Analysis of treatment results in advanced Hodgkin's disease: the case for adjuvant radiotherapy

Changes in lognormal shape parameter guide design of patient-specific radiochemotherapy cocktails

Uptake of radiopharmaceuticals and chemotherapeutic drugs is nonuniform at the microscopic level. Their distributions are typically lognormal, suggesting that failure in chemotherapy and targeted radionuclide therapy may be attributable, in part, to the characteristics of this biologically ubiquitous distribution. The lognormal problem can be overcome by using cocktails of 2 or more agents, tailored such that at least 1 agent is strongly incorporated by every cell in the target population. Therefore, critical assessment of the tissue uptake of each cocktail component is warranted.

METHODS

Cellular incorporation of the α-particle-emitting radiochemical ((210)Po-citrate) and 2 anticancer drugs (daunomycin and doxorubicin) was determined using flow cytometry. The role of their lognormal distribution in clonogenic cell survival was evaluated.

RESULTS

The shape parameter of the lognormal distribution was found to be correlated to both intracellular agent concentration and cell survival. Although no difference emerged between the shape parameters for citrate within the first 2 logs of cell kill, those for daunomycin and doxorubicin changed significantly.

CONCLUSION

Changes in the value of the lognormal shape parameter and slope of the cellular drug uptake curves can be used to rapidly screen radiopharmaceuticals and other cytotoxic agents to formulate more effective cocktails for cancer therapy.

Modulation of the sensitivity in Chinese hamster cells to photons and fast neutrons by cisplatin, vinblastine, and bleomycin

Normal tissue toxicity resulting from chemoradiotherapy is of significant clinical concern. This study used normal Chinese hamster fibroblasts from lung (V79) and ovary (CHO-K1) to assess the modulation of cellular response to photons and neutrons by cisplatin, vinblastine, and bleomycin. Based on the colony formation assay, the drug concentration corresponding to 50% cell survival (EC50) of V79 cells was 1.50 ± 0.21 µmol/L for cisplatin, 0.97 ± 0.06 nmol/L for vinblastine, and 1.68 ± 0.11 µmol/L for bleomycin. The corresponding values for CHO-K1 cells were significantly lower for vinblastine (0.54 ± 0.02 nmol/L) and bleomycin (0.49 ± 0.13 µmol/L), but not for cisplatin (1.57 ± 0.20 µmol/L). No radiosensitivity enhancement was apparent when cells were exposed to p(66)/Be neutrons or photons (60Co γ-rays) in the presence of these drugs at EC50 concentrations. These data suggest that concurrent use of these drugs with radiation for the treatment of lung and ovarian diseases radiation does not exacerbate radiation-induced normal tissue toxicity, regardless of the quality of radiation. The relatively higher sensitivity of the ovarian cells to vinblastine and bleomycin might constitute a limitation in the use of these drugs for the treatment of lung lesions.

Extranodal conjunctival Hodgkin's-like lymphoma in a cat

A seven-year-old female spayed Domestic Short-haired cat was brought for examination following a four-month history of conjunctivitis in the right eye. The superior palpebral conjunctiva was diffusely swollen and firm, displacing the right globe ventrally and preventing full closure of the eyelids. The right popliteal lymph node was enlarged as were several other peripheral lymph nodes. An incisional biopsy of the conjunctival swelling revealed a lymphoid neoplasm, the cellular make up of which suggested features of feline Hodgkin's-like lymphoma. Although the neoplasm was poorly responsive to standard chemotherapeutic protocols for lymphoma, radiation therapy rapidly reduced its size. Three years following the initial diagnosis, there has been no recurrence of the conjunctival neoplasm. To the authors' knowledge, there are no previous reports of extranodal or adnexal (conjunctiva, eyelid, orbit) Hodgkin's-like lymphoma in the veterinary literature.