Incidence and correlates of radiation pneumonitis in pediatric patients with partial lung irradiation

PURPOSE

To provide a radiation pneumonitis risk estimate and investigate the correlation of clinical and dosimetric factors in pediatric patients receiving chest irradiation.

METHODS AND MATERIALS

A total of 122 patients diagnosed with sarcoma or Hodgkin lymphoma who received radiotherapy to the chest were evaluated for symptomatic radiation pneumonitis (Common Toxicity Criteria Grade 1 with respiratory symptom or higher grade). Pneumonitis data were collected from either prospective toxicity screenings as part of a clinical trial or through chart review. Dosimetric parameters including V(10)-V(25), mean lung dose, binned lung dose, and tissue complication probability models were used, as well as clinical features to correlate with the development of pneumonitis.

RESULTS

The 1- and 2-year cumulative incidence of symptomatic radiation pneumonitis for all patients was 8.2% and 9.1%, respectively. Nine patients experienced symptomatic Grade 1 toxicity, and 2 experienced Grade 2. From univariate analysis, chemotherapy containing bleomycin (chi(2) test, p = 0.027) and V(24) (logistic regression, p = 0.019) were the clinical and dosimetric factors that resulted in statistically significant differences in the occurrence of pneumonitis. The probability of pneumonitis increased more dramatically with increasing V(24) in patients receiving bleomycin than in those who did not. Adult tissue complication models did not differentiate pediatric patients with radiation pneumonitis from those without.

CONCLUSIONS

The incidence of symptomatic radiation pneumonitis in pediatric patients is low and its severity mild. Parameters frequently used in adult radiation oncology provide some guidance as to risk, but pediatric patients warrant their own specific models for risk assessment, incorporating dosimetry and clinical factors.

Incidence and correlates of radiation dermatitis in children and adolescents receiving radiation therapy for the treatment of paediatric sarcomas

AIMS

To investigate the relationship between the maximum grade of skin toxicity, radiation dose and clinical variables in children receiving treatment for sarcomas involving the bone and soft tissue.

MATERIALS AND METHODS

Between January 2003 and July 2006, 82 patients with musculoskeletal tumours on an Institutional Review Board (IRB)-approved prospective study at St. Jude Children's Research Hospital received three-dimensional conformal or intensity-modulated radiation therapy for local tumour control. Radiation dermatitis was graded according to the National Cancer Institute's Common Toxicity Criteria version 2.0 during and after radiation therapy. The dose to the skin was calculated for each patient from the radiation treatment plan.

RESULTS

The radiation doses delivered to the primary tumour ranged from 4140 to 7020cGy, with a mean dose of 5040cGy. The maximum recorded grade of skin toxicity was: grade 0: seven patients (8.6%); grade 1: 26 patients (31.7%); grade 2: 37 patients (45.1%); grade 3: 10 patients (12.2%); grade 4: two patients (2.4%). A significant association for increased grade of skin toxicity was observed between dose (P<0.01), volume of skin treated above 4000cGy (P=0.03), use of a bolus (P<0.01), Caucasian race (P<0.01) and related pain (P<0.01).

CONCLUSIONS

These findings suggest that the delivered dose, use of a bolus, the volume treated, and race may be used in the clinical setting to predict patients at risk for skin toxicity. Alterations in treatment technique and early therapeutic intervention may help to reduce or eliminate radiation-induced skin side-effects and associated pain.

Preliminary results from a prospective study using limited margin radiotherapy in pediatric and young adult patients with high-grade nonrhabdomyosarcoma soft-tissue sarcoma

PURPOSE

To demonstrate the safety and efficacy of limited margin radiotherapy in the local control of pediatric and young adult patients with high-grade nonrhabdomyosarcoma soft tissue sarcoma (NRSTS).

METHODS AND MATERIALS

Pediatric patients with high-grade NRSTS requiring radiation were treated on an institutional review board approved prospective institutional study of conformal/intensity-modulated/interstitial brachytherapy using a 2-cm anatomically constrained margin.

RESULTS

A total of 32 patients (median age, 15.3 years; range, 2-22 years) received adjuvant (27 patients) or definitive (5 patients) irradiation. With a median follow-up of 32 months, the 3-year cumulative incidence of local failure was 3.7% for patients undergoing irradiation after surgical resection. Four patients experienced local failure; the mean dose to the volume of recurrence was >or=97% of the prescribed dose.

CONCLUSIONS

Delivery of limited margin radiotherapy using external beam or brachytherapy provides a high rate of local tumor control without marginal failure. Further follow-up is required to determine whether normal tissue effects are minimized using this approach.