existing but older reviews were updated using data from current studies. It is hoped that this unified approach will facilitate standardised implementation of SABR across the UK and will allow meaningful toxicity comparisons between SABR studies and internationally.

Radiotherapy in the Management of Orbital Lymphoma: A Single Institution's Experience Over 4 Decades

PURPOSE

To report our institution's treatment techniques, disease outcomes, and complication rates after radiotherapy for the management of lymphoma involving the orbits.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of 44 patients curatively treated with radiotherapy for stage IAE (75%) or stage IIAE (25%) orbital lymphoma between 1969 and 2013. Median follow-up was 4.9 years. Thirty-eight patients (86%) had low-grade lymphoma and 6 (14%) had high-grade lymphoma. Radiation was delivered with either a wedge-pair (61%), single-anterior (34%), or anterior with bilateral wedges (5%) technique. The median radiation dose was 25.5 Gy (range, 15 to 47.5 Gy). Lens shielding was performed when possible. Cause-specific survival and freedom from distant relapse were calculated using the Kaplan-Meier method.

RESULTS

The 5-year local control rate was 98%. Control of disease in the orbit was achieved in all but 1 patient who developed an out-of-field recurrence after irradiation of a lacrimal tumor. The 5-year regional control rate was 91% (3 patients failed in the contralateral orbit and 1 patient failed in the ipsilateral parotid). Freedom from disease, cause-specific survival, and overall survival rates at 5 and 10 years were 70% and 55%, 89% and 89%, and 76% and 61%, respectively. Acute toxicity was minimal. Ten patients (23%) reported worsened vision following radiotherapy, and cataracts developed in 17 patients. Cataracts developed in 13 of 28 patients treated without lens shielding (46%) and 4 of 16 patients (25%) treated with lens shielding.

CONCLUSION

Radiotherapy is a safe and effective local treatment in the management of orbital lymphoma.

Dosimetric comparison between modulated arc therapy and static intensity modulated radiotherapy in thoracic esophageal cancer: a single institutional experience

Purpose

The objective of this study was to compare dosimetric characteristics of three-dimensional conformal radiotherapy (3D-CRT) and two types of intensity-modulated radiotherapy (IMRT) which are step-and-shoot intensity modulated radiotherapy (s-IMRT) and modulated arc therapy (mARC) for thoracic esophageal cancer and analyze whether IMRT could reduce organ-at-risk (OAR) dose.

Materials and Methods

We performed 3D-CRT, s-IMRT, and mARC planning for ten patients with thoracic esophageal cancer. The dose-volume histogram for each plan was extracted and the mean dose and clinically significant parameters were analyzed.

Results

Analysis of target coverage showed that the conformity index (CI) and conformation number (CN) in mARC were superior to the other two plans (CI, p = 0.050; CN, p = 0.042). For the comparison of OAR, lung V₅ was lowest in s-IMRT, followed by 3D-CRT, and mARC (p = 0.033). s-IMRT and mARC had lower values than 3D-CRT for heart V₃₀ (p = 0.039), V₄₀ (p = 0.040), and V₅₀ (p = 0.032).

Conclusion

Effective conservation of the lung and heart in thoracic esophageal cancer could be expected when using s-IMRT. The mARC was lower in lung V₁₀, V₂₀, and V₃₀ than in 3D-CRT, but could not be proven superior in lung V₅. In conclusion, low-dose exposure to the lung and heart were expected to be lower in s-IMRT, reducing complications such as radiation pneumonitis or heart-related toxicities.