Section 1-3

multiple myeloma (description/characteristics, epidemiology, etiology)

• malignant plasma cell tumor

• originates in the marrow but often classified as a primary bone tumor

  • most common primary bone cancer if classified as such

• can take several different forms and be very indolent or very aggressive

  • generally slow growing

• 90% occur after age 40

• more common in African-Americans than whites by 14:1

• viral etiology suggested but still not prov

presentation/symptoms/mets of multiple myeloma

• disseminated disease with involvement of multiple skeletal sites

• common symptoms include

  • spinal cord compressions

  • back pain

  • compression fractures of the vertebra

  • infection

  • easy fatiguability (from anemia)

• appearance of “moth eaten” or “punched out” lesions with clearly defined borders

• doesn’t metastasize to any specific organ

treatment of multiple myeloma (timing, techniques)

• slow growing, therefore, treatment may begin 1-10 years later

• incurable but can be controlled for long periods of time

• surgery only used to repair areas susceptible to pathologic fracture

• best treatment for palliation

  • chemotherapy w/ possible adjuvant RTT

    • RTT often effective in relieving back pain

• RTT treatment for collapsed lumbar vertebra and lower back pain

  • inverted “T” (L spine + SI joints) or spade field

• TBI or HBI used for advanced myeloma w/ widespread bone pain if no response to chemo

  • 500-600 rads to upper half ot he body and similar dose for lower half 6-8 weeks later

soft tissue sarcoma (STS) (description, epidemiology, etiology)

• tumor occurring in the extraskeletal connective tissue

• rare and comprise less tah 1% of all cancers

• 5700 cases and 3700 deaths per year

• most common in adolescents

• etiology unknown but risks factors include

  • old scars

  • previous irradiation

    • radiation-induced sarcomas often arise from breast cancer and Hodgkin’s

  • Von Recklinghausen disease

  • Li-Fraumeni syndrome

presentation/symptoms/mets of STS

• usually found as firm masses in the soft tissue lying beneath the fascia

• can arise anywhere in the body but most common sites of initial presentation are:

  • extremeties

    • lower extremities (39%)

    • upper extremities (11%)

    • most located in upper thigh

  • H&N

• most often mets to the lungs

diagnosis/prognosis/staging/grading/mets of STS

• MRI is best for diagnosis

• histologic grade is most important prognostic factor

• poor prognosis due to

  • local recurrence

  • distant mets

• spread via hematologic route and local invasion

treatment principles for STS

• surgery/excision and chemotherapy are most commonly used

  • consider cosmetic and functional results of surgery

  • debulking only to preserve muscle/limb

• RTT only used as adjunct to surgery due to radioresistance

  • high total doses often exceeding 65 Gy (>75Gy via external beam combined with brachy)

  • GTV + 4cm margin to 50 Gy then GTV + 2cm margin to final dose for abdomen and microscopic disease

    • tighter margins and IMRT used for abdominal area to decrease dose to kidneys and bowel

    • up to 80Gy for extremeties

  • brachytherapy using Ir192 in catheters or I125 seeds placed in tumor bed may be used for recurrent disease

STS that originate from connective tissue of nerve sheaths

fibrosarcoma

STS found predominantly in the rectus abdominus muscle in young women and are essentially benign

desmoid tumors

most common STS (location of occurrence, characteristics)

• Liposarcoma

• can occur anywhere fat is present

• malignant

• radiosensitive (compared to other sarcomas)

most lethal STS

rhabdomyosarcoma

most common site of presentation and histological type for sarcomas of genitourinary tract

uterus, leiomyosarcoma

Kaposi’s sarcoma (appearance, epidemiology)

• soft purplish eruptions on the skin, usually an extremity

• true Kaposi’s is typically seen in Mediterranean and North-African men over 65 years old

• form of Kaposi’s also seen in AIDS patients