Involved field radiation therapy

Radiation therapy is an integral part of treatment and can be used alone for selected patients with early-stage disease, although most patients wiU receive chemotherapy and radiation. Involved-field radiation therapy targets a single field of HL. Extended-field or subtotal nodal radiation targets the involved field and an uninvolved area. Total nodal radiation therapy targets aU areas. 

Albuquerque, K.V., Singla, R., Potkul, R.K., Smith, D.M., Creech, S., Lo, S., Emami, B. (2005). Impact of tumor volume-directed involved field radiation therapy integrated in the management of recurrent ovarian cancer. Gynecol. Oncol. 96 701-4. 

In an attempt to reduce relapse rate and late toxicity, combined-modality therapy using lower doses of radiation and an abbreviated course of chemotherapy has been evaluated.16 The goal of decreased relapse rate has been achieved, but no overall survival benefit has been documented. A limitation of this approach is exposing patients to the additive toxicities of chemotherapy. Trials that have investigated this approach typically have incorporated between two and four cycles of a standard regimen for HL, such as ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) with involved-field radiation. At present, combined-modality therapy is considered to be a standard of care for stage I/II HL. 

Table 129-4). Because of the high relapse rate in patients with early-stage unfavorable disease treated with radiation alone, most clinicians currently favor combined modality therapy (combination chemotherapy and involved-field radiation) to reduce the relapse rate and avoid the toxicity associated with extended-field radiation and the mortality associated with surgical staging. ...

Radiation therapy generally is considered to be the treatment of choice for most patients. Exceptions to this include patients with prior radiation to the treatment site and patients with inherently radioresistant tumors (e.g., melanoma and renal cell carcinoma). The radiation field should include two vertebral bodies above and below the involved area. 

Hodgkin s disease accounts for 1% of all new cancers diagnosed in Western countries and for 15% of all malignant lymphomas. In patients with early stage lA-IIA disease without B-symptoms or bulky adenopathy, therapy consists of either extended field radiotherapy or limited duration chemotherapy, e.g. ABVD (anthracycline, bleomycin, vinblastine, dacarbazine) for 3-4 cycles followed by involved field radiotherapy. Radiation alone results in a 10-year relapse free survival of 70-75% and, because of the efficacy of salvage chemotherapy for those who relapse, an overall survival of 80-85%. The combined modality approach results in fewer relapses but overall survival is similar. In order to reduce the long term morbidity of radiation current trials are exploring combined modality treatment with lower radiation doses versus chemotherapy alone. 

Radiation therapy is the standard treatment for early-stage foUicular lymphoma. Involved-field, extended-field, and total nodal irradiation have been used. Carefully staged patients with either stage I or contiguous stage II disease treated with radiation therapy alone can achieve disease-free survival rates of 40% to 50% and overall survival rates of 60% to 70% at 10 years. Late relapses are uncommon only 10% of patients who reached 10 years without relapse subsequently experienced a recurrence. 

---