Pediatric Tumor

Question 1

Examples of decreased or more limited use of RT in pediatric tumors

Answer 1

Acute Lymphoblastic Leukemia
Hodgkin Lymphoma
Heritable Retinoblastoma

Question 2

What is the cause of decreased or limited use of RT in pediatric tumor

Answer 2

Improvement in outcome of some childhood cancers due to changes in chemotherapy

Continued concern for late effects from RT

Question 3

What is the standard of practice in ALL

Answer 3

Cranial irradiation to prevent CNS relapse

Question 4

Cite the clinical trial and what has RT been replaced with in ALL

Answer 4

Systemic review and meta analysis of 47 randomized trials demonstrated that RT can be replaced with intra-thecal chemotherapy
Richard et al Pediatr Blood Cancer 2013

Question 5

Cite the clinical trial that concluded that Cranial RT in ALL didn’t have impact on risk of relapse

Answer 5

Vora et al JCO 2015
Review of data on relapse and survival 16,623 pt
age 1-18 yrs
newly dxed ALL
1996-2007
10 cooperative study group from around the world

Question 6

What is the standard of care for Hodgkin Lymphoma in pediatric group

Answer 6

ChemoRT

Question 7

What is the new treatment strategy for Hodgkin Lymphoma in pediatric group

Answer 7

Risk based response adapted 
Involved site(IS) or Involved nodal(IN) irradiation has replaced involved fields and extended (prophylactic) field

Question 8

What is the standard of care for heritable retinoblastoma

Answer 8

Bilateral orbital retinoblastoma had been used routinely allowing vision preservation and successful eradication of retinoblastoma

Question 9

What is the new strategy of treatment for heritable retinoblastoma

Answer 9

Orman et al Int J Radiat Oncol Biol Phys 2014
EBRT reserved for patients whose eyes don’t respond adequately to primary systemic or intra-arterial chemotherapy and local consolidation
Late effects of EBRT include secondary malignancies and orbital growth abnormalities

Question 10

Examples of renewed interest and increased application of RT in pediatric tumors

Answer 10

Brain tumors
Sarcoma
Reirradiation
Metastatic disease

Question 11

Radiotherapy for Infant Brain Tumor

Answer 11

Consideration of all normal tissue
MRI based planning
Highly conformal dosimetry to CTV

Question 12

Radiotherapy for infant sarcoma

Answer 12

1. Balance potential for cure, late toxicity and quality of life
2. Decreased utilization of appropriate local therapy results in inferior outcome for Rhabdomyosarcoma
3. Delayed Primary Excision should be used selectively when R0 or R1 resection can be achieved and function can be maintained
4. RT dose can be decreased based on extent of surgical resection but elimination of RT is not advised
5. Omission of RT based on imaging response is not advised
6. Infant Ewing Sarcoma with higher rate of early death may be due to less intensive local therapy

Question 13

Reirradiation for Recurrent Pediatric tumor

Answer 13

Good disease control
Standard fractionated reirradiation well tolerated
Single fraction SRS may have unacceptable toxicity
Hypofractionation/SBRT may improve LC
CSI most beneficial for metastatic failure for ependymoma
CSI may be important for salvage in medulloblastoma

Question 14

Radiotherapy in metastatic disease in pediatric group

Answer 14

Prognosis depends on location and number of distant metastasis
RT is important modality in local treatment of metastatic lesions
More aggressive treatment approach to metastatic sites(SBRT to smaller bone mets) is currently being investigated in cooperative trials