Preparation of pediatric patients for treatment with proton beam therapy

Analysis of person-hours required for proton beam therapy for pediatric tumors

Proton beam therapy (PBT) is effective for pediatric tumors, but patients may require sedation and other preparations, which extend the treatment time. Pediatric patients were classified into sedation and non-sedation cases. Adult patients were classified into three groups based on irradiation from two directions without or with respiratory synchronization and patch irradiation. Treatment person-hours were calculated as follows: (time from entering to leaving the treatment room) × (number of required personnel). A detailed analysis showed that the person-hours required for the treatment of pediatric patients are about 1.4-3.5 times greater than those required for adult patients. With the inclusion of additional time for the preparation of pediatric patients, PBT for pediatric cases is two to four times more labor-intensive than for typical adult cases.

The Multidimensional Assessment for Pediatric Patients in Radiotherapy (M.A.P.-RT) Tool for Customized Treatment Preparation: RADAR Project

Aims: Pediatric patients may experience considerable distress during radiotherapy. Combining psychological interventions with standard therapies can reduce the need for sedation. The RADAR Project aims to use a systematic method of recording data that can reveal patients' difficulties and fragility during treatment.

In this context, the aim of our study was to investigate the ability of a multidimensional assessment tool (M.A.P.-RT schedule) to predict the need for sedation during radiotherapy. The schedule, which is administered during the first evaluation, was created to collect information on patients and their families in a standardized way.

Materials and Methods: The study enrolled pediatric patients (aged 0–18 years or 18–21 with cognitive impairment). Data were collected by means of the M.A.P.-RT module; this explores various thematic areas, and is completed by the radiation oncologist, psychologist and nurse during their first evaluation. Features were selected by means of the Boruta method (random forest classifier), and the totals of the significant partial scores on each subsection of the module were inserted into a logistic model in order to test for their correlation with the use of anesthesia and with the frequency of psychological support. The results of logistic regression (LR) were used to identify the best predictors. The AUC was used to identify the best threshold for the scores in the evaluation.

Results: A total of 99 patients were considered for this analysis. The feature that best predicted both the need for anesthesia and the frequency of psychological support was the total score (TS), the AUC of the ROC being 0.9875 for anesthesia and 0.8866 for psychological support.

Conclusion: During the first evaluation, the M.A.P.-RT form can predict the need for anesthesia in pediatric patients, and is a potential tool for personalizing therapeutic and management procedures.

Age as a decisive factor in general anaesthesia use in paediatric proton beam therapy

Proton therapy for paediatric cancer patients is an effective treatment; however, young children have may have difficulties staying still during irradiation. This study investigated the indication of general anaesthesia in paediatric proton therapy. Background information and anaesthesia/treatment protocols were retrospectively extracted from the medical records of cancer patients under 15 years who underwent proton therapy at Southern TOHOKU General Hospital, Fukushima, Japan between April 2016 and December 2018. The anaesthesia and non-anaesthesia groups were compared to evaluate factors determining the need for general anaesthesia. Thirty-two patients who received 285 irradiations were analysed. The median age was 5 years old (range: 1–15), and 13 patients (40.6%) were female. Twelve (37.5%) patients received general anaesthesia. In the general anaesthesia group, airway management using a laryngeal mask was performed in 11 patients (91.6%). Patient age was significantly lower in the general anaesthesia group than in the non-anaesthetised group (p < 0.001). Considering all background factors, only age was strongly associated with anaesthesia in the univariate logistic regression model (odds ratio 0.55 [95% confidence interval 0.35–0.86]; P < 0.01). Thus, age is one of the most important factors determining the need for general anaesthesia during proton therapy in children.

Analysis of treatment process time for real-time-image gated-spot-scanning proton-beam therapy (RGPT) system

We developed a synchrotron‐based real‐time‐image gated‐spot‐scanning proton‐beam therapy (RGPT) system and utilized it to clinically operate on moving tumors in the liver, pancreas, lung, and prostate. When the spot‐scanning technique is linked to gating, the beam delivery time with gating can increase, compared to that without gating. We aim to clarify whether the total treatment process can be performed within approximately 30 min (the general time per session in several proton therapy facilities), even for gated‐spot‐scanning proton‐beam delivery with implanted fiducial markers. Data from 152 patients, corresponding to 201 treatment plans and 3577 sessions executed from October 2016 to June 2018, were included in this study. To estimate the treatment process time, we utilized data from proton beam delivery logs during the treatment for each patient. We retrieved data, such as the disease site, total target volume, field size at the isocenter, and the number of layers and spots for each field, from the treatment plans. We quantitatively analyzed the treatment process, which includes the patient load (or setup), bone matching, marker matching, beam delivery, patient unload, and equipment setup, using the data obtained from the log data. Among all the cases, 90 patients used the RGPT system (liver: n = 34; pancreas: n = 5; lung: n = 4; and prostate: n = 47). The mean and standard deviation (SD) of the total treatment process time for the RGPT system was 30.3 ± 7.4 min, while it was 25.9 ± 7.5 min for those without gating treatment, excluding craniospinal irradiation (CSI; head and neck: n = 16, pediatric: n = 31, others: n = 15); for CSI (n = 11) with two or three isocenters, the process time was 59.9 ± 13.9 min. Our results demonstrate that spot‐scanning proton therapy with a gating function can be achieved in approximately 30‐min time slots.

A systematic review of interventions to reduce psychological distress in pediatric patients receiving radiation therapy

OBJECTIVE

Radiation therapy (RT) is a cornerstone for management of pediatric cancer. For younger patients, unintended radiation to critical organs is a concern and children need to remain immobile. Distress in children is common so many centres sedate pediatric patients. Children often are unable to remain still, due to anxiety. Interventions to reduce distress could also reduce sedation rates. The objectives of this systematic review were to: review the interventions used to address pediatric RT patients' distress and anxiety and assess their effectiveness.

METHODS

A systematic search of qualitative and quantitative studies from 1996 to 2016 was conducted using PRISMA guidelines. Nine articles were identified for inclusion in the final review. These articles were reviewed using a quality rating.

RESULTS

Participants included patients 19 years of age or younger, parents and RTs. All were single-site studies. Five studies had a control group, 3 studies had no control group, and 1 study was qualitative. Quality was not high. Six studies reported significant effects. Only one study reported group differences in children's reported anxiety.

CONCLUSION

Cognitive behavioural approaches appear to be worth exploring further, as are approaches grounded in child development. Therapeutic play, particularly procedural preparation via play, also seems to be a useful starting point.

Comorbidity and quality of life in childhood cancer survivors treated with proton beam therapy

BACKGROUND

The rate of childhood cancer survival has recently reached >80%. Various adverse events among childhood cancer survivors (CCS) have been reported. Proton beams are able to avoid unnecessary irradiation to normal/vital organs. We conducted a quality of life (QOL) study for CCS who were treated with proton beam therapy (PBT).

METHODS

We included those patients treated with PBT to the brain, head, or neck and who were ≤15 years old at the University of Tsukuba Hospital between 1983 and 2011. Clinical information was collected from medical records. Questionnaires including the Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales (which assess health-related quality of life) were sent to the families/patients.

RESULTS

Sixty patients were included. Median age at treatment was 6.2 years. The number of patients with status alive/dead/unknown was 32/24/4. Median follow-up period was 63.0 months (range, 48-340 months) for survivors. Questionnaires were sent to 25 families/patients and 19 were returned. PedsQL was assessed for 17 patients. Eleven of 32 living patients had at least one comorbidity grade 3/4. Average QOL score was above that for Japanese schoolchildren and adolescents. There was no correlation with comorbidity, and only longer time from treatment was correlated with a higher PedsQL score (P = 0.006).

CONCLUSION

CCS who were treated with multimodal treatment using PBT had a higher QOL score. Higher score was related to longer time since treatment, regardless of comorbidity.

Proton Beam Therapy for Pediatric Brain Tumor

Cancer is a major cause of childhood death, with central nervous system (CNS) neoplasms being the second most common pediatric malignancy, following hematological cancer. Treatment of pediatric CNS malignancies requires multimodal treatment using a combination of surgery, chemotherapy, and radiotherapy, and advances in these treatments have given favorable results and longer survival. However, treatment-related toxicities have also occurred, particularly for radiotherapy, after which secondary cancer, reduced function of irradiated organs, and retarded growth are significant problems. Proton beam therapy (PBT) is a particle radiotherapy with excellent dose localization that permits treatment of liver and lung cancer by administration of a high dose to the tumor while minimizing damage to surrounding normal tissues. Thus, PBT has the potential advantages for pediatric cancer. In this context, we review the current knowledge on PBT for treatment of pediatric CNS malignancies.

A comparative study of dose distribution of PBT, 3D-CRT and IMRT for pediatric brain tumors

Introduction

It was reported that proton beam therapy (PBT) reduced the normal brain dose compared with X-ray therapy for pediatric brain tumors. We considered whether there was not the condition that PBT was more disadvantageous than intensity modulated photon radiotherapy (IMRT) and 3D conventional radiotherapy (3D-CRT) for treatment of pediatric brain tumors about the dose reduction for the normal brain when the tumor location or tumor size were different.

Methods

The subjects were 12 patients treated with PBT at our institute, including 6 cases of ependymoma treated by local irradiation and 6 cases of germinoma treated by irradiation of all four cerebral ventricles. IMRT and 3D-CRT treatment plans were made for these 12 cases, with optimization using the same planning conditions as those for PBT. Model cases were also compared using sphere targets with different diameters or locations in the brain, and the normal brain doses with PBT, IMRT and 3D-CRT were compared using the same planning conditions.

Results

PBT significantly reduced the average dose to normal brain tissue compared to 3D-CRT and IMRT in all cases. There was no difference between 3D-CRT and IMRT. The average normal brain doses for PBT, 3D-CRT, and IMRT were 5.1–34.8% (median 14.9%), 11.0–48.5% (23.8%), and 11.5–53.1% (23.5%), respectively, in ependymoma cases; and 42.3–61.2% (48.9%), 54.5–74.0% (62.8%), and 56.3–72.1% (61.2%), respectively, in germinoma cases. In the model cases, PBT significantly reduced the average normal brain dose for larger tumors and for tumors located at the periphery of the brain.

Conclusion

PBT reduces the average dose to normal brain tissue, compared with 3D-CRT and IMRT. The effect is higher for a tumor that is larger or located laterally.

Proton beam therapy for a patient with large rhabdomyosarcoma of the body trunk

Background

We present the clinical course of a pediatric patient with large rhabdomyosarcoma of the body trunk who received proton beam therapy (PBT).

Case presentation

A 1-year-old girl was diagnosed with stage IV alveolar rhabdomyosarcoma in 2008. A large tumor was located in the central diaphragm and had infiltrated the liver and pericardium with peritoneal dissemination. Chemotherapy was immediately started with six courses of vincristine, actinomycin-D and cyclophosphamide (VAC) firstly, and secondly followed by 2 courses of ifosfamide, carboplatin and etoposide (ICE), but a large tumor of 15 cm in size remained. The tumor was inoperable because of its location, and photon radiotherapy could not be performed due to limited liver tolerance. The patient was referred to our hospital and received PBT at a dose of 54 GyE in 30 fractions in June 2009.

The tumor quickly responded and 95 % of volume reduction was achieved at the end of PBT. However, marginal recurrence in the caudal part of the irradiated field, where we reduced the proton dose because of the presence of the intestine, was detected in August 2010. The recurrent tumor size was less than 1 cm. Chemotherapy with VAC followed by topotecan and carboplatin (TC) was again tried, but the tumor size was stable. Repeated PBT was not possible because of limited intestinal tolerance; therefore, intraoperative radiotherapy was conducted with 20 Gy of electron beams in April 2011. The tumor was subsequently well controlled, but secondary myelodysplastic syndrome developed and the patient died of hemophagocytic syndrome after umbilical cord blood transplantation in May 2012.

Conclusion

PBT was performed safely and effectively for a 1-year-old girl with alveolar rhabdomyosarcoma with liver and cardiac invasion that was resistant to surgery and chemotherapy. This case illustrates that PBT can be useful in cases that are difficult to treat with conventional radiotherapy.

Anesthesia complications of pediatric radiation therapy

PURPOSE

Complications of anesthesia for pediatric radiation therapy are imperative for both radiation oncologists and anesthesiologists to clinically assess and manage. We performed the first systematic review to date addressing this important issue.

METHODS

A systematic search of PubMed and EMBASE was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Searches were not restricted based on publication date. Nine original investigations were identified, analyzed, and collated for this report.

RESULTS

General anesthesia has proven superior to conscious sedation with regard to maintaining satisfactory procedural sedation while maintaining low respiratory and cardiovascular complication rates. Although agents such as ketamine (complication rates approaching 23%-24%) have been used in the past, other agents such as propofol and volatile anesthetics have lower complication rates because of improved drug side effect profiles (0.01%-3.5%). Most common complications are respiratory-based (eg, airway obstruction, broncho/laryngospasm, desaturation, apnea), followed by those that are cardiovascular-based (eg, tachy/bradycardia, arrhythmias, hypotension) and nausea/vomiting. Though procedure duration and anesthetic dose can be associated with higher complication risks, prior or concurrent chemotherapy does not confer added risks other than neutropenia-related sepsis. Other potential complications include those with vascular access devices, observed in up to 20% to 25%, with peripherally inserted central catheters having the highest rates of vascular complications and port catheters the lowest.

CONCLUSIONS

Rates of anesthetic complications encountered in pediatric radiation therapy are similar, if not lower, than rates reported in controlled operating room settings, implying that anesthesia for pediatric radiation therapy is safe, with low complication rates periprocedurally. Propofol infusion and oxygen delivery via nasal cannula offer the lowest immediate anesthetic complication rates and are hence most recommended for use. Though the long-term neurocognitive consequences of multiple anesthetics in pediatric patients have yet to be clearly defined, health care providers should be cognizant of the potentially serious implications.

Relative biological effectiveness of carbon ions for tumor control, acute skin damage and late radiation-induced fibrosis in a mouse model

BACKGROUND

The aim of the present study was to compare the biological effectiveness of carbon ions relative to x-rays between tumor control, acute skin reaction and late RIF of CDF1 mice.

MATERIAL AND METHODS

CDF1 mice with a C3H mouse mammary carcinoma implanted subcutaneously on the foot of the right hind limb were irradiated with single fractions of either photons, or (12)C ions using a 30-mm spread-out Bragg peak. The endpoint of the study was local control (no tumor recurrence within 90 days). For the acute skin reaction, non-tumor bearing CDF1 mice were irradiated with a comparable radiation scheme, and monitored for acute skin damage between Day 7 and 40. Late RIF was assessed in the irradiated mice.

RESULTS

The TCD50 (dose producing tumor control in 50% of mice) values with 95% confidence interval were 29.7 (25.4-34.8) Gy for C ions and 43.9 (39.2-49.2) Gy for photons, with a corresponding Relative biological effectiveness (RBE) value of 1.48 (1.28-1.72). For acute skin damage the MDD50 (dose to produce moist desquamation in 50% of mice) values with 95% confidence interval were 26.3 (23.0-30.1) Gy for C ions and 35.8 (32.9-39.0) Gy for photons, resulting in a RBE of 1.36 (1.20-1.54). For late radiation-induced fibrosis the FD50 (dose to produce severe fibrosis in 50% of mice) values with 95% confidence interval were 26.5 (23.1-30.3) Gy for carbon ions and 39.8 (37.8-41.8) Gy for photons, with a RBE of 1.50 (1.33-1.69).

CONCLUSION

The observed RBE values were very similar for tumor response, acute skin damage and late RIF when irradiated with large doses of high- linear energy transfer (LET) carbon ions. This study adds information to the variation in biological effectiveness in different tumor and normal tissue models.