Radiation Oncology/Hodgkin/Review

Review of Hodgkin's Lymphoma

Epidemiology

US incidence: ~8000
US deaths: ~1300
Age: bimodal, peak in 20's and 50's
Risk factors: likely genetic predisposition (increased incidence in Jews, siblings, HLA antigens)
Two separate entities
- Classical Hodgkin's Lymphoma (CHL) - Reed-Sternberg cells
- Lymphocyte-predominant Hodgkin's Lymphoma (LPHL) - "popcorn" lymphocyte cells

Clinical presentation: lymph node mass(es)
Diagnosis
- Excisional lymph node biopsy
- Core needle biopsy may be adequate
- FNA is insufficient
Pathology
- CHL: Reed-Sternberg cells sufficient, CD15+ and CD30+
- LPHL: CD20+ and CD45+, epithelial membrane antigen
Workup
- Determination of B symptoms: fever >38C, drenching sweats, weight loss >10% weight
- Exam: lymphoid regions, liver, spleen
- Labs: CBC, differential, ESR, LDH, albumin, LFT, Bun/Cr
- Bone marrow biopsy: Stage IB/IIB, III-IV
- Imaging: CT neck/chest/abdomen/pelvis or PET/CT
  - PET: higher sensitivity for nodal regions (92% vs 83%) and organ involvement (86% vs 37%), though more false positives
Staging (Ann Arbor system; EORTC unfavorable criteria):
- Early stage favorable (I-II, no unfavorable features)
- Early stage unfavorable bulky (I-II, bulky mediastinum ratio >0.33 or size >= 10cm)
- Early stage unfavorable non-bulky (I-II, B symptoms, or >3 sites of disease, or ESR >50)
- Advanced (III-IV)
- Advanced unfavorable (age >=45, male, stage IV, albumin <4, WBC >15k, WBC <600
Response criteria
- Need for additional treatment based on response
- 2007 IWG Guidelines using IHC, flow cytometry, PET: CR, PR, SD, relapsed, PD