INTRODUCTION• Are group of cancers which originates fromReticuloendothelial systems• It was named after Thomas Hodgkin who first described it in1832.• Dorothy Reed and Carl Stenberg first described the malignantcells of Hodgkin’s lymphoma called Reed Stenberg cells.• Hodgkins lymphoma was the first cancer which could besuccessfully treated by radiation therapy and also bycombination chemotherapy.
Epidemiology• Accounts for 0.58% of all cancers diagnosed and 0.23% of all cancer deathsin U.S each year.• Incidence is less than 3 per 100,000• In 2010 in U.S 8490 cases were registered (4670 males, 3820 females) andaccounted for 1320 deaths.• It has a slightly male predominance (1.1:1)• It is rare in children younger than 10 years• It has Bimodal peak of distribution (25-30 yrs and >55 yrs)
Risk Factors• First degree relatives have five fold increase in risk for Hodgkins Disease.• Associated with EBV infection mainly with mixed cellularity type.• Associated with Infectious Mononucleosis. Incidence is about 2.55 timeshigher• High socio economic status.• Prolonged uses of human growth hormone
Natural History• Hodgkins lymphoma arises in a single node or a chain of nodes andspreads first to anatomically contiguous lymphoid tissue.• Visceral involvement by Hodgkins lymphoma may be secondary toextension from adjacent lymph nodes.• Haematogenous spread occurs to liver or multiple bony sites• It rarely involves the gut associated lymphoid tissue such as Waldeyer ringand Peyers patches.• Mechanism of spleen involvement is unclear but all pts with hepatic andbone involvement are associated with splenic involvement.
Clinical features• Most common presentation isasymptomatic lymphnode enlargementtypically in the neck.• Cervical lympnodes are involved in 80%cases .• Mediastinal involvement is seen in about50% cases .they produce symps likeChest painCoughDyspnoea• Infradiaphragmatic involvement is seenin 5% cases and usually seen with olderpatients.
Clinical features cont…• B symptoms About 33% presents with B symptoms overall. Only 15-20% of stage I-II have B symptoms likeo Fever(>38oC) May first present as fever of unknown origin Fever persists for days to weeks followed by afebrile intervals and thenrecurrence Such type of pattern is called Pel Ebstein Fevero Drenching night sweatso Weight loss(> 10% in 6 mths)
Clinical features cont…• Other less frequently symptoms are Pruritus Alcohol induced pain over involved lymph nodes Nephrotic syndrome Erythema nodosum Cerebellar degeneration Immune hemolytic anaemia, Thrombocytopenia Hypercalcaemia
Diagnostic Workup• History• Complete physical examination• Confirmatory workup Excisional biopsy of the lymph node Staging workup Chest x ray(pa,lat) Usg neck,whole abdomen CT scan thorax,abdomen and pelvis FDG PET scan
PET SCAN• PET Scan has become an integralcomponent of initial staging.• Information provided by PET hasbeen recently incorporated in thelymphoma guidelines for responseevaluation after completion oftreatment.• Useful for follow up study toevaluate residual masses , dx ofearly recurrence and predictingoutcome.• It has a specificity of 90-95%
Revised International Workshop Criteria With PET Scan
Bone Marrow Biopsy• Less commonly put into practice• Overall involvement of bone marrow in Hodgkins lymphoma is5%.• Indicated in pts with B symptoms Clinical evidence of sub diaphragmatic disease Stage iii-iv Recurrent disease
Lymphocyte predominant Hodgkins lymphoma• <5% of Hodgkins lymphoma• Mainly involves cervical,axillary ormediastinal• “L&H” cells or Popcorn cells areseen• Positive for CD20,45• Negative for CD15,30.EBV
Nodular Sclerosis• Most common type diagnosed.About 70%• Lacunar ceells are seen• CD 15 and 30 positive• EBV negative• Only subtype without a malepredominance• Seen in younger pts with stage I –II disease
Mixed Cellularity• Constitutes about 20%• More common in young children• CD 15,30 EBV positive• Presents in advanced stages• Tendency to involve spleen,bonemarrow
Lymphocyte Depleted• Constitutes <5%• Worst prognosis of all subtypes• Older males• Advanced stage• HIV infection
StagingI Involvement of a single lymph nodeOr,lymphoid structureOr single extralymphatic siteII Involvement of two or more lymphnode region on same side of diaphragmLocalized contiguous involvement of only one extranodal organ or site andlymphnode regions on same side of diaphragmIII Involvement of lymphnode regions on both side of diaphragmIII1 With or without involvement of splenic,hilar.celiac or portal nodesIII2 With involvement of paraaortic ,iliac,and mesenteric nodesIV Diffuse or disseminated involvement of one or more extranodal organs ortissues,with or without involvement of associated lymphnodes.
Radiotherapy• Radiation therapy is the most effective single therapeutic agent fortreating Hodgkins lymphoma.• The main objective of radiation in Hodgkins lymphoma is to treat involvedand contiguous field.• Radiotherapy can be given by• 2D Planning• 3D Planning• IMRT
• Pre RT Evaluation: Oro dental prophylaxis Pulmonary function test Pre chemotherapy and post chemotherapy information from CT or PET scan Position Usually supine. Arms up position pulled up the axillary node further from the chest wall,thereby permitting more generous lung shielding. Arms down or akimbo position permitted shielding of the humeral head andminimize the effect of tissue folds in supraclavicular If neck is to be treated head in hyperextension Frog leg for inguinal nodes
• Immobilization Mask for head and neck Body cast for pelvis OTHERS Oophoropexy in young females Fields are shaped using multileaf collimators Respiatory gating has to be taken care of
Mantle technique• Target volume definition. The target volume for mantle field includes the Occipital Submental Submandibular Ant and Post cervical Infraclavicular Axillary Medial pectoral Paratracheal Mediastinal and hilar nodes
• Treatment Field: Superiorly: Inferior portion ofmandible bisecting the mastoidprocess Laterally: Both the axillae Inferiorly: T10-11 interspace
• BLOCKS : Larynx anteriorly Humeral heads Spinal cord if >40 Gy Heart after 30 Gy Lung blocks: The upper border of lung block curves centrally toinclude infraclavicular nodesThe medial borders are shaped so as to treat the hilar nodes.A gapof 8-10 cm is left in midline between blocks to treatmediastinal nodes.
Subdiaphragmatic Fields• The classical subdiaphragmatic field is the Inverted-Y.• Target Volume: Para aortic Pelvis Inguinal nodes(b/l) Spleen
• Treatment Fields: For Paraaortic Superiorly:The T10-11 vertebrae Inferiorly:The lower limit of L4 Laterally:width of transverse process. Pelvis F ield: Laterally:1.5-2 cm lat to the widest point in pelvis Inferiorly:Lesser trochanter.
Inverted “Y” FieldPara aortic fields pelvic field
• BLOCKS: Central midline block for Bladder Small bowel Oophoropexy if performed Testicular shielding
IFRT• Involved field radiotherapy.• IFRT is the most commonly used technique at present• Targets a smaller area rather than a classical extended field.• IFRT(ASTRO 2002)DEFINITION IFRT encompasses region and not an individual lymph node. Initially involved Pre chemo sites and volume are treated Exception to above rule is for transverse diameter of mediastinum andparaaortic lymphnodes for which reduced post chemo volume is treated.
3DCRT• GTV:Original prechemo volumeof involved lymphnodes clinicallyand radiologically• CTV:GTV with whole nodalregions that contains the involvedlymphnodes.• PTV:Depends onimmobilization,reproducibility,organ motion.usually 10 mm marginis added to CTV
• INRT• Newer concept evolved with advent and more usage of ct and PET scan• Target volume is based on initial macroscopic prechemo disease ratherthan based on lymphnode region.• Treatment Portals: Beam arrangement is often // & opposite pair fields(ap-pa) DOSE Early stage :after complete response to chemotherapy 20 Gy in 10# Advanced stage with residual disease after chemotherapy30 Gy in 15# with additional 6 Gy in 3# depending on bulk of disease
• LATE REACTIONS Radiation Pneumonitis(6-12 wks) Radiation Pericarditis Subclinical Hypothyroidism:most common delayed symotoms Herpes Zoster infections: Lhermittes sign(1-2 mths)
• Late Reactions(cont…) Streptococcus pneumoniae and H influenzae infection following splenicradiation. Azoospermia in males Premature menopause in females Secondary malignancy:• Leukaemia• Lymphoma(diffuse large cell type most common after 5 years)• Solid Tumors:In males Lung (>30 Gy),colorectalIn females Breast,lung,colorectal
Conclusion• Radiation therapy is the most effective single therapeutic agent fortreating Hodgkins lymphoma• The management of Hodgkins lymphoma has evolved from extended fieldradiation to a combined modality of chemo radiation or chemo alone.• Interest is in achieving the best therapeutic ratio by minimizing latetoxicity while maintaining effectiveness.• With improvement in diagnostic modality and PET scanning and improvedtreatment policy the results in future will be encouraging.